Final Report GHG - Assumptions, Calculations, and ... · CO2(eq) CO2 equivalent CPCN Certificate of...

PNNL-21494

Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830

Assumptions, Calculations, and Recommendations Related to a Proposed Guidance Update on Greenhouse Gases and Climate Change FINAL Technical Evaluation Report EG Chapman KA Cort JP Rishel SE Gulley JM Niemeyer October 2012

PNNL-21494

Assumptions, Calculations, and Recommendations Related to a Proposed Guidance Update on Greenhouse Gases and Climate Change FINAL Technical Evaluation Report EG Chapman KA Cort JP Rishel SE Gulley JM Niemeyer October 2012 Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830 Pacific Northwest National Laboratory Richland, Washington 99352

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Abstract

This report summarizes Pacific Northwest National Laboratory (PNNL) staff’s efforts in reviewing existing supplemental U.S. Nuclear Regulatory Commission (NRC) staff guidance that addresses the effects of greenhouse gases (GHGs) and of climate change for new reactor applications. This review emphasizes consideration of the methodology, assumptions, and calculations in the three tables of existing guidance Appendix YYYY (NRC 2011a) because, under the current organization of environmental impact statements for new reactor review, multiple environmental impact statement sections rely on information presented in these tables.

In reviewing calculations on GHG emissions from preconstruction/construction and decommissioning equipment for Table YYYY-1, PNNL staff discovered a transcription error relative to the raw data (UniStar 2007) on which the table is based. However, this error has only a minor effect on emission totals given in the existing guidance. PNNL staff recommend a small adjustment to the emission factor ratio used to calculate values in Table YYYY-1 and the application of an equivalency factor to put units in terms of total GHG emissions. PNNL staff found that the methodology used in estimating GHG emissions from workforce commuting in Table YYYY-2 is consistent with the methodology used by the U.S. Environmental Protection Agency (EPA) in its web-based GHG calculator (EPA 2011a). PNNL staff recommend numerous revisions to assumed values in Table YYYY-2 based on recent new reactor applications, including a reduction of the assumed average commuting distance from 100 miles to 40 miles round trip. Factors required for calculations in Table YYYY-2 were updated to reflect the latest government reports.

Review of Table YYYY-3 on a nuclear power plant’s lifetime GHG footprint involved consideration of both top-down and bottom-up approaches to estimating uranium fuel cycle GHG emissions and overall life-cycle GHG emissions. For a top-down approach, based on information in IPCC (2012) and nuclear-related references therein, PNNL staff recommend using the IPCC (2012) 75th percentile life-cycle assessment value of 45 g CO2(eq)/kWh to estimate the overall lifetime GHG footprint of a nuclear power plant. This recommendation is partially based on the observation that estimates included in IPCC (2012) geographically emphasize Europe and Japan, where lower energy-consuming-enrichment technologies, and lower GHG-emitting electricity sources to drive enrichment, are employed. For a 1000-MW(e) reference reactor operating with a capacity factor of 80 percent for 40 years, the recommended value translates to lifetime emissions of 1.3 × 107 MT CO2(eq), over 27 percent less than the existing guidance estimate of 1.8 × 107 MT CO2(eq). Subtracting emissions associated with activities covered in Tables YYYY-1 and YYYY-2 from this total leads to a top-down emissions estimate of 1.2 × 107 MT CO2(eq) associated with the uranium fuel cycle. For a bottom-up approach for the same reference reactor, the calculations outlined in Harvey (2012) using the estimates of annual fossil fuel usage in Table S-3 of 10 CFR 51.51 yield an estimate of 1.0 × 107 MT CO2(eq) for the uranium fuel cycle when rounded to one decimal place. Adding the emissions associated with activities covered in Tables YYYY-1 and YYYY-2 lead to estimated lifetime emissions of slightly over 1.0 × 107 MT CO2(eq), or approximately 37 CO2(eq)/kWh.

Recommended changes to existing guidance Tables YYYY-1 and YYYY-2 are summarized in Tables 3 and 6, respectively, of this report. Table 10 summarizes changes to Table YYYY-3 if a top-down approach to estimate total and uranium fuel cycle GHG emissions is used, while Table 11 summarizes changes to Table YYYY-3 if a bottom-up approach is used.

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Acronyms and Abbreviations

CH4 methane

CO carbon monoxide

CO2 carbon dioxide

CO2(eq) CO2 equivalent

CPCN Certificate of Public Convenience and Necessity

DOT U.S. Department of Transportation

EIS environmental impact statement

EPA U.S. Environmental Protection Agency

ER environmental report

FHWA Federal Highway Administration

g gram(s)

GHG greenhouse gas

GWP global warning potential

IPCC Intergovernmental Panel on Climate Change

kg kilogram(s)

LCA life-cycle assessment

MdPSC Public Service Commission of Maryland

MT metric ton(s)

MW megawatt(s)

N2O nitrous oxide

NRC U.S. Nuclear Regulatory Commission

PNNL Pacific Northwest National Laboratory

SME subject matter expert

tg teragram(s)

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Contents

Abstract ................................................................................................................................................. iii Acronyms and Abbreviations ............................................................................................................... v 1.0 Background ................................................................................................................................... 1 2.0 General Methodology ................................................................................................................... 1 3.0 Results .......................................................................................................................................... 4

3.1 Construction Equipment GHG Emissions (Table YYYY-1) ............................................... 4 3.1.1 Current Guidance ...................................................................................................... 4 3.1.2 Review of Construction and Decommissioning Emissions Calculations .................. 5 3.1.3 Recommendations ..................................................................................................... 6

3.2 Workforce GHG Footprint Estimates (Table YYYY-2) ...................................................... 8 3.2.1 Current Guidance ...................................................................................................... 8 3.2.2 Review of Commuting Calculations and Recommended Parameter Updates .......... 8 3.2.3 Recommendations ..................................................................................................... 14

3.3 Operations and Uranium Fuel Cycle Emissions and Lifetime GHG Footprint .................... 14 3.3.1 Current Guidance ...................................................................................................... 14 3.3.2 Review of Operations Calculations and Recommended Changes............................. 16 3.3.3 Review of Uranium Fuel Cycle and Overall Life-Cycle Emissions Estimates ......... 16

4.0 Summary ....................................................................................................................................... 24 5.0 References .................................................................................................................................... 26

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Tables

1 Annual Greenhouse Gas Emissions from Fossil Fuel Combustion .............................................. 3 2 Existing Guidance Table YYYY-1 on Preconstruction and Construction Equipment

GHG Emissions ............................................................................................................................ 5 3 Recommended Guidance Table YYYY-1 on Preconstruction and Construction

Equipment GHG Emissions .......................................................................................................... 7 4 Existing Guidance Table YYYY-2 on Workforce GHG Emissions ............................................. 9 5 Review of Preconstruction/Construction Workforce and Commuting Assumptions ................... 10 6 Recommended Guidance Table YYYY-2 on Workforce GHG Emissions .................................. 15 7 Existing Guidance Table YYYY-3 on Nuclear Power Plant Lifetime GHG Emissions .............. 16 8 IPCC Results of a Literature Review of the Life-Cycle Analyses of Greenhouse Gas

Emissions from Nuclear Energy ................................................................................................... 18 9 References Related to the GHG Life-Cycle Emissions from a Nuclear Power Plant Cited

in IPCC (2012) .............................................................................................................................. 19 10 Recommended Values for Guidance Table YYYY-3 on Nuclear Power Plant Lifetime

GHG Emissions Based on a Top-Down Approach for Estimating Uranium Fuel Cycle Emissions ...................................................................................................................................... 23

11 Recommended Values for Guidance Table YYYY-3 on Nuclear Power Plant Lifetime GHG Emissions Based on a Bottom-Up Approach for Estimating Uranium Fuel Cycle Emissions ...................................................................................................................................... 24

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1.0 Background

Existing guidance for U.S. Nuclear Regulatory Commission (NRC) staff is given in NRC (2011a) for incorporating and addressing greenhouse gas (GHG) and climate change issues in preparing environmental impact statements (EISs) for new reactor reviews. This guidance contains an April 8, 2010 memorandum from Barry Zalcman to Brent Clayton (NRC 2010a). The Zalcman memorandum provides background on why NRC EISs for new reactors have begun addressing GHGs and climate change, including a summary of recent Commission and Council on Environmental Quality guidance along with a review of the December 15, 2009 endangerment finding (74 FR 66496) issued by the Administrator of the U.S. Environmental Protection Agency (EPA). More recently, the EPA has proposed a new rule setting standards of performance for GHG emissions from new fossil fuel-fired electric utility generating units (77 FR 22392). The proposed new rule sets an emission standard of 454 kilograms of carbon dioxide (CO2) per megawatt-hour on an annual basis for new fossil fuel-fired units with baseload ratings larger than 73 MW.

The Zalcman memo (NRC 2010a) addresses EIS format and content for GHG discussions by providing a generic analysis for affected EIS sections, and provides guidance on how to adapt the generic analysis to the specific circumstances of a proposed project. A significant component of the generic analysis is contained in the Zalcman memorandum Attachment 3 entitled “Appendix YYYY Carbon Dioxide Footprint Estimates for a Reference 1000-MW(e) Reactor.” Under the current organization of EISs for new reactor application reviews, EIS sections in Chapters 4, 5, 6, 7, and 9 address GHGs and climate change. These sections repeatedly reference Appendix YYYY and its three tables summarizing construction equipment CO2 emissions, workforce CO2 footprint estimates, and the nuclear power plant lifetime CO2 footprint.

The NRC requested Pacific Northwest National Laboratory (PNNL) staff review material in the existing GHG and climate change guidance, emphasizing in its review the values currently used in the three Appendix YYYY tables. This report summarizes the review efforts, details recommendations for updating certain values in the tables, and provides the rationale for either updating or retaining these values. We begin by describing the general methodology used in the review, including an explanation of units. Review results, including explanation of implicit assumptions, and recommended changes to each table are then presented. We close with an overall summary of recommended changes.

2.0 General Methodology

PNNL staff began their review by focusing on Attachment 3 (Appendix YYYY) of the April 8, 2010 memorandum from Barry Zalcman to Brent Clayton (NRC 2010a) as incorporated in the March 4, 2011 interim guidance memorandum from Brent Clayton to Scott Flanders (NRC 2011a). We checked cited references for various values used in the three current Appendix YYYY tables to confirm the accuracy of existing numbers, and assessed the reasonableness of both inherent calculation assumptions and explicit assumptions stated in the existing guidance. For references comprising part of a continuing series (e.g., Federal Highway Administration [FHWA] annual statistical reports), the most recent documents were obtained to determine if values for certain variables had changed. As discussed in Section 3.2, PNNL

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socioeconomic subject matter experts (SMEs) conducted an independent assessment of various workforce commuting assumptions, based on their experience with recent EISs and applicant environmental reports (ERs).

PNNL staff relied heavily on reports issued by various agencies of the U.S. Government to inform its review and its recommendations for using specific values. Assessments issued by the Intergovernmental Panel on Climate Change (IPCC) were also consulted based on government acceptance and approval of such IPCC reports because, as stated by the EPA Administrator in her endangerment finding, “…such review and acceptance by the U.S. Government lends further support for placing primary weight on these major assessments” (74 FR 66496).

CO2 is the compound most commonly associated with GHGs. However, GHGs also include methane (CH4), nitrous oxide (N2O), various hydrofluorocarbons, various perfluorocarbons, and sulfur hexafluoride (74 FR 66496; IPCC 2007). The relative ability of a specific GHG to trap heat in the atmosphere is captured by its global warming potential (GWP). The GWP is defined as the ratio of the time-integrated radiative forcing resulting from the instantaneous release of a unit mass of the specific gas relative to that of a unit mass of a reference gas, where CO2 is typically used as the reference gas (IPCC 2001). The GWP of a specific greenhouse gas thus can be viewed as the ratio of heat trapped by one unit mass of that gas to that of one unit mass of CO2 over a specified time period; the time period must be indicated because different gases have different atmospheric lifetimes. Note that the GWP of CO2 is always equal to 1 regardless of the time period because CO2 serves as the reference gas. GWPs can be used to convert masses of GHGs to the common unit of “CO2 equivalent” (CO2(eq)). The quantities “grams CO2 equivalent,” abbreviated as “g CO2(eq),” “kilograms CO2 equivalent” (“kg CO2(eq)”, equal to 103 g CO2(eq)), “metric tons CO2 equivalent” (“MT CO2(eq)”, equal to 106 g CO2(eq)), and “teragrams CO2 equivalent” (“Tg CO2(eq)”, equal to 1012 g CO2(eq)) are often used when discussing mixtures of GHG.

For the purposes of this review, CO2, CH4, and N2O are the GHGs of concern. These compounds are released as the result of fossil fuel combustion from equipment used in the preconstruction, construction, operation, and decommissioning of a nuclear power plant, and from vehicles used in workforce commuting. The GWP of CH4 and N2O must be considered for such emissions. The EPA uses 100-year GWPs from IPCC (1996) “…to be consistent with the international standards under the United Nations Framework Convention on Climate Change…” (EPA 2011b). These GWPs are not necessarily the values currently recommended by the IPCC as the most scientifically accurate, which are updated via the web page http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-errata.pdf, but are the GWPs used in documents issued by various U.S. government agencies. Throughout this report, we use mass units of CO2(eq) when referring to mixtures of GHGs and mass units of CO2 (e.g., “kg CO2”) when referring to carbon dioxide as a single gas. All CO2(eq) values are based on 100-year GWPs as specified in EPA (2011b).

Table 1 illustrates that CO2 dominates the annual GHG emissions from fossil fuel combustion by mobile sources relevant to the life cycle of a nuclear power plant. Based on data tables from the EPA (EPA 2007a, 2009, 2012a, 2012b), the contribution of CO2 to GHG emissions from gasoline-powered passenger vehicles has varied slightly since 2005, but has remained essentially constant for diesel-powered passenger vehicles and for construction equipment. Note the contributions of CH4 and N2O in Table 1 are reported in Tg CO2(eq); i.e., cited data tables in EPA (2007a, 2009, 2012a, 2012b) already have incorporated the appropriate IPCC (1996) GWP factors.

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Table 1. Annual Greenhouse Gas Emissions from Fossil Fuel Combustion

Fuel/Vehicle Type Base Year CO2

(Tg CO2(eq)) CH4

(Tg CO2(eq)) N2O

(Tg CO2(eq)) Total GHG Emissions

(Tg CO2(eq)) CO2(eq) Factor(a)

Gasoline/Passenger Cars 2010(b) 753.8 0.9 10.8 765.5 0.985

Gasoline/Passenger Cars 2007(c) 620.9 0.9 13.7 635.5 0.977(d)

Gasoline/Passenger Cars 2005(e) 610.4 1.1 17 628.5 0.971(d)

Diesel/Passenger Cars 2010(b) 3.7 <0.05 <0.05 3.7 1.000

Diesel/Passenger Cars 2007(c) 4.1 <0.05 <0.05 4.1 1.000

Diesel/Passenger Cars 2005(d) 4.4 <0.05 <0.05 4.4 1.000

Non-Road/Construction-Mining Equipment(f) 2010(g) 73 0.1 0.6 73.7 0.991

Non-Road/Construction-Mining Equipment(f) 2007(g) 67.8 0.1 0.5 68.4 0.991

Non-Road/Construction-Mining Equipment(f) 2005(g) 65.9 0.1 0.5 66.5 0.991

(a) Calculated as the ratio of CO2 Emissions to Total GHG Emissions. (b) EPA (2012a) Tables 3-12, 3-13, and 3-14. (c) EPA (2009) Tables 3-12, 3-13, and 3-14. (d) In 2011, the FHWA changed its vehicle classifications, and the 2005 and 2007 data presented in EPA (2012a) were adjusted to reflect this new definition.

The adjusted data result in CO2(eq) factors of 0.972 for 2005 and 0.978 for 2007. (e) EPA (2007a) Tables 3-7, 3-21, and 3-22. (f) EPA (2012a) notes that this category includes equipment, such as cranes, dumpers, and excavators, as well as fuel consumption from trucks that are used

off-road in construction. (g) EPA (2012a) Tables 3-13 and 3-14 and EPA (2012b) Table A-109.

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3.0 Results

This section summarizes the results of PNNL staff’s review of Appendix YYYY, organized according to each of its three tables: Construction Equipment GHG Emissions (Table YYYY-1), Workforce GHG Footprint Estimates (Table YYYY-2), and Uranium Fuel Cycle and Lifetime GHG Footprint (Table YYYY-3).

3.1 Construction Equipment GHG Emissions (Table YYYY-1)

Table YYYY-1 summarizes CO2 emissions from equipment used in preconstruction/construction and decommissioning activities. Under the organization of EISs for new reactor application reviews current at the time existing guidance was written, EIS Sections 4.7.1 (Construction and Preconstruction Activities), 6.3 (Decommissioning Impacts), and 7.6.2 (Greenhouse Gas Emissions) reference estimates in this table.

3.1.1 Current Guidance

Table 2 reproduces existing guidance Table YYYY-1. The CO2 emission estimates in this table are based on data presented in UniStar’s (2007) application for a Certificate of Public Convenience and Necessity (CPCN) to the Public Service Commission of Maryland (MdPSC) for building the proposed Calvert Cliffs Nuclear Power Plant Unit 3. The CPCN application (UniStar 2007) considered the following areas of plant construction in developing emission estimates for criteria air pollutants:

• Earthwork and Dewatering

• Batch Plant Operations

• Concrete

• Lifting and Rigging

• Shop Fabrication

• Warehouse Operations

• Equipment Maintenance.

Section 5.5.1 of UniStar (2007) provides detailed estimates of construction equipment and associated fuel type, engine size, and total hours of operation for each year of the expected 7-year building period. These data, along with EPA emission factors for combustion sources (EPA 2004), were used in UniStar (2007) to develop emission estimates for various criteria air pollutants including carbon monoxide (CO), volatile organic compounds, nitrogen oxides, particulate matter, and sulfur dioxide. MdPSC (2008) reviewed the UniStar (2007) construction emission estimates and found the values to be acceptable.

As CO2 is not a criteria air pollutant, UniStar (2007) did not provide explicit estimates of CO2 emissions in the CPCN application. However, as noted in Table 3.3-1 of Chapter 3.3 of the EPA’s AP-42 emission factors for uncontrolled gasoline and diesel industrial engines (EPA 1995, 2012d), the majority of the carbon (approximately 99%) in the fuel is converted to CO2 upon combustion. As discussed in existing guidance Appendix YYYY, a scaling factor of 165 was applied to UniStar’s (2007) CO

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emissions to estimate the corresponding CO2 emissions; the scaling factor is based on the average ratio of CO2 to CO emission factors for both gasoline and diesel industrial engines as presented in Chapter 3.3 of EPA (1995).

Table 2. Existing Guidance Table YYYY-1 on Preconstruction and Construction Equipment GHG Emissions

Table YYYY-1. Construction Equipment CO2 Emissions (metric tons equivalent)

Equipment Construction Total(a) Decommissioning Total(b)

Earthwork and Dewatering 1.1 × 104 5.4 × 103

Batch Plant Operations 3.3 × 103 1.6 × 103

Concrete 4.0 × 103 2.0 × 103

Lifting and Rigging 5.4 × 103 2.7 × 103

Shop Fabrication 9.2 × 102 4.6 × 102

Warehouse Operations 1.4 × 103 6.8 × 102

Equipment Maintenance 9.6 × 103 4.8 × 103

Total(c) 3.5 × 104 1.8 × 104

(a) Based on hours of equipment usage over 7-year period. (b) Based on equipment usage over 10-year period. (c) Total not equal to the sum due to rounding.

Because UniStar’s (2007) CPCN application is for plant construction and operation, it does not provide emission estimates associated with decommissioning. Section 6.3 of the existing supplemental NRC staff guidance notes that decommissioning of a plant is expected to take 10 years and existing Appendix YYYY assumes CO2 emissions from decommissioning are one-half of those from construction.

Because emissions from preconstruction/construction and decommissioning activities represent such a small part of the overall GHG footprint for a nuclear power plant, the NRC requested that PNNL staff not attempt to update values at this time. Instead, PNNL staff were to provide the basis and assumptions for the values in guidance Table YYYY-1, and validate any calculations used in generating these values.

3.1.2 Review of Construction and Decommissioning Emissions Calculations

The NRC requested that PNNL staff validate the calculations used to estimate construction and decommissioning equipment CO2 emissions presented in existing guidance Table YYYY-1 (Table 2 of this report). As discussed in Section 3.1.1, the CO2 emissions are based on scaled CO emissions provided by UniStar (2007) for building the proposed Calvert Cliffs Nuclear Power Plant Unit 3. A scaling factor was applied to the UniStar (2007) CO emissions to calculate the corresponding CO2 emissions. The scaling factor of 165 is based on the average ratio of CO2 to CO emission factors presented in Table 3.3-1 of the EPA’s AP-42 emission factors for uncontrolled gasoline and diesel industrial engines (EPA 1995). PNNL staff believes the use of a scaling factor based on AP-42 emission factors for uncontrolled gasoline and diesel industrial engines is a reasonable method for deriving CO2 emissions from UniStar’s (2007) CO estimates. Appendix YYYY notes that emissions from decommissioning are assumed to be one-half of the emissions from construction. PNNL staff could not determine a basis or reference for the

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“one-half” factor. However, this factor seems reasonably conservative, since decommissioning typically involves less earth moving and material hauling, and fewer labor hours; therefore, emissions are expected to be less than that from preconstruction and construction.

To validate the CO2 emission estimates from preconstruction and construction presented in existing guidance Table YYYY-1, PNNL staff reviewed the spreadsheet that was used as the basis for the estimates. The spreadsheet contains a detailed listing of construction equipment and corresponding CO emission factors, associated fuel type, engine size, and total hours of operation for each year of plant construction; the data are taken from Section 5.5.1 (Tables 5.5-2 and 5.5-3) of UniStar’s CPCN application (UniStar 2007). A yearly estimate of CO emissions (lb) for each piece of construction equipment is calculated by multiplying the CO emission factor (lb/hp-hr) by the engine size (hp) and hours (hr) of operation. The yearly estimates are summed across all 7 years of the expected building period to obtain total CO emissions in pounds (lb). Conversion factors are then applied to convert from pounds (lb) to metric tons (MT) of CO. Finally, NRC staff applied a factor of 165 to scale CO to CO2 emissions. Emissions from decommissioning are calculated by simply halving the values obtained for preconstruction and construction.

In comparing the spreadsheet values to the original UniStar (2007) tables, it was noted that the “Year 3” hourly estimate for the “Concrete Transport Trucks, Agitator/Mixer, 10cy capacity” had been entered in error into the spreadsheet—a value of 2,400 hours had been entered instead of the 24,000 hours indicated in Table 5.5-2 of UniStar (2007). Correcting this error would result in a slight increase for the “Concrete” category in Table YYYY-1 (Table 2 of this report); concrete preconstruction/construction CO2 emissions would increase from 4.0 × 103 MT CO2 to 5.1 × 103 MT CO2. For concrete decommissioning, CO2 emissions would increase from 2.0 × 103 MT CO2 to 2.5 × 103 MT CO2. As a consequence of correcting this transcription error, total preconstruction/construction emissions also would increase slightly from 3.5 × 104 MT CO2 to 3.7 × 104 MT CO2, a difference of less than 6 percent. The remaining spreadsheet entries and methodology for calculating CO2 emissions were found to be correct. However, as discussed in the next section, we recommend minor adjustments to certain factors used in the calculation methodology.

3.1.3 Recommendations

As discussed in Section 3.1.1, a scaling factor based on the average ratio of CO2 to CO emission factors for both gasoline and diesel industrial engines in EPA (1995) was applied to UniStar’s (2007) CO emissions to estimate the corresponding CO2 emissions. PNNL staff recommend changing the scaling factor to one derived solely from emission factors for diesel industrial engines as given in the EPA’s most recent update (EPA 2012d). The rationale for this recommendation is based on the observation that equipment listed in UniStar (2007) is almost exclusively diesel-fuel based; therefore, it is appropriate to use emission factors for industrial diesel engines to develop the scaling factor. The recommended approach also is more conservative because the CO2 to CO emission factor ratio is higher for industrial diesel engines than for industrial gasoline engines. EPA (2012d) currently lists diesel emission factors of 1.15 lb/hp-hr for CO2 and 6.68 × 10-3 lb/hp-hr for CO, resulting in a scaling factor of 172. This value is slightly more than four percent higher than the previously used scaling factor of 165.

As discussed in Section 2.0, CO2 dominates the GHG emissions from fossil fuel combustion but other GHGs, such as CH4 and N2O, are also emitted. The use of a CO2 to total GHG equivalency factor is

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needed to account for these other GHG emissions; estimates of CO2 emissions are divided by the equivalency factor to yield total GHG emissions. Table YYYY-1 of the existing guidance (Table 2 of this report) only accounted for CO2 emissions (i.e., it assumed an equivalency factor of 1.0). As Table 1 shows, EPA (2012a, 2012b) data indicate a CO2(eq) factor of 0.991 for non-road/construction-mining equipment. Consistent with data in EPA (2012a, 2012b), PNNL staff recommend using an equivalency factor equal to 0.991. Use of this factor results in only a very slight increase in emissions. Nevertheless, it provides consistency in units as CO2(eq) emissions are used elsewhere throughout the existing guidance.

Table 3 presents revisions to guidance Table YYYY-1 on construction equipment GHG emissions based on these two recommendations. Changes from existing guidance (Table 2) are highlighted in yellow. As shown in Table 3, using a CO2 to CO scaling factor of 172 and a CO2(eq) factor of 0.991 results in an increase of approximately 11 percent in preconstruction/construction GHG emissions, from 3.5 × 104 to 3.9 × 104 MT CO2(eq), and an approximately 5 percent increase in decommissioning GHG emissions, from 1.8 × 104 to 1.9 × 104 MT CO2(eq). These totals and the revised “Concrete” equipment emissions also reflect correction of a transcription error in the original spreadsheet used to develop the emission estimates (see Section 3.1.2).

Table 3. Recommended Guidance Table YYYY-1 on Preconstruction and Construction Equipment GHG Emissions. Changes from existing guidance (Table 2) are highlighted in yellow.

Table YYYY-1. GHG Emissions From Equipment Used in Preconstruction/Construction and Decommissioning

Equipment Preconstruction/Construction Total

(MT CO2(eq))(a) Decommissioning Total

(MT CO2(eq))(b)

Earthwork and Dewatering 1.2 × 104 6.0 × 103

Batch Plant Operations 3.4 × 103 1.7 × 103

Concrete 5.4 × 103 2.7 × 103

Lifting and Rigging 5.6 × 103 2.8 × 103

Shop Fabrication 9.7 × 102 4.9 × 102

Warehouse Operations 1.4 × 103 7.2 × 102

Equipment Maintenance 1.0 × 104 5.0 × 103

Total(c) 3.9 × 104 1.9 × 104

(a) Based on hours of equipment usage over 7-year period. (b) Based on equipment usage over 10-year period. (c) Total not equal to the sum due to rounding.

PNNL staff considered whether preconstruction/construction equipment GHG emissions should be scaled to a 1000 MW(e) reference reactor. We think these emissions are more likely to be related to the amount of required terrain modification than to the size of a reactor in MW(e). Current guidance states the preconstruction/construction equipment emissions estimates are for a site requiring a moderate amount of terrain modification; we recommend any revisions to the guidance retain this statement.

As previously noted, GHG emission estimates provided in Table 3 are based on data presented in UniStar’s (2007) CPCN application to the MdPSC for the building of the proposed Calvert Cliffs Nuclear

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Power Plant Unit 3. The MdPSC reviewed the UniStar (2007) construction emission estimates and found the values to be acceptable (MdPSC 2008). Since the UniStar (2007) submission, other applicants have provided detailed emission estimates to the NRC for the purposes of conformity determinations. PNNL staff recommends reviewing these additional emission estimates as another way to confirm the values provided in the recommended guidance Table YYYY-1 (Table 3). Such a review is unlikely to significantly alter the small contribution of preconstruction/construction and decommissioning equipment to the total lifetime GHG footprint of a nuclear power plant, but will make discussions in EIS sections referring to Table YYYY-1 more robust.

3.2 Workforce GHG Footprint Estimates (Table YYYY-2)

Table YYYY-2 summarizes GHG emissions associated with workforce commuting during the construction, operation, and decommissioning of a nuclear power plant. Under the current organization of EISs for new reactor application reviews, EIS Sections 4.7.2 (Traffic), 5.7.1 (Air Quality Impacts), and 6.3 (Decommissioning Impacts) reference values in this table.


Table 4 reproduces existing guidance Table YYYY-2. The estimates in this table follow the methodology used on EPA’s web-based Greenhouse Gas Equivalencies Calculator (available at http://www.epa.gov/cleanenergy/energy-resources/calculator.html), as outlined in EPA (2011a). This methodology is based on estimating the total gallons of fuel burned during commuting, and then using EPA-derived factors to calculate the GHG emissions associated with burning this amount of fuel. Fuel usage is based on assumptions related to workforce size, carpooling, commuting distance, total workdays, and average fuel efficiency of the commuting vehicles. Consistent with EPA methodology, results are reported in MT CO2(eq) because, as discussed in Section 2, CH4 and N2O are also emitted by vehicular fossil fuel combustion.

3.2.2 Review of Commuting Calculations and Recommended Parameter Updates

PNNL staff found the overall approach used to estimate workforce GHG emissions to be technically sound. Our review thus concentrated on assessing the assumptions associated with estimating the amount of fuel consumed in commuting, checking for updated factors necessary for the calculations, and confirming the accuracy of the calculations.

Review of Assumptions. Preconstruction and construction impacts on traffic patterns are addressed as part of the NRC environmental review process for new license applications. PNNL Socioeconomic SMEs compared currently assumed Table YYYY-2 values for round trips per day, miles per round trip, days per year, and duration of the preconstruction/construction period with values used in seven recent EISs (draft and final) and applicant-submitted ERs. The SMEs also independently calculated a weighted-average-likely-commuting-distance based on the distance from a proposed plant to the communities identified as the most probable to house construction workers. The results of this review are given in Table 5. As shown there, the number of estimated daily commuting round trips depends heavily on the size of the peak workforce, which varies substantially among the seven reviewed sites and does not appear to be linearly related to the number of units being constructed. On a megawatt capacity basis, the

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estimated size of the average workforce also varies significantly from project to project, ranging from approximately 1.1 (Levy and Vogtle) to 2.0 workers per MW (Comanche Peak). Existing guidance emphasis on appropriately scaling variables to account for differences in workforce numbers clearly needs to be maintained. Based on the rideshare assumptions coupled with the average daily workforce per MW, scaled to a 1000 MW reference reactor, PNNL staff recommend the commuting roundtrips per day during preconstruction/construction in the generic analysis be decreased from 1250 to 1000 to better reflect the maximum value of the seven reviewed sites. Using the rounded maximum value from Table 5 of 1000 for the number of roundtrips and reasonable values for the remaining calculation variables will produce a conservative (i.e., on the high side), but still likely reasonable, estimate of GHG emissions related to employee commuting during preconstruction and construction.

Table 4. Existing Guidance Table YYYY-2 on Workforce GHG Emissions

Table YYYY-2. Workforce CO2 Footprint Estimates

Construction Workforce

Operational Workforce

Decommissioning Workforce

SAFSTOR Workforce

Round trips per day 1250 200 150 20

Miles per round trip 100 100 100 100

Days per year 365 365 250 365

Years 7 40 10 40

Miles Traveled 3.2 × 108 2.9 × 108 3.8 × 107 2.92 × 107

Miles per gallon(a) 19.7 19.7 19.7 19.7

Gallons fuel burned 1.6 × 107 1.5 × 107 1.9 × 106 1.58 × 106

Metric tons CO2 per gallon(b) 8.81 × 10-3 8.81 × 10-3 8.81 × 10-3 8.81 × 10-3

Metric tons CO2 1.4 × 105 1.3 × 105 1.7 × 104 1.3 × 104

CO2 equivalent factor(c) 0.971 0.971 0.971 0.971

Metric tons CO2 equivalent 1.5 × 105 1.3 × 105 1.7 × 104 1.3 × 104

(a) FHWA (2006). (b) EPA (2007b). (c) EPA (2007a).

The size of the operational, decommissioning, and SAFSTOR workforces will also affect the number assumed for daily commuting round trips in each of these categories. According to Table C.4 of Generic Environmental Impact Statement for License Renewal of Nuclear Plants Volumes 1 and 2 (NRC 1996), the actual operating-period employment at nuclear power plants has averaged on the order of 800 staff per unit. Most currently proposed new reactors are additions to existing facilities with projected increases in permanent employment well below this level. However, using a value of 800 staff per unit is a conservative assumption and potentially can help account for increased workforce commuting that occurs during outages. Although an individual employee is assumed to work 250 days per year, preconstruction/construction activities at a nuclear facility usually occur 7 days a week. The average workforce estimate of 800 staff per unit was scaled by a factor of 250/365 to determine the average daily onsite workforce of approximately 550. Assuming no carpooling (1.0 person per vehicle), as is usually

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Table 5. Review of Preconstruction/Construction Workforce and Commuting Assumptions

Calvert Cliffs Levy Comanche Peak Bell Bend Lee STP Vogtle

Reactor Type EPR AP1000 APWR EPR AP1000 ABWR AP1000

Number of Units 1 2 2 1 2 2 2

Proposed Nominal Power Output (MW) 1600 2210 1700 1600 2210 2700 2210

Approximate Building Period (years) 9 6.5 7 7 5.25

Peak Workforce (persons) 3950 3440 4953 3950 4613 5950 3500

Reference for Peak Workforce CC ER Ch 4(a) Levy ER Ch 4(b) CPN ER Ch 4(c) BB ER Ch 4(d) Lee EIS Sec 4.5(e) STP EIS 4.8(f)

VEGP EIS Ch. 4(g)

Average Workforce Based on Vogtle’s Average to Peak Ratio of 70% (persons)

2765 2408 3467 2765 3229 4165 2450

Average Workforce per Proposed Nominal Power Output (persons/MW)

1.73 1.09 2.04 1.73 1.46 1.54 1.11

Average Workforce Scaled to 1000 MW Reference Reactor (persons)

1728 1090 2039 1728 1461 1543 1109

Carpooling Assumption (persons/vehicle) 1.8 1.7 1.8–2.3 1.3 1 1.14 1.8

Reference for Carpooling Assumption VEGP EIS Ch. 4(g) Kimley-Horn (2009)(h)

CPN ER Ch. 4(c) KLD (2008)(i) Lee EIS Sec. 4.8(e) DOT (2003)(j)

VEGP EIS Sec. 4.8(g)

Average Work-days/year 250 250 NA(k) 250 250 250 250

Estimated Round Trips per Day(l) 1052 970 1319 1457 2212 2502 932

Estimated Round Trips per MW Basis 0.658 0.439 0.776 0.910 1.001 0.927 0.422

Estimated Round Trips for 1000 MW Reference Reactor

658 439 776 910 1001 927 422

Assumed One-way Commute Distance (miles)

20 20 NA(k) 40 20 20 20

Reference for Assumed One-way Commute Distance

DOT (2003)(j) DOT (2003)(j) NA(k) KLD (2008)(i) Lee EIS Sec. 4.8(e) DOT (2003)(j)

VEGP EIS Sec. 4.8(g)

#1 Likely Commute Distance 30 15 15 8 10 13 37

City/County Name North Beach, Calvert County

Crystal River, Citrus County

Granbury, Hood County

Berwick, Columbia County

Gaffney, Cherokee County

Bay City, Matagorda

County

Martinez, Columbia County

Reference CC EIS Sec 4.4.2(m) Levy EIS Sec 4.4.2(n)

CPN EIS Sec 4.4.2(o)

BB ER Ch 4(d) Lee EIS Sec 4.5(e) STP EIS 2.5(f)

Vogtle EIS 2.8(g)

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Table 5. (contd)

Calvert Cliffs Levy Comanche Peak Bell Bend Lee STP Vogtle

#2 Likely Commute Distance 21 21.5 8 23 29 43 32.5

City/County Name Leonardtown, St. Mary's County

Levy and Marion Counties

Glen Rose, Somervell County

Wilkes-Barre Luzerne County

Rock Hill, York County

Angleton, Freeport &

Lake Jackson, Brazoria County

Augusta, Richmond

County

Reference CC EIS Sec 4.4.2(m) Levy EIS Sec 4.4.2(n)

CPN EIS Sec 4.4.2(o)

BB ER Ch 4(d) Lee EIS Sec 4.5(e) STP EIS 2.5(f)

Vogtle EIS 2.8(g)

#3 Likely Commute Distance NA(k) NA(k) NA(k) NA(k) NA(k) NA(k) 16.8

City/County Name NA(k) NA(k) NA(k) NA(k) NA(k) NA(k) Waynesboro, Burke Co.

Reference NA(k) NA(k) NA(k) NA(k) NA(k) NA(k) Vogtle EIS 2.8

Approximate percentage of employees commuting from #1 and #2 location

91% 85% 67% 87% 100% 83% 80%

(Weighted) Average of #1 and #2 commute distances (miles)

27 18 13 15 20 21 30

Weights (68% Calvert/ 28% St. Mary's)

(45% Citrus/ 20% Levy/

20% Marion)

(44% Hood/ 23% Somervell)

45% Columbia/ 42% Luzerne

(50% Cherokee/ 50% York)

(60.7% Matagorda/

22.4% Brazoria

(34% Columbia/ 26% Richmond/

20% Burke

(a UniStar (2009). (b) PEF (2008). (c) Luminent (2009). (d) UniStar (2011). (e) NRC (2011b). (f) NRC (2011c). (g) NRC (2011f). (h) Kimley-Horn (2009). (i) KLD (2008). (j) DOT (2003). (k) NA = Not applicable. (l) Although an individual employee is assumed to work 250 days per year, preconstruction/construction activities at a nuclear facility usually occur 7 days a week. The average workforce estimate

thus must be scaled by a factor of 250/365 to determine the average daily onsite workforce, and then divided by the assumed carpooling value to obtain the estimated daily number of commuting round trips.

(m) NRC (2011d). (n) NRC (2010b). (o) NRC (2011e).

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assumed in EIS socioeconomic discussions related to operations, this equates to approximately 550 round trips per day. A value of 200 roundtrips per day is currently assumed for the operational workforce, based on estimates in combined license applications existing at the time the guidance was written (NRC 2010a). We recommend that the assumed value per unit for operational workforce commuting be increased from 200 to 550 round trips per day. Currently assumed commuting round trips per day for decommissioning and SAFSTOR workforces are based on workforce levels of 300 and 40 employees, respectively, coupled with an implicit carpooling assumption of 2.0 persons per vehicle. The assumed decommissioning workforce size is slightly larger than the range of 100–200 employees given in Table J-1 of NRC (2002). PNNL staff has no definitive basis for altering the currently assumed values. However, for consistency with the construction and operations approach of using a higher end value for the number of roundtrips and reasonable values for remaining calculation variables, PNNL staff recommend that values of 200 and 40 round trips per day for the decommissioning and SAFSTOR workforces, respectively, be assumed.

Table 5 also shows that the currently assumed commuting distance of 100 miles roundtrip is higher than that used in recent EISs and ERs. A one-way distance of 20 miles (round trip, 40 miles) is more commonly used in these documents, and this figure agrees well with the weighted average value of 21 miles one way (42 miles round trip) independently calculated by the PNNL Socioeconomic SMEs based on anticipated housing impacts. Additionally, the U.S. Department of Transportation (DOT 2003) states that the average American commuter travels approximately 15 miles one way (30 miles round trip), and only 11 percent travel more than 30 miles one way (60 miles round trip). Based on these results, we recommend that the Table YYYY-2 assumed value for commuting distance for all four workforce categories be decreased from 100 miles to 40 miles round trip.

As shown in Table 5, recent EISs and ERs suggest that a typical construction worker or employee at a nuclear facility will average 250 work-days per year. However, workers will be on-site every day of the year, and commuting will occur every day of the year. PNNL staff recommends retaining 365 as the appropriate value to use in converting from commuting days to commuting years for the construction, operations and SAFSTOR workforce categories. Decommissioning work is more likely to be conducted during a 5-day/40-hour workweek. Thus, use of a 250 work-days per year conversion factor during decommissioning is logical, and also should be retained.

The currently assumed values reported in Table YYYY-2 for the duration of each activity (7, 40, 10, and 40 years, respectively, for preconstruction/construction, operations, decommissioning, and SAFSTOR) are appropriate and we recommend they be retained. Current guidance assumes a 7-year preconstruction/construction period, and Table 5 indicates this value is reasonable based on schedules for recently proposed reactors. We recommend that current guidance emphasis on appropriately scaling this variable to account for application-specific building schedules be maintained. NRC licenses are issued for a period of 40 years for new facilities; thus a value of 40 years for the operational workforce is appropriate. Estimates for decommissioning and SAFSTOR work appear reasonable, although PNNL staff could not find specific references giving the assumed (or any other) values.

Update of Needed Factors. Determining the amount of GHG emitted by a given workforce depends on using factors related to the average fuel efficiency of vehicles used in commuting and on the average amount of GHG associated with a gallon of fuel.

Existing guidance Table YYYY-2 uses a value of 19.7 miles per gallon (mpg) for the average light duty vehicle fuel efficiency based on FHWA statistics for 2005 (FHWA 2006). Light duty vehicles are

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defined in the guidance, and by both the FHWA and the EPA, to include passenger cars, light trucks, vans, and all sport utility vehicles. As of May 23, 2012, EPA’s web-based Greenhouse Gas Equivalencies Calculator (EPA 2011a), available at http://www.epa.gov/cleanenergy/energy-resources/calculator.html, uses a fuel efficiency value of 20.4 mpg and cites FHWA statistics for 2007 (FHWA 2008). However, the web-based version of FHWA (2008) indicates it was updated in April 2011 using an enhanced FHWA methodology, and now gives a 2007 average of 21.3 mpg for all light duty vehicles. Additionally, FHWA statistics for 2010 (FHWA 2012), dated February 2012, appear to be the most recent available and list an average value of 21.6 mpg for all light duty vehicles. PNNL staff recommend the most current FHWA estimate of 21.6 mpg be used for all workforce categories in calculating GHG emissions associated with commuting. We note this is a conservative assumption for the operational, decommissioning, and SAFSTOR workforces given the recent rule jointly issued by the National Highway Traffic Safety Administration and EPA to raise Corporate Average Fuel Economy standards for model year 2016 light duty vehicles to 34.1 mpg (75 FR 25324), and the proposed rule to increase Corporate Average Fuel Economy standards for model year 2025 light duty vehicles to 49.6 mpg (76 FR 74854). These standards will lead to higher average fleet mpg values as older light duty vehicles are gradually replaced by newer, more fuel efficient vehicles. However, because the rate of this replacement is not known, PNNL staff recommends the conservative approach of using the most recent value from FHWA statistics. We further recommend that this figure periodically and routinely be reviewed, and revised as necessary.

Existing guidance Table YYYY-2 uses a value of 8.81 × 10-3 MT of CO2 emitted per gallon of gasoline combustion based on EPA (2007b). Review of the revision history (EPA 2012c) associated with EPA’s web-based Greenhouse Gas Equivalencies Calculator (EPA 2011a) indicates that this factor was last updated on February 28, 2011, to 8.92 × 10-3 MT of CO2 per gallon of gasoline based on EPA (2010) and IPCC (2006). We recommend updating this factor to the more recent value. PNNL staff note that this value does not address the potential use of diesel-powered or electric passenger vehicles in commuting. However, data in Table 1 show that GHG emissions from diesel-powered passenger vehicles have been far outweighed by emissions from gasoline-powered passenger vehicles, contributing only 0.5% to 0.6% of the total (diesel-powered plus gasoline-powered) vehicle GHG emissions in 2005, 2007, and 2010. As long as gasoline-powered vehicles continue to dominate the commuting workforce, the impact of ignoring diesel-powered and electric passenger vehicles in selecting a value for this factor is expected to be minimal.

Current guidance Table YYYY-2 uses a value of 0.971 for the CO2 equivalency factor. This factor takes into account GHGs such as CH4 and N2O that are emitted with CO2 during the combustion of fossil fuels. Note this factor is equal to the ratio of CO2 to total GHG emissions shown in Table 1 for 2005 for gasoline powered passenger cars. EPA’s web-based Greenhouse Gas Equivalencies Calculator (EPA 2011a) currently uses a value of 0.977, corresponding to a base year of 2007 and the statistics presented in EPA (2009) (see Table 1). However, EPA (2012a, 2012b), released in April, 2012, contains the 2010 emissions data needed for calculating this quantity. As shown in Table 1, the CO2 equivalent factor for gasoline powered passenger cars has a value of 0.985 based on the 2010 data. PNNL staff recommends updating the CO2 equivalent factor in the revised Table YYYY-2 to this most recent value of 0.985.

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Calculated Values. The remaining quantities in existing guidance Table YYYY-2 (miles traveled, gallons of fuel burned, metric tons CO2, and metric tons CO2 equivalent) are calculated based on the previously discussed values and factors. The equations used in the current guidance are correct:

Total Distance Traveled During Period (miles) = Commuting trips (round trips/day) × Commuting Distance (miles/round trip) × Commuting Days (days/year) × Duration (years) (1)

Total Fuel Burned During Period (gallons) = Total Distance Traveled During Period (miles)/ Average Fuel Efficiency (miles/gallon) (2)

Total CO2 Emitted During Period (MT CO2) = Total Fuel Burned During Period (gallons) × Amount of CO2 emitted per gallon fuel burned (MT CO2/gallon) (3)

Total GHG Emitted During Period (MT CO2 (eq)) = Total CO2 Emitted During Period (MT CO2)/ CO2 Equivalency Factor (MT CO2/ MT CO2(eq)) (4)

No changes are needed to these equations.

3.2.3 Recommendations

PNNL staff recommends that selected parameters in existing Table YYYY-2 should be changed to more realistic values and certain factors should be updated to the most current values. We further recommend minor changes in row descriptors and footnotes to clarify the meaning of each quantity, and to make the descriptors more consistent with Equations (1)–(4). Table 6 summarizes our recommended changes and presents the results of calculations based on these new recommended values. Overall, the recommended changes reduce GHG emissions from workforce commuting by over 70, 50, and 24 percent during preconstruction/construction, decommissioning, and SAFSTOR activities, respectively, relative to the amounts in the existing guidance. Estimated GHG emissions from workforce commuting during operations remains approximately the same due to the decrease in assumed commuting distance offsetting the assumed increase in daily round trips.

3.3 Operations and Uranium Fuel Cycle Emissions and Lifetime GHG Footprint

Table 7 reproduces existing guidance Table YYYY-3 for a reference 1000 MW(e) reactor. Under the current organization of EISs for new reactor application reviews, EIS Sections 5.7.1 (Air Quality Impacts), 6.1.3 (Fossil Fuel Impacts), 6.3 (Decommissioning Impacts), 7.6.2 (Greenhouse Gas Emissions), and 9.2.5 (Summary Comparison of Alternatives) reference values in this table.


As shown in Table 7, Table YYYY-3 compiles the CO2 emissions associated with preconstruction/ construction equipment, decommissioning equipment, and workforce commuting as presented in existing Tables YYYY-1 and YYYY-2, adds an estimated 1.9 × 105 MT CO2 for plant operations and 1.7 × 107 MT CO2 for uranium fuel cycle emissions, and sums the values to yield an overall lifetime nuclear power plant footprint of 1.8 × 107 MT CO2. The plant operations estimate is based on assuming

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an average of 600 hours/year use of emergency diesel generators and 200 hours/year use of station blackout diesel generators, calculating CO emissions using emission factors from EPA (1995), and applying a scale factor to estimate corresponding CO2 emissions. The usage figures are based on UniStar’s (2007) CPCN application. The 1.7 × 107 MT CO2 figure is derived by assuming that uranium fuel cycle CO2 emissions are 5 percent of those from a comparably sized coal-fired plant. The 5 percent figure is based on the work of Sovacool (2008) via consideration of his compiled GHG emission estimates for the frontend of the nuclear life cycle and his listed GHG emission estimates for coal-fired plants, and represents an upper end estimate. Sovacool (2008) defines the frontend of the nuclear life cycle as consisting of uranium mining, milling, conversion, and enrichment. Miller and Van Atten (2004) estimated that a coal-fired plant emits about 1 MT CO2 for each megawatt hour (1 MT CO2/MWh) generated; thus, a value of 0.05 MT CO2/MWh was assumed for the uranium fuel cycle. A 1000 MW(e) nuclear reactor operating for 40 years with an 80 percent capacity factor will generate 2.8032 × 108 MWh, yielding approximately 1.4 × 107 MT CO2 over its lifetime for fuel-cycle-related emissions. PNNL staff were not able to determine why this value was adjusted upwards to 1.7 × 107 MT CO2 in the current guidance.

Table 6. Recommended Guidance Table YYYY-2 on Workforce GHG Emissions. Changes from existing guidance (Table 4) are highlighted in yellow.

Table YYYY-2. Workforce GHG Footprint Estimates

Construction Workforce

Operational Workforce

Decommissioning Workforce

SAFSTOR Workforce

Commuting Trips (round trips per day)

1000 550 200 40

Commute Distance (miles per round trip)

40 40 40 40

Commuting Days (days per year) 365 365 250 365 Duration (years) 7 40 10 40 Total Distance Traveled (miles) 1.0 × 108 3.2 × 108 2.0 × 107 2.3 × 107 Average Vehicle Fuel Efficiency(a) (miles per gallon)

21.6 21.6 21.6 21.6

Total Fuel Burned (gallons) 4.7 × 106 1.5 × 107 9.3 × 105 1.1 × 106 CO2 emitted per gallon(b) (MT CO2) 8.92 × 10-3 8.92 × 10-3 8.92 × 10-3 8.92 × 10-3 Total CO2 Emitted (MT CO2) 4.2 × 104 1.3 × 105 8.3× 103 9.6 × 103 CO2 equivalent factor(c) (MT CO2/MT CO2(eq))

0.985 0.985 0.985 0.985

GHG Emitted (MT CO2 (eq)) 4.3 × 104 1.3 × 105 8.4 × 103 9.8 × 103

(a) FHWA (2012). (b) EPA (2010, 2012c). (c) EPA (2012a).

An inherent assumption in calculations related to both the operational and uranium fuel cycle emissions is that the contribution of GHG other than CO2 is negligible. Existing guidance Table YYYY-3 does not explicitly indicate whether its totals are in MT CO2 or MT CO2(eq), but if this inherent assumption is extended to emissions from preconstruction/construction and decommissioning, as taken from existing guidance Table YYYY-1, then the GWP value of 1 MT CO2(eq)/1 MT CO2 applies

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and all units in existing guidance Table YYYY-3 would be in MT CO2(eq). The current guidance lifetime total emission estimate of 1.8 × 107 MT CO2(eq) corresponds to a value of approximately 64 g CO2(eq)/kWh based on the total energy output of the reference reactor.

Table 7. Existing Guidance Table YYYY-3 on Nuclear Power Plant Lifetime GHG Emissions

Table YYYY-3. Nuclear Power Plant Lifetime Carbon Dioxide Footprint

Source Activity

Duration (yr) Total Emissions

(metric tons)

Construction Equipment 7 3.5 × 104 Construction Workforce 7 1.5 × 105 Plant Operations 40 1.9 × 105 Operations Workforce 40 1.3 × 105 Uranium Fuel Cycle 40 1.7 × 107 Decommissioning Equipment 10 1.8 × 104 Decommissioning Workforce 10 1.7 × 104 SAFSTOR Workforce 40 1.3 × 104 TOTAL 1.8 × 107

3.3.2 Review of Operations Calculations and Recommended Changes

As discussed in Section 3.3.1, existing guidance estimates plant operation emissions at 1.9 × 105 MT CO2 based on the equipment usage of UniStar (2007). This value was calculated using UniStar’s (2007) estimate of total CO emissions and applying a factor of 165 to scale from CO to CO2 emissions (see Section 3.1.2 for a discussion of the basis for this scaling factor). Upon review of the calculation, PNNL staff noted that UniStar’s (2007) estimates of plant operation emissions are actually in units of English short tons, not metric tons (MT) as indicated in the original guidance Table YYYY-3 (see Table 7). Therefore, operation emissions in Table 7 should be reduced by a factor of 0.9072 to properly convert the units to MT. Furthermore, since the generators are diesel, we recommend the use of the higher (172) scaling factor that is more appropriate for diesel engines (see Section 3.1.3 for further discussion on use of this factor). Finally, to account for other GHGs resulting from diesel combustion, we recommend the use of the EPA’s equivalency factor of 0.991 for non-road/construction-mining equipment (see Table 1). Accounting for all of these adjustments results in a slight decrease in plant operation emissions—from 1.9 × 105 MT CO2 to 1.8 × 105 MT CO2(eq). With these small corrections and adjustments, we think the emission estimates derived from UniStar’s (2007) analysis are suitably representative of plant operations. However, as with preconstruction/construction estimates, PNNL staff recommend reviewing recent detailed emission estimates provided to the NRC for the purposes of conformity determinations as another way to confirm the value assumed for plant operations.

3.3.3 Review of Uranium Fuel Cycle and Overall Life-Cycle Emissions Estimates

GHG emissions from the uranium fuel cycle clearly dominate calculations of the lifetime footprint in existing guidance, representing over 94 percent of the total. PNNL staff thus concentrated efforts on

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assessing GHG estimates for the uranium fuel cycle and the overall life cycle of nuclear power plants, considering both top-down and bottom-up approaches.

Review of Recent Source Material on Nuclear Plant Life-Cycle GHG Emissions. The IPCC recently issued a special report on renewable energy sources and climate change mitigation (IPCC 2012). This report included an assessment of previously published works on life-cycle GHG emissions from various electricity generation technologies, including nuclear energy. PNNL staff used this report to assess whether the current Table YYYY-3 lifetime total emission of 1.8 × 107 MT CO2, or 64 g CO2(eq)/kWh, was realistic.

IPCC (2012) included in its assessment only material that passed certain screening criteria for quality and relevance. These criteria included:

• Contained in a National Renewable Energy Laboratory comprehensive review of published life-cycle assessments

• Represented a peer-reviewed journal article, scientific conference proceeding, PhD thesis, or report published after 1980 and available in English

• Analyzed a minimum of two life-cycle phases

• Used a “currently accepted attributional LCA [life-cycle assessment] and GHG accounting method”

• Included enough detail on inputs and assumptions to “trace and trust the results”

• Reported numerical results in units “easily convertible” to g CO2(eq)/kWh with “no exogenous assumptions”

• Did not include in total life-cycle estimates the GHG contributions related to land use changes or heat production (related to cogeneration), or else such contributions were reported separately so that they could easily be subtracted from the total.

The IPCC (2012) report also clearly stated “…no attempt was made to identify or screen for outliers, or pass judgment on the validity of input parameter assumptions.”

The IPCC screening yielded 125 estimates of nuclear energy life-cycle GHG emissions from 32 separate references. Percentile values for these 125 estimates were presented in both tabular and graphical form in IPCC (2012) and are reproduced in Table 8.

The IPCC-screened estimates of the life-cycle GHG emissions associated with nuclear energy cover three orders of magnitude, from 1 to 220 g CO2(eq)/kWh. In a normal (Gaussian) distribution the mean, median, and mode coincide, and the distribution is symmetric about this point, i.e., the 25th and 75th percentile values are the same distance from the mean/median/mode. The IPCC percentile values in Table 8 indicate that the distribution is not normal but rather is positively skewed; the distribution has a right side tail that causes the 75th percentile value to be numerically further from the median than the 25th percentile value.

To better understand the reasons for the wide range and skewed distribution of values, PNNL staff attempted to obtain the 32 references that passed the IPCC screening criteria. Table 9 indicates the 31 of the 32 published works that were obtained electronically or via the interlibrary loan network of the PNNL

18

Technical Library. The remaining reference, entitled “Coal in Sustainable Society” (Wibberley 2001), was not readily available and was not examined.

Table 8. IPCC Results of a Literature Review of the Life-Cycle Analyses of Greenhouse Gas Emissions from Nuclear Energy (from Table A.II.4 of IPCC (2012))

Values Nuclear Energy Life-Cycle GHG Emissions

(g CO2(eq)/kWh)

Minimum 1 25th percentile 8 50th percentile 16 75th percentile 45 Maximum 220

Of the 31 references obtained, five dealt with specific reactors, including the British Torness (AEA Technology 2005, 2006), the Swiss Beznau (AXPO Nuclear Energy 2008), the Swedish Ringhals (Vattenfall 2007a), and the Swedish Forsmark (Vattenfall 2007b) nuclear power plants. Sixteen references focused on an explicitly identified country and/or region, with only four of these 16 addressing areas outside Europe or Japan. Authors of the remaining 10 references did not specifically identify a region of interest to which their analysis applied.

The references also varied as to whether they considered specific, selected life-cycle phases or attempted to analyze a more complete life cycle; the IPCC screening criteria required only that at least two phases be considered. There did not appear to be a consensus among the authors on what constitutes the complete life cycle of a nuclear power plant, although the following general phases were mentioned (sometimes with different terminology or organization) in multiple references: mining, refinement, enrichment, fuel fabrication, plant construction, plant operation, decommissioning, and radioactive waste management (cf., AEA Technology 2005; Dones et al. 2007a; Lenzen et al. 2006). A few references, notably Lenzen et al. (2006) and Vattenfall (2007a, 2007b), also included electricity transmission and distribution in their life-cycle analyses. Three of the 31 obtained references focused on CANDU reactors (Badea et al. 2010; Andseta et al. 1998; SECDA 1994). CANDU reactors use heavy water and natural uranium fuel, and GHG emissions attributed to the enrichment phase in these studies are related to heavy water production.

PNNL staff did not perform an exhaustive review of the 31 obtained references in order to accept or reject specific GHG life-cycle estimates, but rather examined them to discern similarities and differences in assumptions and methodology. This examination identified the following parameters and assumptions as having a substantial influence on the predicted life-cycle GHG emissions associated with a nuclear power plant:

• Type of enrichment technology employed

• How electricity used for enrichment is generated

• Grade of mined uranium ore and degree of processing and enrichment required

• Assumed operating lifetime of a nuclear power plant.

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Table 9. References Related to the GHG Life-Cycle Emissions from a Nuclear Power Plant Cited in IPCC (2012)

Author Title Source

AEA Technology (2005)

Environmental Product Declaration of Electricity from Torness Nuclear Power Station

http://www.british-energy.com/documents/EPD_Doc_-_Final.pdf

AEA Technology (2006)

Carbon Footprint of the Nuclear Fuel Cycle http://www.british-energy.com/documents/carbon_footprint.pdf

Andseta et al. (1998)

CANDU Reactors and Greenhouse Gas Emissions http://www.computare.org/Support%20documents/Publications/Life%20Cycle.htm

AXPO Nuclear Energy (2008)

Beznau Nuclear Power Plant http://www.axpo.ch/axpo/en/kernenergie/wissen/kernkraftwerk_beznau.html

Badea et al. (2010)

Comparative Analysis of Coal, Natural Gas and Nuclear Fuel Life Cycles by Chains of Electrical Energy Production

http://www.scientificbulletin.upb.ro/rev_docs/arhiva/full8515.pdf

Beerten et al. (2009)

Greenhouse Gas Emission in the Nuclear Fuel Cycle: A Balanced Appraisal

http://www.sciencedirect.com/science/article/pii/S0301421509005102

Dones et al. (1996)

Greenhouse Gas Emission Inventory Based on Full Energy Chain Analysis

http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/28/013/28013414.pdf

Dones et al. (2004)

Life Cycle Assessment (LCA) of Chinese Energy Chains for Shandong Electricity Scenarios

Obtained via PNNL Technical Library Interlibrary Loan

Dones et al. (2005)

Externalities of Energy: Extension of Accounting Framework and Policy Applications

http://www.externe.info/expolwp6.pdf

Dones et al. (2007a)

Life Cycle Inventories of Energy System: Results for Current Systems in Switzerland and other UCTE Countries

http://www.ecolo.org/documents/documents_in_english/Life-cycle-analysis-PSI-05.pdf

Dones et al. (2007b)

LCA of Current Coal, Gas and Nuclear Electricity Systems and Electricity Mix in the USA

http://gabe.web.psi.ch/pdfs/lca/Dones_etal-LCA_of_current_coal_gas_and_nuclear_electricity_systems_and_electricity_mix_in_the_USA.pdf

Frischknecht (1998)

Life Cycle Inventory Analysis for Decision-Making: Scope-Dependent Inventory System Models and Context-Specific Joint Product Allocation

http://www.esu-services.ch/fileadmin/download/frischknecht-1998-PHD.pdf

Fthenakis and Kim (2007)

Greenhouse-Gas Emissions from Solar Electric- and Nuclear Power: A Life-Cycle Study


Hondo (2005) Life Cycle GHG Emission Analysis of Power Generation Systems: Japanese Case


Kivisto (1995) Energy Payback Period and Carbon Dioxide Emissions in Different Power Generation Methods in Finland


Krewitt et al. (1997)

ExternE National Implementation in Germany http://www.offshore-wind.de/page/fileadmin/offshore/documents/Wirtschaftlichkeit/ExternE_Report_Germany.pdf

Lecointe et al. (2004)

Final Report on Technical Data, Costs and Life Cycle Inventories of Nuclear Power Plants

http://www.needs-project.org/RS1a/RS1a%20D14.2%20Final%20report%20on%20nuclear.pdf

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Table 9. (contd)

Author Title Source

Lenzen et al. (2006)

Life-Cycle Energy Balance and Greenhouse Gas Emissions of Nuclear Energy in Australia

http://www.isa.org.usyd.edu.au/publications/documents/ISA_Nuclear_Report.pdf

Meridian Corporation (1989)

Energy System Emissions and Materiel Requirements https://www.etde.org/etdeweb/servlets/purl/860706-4YG3j9/860706.pdf

Rashad and Hammad (2000)

Nuclear Power and the Environment: Comparative Assessment of Environmental and Health Impacts of Electricity-Generating Systems

http://www.ewp.rpi.edu/hartford/~odells2/EP/Other/references/Nuclear%20power%20and%20the%20environment,%20comparative%20assessment%20of%20environmental%20and%20health%20impacts%20of%20electricity-generating%20systems.pdf

San Martin (1989) Environmental Emissions from Energy Technology Systems http://www.fischer-tropsch.org/DOE/DOE_reports/OSTI/OSTI_860643/OSTI%20860643.pdf

SECDA (1994) Levelized Cost and Full Fuel Cycle Environmental Impacts of Saskatchewan's Electric Supply Options


Tokimatsu et al. (2006)

Evaluation of Lifecycle CO2 Emissions from the Japanese Electric Power Sector in the 21st Century Under Various Nuclear Scenarios


Uchiyama (1996a)

Validity of FENCH-GHG study http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/28/013/28013414.pdf

Uchiyama (1996b)

Life cycle analysis of electricity generation and supply systems Obtained via PNNL Technical Library

Vattenfall (2007a) Summary of Vattenfall AB Generation Nordic Certified Environmental Product Declaration

http://www.google.com/url?sa=t&rct=j&q=summary%20of%20vattenfall%20ab%20generation%202007&source=web&cd=8&sqi=2&ved=0CEoQFjAH&url=http%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fdownload%3Bjsessionid%3D9C7B6356877A4BE879427544504EDB96%3Fdoi%3D10.1.1.176.2226%26rep%3Drep1%26type%3Dpdf&ei=BF2QT8LhBsfPiAKo_7GUAw&usg=AFQjCNFPh7dCsu4cZg8lRhCd6M5h9bXLiw

Vattenfall (2007b) Vattenfall AB Generation Nordic Certified Environmental Product Declaration, EPD, of Electricity from Forsmark Nuclear Power Plant

http://gryphon.environdec.com/data/files/6/7310/epd21.pdf

Voorspools et al. (2000)

Energy Content and Indirect Greenhouse Gas Emissions Embedded in ‘Emission-Free’ Power Plants: Results for the Low Countries


White and Kulcinski (2000)

Birth to Death Analysis of the Energy Payback Ratio and CO2 Gas Emission Rates from Coal, Fission, Wind, and DT-Fusion Power Plants


Wibberley (2001) Coal in a Sustainable Society Not obtained

Yasukawa et al. (1992)

Life cycle CO2 emission from nuclear power reactor and fuel cycle system


Yasukawa et al. (1996)

Integration of indirect CO2 emissions from the full energy chain http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/28/013/28013414.pdf

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The majority of studies identified the enrichment process as the greatest consumer of energy, and the greatest producer of GHG, associated with the overall life cycle of a nuclear power plant. The energy requirements of the enrichment process depend on whether gaseous diffusion or centrifugation, or a mix of the two, is used. Gaseous diffusion technology is more energy intensive than centrifugation, with several studies (Fthenakis and Kim 2007; AEA Technology 2005) stating that gaseous diffusion requires approximately 40 times more electricity than using gas centrifuges. The source of this electricity also affects the GHG emissions associated with the enrichment phase; electricity produced by coal-fired plants, for example, will contribute substantially more GHG emissions than electricity produced by hydroelectric dams. The work of Tokimatsu et al. (2006) illustrates the impact of enrichment technology and background electricity source assumptions on GHG emission estimates. They calculated that CO2 emissions associated with nuclear plants in Japan diminished from about 200 g CO2/kWh in 1970, when Japan began to utilize nuclear power, to approximately 10 g CO2/kWh in 2000. The authors note the decrease corresponds to the introduction of domestic centrifuge enrichment plants and the increased contribution of nuclear power plants, relative to older fossil-fuel plants, in Japan’s overall energy portfolio. PNNL staff’s examination of the 31 obtained references indicates that the assumed enrichment technology and the assumed background mix of electricity sources has the largest impact on the magnitude of GHG emissions calculated for a nuclear power plant.

Studies assuming enrichment mainly via centrifugation and supply by low GHG-emitting electricity sources, or including such a scenario in sensitivity studies, consistently yielded GHG emission estimates less than the IPCC median value of 16 g CO2(eq)/kWh. Such studies were more likely to comment on the sensitivity of their results to the assumed uranium ore grade. For example, AEA Technology (2006) notes that, over the lifetime of the British Torness nuclear power plant, the GHG emissions associated solely with mining and milling a low grade 0.028 percent uranium ore would be approximately double that associated with a higher grade 0.21 percent uranium ore. Most studies did not specify a burn rate or frequency of fuel re-loading, but the sensitivity tests of Lenzen et al. (2006) indicate that values assumed for these parameters also affect total life-cycle GHG emissions by impacting the amount of uranium used (and thus GHG emissions associated with mining, refinement, and enrichment) over the functioning lifetime of a nuclear power plant.

Not all references clearly stated the assumed lifetime of the nuclear plant under consideration. Of those that did, values ranged from 30 to 50 years. The assumed lifetime—and capacity factor, which even fewer references explicitly stated—directly affects the total amount of electricity generated by a plant. This total is used as the denominator in calculations to determine GHG emissions per kilowatt hour.

Only Dones et al. (2007b) conducted an analysis that explicitly identified the United States as the country of interest, calculating an overall nuclear plant life-cycle GHG emission value of 13 g CO2(eq)/kWh for their reference year of 2004. They used U.S.-specific averages for parameters such as the percentage of diffusion and centrifugation technologies used for enrichment, enrichment level, fuel burn-up, and power plant thermal efficiency. These averages were derived from information reported by the NRC, the DOE/Energy Information Administration, and other sources. Electricity used for enrichment was based on the mix of sources in the country of origin. For example, they assumed that 11.8 percent of the total uranium fuel was supplied by the Kentucky-based USEC diffusion enrichment plant, with the electricity used to power this enrichment assumed to correspond to the 2006 Tennessee Valley Authority energy mix of 68.5 percent hard coal, 26.1 percent nuclear, and 5.4 percent hydroelectric. Dones et al. (2007b) did not model a U.S. site as the final radioactive waste repository but instead based contributions of this life-cycle phase on Swiss repositories. However, they note this phase

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is a relatively minor contributor to total life-cycle GHG, stating “…even a factor of two to ten difference in the energy and material specific uses (per kWh generated or kg heavy metal of spent fuel stored) would not significantly change the cumulative results” (Dones et al. 2007b).

Although Meridian Corporation (1989) and San Martin (1989) did not explicitly identify the United States as the country of interest, these reports can be assumed to focus on the United States. Meridian Corporation (1989) indicates on its title page that the report was prepared for the Deputy Assistant Secretary for Renewable Energy, DOE. The title page of San Martin (1989) states the author is the Deputy Assistant Secretary for Renewable Energy, DOE, and the report appears to draw heavily on Meridian Corporation (1989). Both reports consider the same five power production technologies, including a 1000-MW boiling water nuclear reactor producing 6130 GWh annually over a useful life of 30 years. Both reports also include the same life-cycle phases of nuclear plant (mining, refinement, enrichment, fuel fabrication, plant construction, and plant operation), and both use a method where “a coefficient for CO2 emissions as a function of the electric generating fuel mix in the U.S. was calculated and then applied to the electricity demand of the nuclear plant” (Meridian Corporation 1989; San Martin 1989). No GHGs other than CO2 were considered in either study. Meridian Corporation (1989) reported life-cycle emissions of 8.59 tons CO2/GWh for the reference reactor, equivalent to 8.59 g CO2(eq)/kWh assuming negligible contributions from other GHGs, while San Martin reported emissions of 7.8 CO2/GWh, equivalent to 7.8 g CO2(eq)/kWh using the same assumption. We were unable to determine why the reported values differed between the two reports.

Top-Down Approach: Potential Changes to Table YYYY-3 Based on Nuclear Plant Life-Cycle GHG Emission Estimates. Information presented in IPCC (2012) represents the best current estimates of GHG emissions associated with a nuclear power plant. Although there is no consensus on exactly what phases and activities constitute the overall life cycle, there is general agreement that, for a light water reactor, the enrichment process and the source of electricity to drive this enrichment process are the largest contributors to GHG emissions. The wide range of values given in IPCC (2012) and reproduced in Table 8 appears to reflect different assumptions affecting the GHG emissions associated with the enrichment process. The geographical emphasis of the included references on Europe and Japan, where enrichment by centrifugal diffusion is common and the background energy mix is not dominated by coal-fired power plants, likely contributes to the skewed distribution reflected in Table 8.

Because of this geographic emphasis, we are reluctant to recommend use of the median value of 16 g CO2(eq)/kWh for the overall GHG footprint of a nuclear power plant. It can be argued that the American-oriented studies by Dones et al. (2007b), Meridian Corporation (1989), and San Martin (1989) are all below this median value. However, the latter two references are the oldest included in IPCC (2012) and clearly are not as complete as other studies in considering various life-cycle phases. The unexplained difference in reported emission values between the two studies is also troubling. We do not think use of the sole remaining reference to justify selection of the IPCC median value and to negate potential criticisms relative to geographic bias is technically justified.

Given that the median value may reflect geographic bias and that the maximum value likely reflects unrealistic worst case assumptions in sensitivity studies, we recommend use of the 75th percentile value of 45 g CO2(eq)/kWh as a conservative (i.e., potentially high rather than potentially low) estimate of GHG emissions associated with the total life cycle of a nuclear power plant. We note that this value is about 30 percent lower than the 64 g CO2(eq)/kWh that can be calculated from existing guidance, and substantially lower than the median values of 469, 840, and 1001 g CO2(eq)/kWh reported by in IPCC

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(2012) for natural gas-, oil-, and coal-fired plants, respectively. It is also an order of magnitude lower than the proposed EPA rule limiting new fossil-fuel electric generating units to 454 kg CO2/MWh (77 FR 22392), equivalent to 454 g CO2/kWh. Using 45 g CO2(eq)/kWh as the life-cycle total means that the 1000 MW(e) reference nuclear reactor operating for 40 years with an 80 percent capacity factor and generating 2.8032 × 108 MWh will emit a total of 1.26 × 107 MT CO2(eq) of GHGs.

IPCC (2012) does not break out GHG emissions associated with specific nuclear plant life-cycle phases. However, in a top-down approach to estimate uranium fuel cycle GHG emissions, contributions from various activities covered in revised Tables YYYY-1 and YYYY-2 can be subtracted from the overall total, along with GHG emissions from plant operations. References included in IPCC (2012) clearly indicate the enrichment process, which is part of the uranium fuel cycle as currently defined in EISs for new reactor application reviews, is the life-cycle phase that will dominate this remainder.

Using the lifetime total of 1.26 × 107 MT CO2(eq) and subtracting contributions from plant operations and from other activities listed in Tables 3 and 6 yields an estimate of 1.2 × 107 MT CO2(eq) for the uranium fuel cycle. This top-down approach leads to an estimate that is approximately 29 percent less than the existing guidance value of 1.7 ×107 MT CO2(eq).

Table 10 summarizes changes to Table YYYY-3 that would occur if the top-down approach to estimating uranium fuel cycle emissions is adopted.

Table 10. Recommended Values for Guidance Table YYYY-3 on Nuclear Power Plant Lifetime GHG Emissions Based on a Top-Down Approach for Estimating Uranium Fuel Cycle Emissions. Changes from existing guidance table (Table 7) are highlighted in yellow.

Table YYYY-3. Nuclear Power Plant Lifetime GHG Footprint

Source Activity Duration (yr) Total Emissions (MT CO2(eq))

Construction Equipment 7 3.9 × 104

Construction Workforce 7 4.3 × 104

Plant Operations 40 1.8 × 105

Operations Workforce 40 1.3 × 105

Uranium Fuel Cycle 40 1.2 × 107

Decommissioning Equipment 10 1.9 × 104

Decommissioning Workforce 10 8.4 × 103

SAFSTOR Workforce 40 9.8 × 103

TOTAL(a) 1.3 × 107 (a) Total not equal to the sum due to rounding.

Bottom-up Approach: Potential Changes to Table YYYY-3 Based on Uranium Fuel Cycle GHG Estimates Derived from Table S-3. Harvey (2012) outlines calculations to estimate GHG emissions using the values of annual fossil fuel usage to support the uranium fuel cycle presented in Table S-3 of 10 CFR 51.51. The annual fossil fuel usage listed in Table S-3 consists of 118,000 MT of coal and 135,000,000 standard cubic feet of natural gas. Using EPA emission factors, the calculations in Harvey (2012) yield an estimate of 1.0 × 107 MT CO2(eq) for the uranium fuel cycle when rounded to one

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decimal place. Adding the emissions associated with activities covered in Tables YYYY-1 and YYYY-2 yield a lifetime estimate of 1.0 × 107 MT CO2(eq), or approximately 37 CO2(eq)/kWh, for a 1000 MW(e) reference nuclear reactor operating for 40 years with an 80 percent capacity factor. This value is over 40 percent lower than the 1.8 × 107 MT CO2 value in the existing guidance. PNNL staff agree with the general methodology used in Harvey (2012), but did not conduct an exhaustive review of all factors and equations used in the calculations. We recommend that the assumptions used to derive the annual fossil fuel usage estimates presented in Table S-3 be reviewed to understand any uncertainties associated with these values, and thus better understand uncertainties associated with the GHG emission estimates based on this bottom-up approach.

Table 11 summarizes changes to Table YYYY-3 that would occur if the bottom-up approach to estimating uranium fuel cycle emissions via Harvey (2012) is adopted. PNNL staff note that existing Tables YYYY-1 and YYYY-2 and recommended revisions to them, along with existing Table YYYY-3, are all based on bottom-up approaches. Adopting a bottom-up approach when revising Table YYYY-3 would continue this consistency. In either case, we recommend maintaining the current guidance emphasis on tailoring estimates in the generic analysis to the specific application under consideration.

Table 11. Recommended Values for Guidance Table YYYY-3 on Nuclear Power Plant Lifetime GHG Emissions Based on a Bottom-Up Approach for Estimating Uranium Fuel Cycle Emissions. Changes from existing guidance table (Table 7) are highlighted in yellow.

Table YYYY-3. Nuclear Power Plant Lifetime GHG Footprint

Source Activity Duration (yr) Total Emissions (MT CO2(eq))

Construction Equipment 7 3.9 × 104

Construction Workforce 7 4.3 × 104

Plant Operations 40 1.8 × 105

Operations Workforce 40 1.3 × 105

Uranium Fuel Cycle(a) 40 1.0 × 107

Decommissioning Equipment 10 1.9 × 104

Decommissioning Workforce 10 8.4 × 103

SAFSTOR Workforce 40 9.8 × 103

TOTAL(b) 1.0 × 107 (a) Based on Harvey (2012). (b) Total not equal to the sum due to rounding.

4.0 Summary

PNNL staff reviewed assumptions, factors, and calculations in existing NRC GHG and climate change guidance (NRC 2011a). Emphasis was placed on reviewing values in the three tables of current guidance Appendix YYYY as both the text of this Appendix and discussions in other EIS sections rely on values from these tables.

Existing guidance estimates of GHG emissions from preconstruction/construction and decommissioning equipment (Table YYYY-1) are based on material provided to the State of Maryland

25

for building proposed Calvert Cliffs Nuclear Power Plant Unit 3 (UniStar 2007). In keeping with an NRC request to not update the base material for this table at this time, PNNL staff reviewed previously prepared spreadsheets and calculations on which these equipment emissions estimates were based. A transcription error was noted relative to data in Section 5.5 of UniStar (2007), and calculations included the inherent assumption that contributions from GHG gases other than CO2 were negligible. Values given in existing guidance Table YYYY-1 use a scaling factor based on EPA (2005) CO and CO2 emission factors for both gasoline and diesel industrial engines. PNNL staff recommend correcting the transcription error, using a scaling factor based on EPA (2012) CO and CO2 emission factors for diesel industrial engines, and applying an equivalency factor to put emissions in units of total GHG emissions. Cumulatively these recommendations increase the estimated preconstruction/construction GHG emissions by approximately 11 percent and estimated decommissioning GHG emissions by approximately 5 percent relative to existing guidance values. Recommended revisions to Table YYYY-1 are presented in Table 3 of this report. PNNL staff recommend the NRC consider reviewing recent detailed emissions estimates submitted for the purpose of air conformity determinations as another way to confirm the values provided in revised Table YYYY-1. Such a review is unlikely to significantly alter the small contribution of preconstruction/construction and decommissioning equipment to the total lifetime GHG footprint of a nuclear power plant, but will make discussions in EIS sections referring to Table YYYY-1 more robust.

Methodology, assumptions, and factors related to estimating GHG emissions from workforce commuting (Table YYYY-2) were reviewed. The methodology used for these calculations conforms to that used by the EPA on their web-based Greenhouse Gas Equivalencies Calculator (EPA 2011a). PNNL Socioeconomic SMEs compared currently assumed values for parameters such as the number of workforce commuting round trips per day, commuting distance, commuting days per year, and duration of various activities with values used in recent EISs and applicant-submitted ERs. Based on this review, numerous changes in assumed values were recommended, including a decrease in commuting distance from 100 to 40 miles round trip. Factors required for the calculations were updated using data from the most recent EPA and FHWA publications. Recommended revisions to Table YYYY-2 are presented in Table 6 of this report. The cumulative effect of the recommended changes is to reduce GHG emissions from workforce commuting by over 70, 50, and 24 percent during preconstruction/construction, decommissioning, and SAFSTOR activities, respectively, relative to the amounts in existing guidance. Estimated GHG emissions from operations workforce commuting remains approximately the same due to offsetting effects of various assumptions.

A recent IPCC report (IPCC 2012) included discussion of GHG emissions associated with the total life cycle of a nuclear power plant and provided a range of values that spans more than two orders of magnitude. The IPCC (2012) report and 31 of its 32 cited nuclear-related references were examined to evaluate the reasonableness of the total lifetime footprint of 1.8 × 107 MT CO2 for a 1000 MW(e) reference reactor, equivalent to 64 g CO2(eq)/kWh, given in existing guidance (Table YYYY-3). PNNL staff did not perform an exhaustive review of the 31 obtained references in order to accept or reject specific GHG life-cycle estimates, but rather examined them to discern similarities and differences in assumptions and methodology. This examination revealed four factors as having a substantial influence on the predicted life-cycle GHG emissions associated with a nuclear power plant, with the first two factors having the most profound impact:

• Type of enrichment technology employed

• How electricity used for enrichment is generated

26

• Grade of mined uranium ore and degree of processing and enrichment required

• Assumed operating lifetime of a nuclear power plant.

Estimates included in IPCC (2012) show a geographic emphasis on Europe and Japan, where enrichment by centrifugal diffusion is common and the overall energy mix to drive enrichment is not dominated by large GHG emitters such as coal-fired power plants. Based on this and other considerations, PNNL staff recommends using the IPCC (2012) 75th percentile value of 45 g CO2(eq)/kWh as a defensible estimate of the overall lifetime GHG footprint should a top-down approach to estimating uranium fuel cycle GHG emissions be adopted. This corresponds to a value of 1.3 × 107 MT CO2(eq) for a 1000 MW(e) reactor operating with a capacity factor of 80 percent for 40 years, a reduction of over 27 percent from the existing guidance estimate. Subtracting emissions related to equipment use and workforce commuting leads to a value of 1.2 × 107 MT CO2(eq) for the uranium fuel cycle of the reference reactor, a reduction of 29 percent from the existing guidance value of 1.7 × 107 MT CO2(eq). Calculations outlined in Harvey (2012) using the estimates of annual fossil fuel usage in Table S-3 of 10 CFR 51.51 yield an estimate of 1.0 × 107 MT CO2(eq) for the uranium fuel cycle when rounded to one decimal place. Adding the emissions associated with activities covered in Tables YYYY-1 and YYYY-2 in a bottom-up approach lead to estimated lifetime emissions of slightly over 1.0 × 107 MT CO2(eq), or approximately 37 CO2(eq)/kWh. This total lifetime value is over 40 percent lower than the existing guidance estimate.

5.0 References

10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions.”

74 FR 66496. December 15, 2009. “Endangerment and Cause or Contribute Findings for Greenhouse Gases Under Section 202(a) of the Clean Air Act.” Federal Register, U.S. Environmental Protection Agency, Washington, D.C.

75 FR 25324. May 7, 2010. “Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards; Final Rule.” Federal Register, U.S. Environmental Protection Agency, U.S. Department of Transportation, and National Highway Traffic Safety Administration, Washington, D.C.

76 FR 74854. December 1, 2011. “2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel Economy Standards; Proposed Rule.” Federal Register, U.S. Environmental Protection Agency, U.S. Department of Transportation, and National Highway Traffic Safety Administration, Washington, D.C.

77 FR 22392. April 13, 2012. “Standards of Performance for Greenhouse Gas Emissions for New Stationary Sources: Electric Utility Generating Units.” Federal Register, U.S. Environmental Protection Agency, Washington, D.C.

AEA Technology. 2005. Environmental Product Declaration of Electricity from Torness Nuclear Power Station. British Energy, London, United Kingdom.

27

AEA Technology. 2006. Carbon Footprint of the Nuclear Fuel Cycle. British Energy, London, United Kingdom.

Andseta S, MJ Thompson, JP Jarrell, and DR Pendergast. 1998. “Candu reactors and greenhouse gas emissions.” In Canadian Nuclear Society 19th Annual Conference, DB Buss and DA Jenkins (eds.), Canadian Nuclear Association, Toronto, Ontario, Canada.

AXPO Nuclear Energy. 2008. Beznau Nuclear Power Plant. Axpo AG, Baden, Germany.

Badea AA, I Voda, and CF Dinca. 2010. “Comparative analysis of coal, natural gas and nuclear fuel life cycles by chains of electrical energy production.” UPB Scientific Bulletin, Series C: Electrical Engineering 72(2):221–238.

Beerten J, E Laes, G Meskens, and W D’haeseleer. 2009. “Greenhouse gas emissions in the nuclear live cycle: A balanced appraisal.” Energy Policy 37(12):5056–5068.

Dones R, S Hirschbers, and I Knoepfel. 1996. “Greenhouse gas emissions inventory based on full energy chain analysis.” In IAEA Advisory Group Meeting on Analysis of Net Energy Balance and Full-energy-chain Greenhouse Gas Emissions for Nuclear and Other Energy Systems, pp. 95–114.

Dones R, X Zhou, and C Tian. 2004. “Life cycle assessment (LCA) of Chinese energy chains for Shandong electricity scenarios.” International Journal of Global Energy Issues 22(2/3/4):199–224.

Dones R, T Heck, C Bauer, S Hirschberg, P Bickel, P Preiss, L Panis, and I De Vlieger. 2005. Externalities of Energy: Extension of Accounting Framework and Policy Applications: New Energy Technologies. ENG1-CT-2002-00609, Paul Scherrer Institute, Villigen, Switzerland.

Dones R, C Bauer, R Bolliger, B Burger, T Heck, A Roder, MF Emenegger, R Frischknecht, N Jungbluth, and M Tuchschmid. 2007a. Life Cycle Inventories of Energy Systems: Results for Current Systems in Switzerland and Other UCTE Countries. Ecoinvent Report No. 5, Paul Scherrer Institute, Villigen, Switzerland.

Dones R, C Bauer, and T Heck. 2007b. LCA of Current Coal, Gas and Nuclear Electricity Systems and Electricity Mix in the USA. Paul Scherrer Institute, Villigen, Switzerland.

DOT (U.S. Department of Transportation). 2003. “From Home to Work, the Average Commute is 26.2 Minutes.” OmniStats 3(4):1–4.

EPA (U.S. Environmental Protection Agency). 1995. Compilation of Air Pollutant Emission Factors Volume 1: Stationary Point and Area Sources. AP-42, 5th Edition, Office of Air and Radiation Research, Research Triangle Park, North Carolina.

EPA (U.S. Environmental Protection Agency). 2004. “Exhaust and Crankcase Emission Factors for Nonroad Engine Modeling – Compression-Ignition.” EPA420-P-04-009, Washington, D.C.

EPA (U.S. Environmental Protection Agency). 2007a. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2005. Washington, D.C.

28

EPA (U.S. Environmental Protection Agency). 2007b. “Conversion Factors to Energy Units (Heat Equivalents) Heat Contents and Carbon Content Coefficients of Various Fuel Types.” Inventory of U.S. Greenhouse Gas Emissions and Sinks: Fast Facts 1990-2005. EPA-430-R-07-002, Washington, D.C.

EPA (U.S. Environmental Protection Agency). 2009. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2007. Washington, D.C.

EPA (U.S. Environmental Protection Agency). 2010. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2008. Annex 2 (Methodology for Estimating CO2 Emissions from Fossil Fuel Combustion). EPA #430-R-10-006, Washington, D.C.

EPA (U.S. Environmental Protection Agency). 2011a. “Clean Energy: Calculations and References.” Accessed May 23, 2012 at http://www.epa.gov/cleanenergy/energy-resources/refs.html.

EPA (U.S. Environmental Protection Agency). 2011b. “High Global Warming Potential (GWP) Gases—Science.” Accessed June 2, 2012 at http://www.epa.gov/highgwp/scientific.html.

EPA (U.S. Environmental Protection Agency). 2012a. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2010. EPA 430-R-12-001, Washington, D.C.

EPA (U.S. Environmental Protection Agency). 2012b. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2010 Annexes. EPA 430-R-12-001, Washington, D.C. Available at http://www.epa.gov/climatechange/Downloads/ghgemissions/US-GHG-Inventory-2012-Annexes.pdf.

EPA (U.S. Environmental Protection Agency). 2012c. “Green Power Partnership: Revision History.” Accessed May 18, 2012 at http://www.epa.gov/greenpower/pubs/calc-rev-history.htm.

EPA (U.S. Environmental Protection Agency). 2012d. “Technology Transfer Network Clearinghouse for Inventories & Emissions Factors: AP-42, Fifth Edition, Volume I, Chapter 3: Stationary Internal Combustion Sources.” Accessed June 12, 2012 at http://www.epa.gov/ttn/chief/ap42/ch03/index.html.

FHWA (Federal Highway Administration). 2006. Highway Statistics 2005 (Table VM-1). Office of Highway Policy Information, Washington, D.C.



Frischknecht R. 1998. Life Cycle Inventory Analysis for Decision-Making: Scope-Dependent Inventory System Models and Context-Specific Joint Product Allocation. Dissertation submitted to the Swiss Federal Institute of Technology Zurich, Switzerland.

Fthenakis VM and HC Kim. 2007. “Greenhouse-gas emissions from solar electric- and nuclear power: A life-cycle study.” Energy Policy 35(4):2549–2557.

29

Harvey B. 2012. “Greenhouse emissions for the fossil fuel sources identified in Table S-3.” Office of New Reactors, U.S. Nuclear Regulatory Commission, Washington, D.C. Accession No. ML12299A401.

Hondo H. 2005. “Life cycle GHG emission analysis of power generation systems: Japanese case.” Energy 30(11–12):2042–2056.

IPCC (Intergovernmental Panel on Climate Change). 1996. Climate Change 1995: The Science of Climate Change. Contribution of Working Group I to the Second Assessment Report of the Intergovernmental Panel on Climate Change, JT Houghton, LG Meira Filho, BA Callander, N Harris, A Kattenberg, and K Maskell (eds,), Cambridge University Press, Cambridge, United Kingdom.

IPCC (Intergovernmental Panel on Climate Change). 2001. Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, JT Houghton, Y Ding, DJ Griggs, M Noguer, PJ van der Linden, X Dai, K Maskell, and CA Johnson (eds.), Cambridge University Press, Cambridge, United Kingdom.

IPCC (Intergovernmental Panel on Climate Change). 2006. IPCC Guidelines for National Greenhouse Gas Inventories. Geneva, Switzerland.

IPCC (Intergovernmental Panel on Climate Change). 2007. Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II, and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, RK Pachauri and A Reisinger (eds.), Geneva, Switzerland.

IPCC (Intergovernmental Panel on Climate Change). 2012. IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation. O Edenhofer, R Pichs-Madruga, Y Sokona, K Seyboth, P Matschoss, S Kadner, T Zwickel, P Eickemeier, G Hansen, S Schlömer, and C von Stechow (eds.), Cambridge University Press, Cambridge, United Kingdom.

Kimley-Horn (Kimley-Horn and Associates, Inc.). 2009. Traffic Study: Levy County Advanced Reactor Site, Levy County, Florida. Tampa, Florida.

Kivisto A. 1995. “Energy Payback Period and Carbon Dioxide Emissions in Different Power Generation Methods in Finland.” In IAEE International Conference, July 5–8, 1995, International Association for Energy Economics, Washington, D.C., pp. 191–198.

KLD (KLD Engineerings, PC). 2008. Traffic Impact Study Related to the Construction and Operation of the Bell Bend Nuclear Power Plant, Preliminary Findings Report. Revision 2, Commack, New York.

Krewitt W, P Mayerhofer, R Friedrich, A Truckenmuller, T Heck, A Gressmann, F Raptis, F Kaspar, J Sachau, K Rennings, J Diekmann, and B Praetorius. 1997. ExternE National Implementation in Germany. University of Stuttgart, Stuttgart, Germany, 189 pp.

Lecointe C, D Lecarpentier, V Maupu, D LeBoulch, R Richard, C Garzenne, TM Bachmann, and R Dones. 2004. Final Report on Technical Data, Costs and Life Cycle Inventories of Nuclear Power Plants. Sixth Framework Programme.

Lenzen M, C Dey, C Hardy, and M Bilek. 2006. Life-cycle Energy Balance and Greenhouse Gas Emissions of Nuclear Energy in Australia. ISA, University of Sydney, Sydney, Australia.

30

Luminant (Luminant Generation Company, LLC). 2009. Comanche Peak Nuclear Power Plant Units 3 and 4, COL Application; Part 3, Environmental Report. Revision 1, Glen Rose, Texas.

MdPSC (Public Service Commission of Maryland). 2008. In the Matter of: Application of UniStar Nuclear Energy, LLC and UniStar Nuclear Operating Services, LLC for a Certificate of Public Convenience and Necessity to Construct a Nuclear Power Plant at Calvert Cliffs in Calvert County, Case No. 9127. Section 4.2.4, Department of Natural Resources, Baltimore, Maryland.

Meridian Corporation. 1989. Energy System Emissions and Materiel Requirements. Alexandria, Virginia.

Miller PJ and C Van Atten. 2004. North American Power Plant Air Emissions. Commission for Environmental Cooperation of North America, Montreal, Canada.

NRC (U.S. Nuclear Regulatory Commission). 1996. Generic Environmental Impact Statement for License Renewal of Nuclear Plants Volumes 1 and 2. NUREG-1437, Washington, D.C. Accession Nos. ML040690705 and ML040690738.

NRC (U.S. Nuclear Regulatory Commission). 2002. Final Generic Environmental Impact Statement of Decommissioning of Nuclear Facilities: Regarding the Decommissioning of Nuclear Power Reactors. NUREG-0586, Supplement 1, Volumes 1 and 2, Washington, D.C. Accession Nos. ML023470327 and ML023500228.

NRC (Nuclear Regulatory Commission). 2010a. Staff Memorandum from B Zalcman to HB Clayton dated April 8, 2010, regarding “Supplemental Staff Guidance to NUREG 1555, ‘Environmental Standard Review Plan,’ (ESRP) for Consideration of the Effects of Greenhouse Gases and of Climate Change.” Washington, D.C. Accession No. ML100990185.

NRC (U.S. Nuclear Regulatory Commission). 2010b. Environmental Impact Statement for Combined Licenses (COLs) for Levy Nuclear Plant Units 1 and 2, Volumes 1, 2, and 3. NUREG-1941, Office of New Reactors, Washington, D.C. Accession Nos. ML12100A063, ML12100A068, and ML12100A070.

NRC (U.S. Nuclear Regulatory Commission). 2011a. Staff Memorandum from B Clayton to SC Flanders, dated March 4, 2011, regarding “Revision 1 - Addressing the Construction and Preconstruction Activities, Greenhouse Gas Issues, General Conformity Determinations, Environmental Justice, the Need for Power, Cumulative Impact Analysis and Cultural/Historical Resources Analysis Issues In Environmental Impact Statements.” Washington, D.C. Accession No. ML110380369.

NRC (U.S. Nuclear Regulatory Commission). 2011b. Environmental Impact Statement for Combined Licenses (COLs) for William States Lee III Nuclear Station Units 1 and 2, Volumes 1 and 2. NUREG-2111, Office of New Reactors, Washington, D.C. Accession Nos. ML11341A101 and ML11343A011.

NRC (U.S. Nuclear Regulatory Commission). 2011c. Environmental Impact Statement for Combined Licenses (COLs) for South Texas Project Electric Generating Station Units 3 and 4, Volumes 1 and 2. NUREG-1937, Office of New Reactors, Washington, D.C. Accession Nos. ML11049A000 and ML11049A001.

31

NRC (U.S. Nuclear Regulatory Commission). 2011d. Environmental Impact Statement for Combined License (COL) for Calvert Cliffs Nuclear Power Plant Unit 3, Volumes 1 and 2. NUREG-1936, Office of New Reactors, Washington, D.C. Accession Nos. ML101000012 and ML00029A179.

NRC (U.S. Nuclear Regulatory Commission). 2011e. Draft Environmental Impact Statement for Combined Licenses (COLs) for Comanche Peak Nuclear Power Plant Units 3 and 4, Volumes 1 and 2. NUREG-1943, Office of New Reactors, Washington, D.C. Accession Nos. ML11131A001 and ML11131A002.

NRC (U.S. Nuclear Regulatory Commission). 2011f. Environmental Impact Statement for Combined Licenses (COLs) for Vogtle Electric Generating Plant Units 3 and 4. NUREG-1947, Office of New Reactors, Washington, D.C. Accession No. ML11076A010.

PEF (Progress Energy Florida, Inc.). 2008. Levy Nuclear Plant Units 1 and 2 COL 21 Application, Part 3: Applicant’s Environmental Report – Combined License Stage. Revision 0, Raleigh, North Carolina.

Rashad SM and FH Hammad. 2000. “Nuclear Power and the Environment: Comparative Assessment of Environmental and Health Impacts of Electricity-Generating Systems.” Applied Energy 65:211–229.

San Martin RL. 1989. Environmental Emissions from Energy Technology Systems: The Total Fuel Cycle. U.S. Department of Energy, Washington, D.C.

SECDA (Saskatchewan Energy Conservation and Development Authority). 1994. Levelized Cost and Full Fuel Cycle Environmental Impacts of Saskatchewan’s Electric Supply Options. SECDA Publication No. T800-94-004, Saskatoon, Saskatchewan, Canada.

Sovacool BK. 2008. “Valuing the Greenhouse Gas Emissions from Nuclear Power: A Critical Survey.” Energy Policy 36(8):2950–2963.

Tokimatsu K, T Asami, Y Kaya, T Kosugi, and E Williams. 2006. “Evaluation of Lifecycle CO2 Emissions from the Japanese Electric Power Sector in the 21st Century Under Various Scenarios.” Energy Policy 34(7):833–852.

Uchiyama Y. 1996a. Validity of FENCH-GHG Study. In: IAEA Advisory Group Meeting on Analysis of Net Energy Balance and Full-energy-chain Greenhouse Gas Emissions for Nuclear and Other Energy Systems, Beijing, China, October 4–7, 1994, International Atomic Energy Agency, Vienna, Austria, pp. 85–94.

Uchiyama Y. 1996b. “Life Cycle Analysis of Electricity Generation and Supply Systems.” In Electricity, Health and the Environment: Comparative Assessment in Support of Decision Making, International Atomic Energy Agency, Vienna, Austria, pp. 279–291.

UniStar (UniStar Nuclear Services, LLC). 2007. Technical Report in Support of Application of UniStar Nuclear Energy, LLC and UniStar Nuclear Operating Services, LLC for Certificate of Public Convenience and Necessity Before the Maryland Public Service Commission for Authorization to Construct Unit 3 at Calvert Cliffs Nuclear Power Plant and Associated Transmission Lines – Public Version. Baltimore, Maryland.

32

UniStar (UniStar Nuclear Services, LLC). 2009. Calvert Cliffs Nuclear Power Plant Unit 3 Combined License Application, Part 3: Environmental Report. Revision 6, Baltimore, Maryland.

UniStar (UniStar Nuclear Services, LLC). 2011. Bell Bend Nuclear Power Plant Combined License Application, Part 3: Environmental Report. Baltimore, Maryland.

Vattenfall. 2007a. Summary of Vattenfall AB Generation Nordic Certified Environmental Product Declaration, EPD® of Electricity from Ringhals Nuclear Power Plant. Report No. S-P-00026 2007-11-01, Vattenfall, Stockholm, Sweden.

Vattenfall. 2007b. Vattenfall AB Generation Nordic Certified Environmental Product Declaration, EPD, of Electricity from Forsmark Nuclear Power Plant. Report No. S-P-00088, Vattenfall, Stockholm, Sweden.

Voorspools KR, EA Brouwers, and WD D’Haeseleer. 2000. “Energy Content and Indirect Greenhouse Gas Emissions Embedded in ‘Emission-Free’ Power Plants: Results for the Low Countries.” Applied Energy 67(3):307–330.

Wibberley L. 2001. Coal in a Sustainable Society. Australian Coal Association Research Program, Brisbane, Queensland, Australia.

White SW and GL Kulcinski. 2000. “Birth to Death Analysis of the Energy Payback Ratio and CO2 Gas Emission Rates from Coal, Fission, Wind, and DT-Fusion Electrical Power Plants.” Fusion Engineering and Design 48(3–4):473–481.

Yasukawa S, Y Tadokoro, and T Kajimaya. 1992. “Life Cycle CO2 Emission from Nuclear Power Reactor and Fuel Cycle System.” In Expert Workshop on Life-cycle Analysis of Energy Systems, Methods and Experience. Paris, France, May 21–22, 1992, pp. 151–160.

Yasukawa S, Y Tadokoro, O Sato, and M Yamaguchi. 1996. “Integration of Indirect CO2 Emissions from the Full Energy Chain.” In IAEA Advisory Group Meeting on Analysis of Net Energy Balance and Full-energy-chain Greenhouse Gas Emissions for Nuclear and Other Energy Systems, Beijing, China, pp. 139–150.

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