SECURITY-RELATED INFORMATION -WITHHOLD UNDER 10 CFR 2.390

(~ DUKE ENERGY~

OCTJ '.1'5 ZOJI

Serial: RNP-RA/16-0079

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261 I RENEWED LICENSE NO. DPR-23

R. Michael Glover H. B. Robinson Steam

Electric Plant Unit 2 Site Vice President

Duke Energy Progress 3581 West Entrance Road

Hartsville, SC 29550

0 : 843 857 1704 F: 843 857 1319

Mike.GICNB'@Jilke-mergy.com

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805, "PERFORMANCE-BASED STANDARD FOR LIGHT WATER REACTOR ELECTRIC GENERA TING PLANTS"

Dear Sir/Madam:

By letter dated September 16, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 13267A211) Duke Energy Progress, Inc. (OEP) submitted a license amendment request (LAR) for H.B. Robinson Steam Electric Plant, Unit No. 2 (HBRSEP2). This LAR would adopt a new fire protection licensing basis that complies with the requirements of Title 1 O of the Code of Federal Regulations, Sections 50.48(a) and (c); the guidance in Regulatory Guide 1.205, Revision 1, "Risk-Informed, Performance-Based Fire Protection for Existing Light­Water Nuclear Power Plants"; and National Fire Protection Association (NFPA) 805, "Performance­Based Standard for Fire Protection for Light-Water Reactor Electric Generating Plants" (2001 Edition).

By letter dated July 31 , 2015 (ADAMS Accession No. ML 15212A136), DEP submitted a response to a NRC request for additional information (RAI) . The NRC staff determined that additional information is needed to complete its review related to probabilistic risk assessment (PRA). A draft of that information request was received by DEP via email message on November 20, 2015 (ADAMS Accession No. 15324A328), officially via letter dated March 2, 2016 (ADAMS Accession No. ML 16048A349). An RAl clarification call was held on December 7, 2015. The NRC staff also held an onsite audit February 9-10, 2016, to establish a proposed resolution of outstanding issues associated with the HBRSEP2 NFPA 805 review.

By letter dated May 25, 2016 (ADAMS Accession No. ML 16158A006 and ML 16158A267), DEP revised the LAR Attachment L, "NFPA 805, Chapter 3 Requirements for Approval," by adding an additional approval request not submitted with the original LAR. DEP requested NRC staff review and approval of a performance-based method to demonstrate an equivalent level of fire protection for the requirements of NFPA 805 Section 3.3.4, Insulation Materials, because the insulation materials do not meet the definition of limited combustible due to the heat value exceeding 3500

Enclosure 2 to this letter contains SECURITY-RELATED INFORMATION -WITHHOLD UNDER 10 CFR 2.390

Upon removal of Enclosure 2, this letter is decontrolled.

SECURITY-RELATED INFORMATION -WITHHOLD UNDER 10 CFR 2.390

U.S. Nuclear Regulatory Commission Serial: RNP-RA/16-0079 Page2

Btu/lb. Based on the information provided by DEP in its request, the NRC staff requested additional information to complete its review. Enclosure 1 of this submittal provides the response to this request and DEP's revision to LAR Attachment L, Approval Request 5.

Discussions with the staff regarding the retirement of Fire Protection FAQ 08-0046, prompted DEP to provide new LAR section 4.8.3.3 to discuss the sensitivity for the credit given for in-cabinet Incipient Detection in the analysis. This also prompted the revision of Implementation Item 14, from Table S-3 in the LAR. Enclosure 2, which contains security-related information, conveys this revision to Table S-3.

Please address any comments or questions regarding this matter to Mr. Tony Pila, Acting Manager - Nuclear Regulatory Affairs at (843) 857-1409.

There are no new regulatory commitments made in this letter.

I declare under penalty of perjury that the foregoing is true and correct. Executed on 0-...l-o~ar S , 2016.

R. Michael Glover Site Vice President

RMG/jmw

Enclosure 1: NFPA 805 Section 3.3.4, Insulation Materials, RAI response and revision to LAR Attachment L, Approval Request 5

Enclosure 2: Revision of Implementation Item 14 from Table S-3.

cc: Region Administrator, NRC, Region II Mr. Dennis Galvin, NRC Project Manager, NRR NRC Resident Inspector, HBRSEP2 Ms. S. E. Jenkins, Manager, Infectious and Radioactive Waste Management Section (SC) (w/o Attachment)

Enclosure 2 to this letter contains SECURITY-RELATED INFORMATION - WITHHOLD UNDER 10 CFR 2.390

Upon removal of Enclosure 2, this letter is decontrolled.

U. S. Nuclear Regulatory Commission Enclosure 1 to Serial: RNP-RA/16-0079 9 Pages (including this cover sheet)

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION

STANDARD 805, “PERFORMANCE-BASED STANDARD FOR LIGHT WATER REACTOR ELECTRIC GENERATING PLANTS”

Duke Energy Attachment L – NFPA 805 Chapter 3 Requirements for Approval

HBRSEP LAR Rev 2 Page L-15

Approval Request 5

NFPA 805 Section 3.3.4

NFPA 805 Section 3.3.4 states:

“Thermal insulation materials, radiation shielding materials, ventilation duct materials, and soundproofing materials shall be noncombustible or limited combustible.”

Per the HBRSEP piping and equipment thermal insulation specification, AP Armaflex, Insul-Tube 180 and Insul-Sheet thermal insulation materials are used at HBRSEP. These insulation materials meet the flame spread rating criteria but do not meet the NFPA 805 Section 3.3.4 definition of non-combustible or limited combustible regarding heat value content. This approval request is limited to the thermal insulation materials used at HBRSEP.

NFPA 805 Section 1.6.36 has re-defined earlier definitions of non-combustible material to the now current definition of limited combustible material:

Material that, in the form in which it is used, has a potential heat value not exceeding 3500 Btu/lb (8141 kJ/kg) and either has a structural base of noncombustible material with a surfacing not exceeding a thickness of 1/8 in. (3.2 mm) that has a flame spread rating not greater than 50, or has another material having neither a flame spread rating greater than 25 nor evidence of continued progressive combustion, even on surfaces exposed by cutting through the material on any plane.

Therefore the above described thermal insulation materials utilized at HBRSEP are considered to be in deviation from the NFPA 805 Chapter 3 element, for which approval is requested for continued use of these thermal insulation materials.

Basis for Request:

In several areas at HBRSEP, exposed thermal insulation materials are installed for industrial personnel safety and on miscellaneous system piping to prevent sweating. These materials met the Branch Technical Position (BTP) APCSB 9.5.1/Appendix R requirements for limited combustibles by complying with the flame spread rating of 25 or less as measured using the test method of ASTM E-84, but do not meet the current decreased heat value content requirement based on the definition of a limited combustible due to the heat value exceeding 3500 Btu/lb. Typical thermal insulation materials were noted as having heat contribution values of approximately 9,000 to11,000 Btu/lb, which, while higher than the definition, is not considered to contribute appreciably to the spread of fire, nor represent a secondary combustible beyond those currently analyzed in the FPRA due to the limited applications. The basis for the approval request of this deviation is:

• The forms in which the thermal insulation are installed and the conditions anticipated meet the intent of the revised limited combustible material definition because the materials used at HBRSEP have a flame spread rating of 25 or less

Duke Energy Attachment L – NFPA 805 Chapter 3 Requirements for Approval

HBRSEP LAR Rev 2 Page L-16

and will not support continued progressive combustion. Specifically, the thermal insulation materials used at HBRSEP have fuel contribution, flame spread, and smoke developed ratings of 25, 25, and 50 per ASTM E-84, respectively. Although the thermal insulation materials exceed the NFPA 805 heat value of 3500 Btu/lb, AP Armaflex will not contribute significantly to fire per ASTM E-84, and Insul-Tube 180 and Insul-Sheet are self-extinguishing per ASTM D635.

• The forms in which the thermal insulation are installed and the conditions anticipated do not impact the three echelons of defense-in-depth:

o Echelon 1 is not impacted because the thermal insulation does not introduce new ignition sources and presents a negligible hazard in terms of secondary or intervening combustibles. The forms in which the thermal insulation are installed and the conditions anticipated meet the intent of the revised limited combustible material definition because the materials used at HBRSEP have a flame spread rating of 25 or less and will not support continued progressive combustion.

o Echelon 2 is not impacted because the limited applications of exposed thermal insulation materials installed for industrial personnel safety and on miscellaneous system piping do not result in increased combustible loading which would challenge the design bases of the installed fire protection systems. The presence of the thermal insulation and associated procedural controls do not impact the ability of the automatic suppression and detection systems to perform credited functions, as the materials at HBRSEP are of limited in quantities will not support continued progressive combustion.

o Echelon 3 is not impacted because the limited applications of exposed

thermal insulation materials installed for industrial personnel safety and on miscellaneous system piping do not adversely impact the installed fire protection systems and features, and essential safety functions are maintained and capable of being performed. The insulation material does not impact the post-fire safe shutdown capability in any of the fire areas where it is installed.

• The forms in which the thermal insulation materials are installed and the

conditions anticipated do not impact Nuclear Safety. The limited applications of exposed thermal insulation materials do not compromise post-fire safe shutdown capability as previously designed, reviewed and considered. Adequate defense-in-depth measures are in place as described above to ensure that essential safety functions are maintained and capable of being performed.

• The identified installations were evaluated against the fire scenarios supporting the FPRA. In all instances, the supporting analyses and existing fire scenarios were found to be bounding (expanded zones of influence would not fail additional

Duke Energy Attachment L – NFPA 805 Chapter 3 Requirements for Approval

HBRSEP LAR Rev 2 Page L-17

FPRA targets) or there were no FPRA credited targets in the area. Duke Fleet Procedures which govern the Engineering Change Process are in place to review future installation impacts to the Fire Protection Program and FPRA, resulting in updates to the applicable analyses and calculations as required.

During development of this approval request a number of plant locations were identified where insulation material is used for low point obstruction or head-bump protection (industrial safety). These applications include less than one pound of material affixed to pipes, conduits, and structural components. Additional limited anti-sweat applications were identified primarily in the Turbine Building on piping associated with heating, ventilation and air conditioning systems supporting Power Block structures including the following:

• System 8150 – Containment Building HVAC – piping routed in the Turbine Building

• System 8210 – Auxiliary Building HVAC – piping routed in the Turbine Building • System 8220 – Control Room HVAC – HVAC Equipment Room for the Control

Room • System 8260 – Turbine Building HVAC – piping routed in Turbine Building

Non-HVAC anti-sweat applications were limited to systems (System 4011, Condenser Ball Cleaning) supporting the condenser located on or adjacent to the waterboxes. All of the identified locations were evaluated against the fire scenarios supporting the FPRA. In all instances, the supporting analyses and existing fire scenarios were found to be bounding or there were no FPRA credited targets in the area. The limited applications of exposed thermal insulation material were not of a quantity that would impact the fire scenarios or zones of influences and target failures developed in support of the fire and PRA analysis, and do not compromise automatic fire suppression functions, manual fire suppression functions, or post-fire safe shutdown capability. Duke Fleet Procedures which govern the Engineering Change Process are in place to review future installation impacts to the Fire Protection Program and FPRA, resulting in updates to the applicable analyses and calculations as required.

Duke Energy Attachment L – NFPA 805 Chapter 3 Requirements for Approval

HBRSEP LAR Rev 2 Page L-18

Acceptance Criteria Evaluation:

Nuclear Safety and Radiological Release Performance Criteria:

The use of thermal insulation material other than non-combustible and more than limited combustible in the plant does not affect Nuclear Safety. The limited applications of exposed thermal insulation materials do not compromise post-fire safe shutdown capability. Essential safety functions are maintained and capable of being performed.

The forms in which the thermal insulation materials are installed and the conditions anticipated meet the intent of the revised limited combustible material definition because the materials used at HBRSEP have a flame spread rating of 25 or less and will not support continued progressive combustion. The selection and application of thermal insulation material is controlled per the HBRSEP piping and equipment thermal insulation specification. The Fire PRA development requires the inclusion of the effect of intervening or secondary combustibles to be documented and included in the analysis where determined to have fire effects as part of the performance-based approach. Duke Fleet Procedures which govern the Engineering Change Process are in place to review future installation impacts to the Fire Protection Program and FPRA, resulting in updates to the applicable analyses and calculations as required.

Plant walkdowns and personnel interviews concluded that there were no large concentration installations of thermal insulation in the plant. The most common applications include less than a pound for industrial safety (head-bump protection) and anti-sweat installations on small diameter piping. The impact of the negligible quantities of exposed materials was noted to be bounded by the currently analyzed fire scenario zones of influence, and did not result in new or expanded ZOIs that impacted additional FPRA targets. No existing fire scenarios as considered in the FPRA were adversely impacted.

The use of insulation material other than non-combustible and more than limited combustible has no impact on the radiological release performance criteria. The radiological release review was performed based on the manual fire suppression activities in areas containing or potentially containing radioactive materials and is not dependent on the type of thermal insulation material. The insulation material, regardless of heat contribution value, does not change the radiological release evaluation performed that concluded that potentially contaminated water is contained and smoke is monitored. The insulation materials do not add additional radiological materials to the area or challenge systems boundaries.

Safety Margin and Defense-in-Depth:

The forms in which the thermal insulation are installed and the conditions anticipated meet the intent of the revised limited combustible material definition because the materials used at HBRSEP have a flame spread rating of 25 or less and will not support continued progressive combustion. The insulation material, and specifically the increase in heat contribution in conjunction with the limited applications, does not compromise automatic fire suppression functions, manual fire suppression functions, or post-fire safe shutdown capability. Therefore, the safety margin inherent in the analysis for the fire event has been preserved.

Duke Energy Attachment L – NFPA 805 Chapter 3 Requirements for Approval

HBRSEP LAR Rev 2 Page L-19

The insulation materials in the current configurations are considered as non-cable intervening combustibles and are bound by the FPRA, and safety margin is not affected. The selection and application of thermal insulation material is controlled per the HBRSEP piping and equipment thermal insulation specification. Duke Fleet Procedures which govern the Engineering Change Process are in place to review future installation impacts to the Fire Protection Program and FPRA, resulting in updates to the applicable analyses and calculations as required. The precautions and limitations on the use of these materials do not impact the fire safety analysis of the fire event. Therefore, the inherent safety margin and conservatisms in these analysis methods remain unchanged.

The three echelons of defense-in-depth are,

1) to prevent fires from starting (combustible/hot work controls), 2) rapidly detect, control and extinguish fires that do occur thereby limiting damage

(fire detection systems, automatic fire suppression, manual fire suppression, pre-fire plans), and,

3) provide adequate level of fire protection for systems and structures so that a fire will not prevent essential safety functions from being performed (fire barriers, fire rated cable, success path remains free of fire damage, recovery actions).

The use of insulation material which is non-combustible or more than limited combustible does not affect Echelons 1, 2, and 3. The insulation material, and specifically the increase in heat contribution in conjunction with the limited applications, does not introduce new ignition sources, does not exceed the design bases of installed fire protection systems, does not compromise manual fire suppression functions, and does not adversely impact fire protection systems and features or post-fire safe shutdown capability as previously designed, reviewed and considered.

1) Prevent Fires from Starting:

The thermal insulation does not introduce new ignition sources and presents a negligible hazard in terms of secondary or intervening combustibles. The forms in which the thermal insulation are installed and the conditions anticipated meet the intent of the revised limited combustible material definition because the materials used at HBRSEP have a flame spread rating of 25 or less and will not support continued progressive combustion. Specifically, the thermal insulation materials used at HBRSEP have fuel contribution, flame spread, and smoke developed ratings of 25, 25, and 50 per ASTM E-84, respectively. Although the thermal insulation materials exceed the NFPA 805 heat value of 3500 Btu/lb, AP Armaflex will not contribute significantly to fire per ASTM E-84, and Insul-Tube 180 and Insul-Sheet are self-extinguishing per ASTM D635.

The selection and application of thermal insulation material is controlled per the HBRSEP piping and equipment thermal insulation specification. Duke Fleet Procedures which govern the Engineering Change Process are in place to review future installation impacts to the Fire Protection Program and FPRA, resulting in updates to the applicable analyses and calculations as required.

Duke Energy Attachment L – NFPA 805 Chapter 3 Requirements for Approval

HBRSEP LAR Rev 2 Page L-20

2) Rapidly Detect, Control and Extinguish Fires that do Occur thereby Limiting Damage:

The limited applications of exposed thermal insulation materials installed for industrial personnel safety and on miscellaneous system piping do not result in increased combustible loading which would challenge the design bases of the installed fire protection systems. The presence of the thermal insulation and associated procedural controls do not impact the ability of the automatic suppression and detection systems to perform credited functions, as the materials at HBRSEP are limited in application and will not support continued progressive combustion. Portable fire extinguishers and hose stations are available for manual firefighting activities by the site fire brigade. Therefore, if a fire was to occur damage would be limited.

3) Provide Adequate Level of Fire Protection for Systems and Structures so that a Fire will not Prevent Essential Safety Functions from being Performed :

The limited applications of exposed thermal insulation materials installed for industrial personnel safety and on miscellaneous system piping do not adversely impact the installed fire protection systems and features, and essential safety functions are maintained and capable of being performed. The insulation material does not compromise post-fire safe shutdown capability as previously designed, reviewed and considered.

The forms in which the thermal insulation are installed and the conditions anticipated meet the intent of the revised limited combustible material definition because the materials used at HBRSEP have a flame spread rating of 25 or less and will not support continued progressive combustion. The identified installations were evaluated against the fire scenarios supporting the FPRA. In all instances, the supporting analyses and existing fire scenarios were found to be bounding (expanded zones of influence would not fail additional FPRA targets) or there were no FPRA credited targets in the area. Duke Fleet Procedures which govern the Engineering Change Process are in place to review future installation impacts to the Fire Protection Program and FPRA, resulting in updates to the applicable analyses and calculations as required. The presence of the thermal insulation does not compromise automatic/manual fire protection functions, or post-fire safe shutdown capability and will not prevent essential safety functions from being performed.

Conclusion:

NRC approval is requested for use of thermal insulation materials that meet the flame spread criteria, but do not meet the heat value content criteria of NFPA 805 based on these materials meeting BTP APCSB 9.5.1/Appendix R requirements. HBRSEP has determined that the approach satisfies the following criteria:

• Satisfies the performance goals performance objectives, and performance criteria specified in NFPA 805 related to nuclear safety and radiological release;

• maintains safety margin; and, • maintains fire protection defense-in-depth (fire prevention, fire detection, fire

suppression, mitigation, and post-fire safe shutdown capability).

Duke Energy 4.0 Compliance with NFPA 805 Requirements

HBRSEP LAR Rev 2 Page 58

4.8.3.3 FPRA Credit for In-Cabinet VEWFDS

The Fire PRA used for the Robinson NFPA 805 LAR credited VEWFDS for in-cabinet installations. At the time of the LAR submittal, and throughout the RAI process, FAQ 08-0046 was the only method accepted by the AHJ to apply quantitative credit for VEWFDS for in-cabinet installations. Recently the NRC issued a letter that retired FAQ 08-0046 in anticipation of new guidance that will be published as NUREG-2180.

At this time it is not practical or appropriate to revise the Robinson LAR since all of the formal analysis was completed and reviewed using FAQ 08-0046 and the updated methods have not been finalized. Robinson’s existing PRA update process is in place to evaluate method changes including any updates to the credit applied for VEWFDS.

A sensitivity case was performed based on using the guidance provided in the pre-publication draft NUREG-2180 in order to assess the potential impact. The total potential CDF/LERF as well as the delta CDF/LERF results are provided below for the areas which credited in-cabinet VEWFDS as well as the total. Note that the sensitivity also applied the draft NUREG guidance for area wide application as applicable for the totals.

RNP Using Draft

NUREG-2180

Total CDF

LERF

ES SWGR

(FC200) FA A16

Rod CR

(FC210) FA A17

Hagan Rm (FC230) FA A18

Variant case

3.48E-05 4.03E-06

6.44E-06 7.68E-07

6.82E-07 1.29E-07

4.43E-06 3.99E-07

Compliant case

2.88E-05 3.54E-06

5.03E-06 6.75E-07

3.35E-07 1.07E-07

4.43E-06 3.99E-07

Deltas 6.35E-06 5.42E-07

1.44E-06 9.51E-08

3.47E-07 2.14E-08

0.00E+00 0.00E+00

Based on the sensitivity results the CDF and LERF values generally increase however there are no excessive changes and it is reasonable to continue using the current Robinson LAR as the basis to continue forward with LAR approval process and subsequent self-approval status for Robinson.

Duke Energy 4.0 Compliance with NFPA 805 Requirements

HBRSEP LAR Rev 2 Page 58a

Fire Areas A16 and A17 each have only one fire compartment as shown above. Fire Area A18, however, is comprised of Fire Compartments FC 220, Control Room, and FC 230, Hagan Room. For Table W-5 comparison purposes, the sensitivity results are provided below for Fire A18:

RNP Using Draft

NUREG-2180

Fire Area A18 Control Room and Hagan Room

Variant case

1.19E-05 1.21E-06

Compliant case

1.04E-05 1.06E-06

Deltas 1.51E-06 1.51E-07

The delta in this area is still attributable to control room abandonment. Since there is no delta contribution from the hagan room, changes to incipient detection credit does not impact the delta.