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I respectfully non-concur on Inspection Report (IR) 05200025/2019010. I am doing so because I disagree with the closure of Unresolved Item (URI) 05200025/2018-01, “Welded Reinforcing Bar Splices.”

This URI concerns inspection of welded reinforcing bar splices that are being used in construction of the new AP1000 reactors at the Vogtle Electric Generating Plant (VEGP). These splices are critical structural items that must perform satisfactorily during design basis events.

Commensurate with their importance to safety, welded reinforcing bar splices are typically subject to destructive testing, nondestructive examination (NDE),1 or a combination of both to verify that they meet tensile and quality requirements, respectively. These inspections are in addition to visual examination. Southern Nuclear Operating Company (SNC) is only performing visual examination of welded reinforcing bar splices. As a result, completed welded reinforcing bar splices are not being adequately inspected. Without additional measures being taken, there is insufficient basis to conclude with reasonable assurance that structural integrity will be maintained during design basis events and the plant will be safe to operate.

Welded reinforcing bar splices were not approved as an alternative to lap splices in the AP1000 Design Control Document (DCD) and VEGP Units 3 & 4 Updated Final Safety Analysis Report (UFSAR). As a result, the use of welded reinforcing bar splices in the construction of VEGP Units 3 was determined to be a violation of regulatory requirements. The significance of this violation was screened as minor. I do not believe, however, that the limitation placed in the VEGP Units 3 & 4 UFSAR on the use of welded reinforcing bar splices is by accident or insignificant.

In closing this URI, the NRC will be, in effect, providing SNC with relief from the commitments of the VEGP Units 3 & 4 UFSAR and allowing them to administratively revise their licenses to allow the use of welded reinforcing splices. As a result, nonconforming construction will be accepted “use-as-is” without adequate technical justification.

Welded reinforcing bar splices are important structural connections that are relied upon for overall structural integrity and the performance of safety-related functions. There are no indications that the AP1000 design is inadequate or construction of VEGP Units 3 & 4 deficient. However, the splices must be subject to appropriate quality assurance measures2 to provide confidence that the structure will perform satisfactorily during design basis events. One would not expect a safety-related piping system to be put in service without conducting appropriate inspections to verify the system will perform as designed. Likewise, Seismic Category I structures require adequate inspections to verify they will maintain structural integrity and perform their safety-related functions during design basis events.3 Without performing

1 Also referred to as nondestructive testing (NDT). As used in this document, NDE refers to inspection methods other than visual examination such as ultrasonic or radiographic examination. 2 The introduction to 10 CFR Part 50 Appendix B states that “quality assurance” comprises all those planned and systematic actions necessary to provide adequate confidence that a structure, system, or component will perform satisfactorily in service. Quality assurance includes quality control, which comprises those quality assurance actions related to the physical characteristics of a material, structure, component, or system which provide a means to control the quality of the material, structure, component, or system to predetermined requirements. 3 Structures designated as Seismic Category I must be designed to review functional if the Safe Shutdown Earthquake Occurs. The pertinent requirements of Appendix B to 10 CFR 50 apply to all activities affecting the

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appropriate inspections, the quality of the structural components that utilize welded reinforcing bar splices is indeterminate. Additionally, closure of Inspection, Tests, Analyses, and Acceptance Criteria (ITAAC) may be affected.

Safety concerns associated with welded reinforcing bar splices prompted the State of California to conduct significant investigations of as-built structural components to verify the adequacy of splices installed in highway structures.4 It is reported that many of the welded reinforcing bar splices examined during these investigations did not meet minimum quality requirements and some had to be replaced.5

Concerns about the performance of welded reinforcing bar splices are well founded: inadequate welded reinforcing bar splices have contributed to catastrophic structural failures, most notably during the 1995 Kobe earthquake.6

This URI is being closed based on guidance provided by the Office of New Reactors (NRO) in Technical Assistance Requests7 (TARs) AP V-M-0428 and AP V-M-045.9 The responses to these TARs, however, do not provide a sufficient basis for concluding that the actions SNC has taken to verify the splices meet quality and performance requirements comply with the VEGP Units 3 & 4 UFSAR or are technically adequate. Neither NRO or SNC has provided adequate information to draw these conclusions.

The inspections being performed by SNC at VEGP Units 3 & 4 to verify the adequacy of welded reinforcing bar splices do not meet the commitments of the VEGP Units 3 & 4 UFSAR, are not

safety-related functions of Seismic Category I Structures, Systems, or Components, Regulatory Guide 1.29, “Seismic Design Classification, Revision 4, March 2007. 4Paul Hefner, “Caltrans Reveals Quake Fix Problems; Bad Welds Found at 210-118 Interchange,” Daily News (Los Angeles, California), November 19, 1997; “Editorial: Bungled Bridges?; Independent Probe into Substandard Welds in Retrofit Program is Essential,” Daily News (Los Angeles, California), November 20, 1997; Meg James, “Orange Crush Contains Faulty Welds, Caltrans Says,” Los Angeles Times, September 13, 1999; Meg James, “Welds Suggest Bridge Quake Risk,” Los Angeles Times, September 13, 1999; Charles F. Bostwick, “Freeway Welds Pass Caltrans Test,” Daily News (Los Angeles, California), September 14, 1999; Charles F. Bostwick, “Freeway Welding Being Tested: Inspections Ordered at 5-14 Interchange,” Daily News (Los Angeles, California), September 14, 1999. Meg James, “Caltrans Refused to Use Weld Alternative,” Los Angeles Times, September 19, 1999; Charles F. Bostwick, “Interchange Being Tested; Engineers Examine Bridge Welds at 5-14 Freeway Crossings,” Daily News (Los Angeles, California), September 21, 1999; Associated Press, “Freeways Lacked Review, Only 1 Inspector Checked Welds at Height of Project,” Daily News (Los Angeles, California), October 7, 1999; Sean Holstege, “Defective Welds have Cropped Up Before,” East Bay Times, April 5, 2005, Updated August 17, 2016. 5 See articles referenced in previous footnote. 6 Priestley, M.J.N., Seible, F. Calvi, G.M., “Seismic Design and Retrofit of Bridges,” John Wiley & Sons, Inc., New York, 1996, pp. 14-15; see also “The January 17, 1995 Hyogoken-Nanbu (Kobe) Earthquake, Performance of Structures, Lifelines, and Fire Protection Systems,” United States Department of Commerce Technology Administration, National Institute of Standards and Technology, NIST Special Publication 901, (ICSSC TR18), Gaithersburg, MD, July 1996, p 177 & p 181; and Bruneau, M., “Performance of steel bridges during the 1995 Hyogoken–Nanbu (Kobe, Japan) earthquake—a North American perspective,” Engineering Structures, Vol. 20, No. 12, pp. 1063–1078, 1998. Specifically, Section 3.1, Reinforced Concrete Substructure Failures 7 A TAR is the mechanism that NRO and Region II use to request and document the results of formal construction inspection related interactions. The TAR is used to document regulatory decisions and interpretations based on the existing licensing basis and previous safety findings, Technical Assistance Request (TAR) Process Desktop Guide, 2018. 8 ML18149A340 9 ML19016A408

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commensurate with the importance to safety of the splices, in alignment with NRC guidance on use of welded reinforcing bar splices, or on par with the measures used for inspection of welded reinforcing bar splices in the construction of other U.S. nuclear plants. These measures are also not consistent with the requirements of other design certifications, common practices for structures with potential impacts to public health and safety, or the recommendations of respected and widely adopted industry standards.

NRC guidance on the use of welded reinforcing splices is that they meet the requirements of American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code Section III, Division 2 (ASME Division 2). This guidance, to my knowledge, is based on the importance to safety of welded reinforcing bar splices used in Seismic Category I structures and a reasonable concern with achieving adequate performance and quality requirements. ASME Division 2 requires destructive testing and NDE of welded reinforcing bar splices.

SNC committed to ASME NQA-1-1994, Part II, Subpart 2.5, “Quality Assurance Requirements for Installation, Inspection, and Testing of Structural Concrete, Structural Steel, Soils, and Foundations for Nuclear Power Plants” (Subpart 2.5)10 in their Nuclear Development Quality Assurance Manual (NDQAM). Subpart 2.5, Paragraph 7.13 requires the inspection of welded reinforcing bar splices to comply with ASME Division 2. SNC failed to incorporate these requirements into the VEGP Units 3 & 4 construction specifications.

URI 05200025/2018-01 should be closed to an ITAAC finding and associated more-than-minor violation of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion III, “Design Control” for SNC’s failure to correctly translate the design basis into specifications, drawings, procedures, and instructions. The significance of this violation should be dependent on whether SNC can provide evidence demonstrating that the Structures, Systems, and Components (SSCs) that rely on welded reinforcing bar splices will meet their safety functions. Absent enforcement action, I do not have confidence that appropriate corrective actions will be taken to address this issue.

Background

Concrete is strong in compression but weak in tension. When subjected to loads that create tension, cracks will occur in a concrete structure if the tensile strength of the concrete is exceeded. These cracks can lead to a sudden catastrophic failure due to the inability of the concrete to resist the tensile forces. In a reinforced concrete structure, deformed steel bars, typically referred to as reinforcing bars, are embedded in the concrete in such a way that the tensile forces can be resisted by the bars after the concrete cracks.11 The tensile forces are the result of internal stresses that develop in the concrete and are associated with axial, shear, and torsion forces and bending moments. In some instances, the reinforcing bars may also be used to supplement the concrete in resisting compression forces. The reinforcing bars resemble circular rods with raised ridges to lock the bar to the surrounding concrete. The reinforcing bars are essential components of a reinforced concrete structure that are necessary to resist the loads imposed on the structure and maintain structural integrity. Ideally, continuous reinforcing bars would be installed. However, this is generally not feasible given the standard manufactured lengths of the bars, structural details, and construction considerations. As a

10 When referenced in this document, Subpart 2.5 refers to that of ASME NQA-1-1994 as this is what is adopted in the SNC quality assurance program. 11 James G. MacGregor, Reinforced Concrete Mechanics & Design, 2nd ed., Prentice-Hall, Englewood Cliffs, N.J., 1992, p. 1

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result, the reinforcing bars are typically spliced together at various locations within the structure. The design function of the splice is to join two reinforcing bars together so that the assembly behaves as one continuous reinforcing bar, typically, having the same diameter as the spliced bars but a longer length.

It should be clear from the above description that reinforcing bar splices are key components in reinforced concrete construction.12 The splices are used to provide continuity for the transfer of forces within reinforced concrete structures. They are a potential “weak link” in the structural system and must be installed correctly to ensure acceptable performance. Inadequately installed reinforcing bar splices can lead to structural failure.

Reinforcing bars may be spliced together with lap splices, mechanical connections13, or welded splices.14 Lap splices are typically the most frequently encountered type of reinforcing bar splice. In a lap splice, two bars are laid adjacent to one another with the end of each bar overlapping the other for a calculated distance known as the lap splice length. The force is transferred from one bar to another through the concrete between the bars. For large diameter bars, the lap splice length can be many feet. While prevalent in reinforced concrete construction, lap splices are not allowed for very large bar sizes, increase reinforcement congestion, require adequate space to be installed, and have other limitations that may make them impractical or impossible to install in some instances. In these situations, a mechanical or welded splice may be installed.

A mechanical connection or splice typically makes use of a sleeve that overlaps each bar end to provide a connection between two bars. The sleeve and ends of the bars may be threaded much like a nut and bolt, or the sleeve filled with metal or grout to form a connection. There are many different systems of mechanical connections. All of them rely on a mechanical connection between the bars to transfer forces. In a welded splice, on the other hand, the bars are fused together either directly or indirectly by electric arc welding.

Of the three types of reinforcing bar splices, welded splices require the most stringent controls over the splicing process and the highest level of skill to install correctly. Welding is also typically the least cost-effective method of splicing reinforcing bars. Given these factors, welded splices have generally been used sparingly in the general construction industry. Recommended practice is to minimize their use if possible.15 This recommendation is partly due to concerns about consistently producing welded reinforcing bar splices that meet the specified performance and quality requirements. If used, however, careful consideration should be given to the quality assurance measures implemented to ensure that welded reinforcing bar splices are installed correctly and will perform adequately.

12 ACI 439-3R-07, “Types of Mechanical Splices for Reinforcing Bars” 13 “Manual of Standard Practice,” Concrete Reinforcing Steel Institute (CRSI), 28th Edition, 2nd printing, 2011 defines a mechanical splice in the glossary as a complete assembly of an end-bearing sleeve, a coupler, or a coupling sleeve, and possibly additional material or parts to accomplish the splicing of reinforcing bars; ACI 439-07 has a similar definition and indicates that a mechanical splice was “mechanical splice” was formerly called “mechanical connection” in ACI 318-95 and earlier editions. 14 The CRSI Manual of Standard Practice defines a welded splice in the glossary as a means of joining two reinforcing bars by electric arc welding. Bars may be lapped, butted, or joined with splice plates or angles. 15 “Manual of Standard Practice,” Concrete Reinforcing Steel Institute (CRSI), 28th Edition, 2nd printing, 2011, p 1-4 and Flathua, W.J., “Dynamic Tests of Large Reinforcing Bar Splices,” U.S. Army Engineer Waterways Experiment Station, Technical Report N-71-2, Vicksburg, MS, April 1971 p. 141.

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Welding is a special process that is highly dependent on control of the process and the skill of the welder.16 As a result, both the welding procedure and welder must be qualified to provide confidence that the completed weld will be sufficient. In addition, completed welds must be inspected to verify they meet requirements. The type of inspections conducted to verify weld quality often correlate to the type of weld and associated stress. Highly stressed welds that are used in critical applications typically receive a greater level of inspection than lower stressed welds used in secondary applications.

The main type of welded splice being installed at VEGP Units 3 & 4 is a direct butt joint.17 In this type of splice, the ends or the bars are beveled at an angle such that a groove is formed when the bars are butted together end to end. The groove between bars is filled with weld material to fuse the two bars together. The weld joining the bars together is referred to as a complete joint penetration (CJP) groove weld. By design, the weld has the same strength as the bars and can be highly stressed.

Given their importance, CJP welds are typically subject to ultrasonic or radiographic examination to verify weld quality. These inspections are in addition to visual examination and are important because visual examination only looks at the surface of the weld. Visual examination cannot identify any subsurface defects such as lack of fusion, porosity or slag inclusions that could impact the strength of the weld, nor can it reliably identify microscopic surface cracks or defects. All welds subject to ultrasonic or radiographic examination must first pass visual examination. Typically, all welds are visually examined, and ultrasonic or radiographic examination is conducted on a sampling basis. If defects are found using NDE methods other than visual, a greater number of welds may be inspected using these methods to determine if there is a larger problem with the welding procedure or welder. Welds that do not meet quality requirements are typically repaired.

Historically, destructive testing of welded reinforcing bar splices has also been performed on a sampling basis to verify welded reinforcing bar splices meet tensile strength requirements. This testing may be conducted on production joints cut directly from in-place reinforcement or removable “sister joints” made adjacent to production joints and under the same conditions. If the tested joints do not meet strength requirements, additional joints are tested, and the cause of the problem investigated.

For structures having a high risk to public health and safety in the event of damage or failure, it is common practice to specify that welded reinforcing bar splices be subject to either destructive testing, radiographic examination, or a combination of both, in addition to visual examination, to verify that the required performance and quality requirements have been met. NRC guidance on the use of welded reinforcing bar splices aligns with this practice.

Welded Hoops at Main Steam Line Penetrations through Wall 11

During a routine ITAAC inspection of VEGP Unit 3 conducted the week of January 21, 2018, welded reinforcing bar hoops were observed being installed at the main steam line penetrations

16 A special process is defined as “a process, the results of which are highly dependent on the control of the process or the skill of the operators, or both, and in which the specified quality cannot be readily determined by inspection or test of the product,” ASME NQA-1-1994, “Quality Assurance Requirements for Nuclear Facility Applications,” Terms and Definitions, p 7. Given this definition, I would submit that some destructive testing and NDE other than visual is required to verify welded reinforcing bar splices meet specified requirements. 17 Also referred to as a direct butt splice when two reinforcing bars are spliced together.

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through Wall 11 of the auxiliary building. The design details called for closed hoops. These hoops could not be fabricated from one continuous piece of reinforcing steel. As a result, the design drawings specified for them to be fabricated from two pieces joined together with mechanical or welded splices. Each piece was bent in the form of a U and the pieces were welded together in two places using CJP welds to form one continuous closed hoop of rectangular shape. Two bars sizes were used to form hoops of different diameters. The smaller hoops were formed with #9 bars and the larger hoops used #11 bars. The #9 bars have a diameter of 1.28 inches and the #11 bars have a diameter of 1.41 inches. The #9 and #11 hoops were bundled together in groups of two and installed radially around the main steam line penetration in the wall. The section of Wall 11 at the east main steam line penetration is identified as a critical structural section in the VEGP Units 3 & 4 UFSAR.18 The design of Wall 11 is addressed in VEGP Units 3 & 4 UFSAR Section 3H.5.1.4 and depicted in VEGP Units 3 & 4 UFSAR Figure 3H.5.5. The areas identified as critical sections in the VEGP Units 3 & 4 UFSAR, including this section of Wall 11, are characterized as high risk.19 VEGP Units 3 & 4 UFSAR Section 3H.5.1.4 states the following:

“The wall (Wall 11) is designed to withstand loads such as the dead load, live load, seismic load and the thermal load. The MSIV compartments are break exclusion areas, but the design also considered the compartment pressurization load associated with a one square foot pipe rupture in the MSIV compartments. Wall 11 in the east MSIV compartment is also designed to withstand the jet loads and the reactions at the pipe anchors for the main steam and feedwater line breaks assumed to occur in the east MSIV compartment. Additionally, the Wall 11 design for both MSIV compartments considers loads from postulated breaks in the turbine building, which include turbine building first bay pressurization, jet loads, reactions at the Wall 11 pipe anchors, and pipe whip.”20

According to Westinghouse Electric Company (WEC) structural calculations, the #9 bundled hoops resist any out-of-plane shear forces and the #11 bundled hoops are considered to resist out-of-plane, radial axial forces, and torsion.21 These forces develop in the wall from normal, environmental and abnormal loads. Normal loads are associated with normal plant operation and shutdown, environmental loads are due to winds including tornados, and earthquakes; and abnormal loads are generated by a postulated high-energy pipe break accident. The anchorages at Wall 11 are considered terminal ends of the main steam and feedwater lines. These are safety-related systems between the steam generators and Wall 11 anchorages and are designed to ASME Class 2 or 3 requirements as described in VEGP Units 3 & 4 UFSAR Sections 10.3.1.1 and 10.4.7.1.1, respectively.22

18 VEGP Unit 3 & 4 UFSAR, Tier 1, Table 3.3-7, Revision 6, p 3.3-33 (ML18179A250) 19 Inspection Manual Chapter 2519, “Construction Significance Determination Process,” System/Structure Risk Importance Table for AP1000 Construction SDP Matrix X-Axis, Appendix A, 12/06/17, p. AppA-10. 20 VEGP Unit 3 & 4 UFSAR, Section 3H.5.1.4, Wall at Column Line 11, Revision 7, p 3H-12 (ML18179A277) 21 Westinghouse Electric Company Document No. APP-1200-S3C-101, “Auxiliary Building Wall 11 Reinforcement Design EL 117’-6” to EL 135’-3”,” Revision 0, p. 31. 22 VEGP Units 3 & 4 UFSAR, Revisions 5 & 7, respectively (ML18179A284).

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One of the most critical events for the design of Wall 11 is a postulated high-energy line break of the main steam line occurring in the penetration sleeve through Wall 11, or in the turbine building North of Wall 11. Such an event would place significant out-of-plane forces on Wall 11 at the steam line anchorages.23 The welded hoops are required to resist these forces. This is a non-redundant system. There is no other means of resisting these forces other than the welded hoops. Failure of the welded reinforcing bar splices during such an event could compromise the integrity of Wall 11. Failure of Wall 11 at the main steam line anchorages could, in turn: compromise the integrity of the MSIV compartments; impact the operability of the safety-related equipment and components housed within; and invalidate the assumptions in the accident analysis leading to unanticipated impacts to safety-related structures, systems, and components (SSCs). The VEGP Units 3 & 4 auxiliary buildings are Seismic Category I structures that are designed and constructed in accordance with American Concrete Institute, “Code Requirements for Nuclear Safety Related Concrete Structures (ACI 349-01).”24 ACI 349-01 section 12.14.3.2 requires that all welding conform to American Welding Society, “Structural Welding Code – Reinforcing Steel,” (AWS D1.4-98). The welded reinforcing bar splices were visually examined in accordance with AWS D1.4-98. However, no destructive testing or NDE other than visual was conducted, to my knowledge, of completed welded reinforcing bar splices installed in the structures as required by Subpart 2.5. Unresolved Item (URI) 05200025/2018-01, “Welded Reinforcing Bar Splices” The following paragraphs describing the URI are taken from inspection report 05200025/2018-01.25 During the week of January 22, 2018, the inspectors determined the licensee was not performing destructive tests or NDE of welded reinforcing joints as required by the ASME Code, Section III, Division II, "Code for Concrete Reactor Vessels and Containments." Specifically, testing or NDE reports were not available for the welded reinforcing steel hoops used in the north wall of the main steam east compartment at column line 11, between elevations 117'-6" and 153'-0". The reinforcing hoops at this location were fabricated with direct butt joints using complete joint penetration groove welds. SNC committed to comply with ASME NQA-1-94, Subpart 2.5, in its Nuclear Development Quality Assurance Manual. Specifically, the SNC Nuclear Development Quality Assurance Manual, Version 17, Part II, Section 10.4.1 states, in part, SNC commits to compliance with the requirements of [ASME NQA-1-94, Part II] Subparts 2.5 and 2.8 for establishing appropriate inspection requirements. ASME NQA-1-1994, Subpart 2.5, Paragraph 7.13, "Welded Reinforcing Bar Splices," states, in part, welded reinforcing bar splices shall be subject to the requirements of paragraph 8.5, except provisions of the ASME Code, Section III, Division 2 (ACI 23 Westinghouse Electric Company Document No. APP-GW-P0C-161, “Bulk Flow, Fluid Induced Penetration Loads Due to Postulated Pipe Ruptures Occurring within Penetration Sleeves in the Turbine Building along Line 11 Wall,” Revision 1, 149 pp; Westinghouse Electric Company Document No. APP-GW-P0C-008, “Impact of High-Energy Line Breaks in the Turbine Building on the Line 11 Wall and its Penetrations,” Revision 3, 175 pp. 24 VEGP Unit 3 & 4 UFSAR, Section 3.8.4 (ML17172A242) 25 ML18134A348

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Standard 359) shall also apply. The ASME Code, Section III.2 (2001 Edition with 2003 Addenda), Article XI-1560, "Continuing Joint Performance Tests," requires destructive testing on a sampling basis of welded reinforcement splices to ensure the joints met tensile requirements. Additionally, the ASME Code, Section III.2 (2001 Edition with 2003 Addenda), Article XI-1600, "Examination of Welded Joints of Reinforcing Bar," requires RT examination of joint samples to verify weld quality. The north wall of the main steam east compartment at column line 11, between elevations 117'-6" and 153'-0", is a reinforced concrete wall in the auxiliary building. The inspectors noted Section 3.8.4.4.1 of the UFSAR states, in part, ACI 349-01 is the applicable code for the design and analysis of Seismic Category I reinforced concrete structures in the auxiliary building. ACI 349-01, Subsection 12.14.3.2, requires, in part, all welding to conform to AWS D1.4-98. Neither ACI 349-01 nor AWS D1.4 require inprocess tests or NDE of welded reinforcing splices. As a result, the inspectors questioned whether the ASME NQA-1-94 provisions for the inspection of welded reinforcing steel splices that incorporate by reference the ASME Code, Section III.2 requirements are quality assurance measures that supplement ACI 349-01 requirements and provide confidence that welded joints will perform satisfactorily in service. The licensee provided the inspectors with a position paper (CR 10465176) concerning the applicability of ASME NQA-1-94, Subpart 2.5, Paragraph 7.13 requirements. 52 This issue is an Unresolved Item pending the inspectors' review and evaluation of the licensee's position paper on the applicability of ASME NQA-1-94, Subpart 2.5, Paragraph 7.13 requirements. (URI 05200025/2018001-01, Welded Reinforcing Bar Splices) SNC Response to URI SNC provided a position paper26 concerning the applicability of Subpart 2.5, Paragraph 7.13 requirements for the inspection of welded reinforcing bar splices. In this “white paper”, SNC asserted that the language in the SNC NDQAM and ASME NQA-1-1994 allowed them broad latitude in implementing the requirements of Subpart 2.5. It was also their opinion that Subpart 2.5, Paragraph 7.13 only applies to concrete containment structures. As a result, SNC’s position was that they were in full compliance with the VEGP Units 3 & 4 COLs and no exceptions were required in the SNC NDQAM if the provisions of ASME Division 2, referenced in Subpart 2.5, were not implemented. NRC regional inspectors reviewed the SNC “white paper” and did not believe the arguments presented in it to have much merit. Well it is true that the organization invoking NQA-1-1994 may use judgement in applying the entire standard or portions of the standard, the inspectors felt that the extent of application of the standard should be clearly defined in the organization’s quality assurance program description (QAPD). In their NDQAM, SNC states their commitments, exceptions, and clarifications to specific paragraphs of NQA-1-1994. The inspectors believed that SNC’s position in their “white paper” 26 ML18149A340

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that the language in their NDQAM and NQA-1-1994 provided them broad discretion to implement the requirements of Subpart 2.5 as they see fit did not appear to be consistent with the language in their NDQAM, or the nature of a commitment in general. In effect, it would result in a non-binding commitment. This seemed to be an oxymoron that could, by extension, lead to uncertainty in how SNC is satisfying the requirements of Appendix B.27 Additionally, the inspectors did not find SNC’s position that the requirements of Subpart 2.5, Paragraph 7.13 do not apply to construction of VEGP Units 3 & 4 to be consistent with the scope of NQA-1-1994 Part II, relevant NRC guidance, or other information that was reviewed. Technical Assistance Request (TAR) The language in the SNC NDQAM committing to Subpart 2.5 is taken verbatim from NEI 06-14A, Revision 7. The QAPD template provided in NEI 06-14A, Revision 7 is based on ASME NQA-1-1994 and was endorsed by the NRC28 as a means of satisfying Appendix B. Since the language in the SNC NDQAM had been previously reviewed by the NRC, and because the licensee was challenging the applicability of Subpart 2.5, Paragraph 7.13 to VEGP Units 3 & 4, regional inspectors and management believed it would be beneficial to get NRO perspective on these issues. As a result, a TAR was submitted to NRO to assist in closing the URI. TAR AP-V-M-4229 Two simple questions were asked in TAR AP-V-M-42:

1. In general, when a licensee commits to NQA-1-94 Subpart 2.5 without exception and performs work activities that are within the scope of the subpart, must the relevant requirements of the subpart be implemented?

2. When a licensee commits to NQA-1-94 Subpart 2.5 without exception, do welded

reinforcing splices in Seismic Category I structures designed and constructed to ACI 349 need to conform to the relevant provisions of ASME BPVC SEC III.2?

Regional inspectors held the opinion that the answers to these questions should be yes. March 29, 2019 Response to TAR AP-V-M-42 Question 1 and comments30 The response to this question went through three iterations based on interactions between NRO and Region II. Initially, NRO staff provided the following response: It is the responsibility of the entity applying NQA-1, in this case SNC, to determine to what extent the supplemental requirements of NQA-1 Part II are necessary in order to meet the requirements of Appendix B to 10 CFR Part 50. That evaluation will take into consideration the specific type of nuclear facility, items, or services involved and the nature and scope and the relative importance of the activities being performed. 27 10 CFR 52.79(a)(25) requires an applicant for a combined license (COL) to submit a description of the quality assurance program applied to the design and to be applied to the fabrication, construction, and testing of the facility, and to include a discussion of how the applicable requirements of 10 CFR Part 50, Appendix B have been and will be satisfied. 28 ML092650695 29 ML18149A340 30 In the discussions concerning the TARs, NROs response is provided in italics and my comments in standard text.

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[SNC is committed to NQA-1-94 which the staff found to be acceptable (https://www.nrc.gov/reactors/new-reactors/oversight/quality-assurance/qual-assure-safety.html)]. The staff agrees that the licensee’s exception to certain portions of Subpart 2.5 should have been addressed as an exception in its QAPD. However, from an enforcement standpoint, the staff determines that the issue would be no more than minor as a failure to meet a commitment. This response appears reasonable except for the characterization of the issue as minor in the last sentence. Determining the significance of an inspection issue is typically not the responsibility of NRO staff. I agree that it is the responsibility of the organization invoking NQA-1-1994 to determine the extent to which the standard should be applied.31 However, it is important to recognize that the extent to which the standard is applied needs to be documented in the licensees QAPD which must be submitted to the NRC for approval during licensing.32 Subsequent changes to the QAPD are governed by NRC regulations.33 The licensee does not have the discretion to arbitrarily reduce the commitments of their QAPD. As a result, the flexibility afforded by ASME NQA-1-1994 in determining the extent to which the standard should be applied is constrained by regulation after issuance of a license. If this were not the case, the commitments made in a QAPD would be nonbinding and there would be insufficient basis for determining in licensing actions that the requirements of Appendix B will be met. This point is not one that SNC or NRO staff appear to accept. The SNC NDQAM is based on NEI 06-14A.34 In the safety evaluation report (SER) of NEI 06-14A35, the NRC concluded that the QAPD template:

1. Commits the applicant to the quality standards described in NQA-1-1994, Basic Requirement 10, Supplement 10S-1, and Subparts 2.4, 2.5 and 2.8.36 (No exceptions to Subpart 2.5 are listed)37;

31 The forward to ASME NQA-1-1994 states: “The arrangement of the basic and supplementary requirements in Part 1 (from former NQA-1), requirements for work practices in Part II (from former NQA-2), and nonmandatory guidance and applications appendices in Part III (from former NQA-1 and NQA-2) permits judicious application of the entire Standard or portions of the Standard. The extent to which this Standard should be applied will depend upon the specific type of nuclear facility, items, or services involved and the nature and scope and the relative importance of the activities being performed. The extent of application is to be determined by the organization imposing the Standard. For example, it may only involve the Basic Requirements; Basic Requirements in combination with selected Supplements; Basic Requirements in combination with Supplements with appropriate changes. This Standard is written to allow application to any structure, system, component, or activity that is essential to the satisfactory performance of the facility.” 32 10 CFR 52.79(a)(25) 33 10 CFR 50.54(a)(3) and 10 CFR 50.55(f)(4) 34 VEGP Unit 3 UFSAR, Section 17.8, Reference 201, Nuclear Energy Institute, Technical Report NEI 06-14A, “Quality Assurance Program Description,” Revision 7, July 2009. 35 ML092650695 36 Final Safety Evaluation for Technical Report NEI 06-14, “Quality Assurance Program Description,” Revision 7, Section 3.2.10, “Inspection”, p 11. 37 The parenthetical comment is mine.

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2. Includes regulatory commitments to ASME NQA-1-1994, “Quality Assurance Requirements for Nuclear Facility Applications,” Parts I and II, as described in Sections 3.2.1 through 3.2.18 of this SER;38 and

3. Provides an acceptable format and adequate guidance for establishing a QA program that complies with Appendix B to 10 CFR Part 50.39

Based on the regulations governing the QAPD, the NRC SER of the QAPD template provided in NEI 06-14A, and the wording of the SNC NDQAM, it seems reasonable to conclude that SNC committed to NQA-1-1994, Subpart 2.5 and expect that the supplemental measures for the inspection of concrete construction, including those associated with welded reinforcing bar splices, be implemented. SNC failed to incorporate these requirements into the VEGP Units 3 & 4 construction specifications. March 29, 2019 Response to TAR AP-V-M-42 Question 2 and comments NRO staff initially provided the following response: QVIB staff presented this question to the staff from DEI/SEB with regards to the applicability of ASME BPVC Sec III.2, specifically the welded reinforcing steel hoops that are used as part of the main steam line penetration through wall 11. Based on the design requirements and the location of the reinforcing splices, the staff determined that the requirements of ASME BPVC Sec III.2 are not applicable. The staff evaluated the DCD and UFSAR to verify the applicability of RG 1.94 and RG 1.142. RG 1.94 is not applicable and RG 1.142, as documented in Table 1.9-1, concluded that the additional requirements of ACI 359 (ASME BPVC Sec III.2) are not applicable to the AP1000 design. The staff determined this was acceptable during its evaluation of the DCD, COLA, and subsequent LARs. The staff determined that the performance of additional NDE requirements of ASME BPVC Sec III.2 as stated by paragraph 7.13 are not applicable to the welded reinforcing steel hoops. As mentioned in our response to Question 1 the staff did not identify any safety significance by SNC not performing the amplified information contained in paragraph 7.13. It is unclear how NRO staff arrived at these conclusions. A review of the AP1000 DCD, AP1000 Final Safety Evaluation Report (FSER), VEGP Units 3 & 4 UFSAR, and License Amendment 51 (LAR 15-021) which is specific to Wall 11 did not identify any instances in which the NRC stated that the additional requirements of Division 2 referenced in Subpart 2.5 Paragraph 7.13 are not applicable to the welded hoops used in wall 11 or VEGP Units 3 & 4 in general. On the contrary, welded reinforcing bar splices are not identified as an acceptable substitute for lap splices in the AP1000 DCD and VEGP Units 3 & 4 UFSAR. The NRO position appears to be based on a belief that the ASME Division 2 requirements for welded reinforcing bar splices are not applicable because the area in question is not part of a concrete reactor vessel or containment. 38 Final Safety Evaluation for Technical Report NEI 06-14, “Quality Assurance Program Description,” Revision 7, Section 3.4, “Regulatory Commitments”, p 17. 39 Final Safety Evaluation for Technical Report NEI 06-14, “Quality Assurance Program Description,” Revision 7, Section 4, “Conclusion”, p 17.

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The acceptable types of reinforcing bar splices addressed in the AP1000 DCD and VEGP Units 3 & 4 UFSAR are limited to lap splices or mechanical connections. Welded splices are not discussed. AP1000 DCD and VEGP Units 3 & 4 UFSARs Section 3.8.4.6.1.2 states, in part, “where reinforcing steel splices are necessary and lap splices are not practical, mechanical connections (e.g. threaded splices, swaged sleeves or cadwelds) are used.” Concerning the applicability of ASME Division 2 to the AP1000, the AP1000 FSER documents that the qualification and performance requirements of ASME Division 2 are applied to the mechanical connections used in the shield building.40 It seems reasonable to assume that similar requirements would have been applied if welded reinforcing bar splices were proposed to be used in the AP1000. Regardless, SNC committed to these requirements, in effect, by invoking Subpart 2.5 without exception in the SNC NDQAM. In subsequent discussions, NRO staff agreed that the use of welded reinforcing splices in the construction of VEGP Units 3 & 4 is not consistent with the VEGP Units 3 & 4 UFSAR. I do not believe this limitation is by accident or insignificant. In the Construction Reactor Oversight process (cROP), the critical structural sections are assigned a higher risk than a concrete containment. It is true that Regulatory Guide (RG) 1.94 was not applicable to the AP1000 Design Certification. WEC took exception to this regulatory guide because it was not relevant to the scope of the design certification document (DCD) which focused on design. WEC stated in WCAP-15799, “AP1000 Conformance with SRP Acceptance Criteria,”41 that quality assurance during construction is the responsibility of the combined license (COL) applicant and the AP1000 would comply with ASME NQA-1 Subpart 2.5. SNC’s commitment to RG 1.94 for the COL is addressed in VEGP Units 3 & 4 UFSAR Appendix 1A. Concerning RG 1.94, SNC states that “Quality assurance requirements utilize the more recently NRC endorsed NQA-1 in lieu of the identified outdated standards [ASME N45.2.5-1974]”. This commitment to NQA-1-1994 includes Subpart 2.5 which has comparable requirements for the inspection of welded reinforcing splices as those provided in ASME N45.2.5 and RG 1.94. Moreover, the commitment to RG 1.14242 as documented in VEGP Unit 3 & 4 UFSAR Appendix 1A does not take exception to any requirements of Subpart 2.5 or state that the additional requirements of ASME Division 2 are not applicable to VEGP Units 3 & 4. It seems to be a leap to infer that this is the case simply because WEC took exception to regulatory positions C.9 and C.14 of RG 1.142 in VEGP Units 3 & 4 UFSAR Appendix 1A. The endorsement of ASME NQA-243 in RG 1.142 is not limited to these two regulatory positions, which clearly are not applicable to the AP1000. April 3, 2019 Response to TAR AP-V-M-42 Question 1 and comments After discussion with regional inspectors, NRO revised the response to: 40 NUREG-1793, “Final Safety Evaluation Report Related to Certification of the AP1000 Standard Plant Design Docket No. 52-006,” Supplement 2, p 3-150 (ML112061231). 41 ML032541010 42 Regulatory Guide 1.142, “Safety-Related Concrete Structures for Nuclear Power Plants (Other than Reactor Vessels and Containments,” Revision 2, November 2001. 43 NQA-2 is the predecessor of NQA-1, Part II.

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QVIB staff agrees that if the licensee does not intend to implement portions of ASME NQA-1-1-94 Subpart 2.5, they must take an exception to their QAPD. The above response appears reasonable and consistent with the structure of the SNC NDQAM in which the commitments and exceptions to ASME NQA-1-1994 are documented. April 3, 2019 Response to TAR AP-V-M-42 Question 2 and comments After discussion with regional inspectors, NRO revised the response to: ASME NQA-1-94 Subpart 2.5 Paragraph 7.13 refers to “the requirements of para. 8.5” which states that “inspection shall include visual examination of preparations, welding processes . . . and if deemed necessary, some NDE inspections which are appropriate to the application.” However, based on the telephone conversation QVIB staff held with Region II staff during the week of March 19th, it appears the licensee made a determination for the welded reinforcing steel hoops that are used as part of the main steam line penetration through wall 11 that it was not necessary to perform NDE. Furthermore, QVIB staff consulted the Structural Engineering experts in NRO who informed us that the performance of additional NDE requirements of ASME BPVC Sec III.2 as stated by paragraph 7.13 are not applicable to the welded reinforcing steel hoops since it is not considered a structural item but rebar embedded in concrete. Consequently, it appears the licensee is in compliance with their licensing basis, as they are appropriately following the criteria in ASME NQA-1-1994, Subpart 2.5. This response focuses only on one requirement of Subpart 2.5, Paragraph 7.13. In doing so, it gives the misleading impression that the inspection of welded reinforcing splices only need to conform to the requirements of Subpart 2.5, Paragraph 8.5. The full wording of Subpart 2.5, Paragraph 7.13 is:

“Welded reinforcing bar splices shall be subject to the requirements of para. 8.5, except that the provisions of the ASME Boiler and Pressure Vessel Code, Section III, Division 2 (ACI Standard 359) shall also apply.”

Subpart 2.5, Paragraph 8.5 provides requirements for the inspection of structural steel welding.44 In the construction industry, welding of reinforcing bars and structural steel have typically been treated separately. Each has its own codes and standards and practices. Consistent with this differentiation, Subpart 2.5 distinguishes between the two. Inspection of welded reinforcing bar splices are addressed in Paragraph 7.13 and inspection of structural steel welding is addressed in Paragraph 8.5 of the standard. Yes, Paragraph 7.13 references Paragraph 8.5, as some of these measures are applicable to the inspection of welded reinforcing steel splices as well. The reference to Paragraph 8.5 in Subpart 2.5, Paragraph 7.13, however, should not be taken out of context or given exceptional status: reinforcing steel bars do not fall within the definition of structural steel, nor is the welding of reinforcing bar splices within the scope of AWS D1.1, the welding code which is referenced in Paragraph 8.5.45 44 Structural steel consists of elements of the structural frame that are shown and sized in the structural design drawings, essential to support of design loads. Explicitly excluded from this definition are concrete reinforcing steel bars. “Code of Standard Practice for Steel Building and Bridges,” American Institute of Steel Construction, April 14, 2010. 45 It is also important to recognize that in the nuclear industry, structural steel buildings typically are required to conform to ANSI/AISC N690, “American National Standard Specification for the Design, Fabrication, and Erection of

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The position taken in the TAR response appears to be that the Subpart 2.5, Paragraph 7.13 requirement to comply with ASME Division 2 is made optional by the reference to Paragraph 8.5. It appears NRO staff draws this conclusion because the ASME Subpart 2.5 requirements for the inspection of structural steel welding provided in Subpart 2.5, Paragraph 8.5 do not reference destructive testing and leave it to the discretion of the Engineer to determine if NDE is necessary based on the application. There is little basis for this interpretation. It would subordinate the requirements specific to the inspection of welded reinforcing bar splices to those for structural steel welding. These are apples and oranges. Destructive testing is typically impractical and not used for the acceptance of structural steel welding. Also, for structural steel welding, the requirements for NDE other than visual are addressed in the steel design code. A more reasonable interpretation, in my view, would be that for the inspection of welded reinforcing bar splices, ASME Division 2 provides the specific inspection requirements that are appropriate to the application. Subpart 2.5, Paragraph 7.13 clearly states that the provisions of ASME Division 2 shall also apply for welded reinforcing bar splices. The ASME Division 2 provisions for the inspection of welded reinforcing bar splices are of at least equal standing to the requirements of Paragraph 8.5. Given that ASME Division 2 provides requirements specific to the inspection of welded reinforcing bar splices, which is the scope of Paragraph 7.13, it also seems reasonable to conclude that the provisions of ASME Division 2 would take precedence over the requirements of Paragraph 8.5 if there was a conflict. I do not believe that it is coincidence that the Standard Review Plan and Subpart 2.5 are in alignment that welded reinforcing bar splices should conform to ASME Division 2. The Subpart 2.5 provisions for the inspection of welded reinforcing bar splices originated in RG 1.94 to my knowledge. These provisions were subsequently incorporated into ASME N45.2.5, the predecessor of Subpart 2.5. The NRC appears to have been involved in this process.46 The provisions were also understood at the time to apply broadly to reinforced concrete structures of nuclear facilities not just concrete reactor vessels or containments.47 There appears to be difficulty with accepting that the provisions of ASME Division 2 could be used for concrete structures other than concrete reactor vessels or containments. However, NRO staff seems to hold the opinion that, for the inspection of welded reinforcing bar splices, the measures provided in Subpart 2.5 for the inspection of structural steel welding should take precedence over those specific to welded reinforcing bar splices. A concrete containment and a non-pressure retaining concrete structure may be different apples, but they’re still apples. Before the development of ASME Division 2, both were typically designed and constructed to the same codes. A reinforced concrete structure and a steel structure, on the other hand, are

Steel Safety-Related Structures for Nuclear Facilities.” This code requires NDE other than visual of partial and complete joint penetration welds. 46 Proposed Revision 2* to Regulatory Guide 1.94, ‘Quality Assurance Requirements for Installation, Inspection, and Testing of Structural Concrete, Structural Steel, Soils, and Foundations during the Construction Phase of Nuclear Power Plants’,” Division 1, Task RS 908-5, September 1979, Section 1.3.1, p 6. (ML12298A122) 47Letter from S.B. Jacobs, Chief Licensing Engineer, Stone & Webster Engineering Corporation, dated April 8, 1980, providing comments on draft on Proposed Revision 2 to Regulatory Guide (RG) 1.94 "Quality Assurance Requirements for Installation, Inspection, and Testing of Structural Concrete, Structural Steel, Soils and Foundations During the Construction Phase of Nuclear Power Plants,” September 1979, Section 2 and 3rd Paragraph of Section 7, p 2. (ML17192A356)

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apples and oranges by comparison. A piece of reinforcing steel does not know or care what type of reinforced concrete structure it is used in. It’s still a piece of reinforcing steel and acts in a similar manner to resist design loads. Place that same piece of reinforcing steel in a steel structure, however, and it’s a fish out of water. More surprising is the statement that the welded reinforcing steel hoops are not structural items. This characterization does not appear to have any basis. Wall 11 at the location of the main steam lines is defined as a critical structural section in the AP1000 DCD and VEGP Unit 3 & 4 UFSAR.48 The WEC structural calculations for Wall 11 indicate that the welded steel hoops are required to resist design basis loads.49 April 6, 2019 Response to TAR AP-V-M-42 Question 1 and comments After more discussion between regional inspectors and staff, NRO revised the response to: If a licensee commits to Subpart 2.5 of the NQA-1 standard, then the licensee must meet all the requirements under that Subpart. However, for any Codes and Standards referenced within the Subpart that are not applicable to the scope of work, the licensee is not required to implement those referenced Codes and Standards. NRO staff communicated to regional inspectors that, in their opinion, ASME Division 2 is not applicable to construction of VEGP Units 3 & 4 because the scope of ASME Division 2 is limited to concrete reactor vessels or containments. The AP1000 plants have neither. The Subpart 2.5 requirements are associated with the construction activity, however, not the code of record. Subpart 2.5 Section 7 addresses the inspection of concrete construction. If a licensee is engaging in work activities that fall within the scope of this section than these requirements are relevant whether the code of record is ACI 318, ACI 349, or ASME Division 2. Subpart 2.5 does not assume that any particular code has been invoked. Subpart 2.5 Paragraph 2, “General Requirements” states:

The requirements of Subpart 2.5 apply to any organization or individual participating in work relating to production, preparation, placement, installation, inspection, and testing of structural concrete…”

Work performed under ACI 318, ACI 349, or Division 2 is classified as structural concrete. If Subpart 2.5 was not intended to supplement the requirements of the code of record, what use would it serve? Wouldn’t it be redundant and compliance with the code of record sufficient in itself? ASME Division 2 is referenced in Subpart 2.5 Paragraphs 7.11, 7.12, and 7.13. Assuming these paragraphs only apply to concrete reactor vessels and containments because they reference ASME Division 2 ignores the scope of NQA-1-94 Part II,50 the history and intent of

48 AP1000 DCD and VEGP Unit 3 UFSAR, Section 3.8.4.5.4 and 3H.5.1.4. 49 Westinghouse Electric Company Document No. APP-1200-S3C-101, “Auxiliary Building Wall 11 Reinforcement Design EL 117’-6” to EL 135’-3”,” Revision 0, p. 31. 50 “Quality assurance requirements for the planning and execution of identified tasks during fabrication, construction, modification, repair, maintenance, and testing of systems, components, and structures for nuclear

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these provisions, established NRC guidance, and the common engineering practice of adapting provisions of a design code for use beyond their original intent. Moreover, this interpretation places unreasonable limitations on the applicability of Subpart 2.5 to an extent that would not make sense. Subpart 2.5 provides amplified requirements for the inspection of concrete construction. The requirements of Subpart 2.5 Paragraphs 7.11, 7.12, and 7.13 provide the backbone of an inspection program intended to verify that the construction meets specified requirements. Such a program is applicable to Seismic Category I concrete structures, in general, not just concrete reactor vessels or containments.

The use of ASME Division 2 for the inspection of welded reinforcing bar splices is consistent with NRC guidance provided in the Standard Review Plan (SRP).51 During design review of the AP1000, NRC staff clearly believed that some provisions of ASME Division 2 were applicable to other aspects of the AP1000 as well.

Concerning the proposed use of mechanical couplers in the AP1000 enhanced shield building, NRC staff stated:

“It is the opinion of RES staff that acceptance criteria for qualification and production testing of the mechanical couplers for the SC/RC connections of the AP1000 shield building should be that used for repair of existing RC shield buildings following steam generator replacement operations, which are the criteria in ASME Boiler and Pressure Vessel Code, Section III, Division 2, “Code for Concrete Containments”.52

If the licensee had proposed the use of welded reinforcing steel splices during the AP1000 design certification or VEGP Units 3 & 4 COL licensing processes, it is likely that the NRC would have required compliance with ASME Division 2 for production testing of welded reinforcing bar splices as was done for mechanical connections. Regardless, SNC committed to these measures by invoking Subpart 2.5 without exception in the SNC NDQAM.

April 6, 2019 Response to TAR AP-V-M-42 Question 2 and comments

After more discussion between regional inspectors and staff, NRO revised the response to:

The auxiliary building is built to ACI 349 standards, and therefore welds only need to conform to AWS welding requirements and are excluded from meeting ASME BPV Section III, Division II requirements, as supported by the following:

• The Vogtle Auxiliary Building is designed to ACI 349-01, which states“Specifically excluded from this Code are those structures covered by “Code forConcrete Reactor Vessels and Containments,” ASME Boiler and PressureVessel Code Section III, Division 2, and pertinent General Requirements (ACIStandard 359).”

facilities are contained in Part II,” ASME NQA-1-1994, “Quality Assurance Requirements for Nuclear Facility Applications,” Forward, p iv. 51 NUREG-0800 52 Summary Evaluation Report, Enhanced Shield Building Structure, Westinghouse Electric Company Report APP-1200-S3R-003. Revision 2 AP1000 Design Control Document, Revision 17, U.S. NRC, Office of Nuclear Regulatory Research, October 29th, 2010, pp 42 (ML103080129).

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• Concerning welding, ACI -349, paragraph 12.14.3.2 states that “Except as provided in this code, all welding shall conform to “Structural Welding Code—Reinforcing Steel” (ANSI/AWS D1.4)”

The supporting information provided in the response is taken directly from ACI 349-01. This information does not address NRC guidance on the welded reinforcing bar splices, or the requirement for construction work activities to be conducted under a quality assurance plan meeting Appendix B. In this response, NRO staff appears to confuse conformance with a design and construction code and implementation of appropriate quality measures to verify that construction meets specified requirements. The URI is not associated with meeting ACI 349-01 performance or AWS D1.4-98 welding requirements for welded reinforcing bar splices. It is not a question that the welded splices need to meet the requirements of ACI 349-01 and AWS D1.4-98, or whether these requirements are adequate from a performance standpoint. The URI is associated with the appropriate quality assurance measures that are necessary to verify that the requirements of ACI 349-01 and AWS D1.4-98 are being met. These quality assurance measures are not adequately addressed in ACI 349-01 or AWS D1.4-98, but in Subpart 2.5. The response does not appear to recognize the relationship between ACI 349-01 and Subpart 2.5 and seems to be predicated on a belief that ACI 349-01 provides adequate quality assurance measures for the inspection of concrete construction. This view is inconsistent with the guidance provided in RG 1.142. Reliance on measures solely provided in ACI 349-01 and/or AWS D1.4-98 is inadequate to meet Appendix B. ACI 349-01 and AWS D1.4-98 must be used in conjunction with a quality assurance plan meeting Appendix B. The use of Subpart 2.5 and the standards it references for the inspection of concrete structures is fully consistent and compatible with ACI 349-01 and AWS D1.4. The Subpart 2.5 measures do not replace or alter any provisions of ACI 349-01 and AWS D1.4. Failure to enforce the Subpart 2.5 requirements as committed to in the SNC NDQAM will result in an inspection program for Seismic Category I concrete structures that is not consistent with the requirements of Appendix B. TAR AP-V-M-4553 This TAR was submitted to seek more clarity and justification for the NRO positions on the use of welded reinforcing bar splices in VEGP Units 3 & 4. One question was asked in TAR AP-V-M-45: Is the licensee subject to the requirements of the ASME BPV Code, Section III, Division 2 via NQA-1-1994 Subpart 2.5. for all safety related welded reinforcing bar splices (regardless whether they are located in concrete containments or not)? Please provide a response with technical justification. Response to TAR AP-V-M-45 and comments: The licensee is not subject to the requirements of the ASME B&PV Code, Section III, Division 2 via NQA-1-1994, Subpart 2.5 for all safety related welded reinforcing bar splices. The NRC staff determined that the licensee is committed to Subpart 2.5, “Quality Assurance Requirements for Installation, Inspection, and Testing of Structural Concrete, Structural Steel, Soils, and Foundations for Nuclear Facilities,” of the NQA-1-1994 ASME quality assurance 53 ML19016A408

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standard as a method of meeting Appendix B to 10 CFR Part 50. Subsection 4.0 of Section 10 of Rev. 19 of the NDQAM states that, “SNC commits to compliance with the requirements of Subparts 2.5 and 2.8 for establishing appropriate inspection requirements.” Subpart 2.5 of NQA-1-1994, states that it provides amplified requirements for installation, inspection, and testing of structural steel, soils, and foundations. It supplements the requirements of Part I and shall be used to the extent specified by the organization invoking the Subpart. Therefore, the licensee would specify the extent of the subpart’s applicability. Additionally, the licensee’s commitment encompasses Basic Requirement 10, and Supplement 10S-1 of NQA-1. Basic Requirement 10 states that “Characteristics to be inspected and inspection methods to be employed shall be specified.” Supplement 10S-1, Section 2, states, “Inspection requirements and acceptance criteria shall include specified requirements contained in the applicable design documents approved by the responsible design organization.” Subsection 2.0 of Section 10 of the NDQAM describes the Inspection Program at Units 3 and 4. It requires the establishment of inspections necessary to verify quality, such as for the final acceptance of fabricated and/or installed items during construction. Furthermore, Section 8.5 “Welding,” of Subpart 2.5 states that: “Inspection of structural steel welding shall be performed in accordance with the provisions of Section 6.0 of AWS DI .I, Structural Welding Code - Steel. This inspection shall include visual examination of preparations, welding processes, post-welding operations, and if deemed necessary, some NDE inspections which are appropriate to the application [emphasis added.]” As provided in the discussion above, SNC should be able to provide a documented basis for the inspection requirements deemed necessary for the welded splices application. In this response, NRO staff acknowledges that SNC committed to Subpart 2.5 in the SNC NDQAM, however, they appear to view this as a “soft” commitment. As such, SNC may use discretion in implementing these requirements. My opinion as stated previously is that an exception should be taken in the SNC NDQAM to Subpart 2.5 Paragraph 7.13 if these measures are not going to be implemented for construction of VEGP Units 3 & 4. Please refer to comments on April 3, 2019 Response to TAR AP-V-M-42 Question 2 for discussion of reference to Subpart 2.5 Paragraph 8.5 in Subpart 2.5 Paragraph 7.13. Additional Comments on TAR Responses In discussions with regional inspectors and documented in the notes in the TAR database for TAR AP-M-V-42, NRO staff stated that they consulted with ASME committee members about the applicability of Subpart 2.5 Paragraph 7.13 in developing the TAR responses. While I respect the opinion of the ASME committee members and do not take issue with reaching out to others to inform a response, it is hard to assign much weight to these discussions as I did not participate in them, do not know who was involved, and there is no record of what was discussed. The NRC was involved in the development of Subpart 2.5 and was responsible for approval of the AP1000 DCD and VEGP Units 3 & 4 COLs. The Subpart 2.5 Paragraph 7.13 requirements for welded splices were originally provided as guidance in RG 1.94. It is surprising that the NRC apparently has lost track of the intent of these requirements which correspond to the guidance provided in the SRP. The NRC is empowered to enforce the requirements of the VEGP Units 3 & 4 COLs and should not rely on informal off the record discussions with ASME committee members to make regulatory decisions. Hopefully, this is not

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the case. If much stock was placed in these discussions, then they should have been conducted in a public meeting with the participation of all interested parties. Moreover, the NRC is not bound to accept the opinions of ASME committee members or ASME code cases or interpretations. These should be evaluated using the appropriate regulatory decision-making process on a case by case basis before they are accepted for use.

Follow-up Inspection to Close URI

As documented in the inspection report, a follow-up inspection was conducted to close the URI during the 1st quarter of 2019. The focus of this inspection was on the types of reinforcing steel splices allowed by VEGP Unit 3 & 4 UFSAR Section 3.8.4.6.1.2 and the quality assurance measures being implemented for acceptance of welded reinforcing steel splices.

For this inspection, SNC provided a “white paper”54 asserting that welded reinforcing bar splices were a form of mechanical connection and therefore allowed by the VEGP Units 3 & 4 UFSAR. SNC also took the position in this “white paper” that quality assurance measures being implemented for acceptance of welded reinforcing bar splices were adequate.

The regional inspectors reviewed the SNC “white paper” and did not find the arguments in it convincing. It is true that the purpose of a mechanical or welded reinforcing bar splice is the same and they share similar performance requirements. The design function does not differ between a lap splice, mechanical connection, or welded splice. However, each form of splice has a different means of transferring forces between bars and, historically, each type of splice has been treated separately with its’ own unique requirements. As a result, the inspectors concluded that the use of welded reinforcing bar splices was not in conformance with the VEGP Unit 3 & 4 UFSAR. The significance of this finding was determined to be minor based on the TAR responses. I do not agree with this determination.

For the reasons discussed in this nonconcurrence, the inspectors questioned the conclusion of the SNC “white paper” that the quality assurance measures being implemented at VEGP Units 3 & 4 for the acceptance of welded reinforcing bar splices are adequate. Clearly, in my opinion they are not. Given the TAR responses, however, the inspectors saw no means of compelling SNC to provide more substantial justification for the installed splices.

Supporting Information/Other Considerations

NRC Endorsement of ACI 349-97 and Guidance on the Use of Welded Reinforcing Bar Splices

The NRC endorsed the use of ACI 349-07 in Regulatory Guide (RG) 1.142, “Safety-Related Concrete Structures for Nuclear Power Plants (Other than Reactor Vessels and Containments),” Revision 2.55 The scope of this regulatory guide does not include concrete reactor vessels or containments. These are addressed in another RG.56

54 “ACI 349 AWS D1.4 Basis NDE Welded Rebar,” SNC White Paper on Equivalency of Welded Reinforcing Bar Splices with Mechanical Splices 55 ML013100274 56 Regulatory Guide 1.136, “Design Limits, Loading Combinations, Materials, Construction, and Testing of Concrete Containments, “ Revision 3, March 2007 (ML070310045)

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NRC guidance on the use of welded reinforcing bar splices is that the splices should meet the requirements of ASME Division 2.57 This guidance is provided in Section 3.8 of the SRP and is for all areas inside and outside of containment, regardless of specific reactor type.58 SRP Section 3.8.4.I.6.B is applicable to the VEGP Units 3 & 4 auxiliary buildings: This section states:

“If welding of reinforcing bars is proposed, it should comply with American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code (Code) Section III, Division 2. Any exception to compliance should be supported with adequate justification.”59

Similar requirements are included in the Design-Specific Review Standard for the mPower iPWR Design.60 Concerning these requirements, NRC staff provided the following comment:

“[ASME Division 2, Article] CC-4334 refers to the Mandatory Appendix XI for qualification requirements for arc welding procedures, welders, and welding operators used to arc weld reinforcing bars. These qualification requirements are not in ACI 349, and further ACI 349-2001 is not currently endorsed in RG 1.142. The intent of the referenced provision in the DSRS is that when rebar is spliced by welding for nuclear safety-related applications, the qualification and other requirements for arc welding in ASME Section III, Division 2 should be met.”61

ASME Division 2 and AWS D1.4 have a lot of commonality. As a result, the NRC guidance for welded reinforcing bar splices can largely be satisfied for direct butt splices by either specifying compliance with ASME Division 2 or AWS D1.4, provided Subpart 2.5 is also invoked for the inspection of welded reinforcing bar splices. Either approach is the same for all intents and purposes. Hopefully, some of the discussion that follows will make this clear. The NRC guidance on the use of welded reinforcing bar splices was formerly provided in RG 1.94.62 It is also reflected in the endorsement of ASME NQA-263 in RG 1.142 as a means of addressing shortcomings in ACI 349-97 and satisfying 10 CFR Part 50, Appendix B64 (Appendix B) for safety-related reinforced concrete structures designed and constructed in accordance

57 ANSI/ASME, “Code for Concrete Reactor Vessels and Containments,” Boiler and Pressure Vessel Code, Section III, Division 2. 58 Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition — Design of Structures, Components, Equipment, and Systems (NUREG-0800, Chapter 3) 59 NUREG-0800 - Chapter 3, Section 3.8.4, Revision 2, Other Seismic Category I Structures, dated March 2007 p 3.8.4-6 (ML070550054) 603.8.4 Other Seismic Category I Structures, Design-Specific Review Standard for mPower iPWR Design, Revision 0, May 2013, p 3.8.4-6 (ML13099A316) 61Public Comments on mPower Design Specific Review Standard (DSRS) Section 3.8.3, “Concrete and Steel Internal Structures of Steel or Concrete Containments,” Comment 11, Page 6, September 12, 2013 (ML14050A273). 62 Regulatory Guide 1.94, “Quality Assurance Requirements for Installation, Inspection, and Testing of Structural Concrete and Structural Steel during the Construction Phase of Nuclear Power Plants,” Revision 1. This regulatory guide endorsed ASME N45.2.5-1974. RG 1.94 was withdrawn in September 2010 after ASME N45.2.5 was replaced by Subpart 2.5 which incorporated NRC guidance on use of welded reinforcing bar splices. 63 ANSI/ASME, “Quality Assurance Requirements for Nuclear Facility Applications,” NQA-2, 1983 64 “Quality Assurance Criteria for Nuclear Power Plants and Fuel Processing Plants,” Appendix B to 10 CFR Part 50.

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with ACI 349-97.65 Specifically, the following guidance is provided in RG 1.142 concerning the use of ACI 349-07 and other related standards:

“The ACI 349-97 commentary recommends the use of various ANSI standards for developing quality assurance programs related to the design and construction of safety-related concrete structures. Quality assurance programs developed in accordance with the applicable portions of these ANSI standards and the regulatory guides that endorse them provide an acceptable means of complying with the requirements of Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CFR Part 50. ASME NQA-2-1983 provides standards, such as those for in-process testing of concrete, concrete materials, and reinforcing bar splices and for repairs and inspection of concrete construction, that are not adequately included in ACI 349-97. Hence, ASME NQA-2-1983 provides supplementary provisions for the construction of safety-related concrete structures.”

Supplementing ACI 349-01 with ASME Subpart 2.5 is necessary because ACI 349-01 has minimal requirements for the inspection of concrete construction. ACI Section 1.3.1 states:

“The Owner is responsible for the inspection of concrete construction throughout all work stages. The Owner shall require compliance with design drawings and specifications. The Owner shall also keep records required for quality assurance and traceability of construction, fabrication, material procurement, manufacture, or installation.”

ACI 349-01 is to be used in conjunction with a quality assurance program meeting Appendix B. ACI 349-01 Section 1.5, “Quality Assurance Program” states:

“A quality assurance program covering nuclear safety related structures shall be developed prior to starting any work. The general requirements and guidelines for establishing and executing the quality assurance program during the design and construction phases of nuclear power generating stations are established by Title 10 of the Code of Federal Regulations, Part 50 (10CFR50), Appendix B.”

Moreover, the commentary to this section explicitly references ASME NQA-1 and NQA-2 as being applicable to this quality assurance plan:

“Title 10 CFR 50, Appendix B, requires that the Owner have a quality assurance program approved by the Regulatory Authority and states that the Owner is responsible for the establishment and execution of programs developed by his engineers, construction contractors, and suppliers. More detailed requirements for development and implementation of a quality assurance program are contained in ANSI/ASME NQA-1 and ANSI/ASME NQA-2.”66

65 NQA-2 and ACI 349-97 are the predecessors of NQA-1, Part II and ACI 349-01, respectively. The differences between the different versions of each standard are minimal as they relate to welded reinforcing bar splices: The provisions for welded reinforcing bar splices in NQA-1-1994 are equivalent to those in NQA-2-1983. Likewise, the provisions in ACI 349-01 for welded reinforcing bar splices do not differ materially from those in ACI 349-97. 66 Theses references are to NQA-1-1989 and NQA-2-1989, respectively. NQA-2-1989 Subpart 2.5 Section 8.13 is the same as ASME NQA-1 Part II Subpart 2.5, Section 7.13. Additionally, 10 CFR Part 50 Appendix B is adopted by reference is ACI 349-01 Section 3.8.3.

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Given the lack of detail provided in ACI 349-01, it is reasonable to assume that the quality assurance program would make use of standards that are not directly referenced in ACI 349-01. AP1000 and VEGP Units 3 & 4 Compliance with Standard Review Plan (NUREG-0800) Compliance with the acceptance criteria of the Standard Review Plan (NUREG-0800) is addressed in Section 1.9.2 of the AP1000 DCD and VEGP Unit 3 & 4 UFSAR. This information was required to be provided by NRC regulations, specifically 10 CFR 57.79(a)(4) to my knowledge. WEC furnished WCAP-15799, “AP1000 Conformance with SRP Acceptance Criteria,” with this information. This document was also referenced in the VEGP Units 3 & 4 COLs. In this document, it is stated that construction of the AP1000 will comply with Subpart 2.5 and no exception is taken to the NRC acceptance criteria for welded reinforcing splices given in SRP Section 3.8.4.I.6.B.67 ASME NQA-1-1994, Part II, Subpart 2.5 (Subpart 2.5)68 and ASME Division 2 Significant portions of the VEGP Unit 3 & 4 containment internal structures (CIS), shield buildings, and auxiliary buildings are constructed of reinforced concrete. Subpart 2.5, Section 7 provides requirements for the Inspection of concrete construction. As a result, the requirements of Subpart 2.5, Section 7, except for those associated with pre-stressed concrete,69 are relevant to work being performed at VEGP Units 3 & 4. Subpart 2.5, paragraphs 7.11, 7.12, and 7.13 are associated with the in-process tests of concrete and reinforcing steel, mechanical splice testing, and welded reinforcing bar splices, respectively. These paragraphs are central to the requirements provided in Subpart 2.5 for the inspection of concrete construction and form the framework of an inspection program intended to verify the material and construction meet specified requirements. They rely heavily on provisions of ASME Division 2 to specify the types of inspections and tests that are required and the frequency of performing these inspections and tests. As a result, they reference ASME Division 2 for convenience. Apparently, these references have caused confusion because ASME Division 2 was originally developed for the design and construction of concrete reactor vessels and containments. The specific sections of ASME Division 2 referenced in Subpart 2.5, however, can be leveraged for use in other types of structures because they are general provisions: they are not associated with any features that are unique to concrete reactor vessels or containments; nor are they dependent on the analysis or design methodology adopted by a specific design code. The Division 2 provisions referenced in Subpart 2.5 are relevant for the inspection of structural concrete, in general, regardless of the type of structure and have general adaptability for use with other codes and standards.70 67 WCAP-15799, “AP1000 Conformance with SRP Acceptance Criteria,” dated August 2003, Revision 1, September 9, 2003, p 3-22 and 3-27, respectively 68 ASME NQA-1-1994, Part II, Subpart 2.5, “Quality Assurance Requirements for Installation, Inspection, and Testing of Structural Concrete, Structural Steel, Soils, and Foundations for Nuclear Power Plants” 69 VEGP Units 3 & 4 Nuclear Island structures do not make use of prestressed concrete. As result, ASME NQA-1-1994, Part II, Subpart 2.5, Paragraphs 7.8 and 7.9 are not applicable. 70 These provisions rely on conformance with ASTM Standards that apply to all types of facilities, or splicing systems or methods that have general use as well.

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The adaptation of code provisions for use outside or their original intent or scope is not unique to Subpart 2.5. One prominent example is provided in the AP1000 FSER where that NRC partially based its acceptance of the design of the RC/SC connections of the AP1000 shield building on a WEC commitment to meet ASME Division 2 criteria for qualification and production testing of mechanical connectors used in the design.71 This commitment was necessary because the design of the AP1000 shield building is not within the scope of ASME Division 2 and the type of connector proposed for use was not addressed in Subpart 2.5, Paragraph 7.12. The potential use of ASME Division 2 provisions outside of their intended scope is recognized by the code committee and addressed in the forward to the standard which states:

“The Code Committee does not rule on whether a component shall or shall not be constructed to the provisions of the Code. The Scope of each Section has been established to identify the components and parameters considered by the Committee in formulating the Code rules. Laws or regulations issued by municipality, state, provincial, federal, or other enforcement or regulatory bodies having jurisdiction at the location of an installation establish the mandatory applicability of the Code rules, in whole or in part, within their jurisdiction. Those laws or regulations may require the use of this Code for vessels or components not considered to be within its Scope or may establish additions or deletions in that Scope. Accordingly, inquiries regarding such laws or regulations are to be directed to the issuing enforcement or regulatory body.”

The tests referenced in Subpart 2.5 paragraphs 7.11, 7.12, and 7.13 are relevant to structures designed and constructed in accordance with ACI 349-01. ACI 349-01, subsection 3.1.1 states: “The Owner shall have the right to order testing of any materials used in concrete construction to determine if materials are of quality specified.” ACI 349-01 Chapter 3, “Materials” specifies the ASTM standards to which material used in reinforced concrete must conform. The standards cited are consistent with those specified in ASME Division 2. However, ACI 349-01 does not specify any in-process tests or the frequency of such tests. Clearly, these requirements must be supplemented with a testing program to verify conformance with the requirements. These tests and their frequency are specified in Subpart 2.5 by reference to ASME Division 2.72 As the example given earlier also shows, the NRC clearly believed that ASME Division 2 was applicable to qualification and testing of the mechanical connectors used in the AP1000 shield building. Welded reinforcing bar splices are addressed in ASME Subpart 2.5, paragraph 7.13 which states: “Welded reinforcing bar splices shall be subject to the requirements of para. 8.5, except that the provisions of the ASME Boiler and Pressure Vessel Code, Section III, Division 2 (ACI Standard 359) shall also apply.”

71 NUREG-1793, “Final Safety Evaluation Report Related to Certification of the AP1000 Standard Plant Design Docket No. 52-006,” Supplement 2, p 3-150 (ML112061231). Regrettably, SNC unilaterally reduced this commitment in E&DCR SV0-CR01-GEF-001039, “Revision of Taper Threaded Mechanical Splice Testing and Inspection Requirements,” Revision 0 72 The tests and required frequency is provided in ASME Division 2, Table CC-5200-1, “Minimum Testing Frequencies for Concrete Constituents and Concrete”

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The Subpart 2.5, Paragraph 7.13 measures appear to trace their origin to Regulatory Guide 1.94, Revision 173 and are applicable to all nuclear facilities invoking NQA-1 Subpart 2.5 to my knowledge.

Welded reinforcing bar splices are addressed in ASME Division 274 Article CC-4334, "Arc Welded Joints" and Appendix XI, "Qualifications for Arc Welding Reinforcing Bars." These measures require destructive testing (XI-1560, "Continuing Joint Performance Tests") and NDE (XI-1600, "Examination of Welded Joints of Reinforcing Bar") to verify welded reinforcing bar splices meet the tensile weld quality requirements, respectively.

AP1000 DCD and VEGP Units 3 & 4 UFSARs

Welded reinforcing bar splices do not appear to have been proposed for use during the review and approval of the AP1000 DCD or VEGP Units 3 & 4 COLs.

AP1000 DCD and VEGP Units 3 & 4 UFSARs Section 3.8.4.6.1.2 states, in part, “where reinforcing steel splices are necessary and lap splices are not practical, mechanical connections (e.g. threaded splices, swaged sleeves or cadwelds) are used.”

As discussed previously, mechanical connectors are different than welded splices. When the above statement from the VEGP Units 3 & 4 UFSAR is placed in the context of the DCD and COL review processes, which were performed according to the SRP, it is reasonable to conclude that the acceptable types of splices are limited to either lap splices or mechanical connections. This conclusion is based on the SRP acceptance criteria requiring that welded splices meet ASME Division 2, and if not, any deviations be justified.

Apparently, SNC overlooked this statement in the VEGP Units 3 & 4 UFSAR and assumed that welded reinforcing bar splices were acceptable for use in the construction of VEGP Units 3 & 4 because they are allowed by ACI 349-01. They also overlooked the NRC guidance on the use of welded reinforcing bar splices and assumed the splices only needed to meet ACI 349-01 criteria.

ACI 349-01 requires that all welding conform to AWS D1.4 and welded splices develop 125% of the yield strength of the bar.75

To compound matters, SNC assumed that AWS D1.4 only requires visual examination of completed welds, and therefore visual examination alone is adequate to verify that a weld completed in accordance with AWS D1.4 is adequate. NRO staff appear to be making this same mistake. AWS D1.4 also includes provisions for the radiographic examination of welds.

The focus of AWS D1.4 is not nuclear safety-related construction. It is a code with a broad range of applicability. AWS D1.4 does not specify the appropriate types of inspections for a

73 An overview of the history and consolidation of NRC-endorsed standards is provided in Regulatory Guide 1.28, “Quality Assurance Program Criteria (Design and Construction),” Revision 4. RG 1.28, Appendix A, “Evolution of Quality Assurance Standards and the Endorsing Regulatory Guides,” indicates in Table A-3 that standards endorsed by RG 1.94 were incorporated into NQA-1 Subpart 2.5. Regulatory Guide 1.94 was subsequently withdrawn in 9/2010. 74 ASME Boiler and Pressure Vessel Code, Section III, Division 2, “Code for Concrete Reactor Vessels and Containments,” 2001 Edition with 2003 Addenda (ACI Standard 359-01). 75 ACI 349-01 Sections 3.5.2, 12.14.3.2, and 12.14.3.3.

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specific application of the code because the range of use of the code is so broad as to make addressing every possible application within the standard impractical. This is true of other AWS standards as well. The following statement from the American Institute of Steel Construction (AISC) steel design guide 21 describes the AWS philosophy:

“Because of the diversity of projects that can be governed by AWS D1.1, it is impossible for a single document to specify appropriate inspection requirements, including the extent and type of NDT76 to be performed, acceptance criteria, and who is responsible for various inspection tasks. AWS D1.1, therefore, relies on the engineer to specify such NDT requirements.”77

It is important to recognize that safety-related steel structures used in VEGP Units 3 & 4 are designed and according to AISC N690-94.78 This standard requires all welding conform to AWS D1.1. However, it also limits reliance on the engineer to determine minimum inspection requirements by specifying that NDE other than visual be performed on a sampling basis for partial and complete joint penetration welds. One of the shortcomings of ACI 349-01 is that is does not take the same approach and explicitly specify destructive testing or NDE other than visual for welded reinforcing bar splices. ACI 349-01, Section 12.14.3.6 states:

“All welded splices and mechanical connections shall be visually examined by a qualified and experienced inspector to assure that they are properly installed at the place of construction. Where it is deemed necessary, the engineer shall be permitted to require destructive tests of production splices to assure compliance with 12.14.3.3 and 12.14.3.4.”

It is incorrect, however, in my view to conclude from the above provision that visual inspection alone is adequate to verify that a welded reinforcing bar splice completed in accordance with ACI 349-01 and AWS D1.4 meets requirements. This provision was not intended to imply that radiographic examination is not required for welded reinforcing bar splices used in safety-related structures to my knowledge. ACI 349-01 recognizes that destructive tests of splices may be warranted and adopts by reference AWS D1.4 for welding of reinforcing bars. The appropriate inspection requirements for welded reinforcing bar splices used in nuclear safety-related structures are addressed in the SRP and ASME Subpart 2.5. These inspection requirements supplement ACI 349-01 and AWS D1.4 requirements and are fully compatible with these standards. The supplemental inspection requirements of ASME Subpart 2.5, Paragraph 7.13 provide measures for implementing the destructive tests of welded reinforcing bar splices referenced in ACI 349-01 Section 12.14.3.6. If destructive tests are to be performed, a testing plan which identifies the samples and frequency of testing must be developed. These are addressed in ASME Division 2. 76 Non-destructive Testing. Another name for Non-destructive Examination (NDE) 77 Duane K. Miller, “Welded Connections - A Primer for Engineers,” Steel Design Guide 21, American Institute of Steel Construction, Inc. June 2006, p 102. 78 ANSI/AISC N690-1994, “American National Standard Specification for the Design, Fabrication, and Erection of Steel Safety-Related Structures for Nuclear Facilities,” American Institute of Steel Construction, Inc., Chicago, Ill., 1994.

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Likewise, AWS D1.4-98 allows the engineer to specify nondestructive examination of welds in addition to visual. Such inspection is addressed in Section 7.7, Nondestructive Testing. Of note, subsection section 7.7.1 requires that when nondestructive examination in addition to visual is required, it shall be so stated in the information furnished to the bidders. This information shall designate the welds to be examined, the extent of examination of each weld, and method of testing. Subsection 7.7.3 also requires that when radiographic examination is used, the procedure and technique shall be in accordance with industry standard practice. Both the requirements of AWS D1.4-98 subsections 7.7.1 and 7.7.3 are satisfied by specifying conformance with ASME Division 2 requirements for welded splices. It should also be noted that the standards of acceptance for weld quality requirements are consistent between AWS D1.4-98 and ASME Division 2. The acceptance criteria provided in AWS D1.4-98 Table 4.1, Radiographic Acceptance Criteria are the same as that provided in ASME Division 2 Table XI-1620-1, Radiograph Acceptance Criteria. This is not the only example where AWS D1.4 and ASME Division 2 requirements for welded reinforcing bars splices are in alignment. ASME Division 2, ACI 349-01, and AWS D1.4-98 requirements for welded splices overlap in many areas. A complete joint penetration weld made in accordance with either ASME Division 2 or AWS D1.4-98 should develop the full strength of the spliced bar. The provisions for welding performance specification (WPS) and welder performance qualification are largely the same between both codes, as is the acceptance criteria for completed welds. Later editions of ASME Division 2, in fact, adopt by reference AWS D1.4 measures for allowable electrodes, and WPS and welder performance qualification.79 One difference between the two codes is that ASME Division 2 limits the types of welds to complete joint penetration welds while AWS D1.4 allows some other types of joints. AWS D1.4, however, recommends that direct butt joints be used for bars greater than #6. Given, the amount of reinforcing typically required for nuclear safety-related structures, it would be surprising if splices other than direct butt joints were used extensively. The main differences between ASME Division 2 and AWS D1.4 requirements for welded reinforcing bar splices, that appear to be material to construction of VEGP Units 3 & 4, are that ASME Division explicitly requires destructive testing and radiographic examination while AWS D1.4 does not for the reasons stated above. As a result, AWS D1.4 needs to be supplemented with other measures when used for nuclear safety-related structures. Specifying compliance with either ASME Division 2 or ACI 349-01 and AWS D1.4, for direct butt splices, should be acceptable provided ACI 349-01 and AWS D1.4 are supplemented with adequate measures for the inspection of welded reinforcing bar splices. These supplemental measures can be specified by invoking ASME Subpart 2.5. Implementation of the Subpart 2.5 provisions for welded splices requires some judgment. The reference to ASME Division 2 in Section 7.13 has clearly has created some confusion and proven to be a distraction. I get the sense that there is a belief that, if enforced, these references would impose new design and construction requirements on the licensee that replace provisions within the codes and standards on which the AP1000 design certification and VEGP Units 3 & 4 COLs were based. If this were true, I would share that concern. However, I do not believe this is the case at all. 79 “Qualifications for Arc Welding Reinforcing Bars,” Boiler and Pressure Vessel Code, Section III, Division 2, Mandatory Appendix D2-VIII, 2017, pp. 156-162

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It’s important to keep in mind that the provisions of Subpart 2.5 are quality assurance measures. In a strict sense, these provisions do not establish any new design or construction requirements to my knowledge. The Subpart 2.5 measures do not alter the design, fabrication, construction, or performance requirements of welded reinforcing bar splices. These requirements are adequately addressed in ACI 349-01, RG 1.142, and AWS D1.4-98. Adherence to these requirements should result in a safe structure. The quality assurance measures specified in ASME Division 2 provide a means of concluding the construction is adequate by demonstrating that the performance and quality requirements of ACI 349-01 and AWS D1.4-98 have been met. Quality Assurance, however, is important, especially for structures which have significant impacts to public health and safety in the event of failure. This is very much true when relying on the use of a special process, such as welding, in a critical application of an important structural system. This relationship between performance requirements and quality assurance measures is not isolated to welded splices. For example, adherence to ACI 349-01 requirements for concrete mix design should result in concrete mixes that meet design and performance requirements. However, in-process tests of concrete cylinders are still required to assure that the as placed mixes meet specified requirements. The quality assurance measures implemented to verify the as-built construction meets the specified requirements are intended to provide confidence that the system will perform satisfactorily in service. Failure to perform adequate quality assurance measures may call into question the quality of construction and impact ITAAC closure. It would have been preferable if the requirements for the inspection of welded reinforcing bar splices had been stated more clearly in Subpart 2.5 or, better still, if they were addressed in ACI 349-01 or a current regulatory guide. Unfortunately, they were not. Regardless, when a code or standard is incorporated by reference in another code or standard, it becomes part of the code or standard in which it is referenced. SNC Nuclear Development Quality Assurance Manual (NDQAM) VEGP Units 3 & 4 UFSAR Section 17.5 states, in part:

“The Quality Assurance Program in place during the design, construction, and operations phases is described in the QAPD, which is maintained as a separate document. This QAPD is incorporated by reference (see Table 1.6-201). This QAPD is based on NEI 06-14A, “Quality Assurance Program Description” (Reference 201). Conformance statements for QA-related Regulatory Guides (including Regulatory Guides 1.28, 1.30, 1.33, 1.38, 1.39, 1.94, and 1.116) are provided in Appendix 1A. The QAPD is the SNC Nuclear Development Quality Assurance Manual.”80

SNC Nuclear Development Quality Assurance Manual (NDQAM), Version 17 Section 4.0, "NQA-1-1994 Commitment/ Exceptions" states, in part: “SNC commits to compliance with the requirements of Subparts 2.5 and Subpart 2.8 for establishing appropriate inspection requirements." No exceptions to NQA-1-1994 Subpart 2.5 are taken in the SNC NDQAM. VEGP Unit 3 & 4 UFSAR Appendix 1A states that the commitment to RG 1.94 is replaced by a commitment to Subpart 2.5. This treatment is consistent with the replacement of the commitment to ASME N45.2.5 and RG 1.94 with a commitment to Subpart 2.5 in the SNC

80 VEGP Units 3 & 4 UFSAR, Section 17.5, Revision 1, p 17.5-1 (ML18179A292)

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Quality Assurance Topical Report (QATR).81 Commitment to Subpart 2.5, Paragraph 7.13 in the SNC QATR is addressed in material submitted to the NRC.82 Concerning this change, SNC stated:

“ASME NQA-1 -1994 provides the necessary requirements to address the scope of activities formerly addressed by Regulatory Guide 1.94 and ANSI N45.2.5 for installation of structural concrete and structural steel. Accordingly, the proposed QATR represents a change to commitments contained in the QAP description from Regulatory Guide 1.94 and ANSI N45.2.5, as cited above, to ASME NQA-1-1994, as delineated in Enclosure 4.”83

In the Enclosure 4 referenced above, SNC commits to Subpart 2.5, Paragraph 7.13.84 This commitment is reflected in the SER of the SNC QATR which states, in part, “[f]or situations comparable to original construction, SNC commits to Subparts 2.5 and 2.8 for establishing inspection requirements.”85 Treatment of Welded Reinforcing Bar Splices in other Design Certifications Welded reinforcing bar splices were proposed for use in areas outside of containment during review of the Economic Simplified Boiled Water (ESBWR) reactor standard design. ESBWR DCD Section 3.8.4.6.386 states, in part, that Welding of reinforcing bars complies with all the applicable requirements of ASME Code Section III, Division 2. This information is designated as Tier 2*. Concerning the use of welded reinforcing bar splices in these areas, NRC staff made the following comment in the FSER:

“The staff noted that the applicant’s proposed DCD Tier 2, Section 3.8.4.6 referenced only ACI 349-01 and applicable RGs for splices. SRP Section 3.8.4.I.6 requires, by reference to SRP Section 3.8.3.I.6, that the welding of reinforcing bars (splices) comply with the applicable sections of ASME Code, Section III, Division 2….The staff’s position is that welding of reinforcing bars should comply with all the applicable sections of ASME

81 “Licensee Handout for May 2, 2006, Public Meeting Quality Assurance Topical Report Southern Nuclear Operating Company,” Slide 3, (ML061350224); and Enclosure 1, Southern Nuclear Operating Company Quality Assurance Topical Report Red-line Markup Revision Ob,” p. 32 (ML071270283) 82 “Enclosure 1, Southern Nuclear Operating Company Quality Assurance Topical Report Red-line Markup Revision Ob,” p. 32 (ML071270283) 83 “Enclosure 2, Description of Proposed Change/Basis for Concluding the Revised Program Continues to Satisfy 10 CFR 50, Appendix B,” p. 9 (ML071270283) 84 “Enclosure 4, NQA- 1-1994 Conformance Matrix,” p. 32 (ML071270283) 85 “Approval of Southern Nuclear Operating Company, Inc.’s Quality Assurance Topical Report,” June 21, 2007, Section 3.2.1.10 Inspection, Enclosure, p. 6 (ML071510506) 86 ESBWR Design Control Document, Tier 2, Section 3.8.4.6.3, Splices of Reinforcing Steel, p. 3.8-43 (ML14100A506).

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Code, Section III, Division 2…This position applies to all seismic Category I concrete structures inside and outside containment.”87

This is the only example in which welded reinforcing bar splices are directly discussed in the DCD or SER to my knowledge. However, as discussed earlier, a commitment to either ASME Division 2 or ACI 349 and AWS D1.4 are equivalent for all intents and purposes for direct butt splices provided RG 1.94 or Subpart 2.5 is also invoked for the inspection of welded reinforcing bar splices. Inspection of Welded Reinforcing Bar Splices in Areas Other than Containment during the Construction of other U.S. Nuclear Plants Time constraints did not allow a more thorough review of inspection requirements for welded reinforcing bar splices in areas other than containment during the construction of other U.S. nuclear plants. A quick review, however, indicated that additional inspection consisting of either tensile testing or radiography, or a combination of both, was performed on welded reinforcing steel splices in areas other than containment during the construction of the following nuclear plants: Diablo Canyon Power Plant, Kewaunee Power Station, Millstone Power Station Unit 3, Nine Mile Point Unit 2, Prairie Island, and River Bend.88 In the above examples, either destructive testing or NDE of welded reinforcing bar splices was explicitly discussed in the safety analyses reviewed. However, as discussed earlier, a commitment to either ASME Division 2 or ACI 349 and AWS D1.4 are equivalent for all intents and purposes for direct butt splices provided RG 1.94 or Subpart 2.5 is also invoked for the inspection of welded reinforcing bar splices. This fact should be kept in mind when surveying safety analyses for past practices. Requirements for the Inspection of Welded Reinforcing Bar Splices on Structures other than Nuclear Power Plants with Potential Impacts to Public Health and Safety in the Event of Failure The nuclear industry is not alone in expecting that welded reinforcing bar splices be subject to destructive testing or NDE other than visual for acceptance. Many State transportation departments require additional inspection of welded reinforcing bar splices - either tensile testing or radiography or a combination of both. Some examples are California, Hawaii, South Carolina, Washington, and Wisconsin. Additionally, the Unified Facility Guide Specifications which are used on Department of Defense (Army, Navy, and Air Force), as well as, National Aeronautics and Space Administration (NASA) projects require additional tensile testing and NDE other than visual for the acceptance of welded reinforcing bar splices.

87 NUREG-1966, “Final Safety Evaluation Report Related to the Certification of the Economic Simplified Boiling-Water Reactor Standard Design,” Volume 1 (Chapter 1-3), Section 3.8.4.3.6, pp 3-335 to 3-336. (ML14099A519). 88 Section 3.8.2.3.6.3, “Splices,” Diablo Canyon Power Plant Units 1 & 2 FSAR Update, Revision 24, September 2018 p. 3.8-60 (ML18285A189); Section 5.2.2.3.11, “Material,” Kewaunee Power Station USAR, Revision 22, March 31, 2010 p. 5.2-38 (ML101170665); Section 3.8.4.6 “Materials, Operating Control, and Special Construction Techniques,” Millstone Power Station Unit 3 Safety Analysis Report, Revision 30, p 3.8-46 (M17212A127); “Inspection and Testing of Reinforcing Steel Welds,” Nine Mile Point Unit 2 FSAR, Amendment 5, October 1983, p. 3.8-72 (ML18018A960); Section 12.2.3.2.2, “Material,” Prairie Island Updated Safety Analysis Report, Revision 23, p. 12.2.3-8 (ML012130037); and Section 3.8.4.6, “Materials, Quality Control, and Special Construction Techniques,” River Bend Station USAR, August 1987, p 3.8-98. (ML17226A126)

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Concrete Reinforcing Steel Institute89 (CRSI) Recommendations CRSI provides recommendations for the use of welded reinforcing bar splices. Along with recommendations, the institute offers the following advice:

“Properly engineered and constructed welded splices require more considerations than a simple statement in the contract documents, “All welded splices shall conform to ‘Structural Welding Code – Reinforcing Steel’ (AWS D1.4/D1.4M:2011).””90

In the CRSI Manual of Standard Practice91, recommendations on the use of welded reinforcing bar splices include the following:

1. Minimize manual arc welding in the field, wherever possible. Consider the use of mechanical splices as an alternative to welded splices.

2. Where arc-welded splices are used, the following are required: a. Welding should conform to AWS D1.4/D1.4M “Structural Welding Code – Reinforcing

Steel” b. … g. Radiography or other suitable nondestructive inspection of a percentage of welds

(normally about 25 percent of the welds selected at random) h. Occasional quality control tests of actual welds removed from the structure when

nondestructive test results are unsatisfactory. The recommendations in the CRSI Manual of Standard Practice are for all types of construction projects and are widely referenced in construction specifications used in the construction industry. Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC) The relevant ITAAC for Wall 11 is VEGP Units 3 & 4 ITAAC 3.3.00.02a.i.c (762). However, welded reinforcing bar splices have also been observed being installed in CIS floors, the shield building reinforced concrete cylindrical wall, and reinforced concrete walls within the radiologically controlled area of the auxiliary building. As a result, VEGP Units 3 & 4 ITAAC 3.3.00.02a.i.a (760), 3.3.00.02a.i.b (761), and 3.3.00.02a.i.d (763) may be affected as well. A simple way to look at the issue, from the perspective of these ITAAC, would be to consider the Design Commitment of the ITAAC to be largely satisfied by conformance with ACI 349-01 and AWS D1.4-98. The quality assurance inspections and tests required by the SNC NDQAM, from this viewpoint, are conducted as part of the “Inspections, Tests, Analyses” to identify any deviations in the as-built construction. Without performing these inspections, some potential deviations may not be identified. ITAAC 3.3.00.02a.i.c is provided at the end of this document as an example. 89 “Founded in 1924, the Concrete Reinforcing Steel Institute (CRSI) is a technical institute and Standards Developing Organization (SDO) that stands as the authoritative resource for information related to steel reinforced concrete construction,” CRSI Website 90 CRSI Website 91 “Manual of Standard Practice,” Concrete Reinforcing Steel Institute (CRSI), 28th Edition, 2nd printing, 2011, Section 1.6.3, pp 1-4 to 1-5.

NCP-2019-002

Attachment A

Page 31 of 32

Proposed Violation of 10 CRF Part 50, Appendix B, Criterion X, “Inspection”

URI 05200025/2018-01 should be closed to an ITAAC finding and associated more-than-minor violation of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion III, “Design Control” for SNC’s failure to correctly translate the design basis into specifications, drawings, procedures, and instructions. The significance of this violation should be dependent on whether SNC can provide evidence demonstrating that the Structures, Systems, and Components (SSCs) that rely on welded reinforcing bar splices will meet their safety functions.

The violation described above would be consistent with other violations of a similar nature, such as: 05200025/2016001-01, 05200026/2016001-01, 05200027/2017003-04, 05200028/2017003-04, 05200025/2018002-01, and 05200025/2018002-02.

Conclusions/Recommendations

SNC is currently not implementing adequate measures for the inspection of welded reinforcing bar splices and is not in compliance with Appendix B.

The TAR responses provide SNC relief from NRC acceptance criteria and the commitments of the SNC NDQAM for the inspection of welded reinforcing bar splices. No clear justification is provided for granting this relief. Without the appropriate inspections being performed on production welded reinforcing bar splices, however, there is not sufficient evidence to demonstrate that the splices meet the specified performance and quality requirements and conclude with reasonable assurance that the structural members in which they are installed will perform satisfactorily during design basis events. As a result, the relevant Inspections, Tests, Analysis, and Acceptance Criteria (ITAAC) may not be met.

The responses to TARs AP V-M-042 and AP V-M-045 should be revised to reflect that SNC committed to Subpart 2.5 Paragraph 7.13 in their NDQAM and that these measures, which require destructive tests and NDE other than visual of welded reinforcing bar splices be performed in accordance with ASME Division 2, are applicable to construction of VEGP Units 3 & 4.

URI 05200025/2018-01 should be closed to an ITAAC finding and associated more-than-minor violation of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion III, “Design Control” for SNC’s failure to correctly translate the design basis into specifications, drawings, procedures, and instructions. The significance of this violation should be dependent on whether SNC can provide evidence demonstrating that the Structures, Systems, and Components (SSCs) that rely on welded reinforcing bar splices will meet their safety functions.

NCP-2019-002

Attachment A

Page 32 of 32

ITAAC 3.3.00.02a.i.c (762)

No. ITAAC No. Design Commitment

Inspections, Tests, Analyses

Acceptance Criteria

762 3.3.00.02a.i.c 2.a) The nuclearisland structures,including the criticalsections listed inTable 3.3-7, areseismic Category Iand are designedandconstructed towithstand designbasis loads asspecified in theDesign Description,without loss ofstructural integrityandthe safety-relatedfunctions.

i) An inspection ofthe nuclear islandstructures will beperformed.Deviations from thedesign due to as- built conditions willbe analyzed for thedesign basis loads.

i.c) A report existswhich reconcilesdeviations duringconstruction andconcludes that theas-built structures inthe non-radiologicallycontrolled area of theauxiliary building,including the criticalsections, conform tothe approved designand will withstand thedesign basis loadsspecified in theDesign Descriptionwithout loss ofstructural integrity orthe safety-relatedfunctions.

NCP-2019-002

1 ATTACHMENT C.8

Attachment C.8

Agreed Upon Summary of Issues (Stated from the NCE’s Perspective)

Overall Problem Statement: Southern Nuclear Company (SNC) is currently not implementing adequate measures for the inspection of welded reinforcing bar splices at Vogtle Electric Generating Plant, Units 3 and 4 (VEGP 3/4) and therefore not in compliance with 10 CFR Part 50, Appendix B, “Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants.” 1) URI 05200025/2018001-01 should be closed to an ITAAC finding and associated more-

than-minor violation of 10 CFR Part 50, Appendix B, Criterion III, “Design Control” for SNC’s failure to correctly translate the design basis into specifications, drawings, procedures, and instructions.

• The significance of this violation should be dependent on whether SNC can provide evidence demonstrating that the structures, systems, and components (SSCs) that rely on welded reinforcing bar splices will meet their safety functions.

2) Welded reinforcing bar splices are not identified as an acceptable substitute for lap splices

in the VEGP 3/4 UFSAR or AP1000 DCD. • NRC inspectors determined the use of welded reinforcing bar splices was not in

conformance with the UFSAR – this issue was dispositioned as a non-documented minor violation. However, the submitter believes issue should be dispositioned as more-than-minor.

• In closing this URI, the NRC will be, in effect, providing SNC with relief from the commitments of the VEGP 3/4 UFSAR and allowing them to administratively revise their licenses to allow the use of welded reinforcing splices. As a result, nonconforming construction will be accepted “use-as-is” without adequate technical justification.

3) The inspections (visual only) performed by SNC of the welded reinforcing bar splices do not

meet the requirements of the VEGP 3/4 UFSAR and their licensing bases. • Nuclear Development Quality Assurance Manual

o SNC commits to compliance with the requirements of ASME NQA-1994, Part II Subparts 2.5 and 2.8 for establishing appropriate inspection requirements. SNC did not take exception to any parts of Subpart 2.5.

o Subpart 2.5, Paragraph 7.13, “Welded Reinforcing Bar Splices,” states, in part, welded reinforcing bar splices shall be subject to the requirements of paragraph 8.5, except provisions of the ASME Code, Section III, Division 2 (ACI Standard 359) shall also apply.

o The Subpart 2.5 requirements are associated with the construction activity. Subpart 2.5 Section 7 addresses the inspection of concrete construction. If a licensee is engaging in work activities that fall within the scope of this section, then these requirements are relevant independent of the code of record. Subpart 2.5 does not assume that any particular code has been invoked; it intends to supplement the requirements of the code of record.

o The position taken in TAR response TAR AP-V-M-42 Question 2 appears to be that the Subpart 2.5, Paragraph 7.13 requirement to comply with ASME Division 2 is made optional by the reference to Paragraph 8.5. It appears this

2 ATTACHMENT C.8

conclusion is because the ASME Subpart 2.5 requirements for the inspection of structural steel welding provided in Subpart 2.5, Paragraph 8.5 do not reference destructive testing and leave it to the discretion of the Engineer to determine if NDE is necessary based on the application. Subpart 2.5, Paragraph 7.13 clearly states that the provisions of ASME Division 2 shall also apply for welded reinforcing bar splices. The ASME Division 2 provisions for the inspection of welded reinforcing bar splices are of at least equal standing to the requirements of Paragraph 8.5.

o ASME Division 2 is referenced in Subpart 2.5 Paragraphs 7.11, 7.12, and 7.13. Assuming these paragraphs only apply to concrete reactor vessels and containments because they reference ASME Division 2 ignores the scope of NQA-1-1994 Part II, the history and intent of these provisions, established NRC guidance, and the common engineering practice of adapting provisions of a design code for use beyond their original intent. The adaptation of code provisions for use outside or their original intent or scope is not unique to Subpart 2.5.

• These measures are also not consistent with the requirements of other design

certifications and NRC guidance. The appropriate inspection requirements for welded reinforcing bar splices used in nuclear safety-related structures are addressed in the Standard Review Plan (SRP) and ASME Subpart 2.5. These inspection requirements supplement American Concrete Institute (ACI), “Code Requirements for Nuclear Safety Related Concrete Structures,” 2001 (ACI 349-01) and American Welding Society (AWS) D1.4 requirements, and are fully compatible with these standards. If the licensee had specifically proposed the use of welded reinforcing steel splices during the AP1000 design certification or VEGP Units 3/4 COL licensing processes, it is likely that the NRC would have required compliance with ASME Division 2 for production testing of welded reinforcing bar splices as was done for mechanical connections.

o ESBWR DCD o mPower iPWR Design o Former guidance in [Regulatory Guide] RG 1.94 for welded splices o RG 1.142 o SRP Section 3.8.4.I.6.B is applicable to the VEGP 3/4 auxiliary buildings:

“If welding of reinforcing bars is proposed, it should comply with American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code (Code) Section III, Division 2. Any exception to compliance should be supported with adequate justification.”

o Safety-related steel structures used in VEGP 3/4 are designed and according to AISC N690-94. This standard requires all welding conform to AWS D1.1. However, it also limits reliance on the engineer to determine minimum inspection requirements by specifying that NDE other than visual be performed on a sampling basis for partial and complete joint penetration welds.

4) Failure to enforce the Subpart 2.5 requirements as committed to in the SNC NDQAM will

result in an inspection program for Seismic Category I concrete structures that is not consistent with the requirements of Appendix B. The URI is associated with the appropriate quality assurance measures that are necessary to verify that the requirements of ACI 349-01 and AWS D1.4-98 are being met. These quality assurance measures are not adequately addressed in ACI 349-01 or AWS D1.4-98, but in Subpart 2.5. • The provisions of Subpart 2.5 are quality assurance measures. They do not establish

any new design or construction requirements.

3 ATTACHMENT C.8

• They provide a means of concluding the construction is adequate by demonstrating that the performance and quality requirements of ACI 349-01 and AWS D1.4-98 have been met.

5) These welded reinforcing bar splices are relied upon for overall structural integrity and performance of safety-related functions of Seismic Category I structures. As such, the quality of said components, is currently indeterminate.

• The inspections performed are not commensurate with the importance to safety of the splices:

i. Critical structural sections (e.g., Wall 11 at the east main steam line penetration) are assigned a higher risk than a concrete containment within the cROP.

ii. Postulated high energy line break of the main steam line through Wall 11 • SNC visual only inspection method is not aligned with the recommendations of

respected and widely adopted construction industry standards. 6) By not implementing certain parts of Subpart 2.5, the licensee has made a reduction in

commitments without prior NRC approval and therefore, not in compliance with 10 CFR 50.54(a)(3) and 10 CFR 50.54(a)(4). • Subsection 4.0 of Section 10 of Rev. 19 of the NDQAM states that, “SNC commits to

compliance with the requirements of Subparts 2.5 and 2.8 for establishing appropriate inspection requirements.” SNC did not take exception to any parts of Subpart 2.5 • Based on the regulations governing the QAPD, the NRC SER of the QAPD template

provided in NEI 06-14A, and the wording of the SNC NDQAM, it seems reasonable to conclude that SNC committed to NQA-1-1994, Subpart 2.5 and expect that the supplemental measures for the inspection of concrete construction, including those associated with welded reinforcing bar splices, be implemented.

• The submitter agrees it is the responsibility of the organization invoking NQA-1-1994 to determine the extent to which the standard should be applied; but believes it is important to recognize that the extent to which the standard is applied needs to be documented in the licensee’s QAPD submitted for NRC approval during licensing. The licensee does not have the discretion to arbitrarily reduce the commitments of their QAPD. As a result, the flexibility afforded by ASME NQA-1-1994 in determining the extent to which the standard should be applied is constrained by regulation after issuance of a license.

7) The quality assurance inspections and tests required by the SNC NDQAM, are conducted

as part of the “Inspections, Tests, Analyses” to identify any deviations in the as-built construction. Without performing these inspections adequately, potential deviations may not be identified (i.e. ITAAC not met). ITAAC that may be impacted: 1) 3.3.00.02a.i.a (760), 3.3.00.02a.i.b (761), 3.3.00.02a.i.c (762), and 3.3.00.02a.i.d (763)

o ITAAC 762 is associated with the subject URI and nonconcurrence Additional Issues to be Addressed: 8) The responses to the TARs do not provide a sufficient basis for concluding that the actions

SNC has taken to verify the splices meet quality and performance requirements comply with the VEGP Units 3 & 4 UFSAR or are technically adequate. Neither NRO or SNC has provided adequate information to draw these conclusions.

1 ATTACHMENT C.9.1

ATTACHMENT C.9.1 Assertion 1: URI 05200025/2018001-01 should be closed to an ITAAC finding and associated more-than-minor violation of 10 CFR Part 50, Appendix B, Criterion III, “Design Control” for SNC’s failure to correctly translate the design basis into specifications, drawings, procedures, and instructions. The NCP approver agreed with this statement in part. Specifically, following additional review, including discussions with the technical staff, and consideration of the information provided in Section A by the NCE, the NRC staff identified one minor violation of a 10 CFR Part 50, Appendix B, Criterion II, “Quality Assurance Program” for the licensee’s failure to carry out policies documented in the licensee’s NDQAM and associated testing commitments in NQA-1-1994, Subpart 2.5, Section 7.13, “Welded Reinforcing Bar Splices”. NRC inspection report 05200025/2019010 has been revised to include the aforementioned violation to address URI 05200025/2018001-01 and the associated follow-up inspection activities. The specifics and screening of the violation is enclosed as Attachment C.9.2 of the NCP form. However, based on the criteria in IMC 0613, the NCP approver agrees with the NRC staff determination that the issue was not an ITAAC finding. See the evaluation of Assertion 7 for additional details on why this issue was not assessed as an ITAAC finding.

Assertion 2: Welded reinforcing bar splices are not identified as an acceptable substitute for lap splices in the VEGP 3/4 UFSAR or AP1000 DCD.

The NCP approver agreed with this statement. Neither the UFSAR, nor the AP1000 DCD specifically identify the use of welded reinforcing bar splices. The reinforcing bar technique described in the UFSAR, Section 3.8.4.6.1.2 states, “In areas where reinforcing steel splices are necessary and lap splices are not practical, mechanical connections (e.g. threaded splices, swaged sleeves or cadwelds) are used.” Southern Nuclear Company (SNC) used welded reinforcing bar splices which are not specifically addressed in the UFSAR Section 3.8.4.6.1.2, Revision 7.2 or the DCD Revision 19. Licensee Construction Specification SV3-CC01-Z0-031, Revision 8, dated August 28, 2017, described the allowable use of welded reinforcing bar splices, although the UFSAR only specified the use of lap splices and mechanical connections. The NRC staff identified a minor violation of 10 CFR Part 50 Appendix B, Criterion V, “Instructions, Procedures, and Drawings,” for the licensee’s failure to adequately review and reconcile licensing basis impacts in accordance with their corrective action program and associated screening procedures for the use of welded rebar splices in the safety-related Unit 3 structure. The licensee initiated condition report (CR) 50050960 to reconcile the differences in the UFSAR and the as-built plant configuration with respect to the use of welded reinforcing bar splices. The specifics and screening of the violation is enclosed as Attachment C.9.2 of the NCP form. Assertion 3: The inspections (visual only) performed by SNC of the welded reinforcing bar splices do not meet the requirements of the VEGP 3/4 Updated Final Safety Analysis Report (UFSAR) and their licensing bases. The NCP approver agreed with this statement in part. Specifically, the NCP approver recognizes that UFSAR, Section 3.8.4.6.1.2 does not specifically allow the use of welded splices and that SNC did not take exception to the additional inspection provisions in NQA-1-1994, Subpart 2.5, Section 7.13, of the NDQAM.

2 ATTACHMENT C.9.1

However, the licensee’s commitments (code of record) for the design, materials, fabrication, construction, inspection, and testing of seismic Category I structures, including Wall 11, is American Concrete Institute (ACI), “Code Requirements for Nuclear Safety Related Concrete Structures,” 2001 (ACI 349-01), which is described in the UFSAR Section 3.8.4.2. Section 12.14.3.1 of ACI 349-01, allows the use of welded splices. In addition, Section 3.8.4.5, “Structural Criteria,” of the UFSAR described supplemental provisions for concrete structures subject to ACI-349-01, which states that supplemental requirements for ACI-349-01 are given in the position on Regulatory Guide (RG) 1.142, “Safety-Related Concrete Structures for Nuclear Power Plants (Other than Reactor Vessels and Containments.” The licensee committed to RG 1.142, Regulatory Positions 2 through 8, 10 through 13, and 15, which did not include the additional testing requirements from ASME Section III, Division 2, “Code for Concrete Reactor Vessels and Containments.” In addition, none of the regulatory positions in RG 1.142 required additional testing requirements for ASME Section III, Division 2. ACI 349-01, Section 1.1, provides that ACI 349-01 covers nuclear safety-related concrete structures, but specifically excludes those structures (i.e., concrete containments) covered by ASME Boiler and Pressure Code Section III, Division 2, and pertinent General Requirements. The auxiliary building is a safety-related concrete structure and not a containment structure. Additionally, Section 3.8.2 of ACI 349-01, provides that where applicable, the requirements of the AWS which include AWS D1.1, “Structural Welding Code—Steel,” and AWS D1.4-98, “Structural Welding Code—Reinforcing Steel,” should also be considered. ACI 349-01, Section 12.14.3.1, states that welded splices and other mechanical connections are allowed. Section 12.14.3.2 provides, in part, that all welding conforms to AWS D1.4. Section 3.5.2 of ACI 349-01, provides that “[w]elding of reinforcing bars shall conform to ‘Structural Welding Code -Reinforcing Steel,’ ANSI/AWS D1.4 of the American Welding Society [AWS].” Therefore, in accordance with the VEGP 3/4 code of record, welding, and the associated inspections of these welds, would be performed in accordance with ACI 349-01, and AWS D1.4. Additionally, Section 12.14.3.3 of ACI 349-01 provides that a full welded splice shall develop at least 125 percent of the specified yield strength of the bar. This requirement is confirmed by tension testing, which may be done during the welding procedure specifications (WPS) and/or welder qualification process. The sample is subjected to the maximum stress that a material can withstand while being stretched or pulled before breaking. Section 12.14.3.6 of ACI 349-01 states that all welded splices and mechanical connections shall be visually examined by a qualified and experienced inspector to assure that they are properly installed at the place of construction. Where it is deemed necessary, the engineer shall be permitted to require the destructive tests of production splices to assure the compliance with 12.14.3.3 and 12.14.3.4. NQA-1-1994, Subpart 2.5, Section 7, “Inspection of Concrete Construction,” does not dictate the specific code of record, but rather it supplements the code of record used in the applicable design. This response to NCP-2019-002 took into consideration the technical opinion and experience of the NRC’s subject matter experts that are associated with Code and Code committee activities, as well as a review of applicable licensing documents. The NCP approver agrees with the NRC staff position that there is reasonable assurance of adequate protection to allow the use of welded reinforcing bars and that the visual inspections performed on those welded splices are in accordance with the approved UFSAR and code of record. Nonetheless, the licensee must reconcile the differences in the UFSAR and the as-built plant configuration with respect to the use of welded reinforcing bar splices. Additionally, the licensee should address the statements in RG 1.70, “Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants, LWR Edition,” and RG 1.206, “Combined License Applications for Nuclear Power Plants,” both of which the licensee is committed to, which state in part, for welding of reinforcing bars, the extent to which the design complies with the ASME Code, Section III, Division 2 (with identification and justification of any exceptions), should be addressed.

3 ATTACHMENT C.9.1

Assertion 4: Failure to enforce the Subpart 2.5 requirements as committed to in the SNC NDQAM will result in an inspection program for Seismic Category I concrete structures that is not consistent with the requirements of Appendix B. The URI is associated with the appropriate quality assurance measures that are necessary to verify that the requirements of ACI 349-01 and AWS D1.4-98 are being met. These quality assurance measures are not adequately addressed in ACI 349-01 or AWS D1.4-98, but in Subpart 2.5. The NCP approver disagreed with this statement. The NCP approver agrees with the NRC staff conclusion that the specified welding provisions outlined in ACI 349-01, Subsection 12.14.3.2, conform to AWS D1.4-98. Further, ACI 349-01, Subsection 1.5, “Quality Assurance Program,” states, “A quality assurance program covering nuclear safety related structures shall be developed prior to starting any work. The general requirements and guidelines for establishing and executing the quality assurance program during the design and construction phases of nuclear power generating stations are established by Title 10 of the Code of Federal Regulations, Part 50, Appendix B.” In addition, Section 17.5, Quality Assurance Program Description (QAPD) of the UFSAR, states in part that the Quality Assurance Program in place during the design, construction, and operations phases is described in the QAPD and is based on NEI 06-14A, “Quality Assurance Program Description”. Section 10.3, NQA-1-1994 Commitment / Exceptions, of NEI 06-14A, states in part that the [licensee] commits to compliance with the requirements of Subparts 2.5 and 2.8 for establishing appropriate inspection requirements. The premise considered is whether the inspection provisions established through ACI 349 and the AWS codes are appropriate and sufficient to determine if the quality of the welded reinforcement bars fabricated in the auxiliary building and as identified in this URI for Wall 11, is adequate. NQA-1-1994, Subpart 2.5, Section 7.13, Welded Reinforcing Bar Splices, states, “Welded reinforcing bar splices shall be subject to the requirements of para 8.5, except that provisions of the ASME Boiler and Pressure Vessel Code, Section III, Division 2 (ACI Standard 359) shall also apply.” The reference to ASME Section III, Division 2, provides for additional inspections of welded reinforcing bars in concrete construction. Whereas, NQA-1-1994, Subpart 2.5, Section 8.5, Welding, states in part, the “inspection shall include visual examination of preparations, welding processes, post-welding operations, and if deemed necessary, some NDE inspections which are appropriate to the application.” The provisions of AWS D1.4 are also important in the consideration of whether performing only visual inspections is adequate. Section 3.5.2 of ACI 349-01, provides that “[w]elding of reinforcing bars shall conform to ‘Structural Welding Code -Reinforcing Steel,’ ANSI/AWS D1.4 of the American Welding Society [AWS].” AWS D1.4 establishes the integrity of the process and certification of the welders to meet the quality standards needed for these structures. AWS D1.4-98 Section 6, “Qualification”, establishes the WPS document which provides direction to the welder or welding operators for making sound and quality production welds as per the code. A WPS is supported by a procedure qualification record. In addition, each welder is qualified, and their work inspected. Since the welders and welding procedures are required to be qualified to AWS D1.4-98, this provides in part, reasonable assurance that the welds have been made to a quality standard. Assertion 5: These welded reinforcing bar splices are relied upon for overall structural integrity and performance of safety-related functions of Seismic Category I structures. As such, the quality of said components, is currently indeterminate. The NCP approver disagreed with the latter portion of the statement that the quality of Seismic Category I structures is currently indeterminate.

4 ATTACHMENT C.9.1

The NCP approver agrees with the NRC staff conclusion that the welded reinforcing bars is adequate (although the licensee must reconcile their current licensing basis with the as-built configuration) and that the use of visual examination of the welds as specified by NQA-1-1994, Subpart 2.5, Section 8.5 (through reference in Subpart 2.5, Section 7.13), ACI 349 and the AWS codes, is appropriate. The basis for this conclusion is the same as discussed in Assertion 4. Therefore, the structural integrity for safety-related functions of the Seismic Category 1 structures is assured. Notwithstanding the NCE’s assertion regarding the risk categorization for Wall 11 in accordance with IMC 2519, “Construction Significance Determination Process,” dated December 6, 2017, the licensee is meeting their commitment to the NRC-approved code of record as documented in the licensee’s UFSAR. In addition, the approved code of record reflects the NRC position that the code conformance reflects reasonable assurance of adequate protection for these welded splices. Assertion 6: By not implementing certain parts of Subpart 2.5, the licensee has made a reduction in commitment without prior NRC approval and therefore, not in compliance with 10 CFR 50.54(a)(3) and 10 CFR 50.54(a)(4). The NCP approver disagrees with this statement. The licensee did not make a change to the NDQAM as approved by NRC and, therefore, is currently in compliance with the regulatory requirements of 10 CFR 50.54(a)(3) and 10 CFR 50.54(a)(4). The NRC staff did determine that the licensee failed to meet commitments as described in the approved NDQAM. Specifically, the licensee failed to carry out policies documented in the licensee’s NDQAM and associated testing commitments in NQA-1-1994, Subpart 2.5, Section 7.13, since they did not perform the inspections in accordance with ASME Section III Division 2, nor did they take exception to the provision. The details of this performance deficiency are included in Attachment C.9.2. As previously stated, the licensee must reconcile their current licensing basis with the as-built configuration. If, as part of their corrective action to the performance deficiency, the licensee changes the NDQAM, a determination will be made at that time as to whether that change constitutes a reduction in commitment. Assertion 7: The quality assurance inspections and tests required by the SNC NDQAM, are conducted as part of the “Inspections, Tests, Analyses” to identify any deviations in the as-built construction. Without performing these inspections adequately, potential deviations may not be identified (i.e. ITAAC not met). The NCP approver agreed with this statement. However, the NRC staff has determined, and the NCP approver agrees, that adequate inspections were performed as part of the “Inspections, Tests, Analyses” of the ITAAC. Specifically, the review of the applicable codes supports that adequate quality assurance inspections and tests were conducted, and the welds (welded reinforcing bar splices) are constructed to AWS D1.4-98, in accordance with the VEGP 3/4 UFSAR. Since the welders and welding procedures are to be qualified to AWS D1.4-98, the welds therefore have been made to a quality standard. The NCP approver determined the inspections conducted were adequate and thus the minor violation of 10 CFR Part 50, Appendix B, Criterion II, is not indicative of a finding that prevents satisfying the acceptance criteria of an ITAAC or invalidates the performance of the inspection, test, or analysis upon which the ITAAC acceptance criteria is based. ITAAC findings are described in IMC 0613. Section 0613-08 of IMC 0613 states in part that “ITAAC findings are findings that prevent satisfying the acceptance criteria of an ITAAC or

5 ATTACHMENT C.9.1

invalidate the inspection, test, or analysis upon which the ITAAC acceptance criteria is based. For ITAAC findings, a clear nexus of the performance deficiency to the ITAAC acceptance criteria must be documented.” The aspect of URI 05200025/2018001-01 implicated by Assertion 7 is being closed to a minor violation of 10 CFR Part 50, Appendix B, Criterion II related to a construction finding under IMC 2504, “Construction Inspection Program: Inspection of Construction and Operational Programs.” Specifically, the unresolved item was related to the licensee’s failure to meet commitments as described in the approved NDQAM. Specifically, the licensee failed to implement the commitments in NQA-1-1994, Subpart 2.5, Section 7.13, since they did not perform the inspections in accordance with ASME Section III Division 2, nor did they take exception to the provision. From the inspections performed at VEGP 3/4 and as stated in the non-concurrence 2019-002 Section A, there were no indications that the AP1000 design was inadequate or construction of VEGP 3/4 was deficient. There were also no regulatory findings of safety significance that have been identified for actual weld failures of welded reinforcing bar splices on Unit 3 because of quality issues, welder’s qualifications, or qualified procedures. As a result, additional inspections for reinforcing bar splices would not prevent satisfying the acceptance criteria of an ITAAC or invalidate the performance of the inspection, test, or analysis upon which the ITAAC acceptance criteria is based. Nonetheless, to meet the acceptance criteria of the ITAAC, the licensee must reconcile the differences in the UFSAR and the as-built plant configuration with respect to the use of welded reinforcing bar splices. Assertion 8: The responses to the TARs do not provide a sufficient basis for concluding that the actions SNC has taken to verify the splices meet quality and performance requirements comply with the VEGP Units 3 & 4 UFSAR or are technically adequate. Neither NRO [now NRR] or SNC has provided adequate information to draw these conclusions. The NCP approver agreed with this statement in part. Specifically, the NCP approver agrees with the NRC staff determination that the licensee’s use of welded splices and the licensee’s failure to implement testing commitments in NQA-1-1994, Subpart 2.5, Section 7.13, did not conform with the UFSAR and NDQAM. However, NRC staff has also concluded, and the NCP approver agrees, that the welded splices are adequate (although the licensee must reconcile their current licensing basis with the as-built configuration) and that the use of visual examination, is appropriate. Additionally, after continued discussions amongst Region II, OGC and NRR staff, NRC staff has determined that the responses to Technical Assistance Requests (TARs) AP-V-M-42, NQA-1-1994, “Subpart 2.5 Clarification,” and AP-V-M-45, “ASME NQA-1-1994, Subpart 2.5, Paragraph 7.13 Requirements for Welded Reinforcing Bar Splices,” did not adequately address the concerns presented. NRC staff also acknowledges, and the NCP approver agrees, that the overall licensing aspects were not adequately captured in these TARs, in that an applicant may propose to use some, all, or none of NQA-1-1994, but if the NDQAM at the time of license issuance commits to an NQA-1-1994 provision without exception, the licensee is obligated to implement the NQA-1-1994 provision as stated.

1 ATTACHMENT C.9.2

ATTACHMENT C.9.2 – Minor Violations Documented in NRC IR 05200025/2019010 Introduction: During the week of January 22, 2018, inspectors identified that the licensee was not performing destructive tests and NDE of welded reinforcing joints for the welded reinforcing steel hoops used in the north wall of the Unit 3 main steam east compartment at column line 11, between elevations 117’-6” and 153’-0”. The tests are in accordance with ASME Boiler and Pressure Vessel Code (BPVC), Section III, Division 2, as referenced in Section 7.13, “Welded Reinforcing Bar Splices,” of ASME NQA-1-1994 Subpart 2.5, which the licensee committed to, without exception, in their Nuclear Development Quality Assurance Manual (NDQAM). The reinforcing hoops at this location were fabricated with direct butt joints using complete joint penetration groove welds. This issue was documented as Unresolved Item (URI) 05200025/2018-01, Welded Reinforcing Bar Splices, in NRC inspection report 05200025/2018001 (ML18134A348). The URI disposition was pending the inspectors’ review and evaluation of the licensee’s corrective actions, if applicable, and their position paper on the applicability of ASME NQA-1-1994, Subpart 2.5, Paragraph 7.13. The licensee generated CR 10465176 to document this issue but concluded that “the ASME BPVC.III.2 reference in Section 7.13 of NQA-1-1994, Subpart 2.5, identifying additional testing for Welded Reinforcing Bar Splices beyond ACI 349 required testing, was not appropriate to [VEGP 3/4] and was assessed as such in accordance with the NDQAM.” The NRC staff reviewed the licensee’s evaluation on the applicability of ASME NQA-1-1994, Subpart 2.5, Paragraph 7.13 and engaged in discussions with the Office of the General Counsel (OGC) and technical staff from the Office of New Reactors (NRO) (now merged with the Office of Nuclear Reactor Regulation) to verify the licensee’s commitments for required inspection and testing activities for welded reinforcing bar splices. Minor Violation of 10 CFR Part 50 Appendix B, Criterion II, “Quality Assurance Program” Following additional inspection conducted on March 25 - 27, 2019, and based on additional discussion and review, the NRC staff determined the licensee’s failure to meet a commitment in their quality assurance program, as written, was a performance deficiency related to a construction finding. Specifically, Southern Nuclear Company (SNC) committed to comply with ASME NQA-1-1994, Subpart 2.5, in its NDQAM, without exception, however, additional testing was not performed in accordance with Section 7.13 of Subpart 2.5. Step 4.1 of Part II, Section 10, “Inspection” of the SNC NDQAM, Version 17.0, states, in part, “that SNC commits to compliance with the requirements of ASME NQA-1-1994, Part II, Subparts 2.5 and 2.8 for establishing appropriate inspection requirements.” Under this commitment, the inspectors noted that no exceptions were cited. ASME NQA-1-1994, Part II, Subpart 2.5, Section 7.13 states, in part, that “welded reinforcing bar splices shall be subject to the requirements of para. 8.5, except that provisions of the ASME Boiler and Pressure Vessel Code (BPVC), Section III, Division 2 (ACI Standard 359) shall also apply.” The ASME Code, Section III.2 (2001 Edition with 2003 Addenda), Article XI-1560, “Continuing Joint Performance Tests,” requires destructive testing on a sampling basis of welded reinforcement splices to ensure the joints met tensile requirements. Additionally, the ASME Code, Section III.2, Article XI-1600, “Examination of Welded Joints of Reinforcing Bar,” requires RT examination of joint samples to verify weld quality.

2 ATTACHMENT C.9.2

The performance deficiency was evaluated against the more-than-minor evaluation questions in Appendix E, “Examples of Minor Construction Issues,” of Inspection Manual Chapter (IMC) 0613, “Power Reactor Construction Inspection Reports,” dated May 1, 2020. This performance deficiency was determined to be minor because ACI 349-01, “Code Requirements for Nuclear Safety Related Concrete Structures,” allowed the use of welded splices, and the licensee was committed to this code in their current licensing basis. Specifically, the subject reinforced concrete wall met the provisions of ACI 349-01 (code of record) for the construction, inspection, and testing of Unit 3 Wall 11, per UFSAR Subsection 3.8.4.2 “Applicable Codes, Standards, and Specifications,” and American Welding Society (AWS) D1.4-98, which is invoked by ACI 349-01. AWS D1.4 establishes the integrity of the process and certification of the welders to meet the quality standards needed for these structures. AWS D1.4-98 Section 6, “Qualification”, establishes the WPS document which provides direction to the welder or welding operators for making sound and quality production welds as per the code. A WPS is supported by a PQR. In addition, each welder is qualified, and their work inspected. Since the welders and welding procedures are required to be qualified to AWS D1.4-98, this provides in part, reasonable assurance that the welds have been made to a quality standard. In addition, the NRC staff determined the following regarding the performance deficiency (PD):

1) the PD did not represent a substantive non-conservative error in a specification, computer program, design report, drawing, calculation or other design document that defines the technical requirements for a structure, system, or component (SSC);

2) the PD did not represent a substantive failure to establish or implement an adequate

program, process, procedure, or quality oversight function;

3) the PD did not represent an adverse condition that rendered the quality of an SSC, unacceptable or indeterminate, and require substantive corrective action;

4) the PD did not represent an irretrievable loss or inadequate documentation of a quality

assurance record that could preclude the licensee from demonstrating the adequacy of quality or from properly evaluating safety-significant activities;

5) the PD did not adversely affect the associated cornerstone objective listed in IMC 0613;

and

6) the PD was not material to the acceptance criteria of an ITAAC (i.e., an ITAAC finding) because the PD did not prevent the licensee from meeting an ITAAC Design Commitment or approved Technical Specification, and the PD did not invalidate the performance of the Inspection, Test, or Analysis described in the ITAAC.

10 CFR Part 50 Appendix B, Criterion II, “Quality Assurance Program,” states, in part, a [quality assurance] program shall be documented by written policies, procedures, or instructions and shall be carried out throughout plant life in accordance with those policies, procedures, or instructions. Contrary to above, since the start of construction of Unit 3 Wall 11, the licensee failed to carry out those policies documented in the licensee’s NDQAM for Unit 3 Wall 11. Specifically, the licensee committed to comply with ASME NQA-1-1994, Subpart 2.5, in its NDQAM, without exception, however, additional testing was not performed in accordance with Section 7.13 of Subpart 2.5, for welded reinforcing steel hoops used in the Unit 3 north wall of the main steam east compartment at column line 11, between elevations 117’-6” and 153’-0”.

3 ATTACHMENT C.9.2

The licensee initiated CR 50050957 to address the failure to meet a commitment in their quality assurance program, as written. This failure to comply with 10 CFR Part 50 Appendix B, Criterion II, constitutes a minor violation that is not subject to enforcement action in accordance with the NRC’s Enforcement Policy.

Minor Violation of 10 CFR Part 50 Appendix B, Criterion V, “Instructions, Procedures, and Drawings” During the URI inspection follow-up activities, the NRC staff identified an additional minor violation of 10 CFR Part 50 Appendix B, Criterion V, “Instructions, Procedures, and Drawings.” The NRC staff determined that the failure to adequately review and reconcile licensing basis impacts for the use of welded rebar splices in a safety related Unit 3 structure was a performance deficiency related to a construction finding. Specifically, VEGP Unit 3 UFSAR Section 3.8.4.6.1.2 states in part that, in areas where reinforcing steel splices are necessary and lap splices are not practical, mechanical connections (e.g. threaded splices, swaged sleeves or cadwelds) are used. UFSAR Section 3.8.4.6.1.2 did not specifically allow for the use of welded reinforcing bar splices. The NRC staff noted that the licensee used welded reinforcing bar splices instead of lap splices or mechanical connections in the hoops around the circular embedment for the main steam line placed in the north wall of the Unit 3 main steam isolation valve east compartment at column line 11 between column lines L and M and elevations 117’-6” to 153’-0”. The licensee initiated Engineering and Design Coordination Report (E&DCR) SV0-CR01-GEF-000543, “Lap Splice Substitution,” Rev. 0, dated 07/28/2015, which approved the use of welded splices. Form F-APP-GW-GAP-147-1, “Licensing Impact Determination,” concluded “Based on the Current Licensing Basis keywords searched, and the Current Licensing Basis document chapters/sections/tables/figures reviewed, no Current Licensing Basis impact is identified.” The licensee utilized procedures APP-GW-GAP-420, “Engineering and Design Coordination Reports,” Rev. 11, and APP-GW-GAP-147, “AP1000 Current Licensing Basis Review,” Rev. 4. to screen the E&DCR. Step 5.8.4 of procedure APP-GW-GAP-420, states in part, that “the impact to safety margins, structural requirements, functional, and performance requirements shall be identified as part of the justification.” Step 7.6 of APP-GW-GAP-147, states in part, that “Licensing Impact Determinations should be performed from a perspective of verbatim compliance to the certified design.” The NRC staff determined that the licensee did not consider the impacts to the current licensing basis or the verbatim compliance to the certified design with respect to the use of welded splices, which was not specifically approved for use per Section 3.8.4.6.1.2 of the licensee’s UFSAR. The performance deficiency was evaluated against the more-than-minor evaluation questions in Appendix E of IMC 0613. This performance deficiency was determined to be minor because ACI 349-01 allowed for use of welded splices, and the licensee was committed to this code in their current licensing basis. Specifically, the subject reinforced concrete wall met the provisions of ACI 349-01 (code of record) for the construction, inspection, and testing of Unit 3 Wall 11, per UFSAR Subsection 3.8.4.2 and AWS D1.4-98, invoked through ACI 349-01. AWS D1.4 establishes the integrity of the process and certification of the welders to meet the quality standards needed for these structures. AWS D1.4-98 Section 6, “Qualification”, establishes the WPS document which provides direction to the welder or welding operators for making sound and quality production welds as per the code. A WPS is supported by a PQR. In addition, each welder is qualified, and their work inspected. Since the welders and welding procedures are

4 ATTACHMENT C.9.2

required to be qualified to AWS D1.4-98, this provides in part, reasonable assurance that the welds have been made to a quality standard. In addition, the NRC staff determined the following regarding the performance deficiency (PD):

1) the PD did not represent a substantive non-conservative error in a specification or other design document that defines the technical requirements for a structure, system, or component (SSC);

2) the PD did not represent a substantive failure to establish or implement an adequate

program, process, procedure, or quality oversight function;

3) the PD did not represent an adverse condition that rendered the quality of an SSC, unacceptable or indeterminate, and require substantive corrective action;

4) the PD did not represent an irretrievable loss or inadequate documentation of a quality assurance record that could preclude the licensee from demonstrating the adequacy of quality or from properly evaluating safety-significant activities;

5) the PD did not adversely affect the associated cornerstone objective listed in IMC 0613;

and

6) the PD was not material to the acceptance criteria of an ITAAC (i.e., an ITAAC finding) because the PD did not prevent the licensee from meeting an ITAAC Design Commitment or approved Technical Specification, and the PD did not invalidate the performance of the Inspection, Test, or Analysis described in the ITAAC.

10 CFR Part 50, Appendix B, Criterion V, “Instructions, Procedures, and Drawings,” states, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings. Contrary to above, since the start of construction of Unit 3 Wall 11, a seismic Category I structure, the licensee failed to accomplish activities affecting quality in accordance with procedures. Specifically, the licensee failed to adequately review and reconcile licensing basis impacts in accordance with corrective action program and associated screening procedures for the use of welded reinforcing bar splices in a safety-related Unit 3 structure. The licensee initiated CR 50050960 to reconcile the differences in the UFSAR and the as-built plant configuration with respect to the use of welded reinforcing bar splices. This failure to comply with 10 CFR Part 50, Appendix B, Criterion V, constitutes a minor violation that is not subject to enforcement action in accordance with the NRC’s Enforcement Policy.