Text

Rulemaking: Proposed Rule: Egulatory Analysis for American Society of Mechanical Engineers Code Cases, RG 1.84, Rev 38; RG 1.147, Rev 19; RG 1.192, Rev 3; and RG 1.193, Rev 6
	ML18099A054
Person / Time
Issue date:	08/31/2018
From:	; Division of Policy and Rulemaking
To:	;
	Margaret Ellenson 415-0894
Shared Package
ML18099A041	List: ML18099A046; ML18099A051; ML18099A054;
References
	NRC-2012-0024, RIN 3150-AJ93
	Download: ML18099A054 (92)
	v • d • e

Regulatory Analysis for the Proposed Rule:

Approval of American Society of Mechanical Engineers Code Cases NRC-2017-0024; RIN 3150-AJ93 AUGUST 2018 U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Policy and Rulemaking

ix Abstract This proposed rule recommends approval, through the U.S. Nuclear Regulatory Commissions (NRCs) regulations, of the latest revisions to the NRC regulatory guides (RGs), listing American Society of Mechanical Engineers (ASME) Code Cases for the ASME Boiler and Pressure Vessel Code (BPV Code) and Operation and Maintenance of Nuclear Power Plants Code (OM Code). These are Code Cases that the NRC finds acceptable or acceptable with NRC-specified conditions (conditionally acceptable). The NRC is issuing three RG revisions that identify the ASME Code Cases proposed for approval by the NRC:

(1)

RG 1.84, Design, Fabrication, and Materials Code Case Acceptability, ASME Section III, Revision 38 (Draft Regulatory Guide (DG)-1345), would supersede the incorporation by reference of RG 1.84, Revision 37, issued March 2017.

(2)

RG 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, Revision 19 (DG-1342), would supersede the incorporation by reference of RG 1.147, Revision 18, issued March 2017.

(3)

RG 1.192, Operation and Maintenance Code Case Acceptability, ASME OM Code, Revision 3 (DG-1343), would supersede the incorporation by reference of RG 1.192, Revision 2, issued March 2017.

This document presents a draft regulatory analysis of the proposed rule for the three RGs that list the Code Cases proposed for NRC approval.

To improve the credibility of the NRC staff cost estimates for this regulatory action, the NRC staff conducted an uncertainty analysis to consider the effects of input uncertainty on the cost estimate and a sensitivity analysis to identify the variables that most affect the cost estimate (i.e., the cost drivers).

x Contents Section Page List of Figures....................................................................................................................................... xvi List of Tables........................................................................................................................................ xvi Abbreviations and Acronyms.............................................................................................................. xvii Abstract.................................................................................................................................................. ix Executive Summary............................................................................................................................. xix

1.

Introduction............................................................................................................................... 1

2.

Statement of the Problem and Objective.................................................................................. 1 2.1 Background.................................................................................................................. 1 2.2 Statement of the Problem............................................................................................ 3 2.3 Objective...................................................................................................................... 4

3.

Identification and Preliminary Analysis of Alternative Approaches........................................... 4 3.1 Alternative 1No Action.............................................................................................. 4 3.2 Alternative 2Incorporate by Reference NRC-Approved ASME BPV and OM Code Cases........................................................................................................................... 5

4.

Estimation and Evaluation of Costs and Benefits..................................................................... 6 4.1 Identification of Affected Attributes.............................................................................. 6 4.2 Analytical Methodology................................................................................................ 9 4.2.1 Regulatory Baseline...................................................................................... 10 4.2.2 Affected Entities............................................................................................ 10 4.2.3 Base Year..................................................................................................... 11 4.2.4 Discount Rates.............................................................................................. 11 4.2.5 Cost/Benefit Inflators..................................................................................... 12 4.2.6 Labor Rates................................................................................................... 12 4.2.7 Sign Conventions.......................................................................................... 14 4.2.8 Analysis Horizon........................................................................................... 14 4.2.9 Cost Estimation............................................................................................. 14 4.2.10 NRC Conditioned Code Cases..................................................................... 15 4.3 Data............................................................................................................................ 20

5.

Results.................................................................................................................................... 20 5.1 Public Health (Accident)............................................................................................. 21 5.2 Occupational Health (Accident and Routine)............................................................. 21 5.3 Industry Implementation............................................................................................. 22 5.3.1 Additional Materials for Subsection NF, Class 1, 2, 3, and Metal Containment Supports Fabricated by Welding................................................................... 22 5.3.2 Underwater Welding,Section XI, Division 1................................................. 24 5.3.3 Evaluation of Pipe Wall Thinning,Section XI................................................ 25 5.3.4 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique for Boiling-Water Reactor Control Rod Drive Housing/Stub Tube Repairs.......................................................................... 26 5.3.5 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique................................................................... 27 5.3.6 Alternative Requirements for Inner Radius Examinations of Class 1 Reactor Vessel Nozzles,Section XI........................................................................... 27

xi 5.3.7 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface.............................................................. 27 5.3.8 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface.............................................................. 28 5.3.9 Alternative Requirements for Boiling-Water Reactor Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1.............................................. 29 5.3.10 Evaluation Criteria for Temporary Acceptance of Degradation in Moderate-Energy Class 2 or 3 Vessels and Tanks...................................... 30 5.3.11 Alternative Examination Coverage Requirements for Examination Category B-F, B-J, C-F-1, C-F-2, and R-A Piping Welds..................................................... 30 5.3.12 Optimized Structural Dissimilar Metal Weld Overlay for Mitigation of Pressurized-Water Reactor Class 1 Items.................................................... 31 5.3.13 Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of Pressurized-Water Reactor Full-Penetration Circumferential Nickel Alloy Dissimilar Metal Welds in Class 1 Items................................................................................................ 32 5.3.14 Ultrasonic Examination of Cast Austenitic Piping Welds from the Outside Surface,Section XI, Division 1...................................................................... 34 5.3.15 Austenitic Stainless Steel Cladding and Nickel-Base Cladding Using Ambient Temperature Machine GTAW Temper Bead Technique.............................. 35 5.3.16 Direct Use of Master Fracture Toughness Curve for Pressure-Retaining Materials of Class 1 Vessels........................................................................................ 36 5.3.17 Ultrasonic Examination in Lieu of Radiography for Welds in Ferritic Pipe.... 36 5.3.18 Flaw Tolerance Evaluation of Cast Austenitic Stainless Steel Piping,Section XI, Division 1....................................................................................................... 37 5.3.19 Alternative Pressure Testing Requirements Following Repairs or Replacements for Class 1 Piping between the First and Second Inspection Isolation Valves,Section XI, Division 1.................................................................................... 38 5.3.20 In Situ VT-3 Examination of Removable Core Support Structures without Removal........................................................................................................ 38 5.4 Industry Operation...................................................................................................... 39 5.4.1 Additional Materials for Subsection NF, Class 1, 2, 3, and Metal Containment Supports Fabricated by Welding................................................................... 41 5.4.2 Underwater Welding,Section XI, Division 1................................................. 41 5.4.3 Evaluation of Pipe Wall Thinning,Section XI................................................ 41 5.4.4 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique for Boiling-Water Reactor Control Rod Drive Housing/Stub Tube Repairs.......................................................................... 41 5.4.5 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique................................................................... 41 5.4.6 Alternative Requirements for Inner Radius Examinations of Class 1 Reactor Vessel Nozzles,Section XI........................................................................... 41 5.4.7 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface.............................................................. 42 5.4.8 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface.............................................................. 42

xii 5.4.9 Alternative Requirements for Boiling-Water Reactor Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1.............................................. 42 5.4.10 Evaluation Criteria for Temporary Acceptance of Degradation in Moderate-Energy Class 2 or 3 Vessels and Tanks...................................... 43 5.4.11 Alternative Examination Coverage Requirements for Examination Category B-F, B-J, C-F-1, C-F-2, and R-A Piping Welds..................................................... 43 5.4.12 Optimized Structural Dissimilar Metal Weld Overlay for Mitigation of Pressurized-Water Reactor Class 1 Items.................................................... 44 5.4.13 Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of Pressurized-Water Reactor Full-Penetration Circumferential Nickel Alloy Dissimilar Metal Welds in Class 1 Items................................................................................................ 44 5.4.14 Ultrasonic Examination of Cast Austenitic Piping Welds from the Outside Surface,Section XI, Division 1...................................................................... 44 5.4.15 Austenitic Stainless Steel Cladding and Nickel-Base Cladding Using Ambient Temperature Machine GTAW Temper Bead Technique.............................. 45 5.4.16 Direct Use of Master Fracture Toughness Curve for Pressure-Retaining Materials of Class 1 Vessels........................................................................................ 45 5.4.17 Ultrasonic Examination in Lieu of Radiography for Welds in Ferritic Pipe.... 45 5.4.18 Flaw Tolerance Evaluation of Cast Austenitic Stainless Steel Piping,Section XI, Division 1....................................................................................................... 45 5.4.19 Alternative Pressure Testing Requirements Following Repairs or Replacements for Class 1 Piping between the First and Second Inspection Isolation Valves,Section XI, Division 1.................................................................................... 46 5.4.20 In Situ VT-3 Examination of Removable Core Support Structures without Removal........................................................................................................ 46 5.5 Total Industry Costs................................................................................................... 46 5.6 NRC Implementation.................................................................................................. 46 5.6.1 Additional Materials for Subsection NF, Class 1, 2, 3, and Metal Containment Supports Fabricated by Welding................................................................... 46 5.6.2 Underwater Welding,Section XI, Division 1................................................. 47 5.6.3 Evaluation of Pipe Wall Thinning,Section XI................................................ 47 5.6.4 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique for Boiling-Water Reactor Control Rod Drive Housing/Stub Tube Repairs.......................................................................... 47 5.6.5 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique................................................................... 47 5.6.6 Alternative Requirements for Inner Radius Examinations of Class 1 Reactor Vessel Nozzles,Section XI........................................................................... 47 5.6.7 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface.............................................................. 47 5.6.8 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface.............................................................. 47 5.6.9 Alternative Requirements for Boiling-Water Reactor Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1.............................................. 48

xiii 5.6.10 Evaluation Criteria for Temporary Acceptance of Degradation in Moderate-Energy Class 2 or 3 Vessels and Tanks...................................... 48 5.6.11 Alternative Examination Coverage Requirements for Examination Category B-F, B-J, C-F-1, C-F-2, and R-A Piping Welds..................................................... 48 5.6.12 Optimized Structural Dissimilar Metal Weld Overlay for Mitigation of PWR Class 1 Items.......................................................................................................... 48 5.6.13 Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of Pressurized-Water Reactor Full-Penetration Circumferential Nickel Alloy Dissimilar Metal Welds in Class 1 Items................................................................................................ 48 5.6.14 Ultrasonic Examination of Cast Austenitic Piping Welds from the Outside Surface,Section XI, Division 1...................................................................... 48 5.6.15 Austenitic Stainless Steel Cladding and Nickel-Base Cladding Using Ambient Temperature Machine GTAW Temper Bead Technique.............................. 49 5.6.16 Direct Use of Master Fracture Toughness Curve for Pressure-Retaining Materials of Class 1 Vessels........................................................................................ 49 5.6.17 Ultrasonic Examination in Lieu of Radiography for Welds in Ferritic Pipe.... 49 5.6.18 Flaw Tolerance Evaluation of Cast Austenitic Stainless Steel Piping,Section XI, Division 1....................................................................................................... 49 5.6.19 Alternative Pressure Testing Requirements Following Repairs or Replacements for Class 1 Piping between the First and Second Inspection Isolation Valves,Section XI, Division 1.................................................................................... 49 5.6.20 In Situ VT-3 Examination of Removable Core Support Structures without Removal........................................................................................................ 49 5.7 NRC Operation........................................................................................................... 49 5.7.1 Additional Materials for Subsection NF, Class 1, 2, 3, and Metal Containment Supports Fabricated by Welding................................................................... 50 5.7.2 Underwater Welding,Section XI, Division 1................................................. 50 5.7.3 Evaluation of Pipe Wall Thinning,Section XI................................................ 50 5.7.4 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique for Boiling-Water Reactor Control Rod Drive Housing/Stub Tube Repairs.......................................................................... 51 5.7.5 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique................................................................... 51 5.7.6 Alternative Requirements for Inner Radius Examinations of Class 1 Reactor Vessel Nozzles,Section XI........................................................................... 51 5.7.7 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface.............................................................. 51 5.7.8 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface.............................................................. 51 5.7.9 Alternative Requirements for Boiling-Water Reactor Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1.............................................. 52 5.7.10 Evaluation Criteria for Temporary Acceptance of Degradation in Moderate-Energy Class 2 or 3 Vessels and Tanks...................................... 52 5.7.11 Alternative Examination Coverage Requirements for Examination Category B-F, B-J, C-F-1, C-F-2, and R-A Piping Welds..................................................... 52

xiv 5.7.12 Optimized Structural Dissimilar Metal Weld Overlay for Mitigation of Pressurized-Water Reactor Class 1 Items.................................................... 52 5.7.13 Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of Pressurized-Water Reactor Full-Penetration Circumferential Nickel Alloy Dissimilar Metal Welds in Class 1 Items................................................................................................ 52 5.7.14 Ultrasonic Examination of Cast Austenitic Piping Welds from the Outside Surface,Section XI, Division 1...................................................................... 53 5.7.15 Austenitic Stainless Steel Cladding and Nickel-Base Cladding Using Ambient Temperature Machine GTAW Temper Bead Technique.............................. 53 5.7.16 Direct Use of Master Fracture Toughness Curve for Pressure-Retaining Materials of Class 1 Vessels........................................................................................ 53 5.7.17 Ultrasonic Examination in Lieu of Radiography for Welds in Ferritic Pipe.... 53 5.7.18 Flaw Tolerance Evaluation of Cast Austenitic Stainless Steel Piping,Section XI, Division 1....................................................................................................... 54 5.7.19 Alternative Pressure Testing Requirements Following Repairs or Replacements for Class 1 Piping between the First and Second Inspection Isolation Valves,Section XI, Division 1.................................................................................... 54 5.7.20 In Situ VT-3 Examination of Removable Core Support Structures without Removal........................................................................................................ 54 5.8 Total NRC Costs........................................................................................................ 54 5.9 Total Costs................................................................................................................. 55 5.10 Improvements in Knowledge...................................................................................... 55 5.11 Regulatory Efficiency................................................................................................. 55 5.12 Other Considerations................................................................................................. 56 5.12.1 National Technology Transfer and Advancement Act of 1995..................... 56 5.12.2 Continued NRC Practice of Incorporation by Reference of ASME Code Editions and Addenda into the Code of Federal Regulations..................................... 56 5.12.3 Increased Public Confidence........................................................................ 56 5.12.4 Reliable Assessment of Cast Austenitic Stainless Steel Materials............... 56 5.13 Uncertainty Analysis................................................................................................... 57 5.13.1 Uncertainty Analysis Assumptions................................................................ 57 5.13.2 Uncertainty Analysis Results........................................................................ 59 5.13.3 Summary of Uncertainty Analysis................................................................. 63 5.14 Disaggregation........................................................................................................... 63 5.15 Summary.................................................................................................................... 63 5.15.1 Quantified Net Benefit................................................................................... 63 5.15.2 Nonquantified Benefits.................................................................................. 64 5.15.3 Nonquantified Costs...................................................................................... 66 5.16 Safety Goal Evaluation.............................................................................................. 66 5.16.1 Section A: Incorporation by Reference of Later Editions and Addenda of Section III, Division 1, of the ASME BPV Code............................................ 66 5.16.2 Section B: Incorporation by Reference of Later Editions and Addenda of Section XI, Division 1, of the ASME BPV and OM Codes............................ 67 5.16.3 Other Circumstances in Which the NRC Does Not Apply the Backfit Rule to the Endorsement of a Later Code....................................................................... 67

xv 5.16.4 Safety Goal Evaluation Result...................................................................... 68 5.17 Results for the Committee to Review Generic Requirements................................... 68

6.

Decision Rationale.................................................................................................................. 69

7.

Implementation Schedule....................................................................................................... 72

8.

References.............................................................................................................................. 72 Appendix A Major Assumptions and Input Data................................................................................ A-1

xvi List of Figures Figure Page Figure 1 Total industry costs (7-percent NPV)Alternative 2........................................... 60 Figure 2 Total NRC costs (7-percent NPV)Alternative 2................................................ 61 Figure 3 Total costs (7-percent NPV)Alternative 2......................................................... 61 Figure 4 Top eight variables for which uncertainty drives the largest impact on total costs (7-percent NPV)Alternative 2........................................................................... 62 List of Tables Table Page Table 1 Total Costs and Benefits for Alternative 2........................................................... xx Table 2 Operating Reactor and Site Information.............................................................. 10 Table 3 CPI-U Inflator....................................................................................................... 12 Table 4 Position Titles and Occupations.......................................................................... 13 Table 5 Conditioned Code Cases.................................................................................... 15 Table 6 Industry OperationAverted Costs for Code Alternative Requests.................... 40 Table 7 N-648-2 Reactor Nozzle Ultrasonic Test Inspection............................................ 42 Table 8 N-695-1 Piping Examination Relief Request....................................................... 42 Table 9 N-696-1 Piping Examination Relief Request....................................................... 42 Table 10 N-705-1 Tank Weld Repairs................................................................................ 43 Table 11 N-766-1 Inlay and Onlay Repair Relief Requests................................................ 44 Table 12 N-838 CASS Flaw Tolerance Evaluation Relief Requests.................................. 45 Table 13 Total Industry Costs............................................................................................ 46 Table 14 NRC Implementation Costs................................................................................. 46 Table 15 NRC Operation CostsReviews of Averted Code Alternative Requests (Operating and New Reactors)............................................................................ 50 Table 16 N-695-1 Piping Examination Relief Request Review.......................................... 51 Table 17 N-696-1 Piping Examination Relief Request Review.......................................... 52 Table 18 N-766-1 Relief Request Reviews........................................................................ 53 Table 19 N-838 Relief Request Reviews............................................................................ 54 Table 20 Total NRC Costs................................................................................................. 55 Table 21 Total Costs.......................................................................................................... 55 Table 22 Uncertainty Analysis Variables............................................................................ 58 Table 23 Descriptive Statistics for Uncertainty Results (7-Percent NPV)........................... 62 Table 24 Disaggregation.................................................................................................... 63 Table 25 Specific CRGR Information Requirements for Regulatory Analysis.................... 68 Table 26 Summary of Totals.............................................................................................. 69

xvii Abbreviations and Acronyms ADAMS Agencywide Documents Access and Management System ASME American Society of Mechanical Engineers ASME Codes ASME BPV and OM Codes ASME OM Committee ASME Committee on Operation and Maintenance of Nuclear Power Plants BLS Bureau of Labor Statistics BPV boiler and pressure vessel BPV Code ASME Boiler and Pressure Vessel Code BWR boiling-water reactor C

Centigrade CASS cast austenitic stainless steel CC concrete containment CFR Code of Federal Regulations CPI Consumer Price Index CPI-U Consumer Price Index for All Urban Consumers CRGR Committee to Review Generic Requirements DG draft regulatory guide EPRI Electric Power Research Institute eV electron volt GDC general design criterion/criteria GTAW gas tungsten arc welding ID inner diameter IGSCC intergranular stress-corrosion cracking ISI inservice inspection IST inservice testing KIc plane strain fracture toughness kHz kilohertz kPa kiloPascal ksi kilopound per square inch LOE level of effort MC metal containment MeV million electron volts

xviii n/cm2 neutrons per square centimeter NPV net present value NRC U.S. Nuclear Regulatory Commission NSAC Nuclear Safety Analysis Center (within EPRI)

NTTAA National Technology Transfer and Advancement Act of 1995 NUREG NRC technical report OM operation and maintenance OM Code ASME Code for Operation and Maintenance of Nuclear Power Plants OMB U.S. Office of Management and Budget PERT program evaluation and review technique PWR pressurized-water reactor RG regulatory guide RT reference temperature R/t radius-to-thickness ratio SOC standard occupational classification UT ultrasonic test UTS ultimate tensile strength VT visual test

xix Executive Summary The U.S. Nuclear Regulatory Commission (NRC) is proposing to amend its regulations to incorporate by reference the latest revisions to three NRC regulatory guides (RGs) approving new, revised, and reaffirmed Code Cases published by the American Society of Mechanical Engineers (ASME). The NRC proposes to incorporate by reference the following three RGs:

(1)

RG 1.84, Design, Fabrication, and Materials Code Case Acceptability, ASME Section III, Revision 38 (Draft Regulatory Guide (DG)-1345)

(2)

RG 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, Revision 19 (DG-1342)

(3)

RG 1.192, Operation and Maintenance Code Case Acceptability, ASME OM Code, Revision 3 (DG-1343)

This regulatory action allows nuclear power plant licensees and applicants for construction permits, operating licenses, combined licenses, standard design certifications, standard design approvals, and manufacturing licenses to voluntarily use the ASME Code Cases newly listed in these RGs as alternatives to engineering standards for the construction, inservice inspection, and inservice testing of nuclear power plant components.

The analysis presented in this document examines the benefits and costs of the proposed rulemaking and implementing guidance relative to the baseline case (i.e., the no-action alternative).

The NRC staff has made the following key findings:

Proposed Rule Analysis. The proposed rule recommended by the staff would result in a cost-justified change based on a net (i.e., taking into account both costs and benefits) averted cost to the industry that ranges from $5.20 million using a 7-percent discount rate to $5.70 million using a 3-percent discount rate. Compared to the regulatory baseline, the NRC would realize a net averted cost that ranges from $1.52 million using a 7-percent discount rate to $1.78 million using a 3-percent discount rate. Table 1 shows the total costs and benefits to the industry and the NRC of proceeding with the proposed rule. The proposed rule alternative would result in net averted costs to the industry and the NRC ranging from $6.72 million using a 7-percent discount rate to

$7.48 million using a 3-percent discount rate.

xx Table 1 Total Costs and Benefits for Alternative 2 Nonquantified Benefits. Other benefits of the recommended proposed rule include the NRCs continued ability to meet its goal of ensuring the protection of public health and safety and the environment through the approval of new editions of the ASME Boiler and Pressure Vessel and Operation and Maintenance Codes, which allow the use of the most current methods and technology. The recommended proposed rule is consistent with the provisions of the National Technology Transfer and Advancement Act of 1995 and implementing guidance in U.S. Office of Management and Budget Circular A-119, Federal Participation in the Development and Use of Voluntary Consensus Standards and in Conformity Assessment Activities, dated January 27, 2016, which encourage Federal regulatory agencies to consider adopting voluntary consensus standards as an alternative to de novo agency development of standards affecting an industry. Finally, the ASME Code consensus process is an important part of the regulatory framework.

Uncertainty Analysis. The regulatory analysis contains a simulation analysis that shows the estimated mean benefit for this proposed rule is $6.72 million with 90-percent confidence that the total net benefit is between $3.61 million and $10.4 million using a 7-percent discount rate. A reasonable inference from the uncertainty analysis is that proceeding with the proposed rule represents an efficient use of resources and averted costs to the NRC and the industry. The hours for relief request preparation and submission by industry is the factor responsible for the largest variation in averted costs.

Decision Rationale. When comparing the proposed rule to the no-action baseline, the staff concludes that the proposed rule is justified from a quantitative standpoint because its provisions would result in millions of dollars of net averted costs (i.e., net benefits) to the NRC and the industry. In addition, the staff concludes that the proposed rule is also Undiscounted 7% NPV 3% NPV

($690,000)

($600,000)

($640,000)

($600,000)

($620,000)

($1,330,000)

($1,200,000)

($1,260,000)

Undiscounted 7% NPV 3% NPV

$6,820,000

$5,800,000

$6,350,000

$2,660,000

$2,110,000

$2,400,000

$9,480,000

$7,910,000

$8,750,000 Undiscounted 7% NPV 3% NPV

$6,140,000

$5,200,000

$5,700,000

$2,020,000

$1,520,000

$1,780,000

$8,160,000

$6,720,000

$7,480,000 Attribute Net Benefits (Costs)

Total Attribute Benefits Total Industry Benefits Total NRC Benefits Total Benefits Industry NRC Attribute Costs Total Industry Costs Total NRC Costs Total Costs

xxi justified when considering nonquantified costs and benefits, because the significance of the nonquantified benefits outweighs those of the nonquantified costs.

1

1. Introduction This document presents the regulatory analysis of the proposed rule for the American Society of Mechanical Engineers (ASME) Code Cases (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18099A041) and the following three associated draft regulatory guides (DGs) from the U.S. Nuclear Regulatory Commission (NRC):

DG-1342, Design, Fabrication, and Materials Code Case Acceptability, ASME Section III, Regulatory Guide (RG) 1.84, proposed Revision 38 (ADAMS Accession No. ML18114A225)

DG-1343, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, RG 1.147, proposed Revision 19 (ADAMS Accession No. ML18114A226)

DG-1345, Operation and Maintenance Code Acceptability, ASME OM Code, RG 1.192, proposed Revision 3 (ADAMS Accession No. ML18114A228)

The recommended regulatory action proposes to incorporate by reference the latest revisions to the three RGs listed above so that the NRC approves the newly identified ASME Code Cases as alternatives for use to the ASME Code editions and addenda.

2. Statement of the Problem and Objective

2.1 Background

The general design criteria (GDC) for nuclear power plants in Appendix A, General Design Criteria for Nuclear Power Plants, to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities, or, as appropriate, similar requirements in the licensing basis for a reactor facility, provide the bases and requirements for the NRCs assessment of the use of generally recognized codes and standards and the potential for, and consequences of, degradation of the reactor coolant pressure boundary. The applicable GDC include GDC 1, Quality Standards and Records; GDC 14, Reactor Coolant Pressure Boundary; and GDC 32, Inspection of Reactor Coolant Pressure Boundary.

GDC 1 requires, in part, the following:

Structures, systems, and components important to safety shall be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. Where generally recognized codes and standards are used, they shall be identified and evaluated to determine their applicability, adequacy, and sufficiency and shall be supplemented or modified as necessary to assure a quality product in keeping with the required safety function.

2 GDC 14 establishes the following:

The reactor coolant pressure boundary shall be designed, fabricated, erected, and tested so as to have an extremely low probability of abnormal leakage, of rapidly propagating failure, and of gross rupture.

Additionally, GDC 32 establishes the following:

Components which are part of the reactor coolant pressure boundary shall be designed to permit (1) periodic inspection and testing of important areas and features to assess their structural and leaktight integrity, and (2) an appropriate material surveillance program for the reactor pressure vessel.

The National Technology Transfer and Advancement Act of 1995 (Public Law 104-113)

(NTTAA) mandates the following:

All Federal agencies and departments shall use technical standards that are developed or adopted by voluntary consensus standards bodies, using such technical standards as a means to carry out policy objectives or activities determined by the agencies and departments.

In carrying out this legislation, Federal agencies are to consult with voluntary consensus standards bodies and participate with such bodies in developing technical standards when such participation is in the public interest and compatible with the agency mission, priorities, and budget resources. If the technical standards are inconsistent with applicable law or otherwise impractical, a Federal agency may elect to use technical standards that are not developed or adopted by voluntary consensus bodies.

Provisions of the ASME Boiler and Pressure Vessel (BPV) Code have been used since 1971 as one part of the framework to establish the necessary design, fabrication, construction, testing, and performance requirements for structures, systems, and components important to safety.

Various technical interests (e.g., utility, manufacturing, insurance, regulatory) are represented on the ASME standards committees that develop, among other things, improved methods for the construction and inservice inspection (ISI) of ASME Class 1, 2, and 3; metal containment (MC); and concrete containment (CC) nuclear power plant components. This broad spectrum of stakeholders helps to ensure that the various interests are considered.

A directive from the ASME Board on Nuclear Codes and Standards transferred responsibility for the development and maintenance of rules for the inservice testing (IST) of pumps and valves from the ASME Section XI Subcommittee on Nuclear Inservice Inspection to the ASME Committee on Operation and Maintenance of Nuclear Power Plants (ASME OM Committee);

this led to the development of the ASME Operation and Maintenance (OM) Code. In 1990, ASME published the initial edition of the OM Code that provides rules for IST of pumps and valves. The ASME OM Committee continues to maintain the OM Code. ASME intended that

3 the OM Code replace the ASME BPV Section XI rules for IST of pumps and valves. The ASME Section XI Committee no longer updates the Section XI rules for IST of pumps and valves that were previously incorporated by reference into NRC regulations.

In 10 CFR 50.55a, Codes and Standards, the NRC requires that nuclear power plant owners construct Class 1, 2, and 3 components in accordance with Section III, Division 1, of the ASME BPV Code. Regulations in 10 CFR 50.55a also require that owners perform ISI of Class 1, Class 2, Class 3, Class MC, and Class CC components in accordance with Section XI, Division 1, of the BPV Code and that they perform IST of Class 1, 2, and 3 safety-related pumps and valves in accordance with the OM Code. ASME develops Code Cases to gain experience with new technology before incorporating it into the ASME Code; permit licensees to use advances in ISI and IST; provide alternative examinations for older plants; respond promptly to user needs; and offer a limited, clearly focused alternative to specific ASME Code provisions.

2.2 Statement of the Problem ASME may revise Code Cases for many reasons, such as incorporating operational examination and testing experience or updating material requirements based on research results. On occasion, an inaccuracy in an equation is discovered, or an examination as practiced is found to be inadequate in detecting a newly discovered degradation mechanism.

Therefore, it follows that when a licensee initially implements a Code Case, 10 CFR 50.55a requires the licensee to implement the most recent version of that Code Case as listed in the approved or conditionally approved tables in 10 CFR 50.55a. An alternative could be submitted and approved through alternative requests under 10 CFR 50.55a(z); in this case, a licensee could request the use of a previous Code Case, and the NRC would evaluate such a request on a case-by-case basis.

ASME BPV Code Section III applies only to new construction (i.e., the edition and addenda to be used in the construction of a plant are selected based on the date of the construction permit and are not changed after that date except voluntarily by the licensee). Thus, if a licensee implements an ASME BPV Code Section III Code Case and if the NRC incorporates by reference a later version of the Code Case into 10 CFR 50.55a and lists it in the RG tables, that licensee may use either version of the Code Case.

Licensee programs under ASME BPV Code Section XI ISI and ASME OM Code IST are updated every 10 years to the latest edition and addenda of ASME BPV Code Section XI that were incorporated by reference into 10 CFR 50.55a and in effect 12 months before the start of the next inspection interval. Licensees that were using a Code Case before the effective date of its revision may continue to use the previous version for the remainder of the 120-month ISI or IST interval. This relieves licensees of the burden of having to update their ISI or IST program each time ASME revises a Code Case. Because Code Cases apply to specific editions and addenda and because ASME may revise Code Cases that are no longer accurate or adequate, licensees that choose to continue using a Code Case during the subsequent ISI interval must

4 implement the latest version incorporated by reference in 10 CFR 50.55a and listed in the RGs, or apply for an alternative request under 10 CFR 50.55a(z).

2.3 Objective The objective of this proposed regulatory action is to incorporate by reference the latest revisions to three RGs that list Code Cases published by ASME and approved by the NRC:

(1)

RG 1.84, Design, Fabrication, and Materials Code Case Acceptability, ASME Section III, Revision 38 (DG-1342)

(2)

RG 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, Revision 19 (DG-1343)

(3)

RG 1.192, Operation and Maintenance Code Case Acceptability, ASME OM Code, Revision 3 (DG-1345)

These revisions supersede the incorporation by reference of RG 1.84, Revision 37, issued March 2017; RG 1.147, Revision 18, issued January 2018; and RG 1.192, Revision 2, issued March 2017. This regulatory action improves the effectiveness of future licensing actions, is consistent with the provisions of the NTTAA that encourage Federal regulatory agencies to consider adopting voluntary consensus standards as an alternative to de novo agency development of standards affecting an industry, and is consistent with the NRC policy of evaluating the latest version of consensus standards already approved by the NRC in terms of their suitability for endorsement by regulation or RG.

3. Identification and Preliminary Analysis of Alternative Approaches Given the existing data and information, the NRC considers a rule change to be the most effective way to implement the NRC-approved ASME Code Cases. The NRC has identified two alternatives to this action: Alternative 1the no-action alternative (i.e., status quo, regulatory baseline)and Alternative 2through rulemaking, incorporate by reference into 10 CFR 50.55a the NRC-approved ASME BPV Code Cases in RG 1.84, Revision 38 (DG-1342), and RG 1.147, Revision 19 (DG-1343), and the ASME OM Code Cases in RG 1.192, Revision 3 (DG-1345).

3.1 Alternative 1No Action The no-action alternative (status quo, regulatory baseline) is a nonrulemaking alternative. The no-action alternative would not revise the NRCs regulations to incorporate by reference the latest revisions to these three RGs and would not make conforming changes to 10 CFR 50.55a to comply with guidance from the Office of the Federal Register for incorporating by reference multiple standards into regulations. The no-action alternative would cause licensees and applicants that want to use these ASME Code Cases to request and receive approval from the NRC for the use of alternatives under 10 CFR 50.55a(z). The NRC does not recommend this alternative for the following reasons:

5 Licensees and applicants would need to submit requests for alternatives to apply Code Cases under 10 CFR 50.55a(z) because those Code Cases have not been approved in the RGs and have not been incorporated by reference in 10 CFR 50.55a. This process would result in increased regulatory burden to licensees, applicants, and the NRC.

Public confidence in the NRC as an effective regulator may be reduced because ASME periodically publishes, revises, and annuls its Code Cases. Under Alternative 1, outdated material and possibly inaccurate information would remain incorporated by reference into the Code of Federal Regulations.

This alternative does not meet the intent of NTTAA, which encourages Federal regulatory agencies to consider adopting voluntary consensus standards as an alternative to de novo agency development of standards affecting an industry.

3.2 Alternative 2Incorporate by Reference NRC-Approved ASME BPV and OM Code Cases Alternative 2 would incorporate by reference the latest revisions to the RGs listing ASME Code Cases that are newly approved by the NRC. This alternative would allow licensees and applicants to implement these ASME Code Cases and their conditions and modifications, if any, without seeking prior NRC approval. This alternative continues the NRCs use of periodic rulemakings to incorporate by reference in 10 CFR 50.55a the latest RGs that list NRC-approved alternatives to the provisions of the ASME BPV and OM Codes.

The NRC recommends the rulemaking alternative for the following reasons:

This alternative reduces the regulatory burden on applicants or holders of licenses for nuclear power plants by eliminating the need to submit plant-specific requests for alternatives in accordance with 10 CFR 50.55a(z), and it reduces the need for the NRC to review those submittals.

This alternative meets the NRCs goal of ensuring the protection of public health and safety and the environment by continuing to provide NRC approval of new ASME Code Editions that allow the use of the most current methods and technology.

This alternative supports the NRCs goal of maintaining an open regulatory process by informing the public about the process and by giving the public the opportunity to participate in it.

This alternative supports the NRCs commitment to participating in the national consensus standard process through the approval of these ASME Code Editions, and it conforms to NTTAA requirements.

6 The initial burden on the NRC to update the regulations by incorporating by reference the editions and addenda of the ASME BPV and OM Codes cited here is more than offset by the reduction in the number of plant-specific alternative requests that the NRC would otherwise evaluate. Section 5 of this analysis discusses the costs and benefits of this alternative relative to the regulatory baseline (Alternative 1).

4. Estimation and Evaluation of Costs and Benefits This section presents the process for evaluating the costs and benefits expected to result from each proposed alternative relative to the regulatory baseline (Alternative 1). All costs and benefits are monetized, when possible. The total costs and benefits are then summed to determine whether the difference between the costs and benefits results in a positive benefit. In some cases, costs and benefits are not monetized because meaningful quantification is not possible.

4.1 Identification of Affected Attributes This section identifies the components of the public and private sectors, commonly referred to as attributes, that are expected to be affected by the alternatives identified in Section 3. The alternatives would apply to licensees and applicants for nuclear power plants and nuclear power plant design certifications. The NRC believes that nuclear power plant licensees would be the primary beneficiaries. The staff developed an inventory of the impacted attributes using the list in NUREG/BR-0058, draft Revision 5, Regulatory Analysis Guidelines of the U.S. Nuclear Regulatory Commission, issued April 2017 (NRC, 2017h).

The rule would affect the following attributes:

Public Health (Accident). This attribute accounts for expected changes in radiation exposure to the public caused by changes in accident frequencies or accident consequences associated with the alternative (i.e., delta risk). Alternative 2, compared to the regulatory baseline (Alternative 1), meets the NRCs goal of ensuring the protection of public health and safety and the environment by continuing to provide the NRCs approval of new ASME Code Cases that allow the use of the most current methods and technology and that may decrease the likelihood of an accident and, therefore, decrease the overall risk to public health.

Occupational Health (Accident). This attribute measures immediate and long-term health effects experienced by site workers because of changes in accident frequency or accident consequences associated with the alternative (i.e., delta risk). A decrease in worker radiological exposure is a decrease in risk (i.e., a benefit); an increase in worker exposures is an increase in risk (i.e., a negative benefit). The use of ASME Code Cases may decrease the incremental risk to occupational health following an accident, but this effect is not easily quantifiable. For example, advances in ISI and IST may lead to an

7 incremental decrease in the frequency of an accident, resulting in averted worker postaccident radiological exposure when compared to the regulatory baseline.

Occupational Health (Routine). This attribute accounts for radiological exposures to workers during normal facility operations (i.e., nonaccident situations). Some operations will cause an increase in worker exposures; sometimes this increase will be a one-time effect (e.g., installation or modification of equipment in a radiation area), and sometimes it will be an ongoing effect (e.g., routine surveillance or maintenance of contaminated equipment or equipment in a radiation area). The use of ASME Code Cases may affect occupational health as a result of radiological exposure during the time required to perform additional weld examinations and pressure testing called for in the Code Case conditions. This additional work will result in increased occupational radiation exposure when compared to the regulatory baseline.

Industry Implementation. This attribute accounts for the projected net economic effect on the affected licensees as they implement the mandated changes. Costs include procedural and administrative activities related to maintenance, inspection, or testing procedures.

Industry Operation. This attribute accounts for the projected net economic effect on all affected licensees caused by routine and recurring activities required by the alternative.

Under Alternative 2, a licensee of a nuclear power plant would no longer be required to submit a Code Case alternative request under the 10 CFR 50.55a(z), which would provide a net benefit (i.e., averted cost) to the licensee.

Under 10 CFR 50.55a, the NRC requires nuclear power plant owners to construct Class 1, 2, and 3 components in accordance with Section III, Division 1, of the ASME BPV Code. Under 10 CFR 50.55a, the NRC also requires owners to perform ISI of Class 1, Class 2, Class 3, Class MC, and Class CC components in accordance with Section XI, Division 1, of the ASME BPV Code and to perform IST of Class 1, Class 2, and Class 3 safety-related pumps and valves in accordance with the ASME OM Code.

Until 2012, ASME issued new editions of the BPV Code every 3 years and addenda to the editions annually except in the years when a new edition was issued. Similarly, ASME has published new editions and addenda of the ASME OM Code regularly.

Starting in 2012, ASME decided to issue editions of its BPV and OM Code (no addenda) every 2 years. ASME also publishes Code Cases quarterly (ASME BPV Code Sections III and XI) or every 2 years (ASME OM Code) to provide alternatives to existing Code requirements developed and approved by ASME. Code Cases are developed to allow licensees to gain experience with new technology before its incorporation into the ASME Code, permit licensees to use advances in ISI and IST, provide alternative examinations for older plants, respond promptly to user needs, and offer a limited and clearly focused alternative to specific ASME Code provisions.

8 Under Alternative 2, licensees and applicants are allowed to implement endorsed ASME Code Cases and their conditions and modifications without seeking prior NRC approval.

This alternative continues the NRCs use of periodic rulemakings to incorporate by reference in 10 CFR 50.55a the latest RGs that list NRC-approved alternatives to the provisions of the ASME BPV and OM Codes.

The Code Case requests and subsequent costs are considered sunk (i.e., already incurred) for issued design certifications, submitted design certifications under review, and reactor applications submitted to the NRC.

NRC Implementation. This attribute accounts for the projected net economic effect on the NRC to place the alternative into operation. To implement Alternative 2, the NRC incurs a cost in relation to Alternative 1 (i.e., regulatory baseline) for developing the proposed and final rule and updating corresponding guidance in RG 1.84, RG 1.147, and RG 1.192.

NRC Operation. This attribute accounts for the projected net economic effect on the NRC after the proposed action is taken. If the NRC does not approve an ASME Code Case that a licensee or applicant wants to use, the licensee or applicant typically will request, under 10 CFR 50.55a(z), permission to use the ASME Code Cases through a submittal. This submittal requires additional NRC staff time to evaluate the Code Case to determine its acceptability and whether any limitations or modifications should apply.

Under Alternative 2, these Code Case alternative requests would not be required, which results in a net benefit (i.e., averted cost) for the NRC.

Because the NRCs costs to review requests for Code Case alternatives submitted to the agency before the effective date of the final rule are sunk costs, this regulatory analysis does not consider them further.

Improvements in Knowledge. This attribute accounts for improvements in knowledge by industry and NRC staff gaining experience with new technology before its incorporation into the ASME Codes and by permitting licensees to use advances in ISI and IST.

Improvements in ISI and IST may also result in the earlier identification of material or equipment degradation that, if undetected, could cause further degradation that eventually leads to a plant transient or the unavailability of plant equipment to respond to a plant transient.

Regulatory Efficiency. This attribute accounts for regulatory and compliance improvements resulting from the implementation of Alternative 2 compared to the regulatory baseline. Alternative 2 would increase regulatory efficiency because licensees and applicants that wish to use NRC-approved ASME Code Cases would not require 10 CFR 50.55a(z) alternative requests. Further, Alternative 2 is consistent with the provisions of the NTTAA that encourage Federal agencies to consider adopting voluntary consensus standards as an alternative to de novo agency development of

9 standards affecting an industry. Alternative 2 is consistent with the NRCs policy of evaluating the latest versions of consensus standards in terms of their suitability for endorsement by regulations and RGs. In addition, Alternative 2 is consistent with the NRCs goal to harmonize with international standards to improve regulatory efficiency for both the NRC and international standards groups.

Other Considerations. This attribute accounts for considerations that are not captured in the preceding attributes. Specifically, this attribute accounts for how Alternative 2 meets specific requirements of the Commission, helps achieve NRC policy, and provides other advantages or detriments.

Attributes with No Effects. Attributes that are not expected to contribute to the results under any of the alternatives include public health (routine); offsite property; onsite property; other government, general public, safeguards and security considerations; and environmental considerations addressing Section 102(2) of the National Environmental Policy Act of 1969.

4.2 Analytical Methodology This section describes the process used to evaluate costs and benefits associated with the proposed alternatives. The benefits include any desirable changes in affected attributes (e.g., monetary savings, improved safety, and improved security). The costs include any undesirable changes in affected attributes (e.g., monetary costs, increased exposures).

Of the 10 affected attributes, the analysis quantitatively evaluates fourindustry implementation, industry operation, NRC implementation, and NRC operation. Quantitative analysis requires a baseline characterization of the affected society, including factors such as the number of affected entities, the nature of the activities currently performed, and the types of systems and procedures that licensees or applicants would implement, or would no longer implement, because of the proposed alternatives. Where possible, the staff calculated costs for these four attributes using three-point estimates to quantify the uncertainty in these estimates.

The detailed cost tables used in this regulatory analysis are included in the individual sections for each of the provisions. The staff evaluated the remaining six attributes qualitatively because the benefits relating to consistent policy application and improvements in ISI and IST techniques are not easily quantifiable or because the data necessary to quantify and monetize the impacts on these attributes are not available.

The staff documents its assumptions throughout this regulatory analysis. For reader convenience, Appendix A summarizes the major assumptions and input data used in this analysis.

10 4.2.1 Regulatory Baseline This regulatory analysis provides the incremental impacts of the proposed rule relative to a baseline that reflects anticipated behavior if the NRC does not undertake regulatory or nonregulatory action. The regulatory baseline assumes full compliance with existing NRC requirements, including current regulations and relevant orders. This is consistent with NUREG/BR-0058, draft Revision 5, which states that in evaluating a new requirement, the staff should assume that all existing NRC and Agreement State requirements have been implemented. Section 5 of this regulatory analysis presents the estimated incremental costs and benefits of the alternatives compared to this baseline.

4.2.2 Affected Entities This proposed rule could affect all operating light-water nuclear power reactors and those operating in the future:

Nuclear facilities. The analysis models 59 plant sites containing one or more operating U.S. light-water nuclear power reactor units in 2019, 55 plant sites in 2021, and 52 plant sites in 2024.1 Operating reactor units. The analysis models 98 reactor units in 2019, 95 reactor units in 2021, and 91 reactor units in 2024. Table 2 shows the operating plant and site numbers used in this analysis across the 6 years of the Code Cases.

Table 2 Operating Reactor and Site Information Future operating reactor units. The staff assumes that the proposed rule would affect five future operating light-water nuclear power reactor units. The future nuclear power 1

The staff assumes that Oyster Creek Nuclear Generating Station will close in 2018 and Three Mile Island Nuclear Station, Unit 1, will close in 2019 based on Exelon Corporations announcements (http://www.exeloncorp.com). The staff assumes that Pilgrim Nuclear Power Station will close in 2019 based on Entergy Nuclear Operations, Inc.s announcement (http://www.entergy.com) and Davis-Besse Nuclear Power Station, Unit 1, will close in 2020 based on FirstEnergy Nuclear Operating Companys announcement (http://www.firstenergycorp.com).

2019 98 59 2020 96 57 2021 95 55 2022 92 53 2023 91 52 2024 91 52 Sites Operating Plants Year

11 reactors considered in this analysis (due to the Code Cases involved) include Vogtle Electric Generating Plant, Units 3 and 4. As of April 2018, eight power reactors that have no published construction schedule hold combined licenses. These reactors are Fermi, Unit 3; Levy Nuclear Plant, Units 1 and 2; North Anna, Unit 3; South Texas Project, Units 3 and 4; and William States Lee III Nuclear Station, Units 1 and 2.

Because of this schedule uncertainty, including all of these plants in this analysis is too speculative, so the staff made an assumption that the Code Cases will affect three of them.

4.2.3 Base Year All monetized costs are expressed in 2019 dollars. Ongoing costs of operation related to the alternative being analyzed are assumed to begin no earlier than 30 days after publication of the final rule in the Code of Federal Regulations unless otherwise stated, and they are modeled on an annual cost basis. The staff assumes that the rule will be effective in 2019.

Estimates are made for one-time NRC implementation costs. The NRC assumes that these costs will be incurred in years 2018 and 2019.

Estimates are made for recurring annual operating expenses. The values for annual operating expenses are modeled as a constant expense for each year of the analysis horizon. The staff performed a discounted cash flow calculation to discount these annual expenses to 2019 dollar values.

4.2.4 Discount Rates In accordance with guidance from U.S. Office of Management and Budget (OMB) Circular No. A-4, Regulatory Analysis, issued September 2003 (OMB, 2003), and NUREG/BR-0058, draft Revision 5, net present value (NPV) calculations are used to determine how much society would need to invest today to ensure that the designated dollar amount is available in a given year in the future. By using NPVs, costs and benefits, regardless of when the cost or benefit is incurred, are valued to a reference year for comparison. The choice of a discount rate and its associated conceptual basis is a topic of ongoing discussion within the Federal Government.

Based on OMB Circular No. A-4 and consistent with NRC past practice and guidance, present-worth calculations in this analysis use 3-percent and 7-percent real discount rates. A 3-percent discount rate approximates the real rate of return on long-term Government debt, which serves as a proxy for the real rate of return on savings to reflect reliance on a social rate of time preference discounting concept.2 A 7-percent discount rate approximates the marginal pretax real rate of return on an average investment in the private sector, and it is the appropriate discount rate whenever the main effect of a regulation is to displace or alter the use of capital in 2

The social rate of time preference discounting concept refers to the rate at which society is willing to postpone a marginal unit of current consumption in exchange for more future consumption.

12 the private sector. A 7-percent rate is consistent with an opportunity cost3 of capital concept to reflect the time value of resources directed to meet regulatory requirements.

4.2.5 Cost/Benefit Inflators The staff estimated the analysis inputs for some attributes based on the values published in the NUREG/BR-0184, Regulatory Analysis Technical Evaluation Handbook (NRC, 1997), or other sources as referenced, which are provided in prior-year dollars. To evaluate the costs and benefits consistently, these inputs are put into base-year dollars. The most common inflator is the Consumer Price Index for All Urban Consumers (CPI-U), developed by the U.S. Department of Labor, Bureau of Labor Statistics (BLS). Using the CPI-U, the prior-year dollars are converted to 2019 dollars. The following formula is used to determine the amount in 2019 dollars:

=

Table 3 summarizes the values of CPI-U used in this regulatory analysis.

Table 3 CPI-U Inflator Base Year CPI-U Annual Averagea Actual/Forecast Percent Change from Previous Year 2016 240.007 2017 245.120 2.13%

2018 251.002 2.4%

2019 257.027 2.4%

Sources:

a BLS Statistics, Databases, Tables & Calculators by

Subject:

CPI Inflation Calculator (BLS, 2018).

b Congressional Budget Office, The Budget and Economic Outlook: 2017 to 2027, issued January 2017 (Congressional Budget Office, 2017).

4.2.6 Labor Rates For the purposes of this regulatory analysis, the staff applied strict incremental cost principles to develop labor rates that include only labor and material costs that are directly related to the implementation and operation and maintenance of the proposed rule requirements. This approach is consistent with the guidance in NUREG/CR-3568, A Handbook for Value-Impact 3

Opportunity cost represents what is foregone by undertaking a given action. If the licensee personnel were not engaged in revising procedures, they would be occupied by other work activities. Throughout the analysis, the NRC estimates the opportunity cost of performing these incremental tasks as the industry personnels pay for the designated unit of time.

13 Assessment, issued December 1983 (NRC, 1983), and general cost-benefit methodology. The NRC incremental labor rate is $131 per hour.4 The staff used the 2017 BLS Occupational Employment and Wages data (www.bls.gov), which provided labor categories and the mean hourly wage rate by job type, and used the inflator discussed above to inflate these labor rate data to 2019 dollars. The labor rates used in the analysis reflect total hourly compensation, which includes wages and nonwage benefits (using a burden factor of 2.4, applicable for contract labor and conservative for regular utility employees).

The staff used the BLS data tables to select appropriate hourly labor rates for performing the estimated procedural, licensing, and utility-related work necessary during and following implementation of the proposed alternative. In establishing this labor rate, wages paid to the individuals performing the work plus the associated fringe benefit component of labor cost (i.e., the time for plant management over and above those directly expensed) are considered incremental expenses and are included. Table 4 summarizes the BLS labor categories that were used to estimate industry labor costs to implement this proposed rule, and Appendix A lists the industry labor rates used in the analysis. The staff performed an uncertainty analysis, which is discussed in Section 5.13.

Table 4 Position Titles and Occupations Position Title (in This Regulatory Analysis)

Standard Occupational Classification (SOC Code)

Managers Top Executives (111000)

Chief Executives (111011)

General and Operations Managers (111021)

Industrial Production Managers (113051)

First-Line Supervisors of Mechanics Installers and Repairers (491011)

First-Line Supervisors of Production and Operating Workers (511011)

Technical Staff Nuclear Engineers (172161)

Physicists (192012)

Nuclear Technicians (194051)

Industrial Machinery Mechanics (499041)

Nuclear Power Reactor Operators (518011)

Administrative Staff Office and Administrative Support Occupations (430000)

First-Line Supervisors of Office and Administrative Support Workers (431011)

Office Clerks, General (439061)

Licensing Staff Lawyers (231011)

Paralegals and Legal Assistants (232011)

Source: BLS, NAICS Code: North American Industry Classification System Code, (BLS, 2017a) 4 The NRC labor rates presented here differ from those developed under the NRCs license fee recovery program (10 CFR Part 170, Fees for Facilities, Materials, Import and Export Licenses, and Other Regulatory Services under the Atomic Energy Act of 1954, as Amended). NRC labor rates for fee recovery purposes are appropriately designed for full-cost recovery of the services rendered and thus include nonincremental costs (e.g., overhead, administrative, and logistical support costs).

14 4.2.7 Sign Conventions The sign conventions used in this analysis are that all favorable consequences for the alternative are positive and all adverse consequences for the alternative are negative. Negative values are shown using parentheses (e.g., negative $500 is displayed as ($500)).

4.2.8 Analysis Horizon The ASME Code Cases are in effect for a span of 3 years, renewable once for 3 additional years, for a total of 6 years.

4.2.9 Cost Estimation To estimate the costs associated with the evaluated alternatives, the staff used a work breakdown approach to deconstruct each requirement down to its mandated activities. For each required activity, the NRC further subdivided the work across labor categories (i.e., executives, managers, technical staff, administrative staff, and licensing staff). The staff estimated the required level of effort (LOE) for each required activity and used a blended labor rate to develop bottom-up cost estimates.

The staff gathered data from several sources and consulted ASME Code working group members to develop LOE and unit cost estimates. The staff applied several cost estimation methods in this analysis and used its collective professional knowledge and judgment to estimate many of the costs and benefits. Additionally, the staff used a buildup method, solicitation of licensee input, and extrapolation techniques to estimate costs and benefits.

The staff began by estimating some activities using the engineering buildup method of cost estimation, which combines incremental costs of an activity from the bottom up to estimate a total cost. For this step, the NRC reviewed previous license submittals, determined the number of pages in each section, and then used these data to develop preliminary LOEs.

The staff consulted subject matter experts within and outside the agency to develop most of the LOE estimates used in the analysis. For example, to estimate licensee costs and averted costs (benefits) related to the NRC conditions on the ASME Codes in the proposed rule, the staff consulted licensees for information on the associated LOE. The staff contributed to the estimation of LOE for review-related activities.

The staff extrapolated to estimate some cost activities, relying on actual past or current costs to estimate the future cost of similar activities. For example, to calculate the estimated averted costs of alternative requests and the costs for preparation of the proposed rule and accompanying regulatory guidance, the staff used data from past projects to determine the labor categories of the staff who would perform the work and estimate the amount of time required

15 under each category to complete the work. If data were not available, the staff estimated the LOE based on similar steps in the process for which data were available.

To evaluate the effect of uncertainty in the model, the staff employed Monte Carlo simulation, which is an approach to uncertainty analysis in which input variables are expressed as distributions. The simulation was run 10,000 times and values were chosen at random from the distributions of the input variables provided in Table 22. The result was a distribution of values for the output variable of interest. Monte Carlo simulation also enables users to determine the input variables that have the greatest effect on the value of the output variable. Section 5.13 gives a detailed description of the Monte Carlo simulation methods and presents the results.

4.2.10 NRC Conditioned Code Cases The NRC staff analyzes ASME Code Cases to determine whether the Code Cases are (1) acceptable without conditions, (2) generally acceptable with conditions, or (3) not approved.

When the NRC generally approves Code Cases with conditions, licensees may incur additional regulatory burden to meet the conditioned Code Cases (i.e., Code Cases with new conditions as a result of this proposed rule). The conditions would specify (for each applicable Code Case) the additional activities that must be performed, the limits on the activities specified in the Code Case, and the supplemental information needed to provide clarity. Table 2 of DG-1342, DG-1343, and DG-1345 includes these ASME Code Cases. The proposed rule and the DGs discuss the NRCs evaluation of the Code Cases and the reasons for the agencys conditions.

The conditioned Code Cases would place an additional resource burden on licensees under the affected attribute of industry operation. Table 5 lists these conditioned Code Cases for this proposed rule.

Table 5 Conditioned Code Cases DG Listing Conditioned Code Case Number New Condition Descriptiona Incremental Resources Requiredb DG-1345 N-71-19

1. The maximum measured ultimate tensile strength (UTS) of the component support material must not exceed 170 ksi in view of the susceptibility of high strength materials to brittleness and stress corrosion cracking.

2. In the last sentence of paragraph 5.2 of Code Case N-71-19, reference must be made to paragraph 5.3.2.3, Alternative Atmosphere Exposure Time Periods Established by Test, of the AWS D1.1 Code for the evidence presented to and accepted by the Authorized Inspector concerning exposure of electrodes for a longer period of time.

3. Paragraph 16.2.2 of Code Case N-71-19 is not acceptable as written and must be replaced with the following: When not exempted by 16.2.1 above, the post weld heat treatment must be performed in accordance with NF-4622 except that ASTM A-710 Grade A Material must be at least 1000°F (540°C) and must not exceed

1. This condition is identical to the condition in the previous version of the Code Case; no incremental resources.

2. This condition is identical to another condition in the previous version of the Code Case; no incremental resources.

3. This condition is identical to another condition in the previous version of the Code Case; no incremental resources.

4. This condition is functionally identical to another condition in the previous version of the Code Case, except for

16 DG Listing Conditioned Code Case Number New Condition Descriptiona Incremental Resources Requiredb 1150°F (620°C) for Class 1 and 2 material and 1175°F (640°C) for Class 3 material.

4. The new holding time-at-temperature for weld thickness (nominal) must be 30 minutes for welds 1/2 inch or less, 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months per inch of thickness for welds over 1/2 inch to 5 inches, and for thicknesses over 5 inches, 5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months plus 15 minutes for each additional inch over 5 inches.

5. The fracture toughness requirements as listed in this Code Case apply only to piping supports and not to Class 1, 2 and 3 component supports.

6. When welding P-Number materials listed in the Code Case, the corresponding S-Number welding requirements shall apply.

correction of a typo; no incremental resources.

5. This condition is identical to another condition in the previous version of the Code Case; no incremental resources.

6. This new condition is an administrative change to address the relabeling of S-Number materials to P-number materials; no incremental resources.

DG-1342 N-516-4

1. Licensees must obtain NRC approval in accordance with 10 CFR 50.55a(z) regarding the welding technique to be used prior to performing welding on ferritic material exposed to fast neutron fluence greater than 1 x 1017 n/cm2 (E > 1 MeV).

2. Licensees must obtain NRC approval in accordance with 10 CFR 50.55a(z) regarding the welding technique to be used prior to performing welding on austenitic material other than P-No. 8 material exposed to thermal neutron fluence greater than 1 x 1017 n/cm2 (E < 0.5 eV).

3. Licensees must obtain NRC approval in accordance with 10 CFR 50.55a(z) regarding the welding technique to be used prior to performing welding on P-No. 8 austenitic material exposed to thermal neutron fluence greater than 1 x 1017 n/cm2 (E < 0.5 eV) and measured or calculated helium concentration of the material greater than 0.1 atomic parts per million.

Conditions 1-3 clarify the existing condition of N-516-3 to be consistent with existing requirements in ASME BPV Code,Section XI, IWA-4660.

DG-1342 N-597-3

1. The corrosion rate shall be reviewed and approved by the NRC prior to the use of this Code Case.

2. Code Case must be supplemented by the provisions of EPRI Nuclear Safety Analysis Center Report 202L-2 for developing the inspection requirements, the method of predicting the rate of wall thickness loss, and the value of the predicted remaining wall thickness.

3. Components affected by flow-accelerated corrosion to which this Code Case are applied must be repaired or replaced in accordance with the construction code of record and Owners requirements or a later NRC approved edition of Section III of the ASME Code prior to the value of tp reaching the allowable minimum wall thickness, tmin, as specified in -3622.1(a)(1) of this Code Case.

4. For those components that do not require immediate repair or replacement, the rate of wall thickness loss is to be used to determine a suitable inspection frequency so that repair or replacement occurs prior to reaching allowable minimum wall thickness, tmin.

1. Substantivelly similar condition exists in N-597-2; therefore, no incremental resources.

2. Identical condition exists in N-597-2; therefore, no incremental resources.

3. Identical condition exists in N-597-2; therefore, no incremental resources.

4. Substantively identical condition exists in N-597-2; therefore, no incremental resources.

5. Substantively identical condition exists in N-597-2; therefore, no incremental resources.

6. Substantially similar condition exists in N-597-2; therefore, no incremental resources.

17 DG Listing Conditioned Code Case Number New Condition Descriptiona Incremental Resources Requiredb

5. Allows the use of this Code Case to calculate wall thinning for moderate-energy Class 2 and 3 piping using criteria in Code Case N-513-2, for temporary acceptance until the next refueling outage.

6. Prohibit the use of this Code Case in evaluating through-wall leakage conditions.

DG-1342 N-606-2

1. Prior to welding, an examination or verification must be performed to ensure proper preparation of the base metal, and that the surface is properly contoured so that an acceptable weld can be produced. This verification is to be required in the welding procedure.

1. Identical condition exists in N-606-1; therefore, no incremental resources.

DG-1342 N-638-7

1. Demonstration for ultrasonic examination of the repaired volume is required using representative samples which contain construction type flaws.

1. Identical condition exists in N-638-6; therefore, no incremental resources.

DG-1342 N-648-2

1. This Code Case shall not be used to eliminate the preservice or inservice volumetric examination of plants with a Combined Operating License pursuant to 10 CFR Part 52, or a plant that receives its operating license after October 22, 2015.

1. Incremental resources for inservice examinations, but not for preservice examinations, which were already prohibited by the previous version of the Code Case.

DG-1342 N-695-1

1. Inspectors qualified using the 0.25 RMS error for measuring the depths of flaws using N-695-1 are not qualified to depth-size inner diameter (ID) surface breaking flaws greater than 50% through-wall in dissimilar metal welds 2.1 inches or greater in thickness. When an inspector qualified using N-695-1 measures a flaw as greater than 50% through-wall in a dissimilar metal weld from the inner diameter the flaw shall be considered to have an indeterminate depth.

1. This condition would result in a requirement for a verbal review of the weld with NRC staff, resulting in incremental resources. In over 15 years of operating experience, however, this situation has not occurred.

Incremental resources based on an assumption that this would happen one time in 6 years.

DG-1342 N-696-1

1. Inspectors qualified using the 0.25 RMS error for measuring the depths of flaws using N-696-1 are not qualified to depth-size inner diameter (ID) surface breaking flaws greater than 50% through-wall in welds 2.1 inches or greater in thickness.

When an inspector qualified using N-696-1 measures a flaw as greater than 50%

through-wall in a weld from the inner diameter the flaw shall be considered to have an indeterminate depth.

1. This condition would result in a requirement for a verbal review of the weld with NRC staff, resulting in incremental resources. In over 15 years of operating experience, however, this situation has not occurred.

Incremental resources based on an assumption that this would happen one time in 6 years.

DG-1342 N-702

1. The applicability of Code Case N-702 for the first 40 years of operation must be demonstrated by satisfying the criteria in Section 5.0 of NRC Safety Evaluation regarding BWRVIP-108 dated December 18, 2007 (ML073600374) or Section 5.0 of NRC Safety Evaluation regarding BWRVIP-241 dated April 19, 2013 (ML13071A240).

2. The use of Code Case N-702 in the period of extended operation is prohibited.

1. This condition is consistent with the approach used by licensees before the Code Case existed; no incremental resources.

2. This condition is consistent with the approach used by licensees before the Code Case

18 DG Listing Conditioned Code Case Number New Condition Descriptiona Incremental Resources Requiredb

3. If VT-1 is used, it shall utilize ASME Code Case N-648-2, Alternative Requirements for Inner Radius Examination of Class 1 Reactor Vessel Nozzles,Section XI Division 1, with associated required conditions specified in Regulatory Guide 1.147.

existed; no incremental resources.

3. This condition is consistent with the approach used by licensees before the Code Case existed; no incremental resources.

DG-1342 N-705

1. The ASME Code repair or replacement activity temporarily deferred under the provisions of this Code Case shall be performed during the next scheduled refueling outage. If a flaw is detected during a scheduled shutdown, an ASME code repair is required before plant restart.

1. Incremental cost due to earlier performance of these activities compared to the 26-month allowance in the Code Case.

DG-1342 N-711-1

1. The Code Case shall not be used to redefine the required examination volume for preservice examinations or when the postulated degradation mechanism for piping welds is PWSCC, Intergranular Stress Corrosion Cracking (IGSCC) or crevice corrosion (CC) degradation mechanisms.

1. Clarifications: There is no degradation mechanism present during preservice; the Code Case refers to the owners program for IGSCC and does not provide direction for CC. Therefore, no cost.

DG-1342 N-754-1

1. The conditions imposed on the optimized weld overlay design in the NRC safety evaluation for MRP-169, Revision 1-A must be satisfied.

2. In lieu of the pre-service and inservice examinations as specified in Section 3(c) of the Code Case, the optimized weld overlay must be examined in accordance with 10 CFR 50.55a(g)(6)(ii)(F).

3. The weld overlay in this Code Case can only be installed on an Alloy 82/182 weld where the outer 25 percent of weld wall thickness does not contain indications that are greater than 1/16 inch in length or depth.

1. Identical condition exists in N-754; therefore, no incremental resources.

2. Identical condition exists in N-754; therefore, no incremental resources.

3. Clarification of what it means to be capable of compliance per paragraph 1.1b of the Code Case; no incremental resources.

DG-1342 N-766-1

1. Credit cannot be taken to reduce preservice and inservice inspection requirements specified by this Code Case on an inlay or onlay if an inlay or onlay is applied to an Alloy 82/182 dissimilar metal weld which contains an axial indication that has a depth of more than 25 percent of the pipe wall thickness and a length of more than half axial width of the dissimilar metal weld, or a circumferential indication that has a depth of more than 25 percent of the pipe wall thickness and a length of more than 20 percent of the circumference of the pipe.

2. In lieu of paragraph 2(e) of the Code Case, pipe with any thickness of inlay or onlay must be evaluated for weld shrinkage, pipe system flexibility, and additional weight of the inlay or onlay.

3. If an inlay or onlay is applied to an Alloy 82/182 dissimilar metal weld which contains an indication that exceeds the acceptance standards of IWB-3514 and is accepted for continued service in accordance with IWB-3132.3 or IWB-3142.4, the subject weld must be

1. Incremental resources to use N-754-1 for welds that do not meet these requirements.

2. Clarification of weld examination process; no incremental resources.

3. Clarification of existing requirements; no incremental resources.

4. Clarification of the expectations of the welding process; no incremental resources.

5. Clarification of the expectations of paragraph 2d of the Code Case; no incremental resources.

19 DG Listing Conditioned Code Case Number New Condition Descriptiona Incremental Resources Requiredb inspected in three successive examinations after inlay or onlay installation.

4. Any detectable subsurface indication discovered by eddy current testing in the inlay or onlay during acceptance examinations is prohibited to remain in service.

5. The flaw analysis of paragraph 2(d) of the case shall also consider primary water stress corrosion cracking growth in the circumferential and axial directions, in accordance with IWB-3640.

DG-1342 N-824

1. Instead of Paragraph 1(c)(1)(-c)(-2), licensees shall use a phased array search unit with a center frequency of 500 kHz with a tolerance of

+/- 20 percent.

2. Instead of Paragraph 1(c)(1)(-d), the phased array search unit must produce angles including, but not limited to, 30 to 55 degrees with a maximum increment of 5 degrees.

1. Condition already incorporated by reference into 10 CFR 50.55a; no incremental resources.

2. Condition already incorporated by reference into 10 CFR 50.55a; no incremental resources.

DG-1342 N-829

1. The provisions of this Code Case, paragraph 3(e)(2) or 3(e)(3) may only be used when it is impractical to use the interpass temperature measurement methods described in paragraph 3(e)(1), such as in situations where the weldment area is inaccessible or when there are extenuating radiological conditions.

1. There is no appreciable cost difference between the temperature measurement techniques of these paragraphs; therefore, no incremental resources expected.

DG-1342 N-830

1. The use of the provision in Paragraph (f) of the Code Case that allows for the use of an alternative to limiting the lower shelf of the 95% lower tolerance bound Master Curve toughness, KJC-lower 95%, to a value consistent with the current KIC curve is prohibited.

1. Clarification to ensure a single methodology is applied to the entire curve used in the analysis; no incremental resources.

DG-1342 N-831

1. The Code Case is prohibited for use in new reactor construction.

1. New reactors can use radiography instead of N-831, resulting in no incremental costs because there is no need to shut down or lengthen an outage; no incremental resources.

DG-1342 N-838

1. Code Case N-838 shall not be used to evaluate flaws in cast austenitic stainless steel piping where the delta ferrite content exceeds 25 percent.

1. Incremental costs to provide a relief request to the NRC before using the Code Case.

DG-1342 N-843

1. If the portions of the system requiring pressure testing are associated with more than one safety function the pressure test and visual examination VT-2 shall be performed during a test conducted at the higher of the operating pressures for the respective system safety functions.

1. Clarification that test should be performed at the higher pressure as per standard procedure; no incremental cost.

DG-1342 N-849

1. Use of the Code Case is limited to plants that are designed with accessible core support structures to allow for in-situ inspection.

2. Prior to initial plant startup, the VT-3 preservice examination shall be performed with the core support structure removed, and shall include all surfaces that are accessible when the core support structure is removed, including all load bearing and contact surfaces.

1. Clarification of the intent of the Code Case as it passed through committee; the Code Case does not apply to the current operating fleet; no incremental resources.

20 DG Listing Conditioned Code Case Number New Condition Descriptiona Incremental Resources Requiredb

2. Clarification of existing code requirements; no incremental resources.

a This information is copied directly from the respective draft regulatory guide.

b These incremental resources are the additional resources necessary to conform to the NRC conditioned Code Case when (1) using the same Code Case with no NRC conditions as the baseline, (2) new Code Cases, or (3) the existing edition of the Code Case as the baseline if the Code Case is not new.

4.3 Data This analysis discusses the data and assumptions used in analyzing the quantifiable impacts associated with each proposed alternative. The staff used data from subject matter experts, knowledge gained from past rulemakings, and information gathered during public meetings and from correspondence to collect data for this analysis. Quantitative and qualitative (i.e., nonquantified) information on attributes affected by the proposed regulatory framework alternatives in the proposed rule came from the staff and from comments on the regulatory analyses provided with the proposed rule. The NRC considered the potential differences between the new requirements and the current requirements and incorporated the proposed incremental changes into this regulatory analysis.

5. Results This section presents the quantitative and qualitative results by attribute relative to the regulatory baseline. As described in the previous sections, costs and benefits are quantified where possible and can have either a positive or a negative algebraic sign, depending on whether the alternative has a favorable or adverse effect compared to the regulatory baseline (Alternative 1). This section discusses those attributes that are not easily represented in monetary values. Although this ex ante cost-benefit analysis5 provides information that can be used when deciding whether to select an alternative, the analysis is based on estimates of the future costs and benefits. Whether the estimates hold in the future, the process of conducting regulatory analyses has value in and of itself because it helps decisionmakers think in depth about specific alternatives and their associated results.

The NRCs regulatory analysis guidelines (NUREG/BR-0058) state that the NRCs periodic review and endorsement of consensus standards, such as new versions of the ASME Code and associated Code Cases, is a special case because consensus standards have already undergone extensive external review and have been endorsed by industry. In addition, endorsement of the ASME Code and Code Cases has been a longstanding NRC policy.

Licensees and applicants participate in the development of the ASME Code and Code Cases and are aware that periodic updating of the ASME Code is part of the regulatory process. Code Cases are ASME-developed alternatives to the ASME BPV and OM Codes that licensees and 5

An ex ante cost-benefit analysis is prepared before a policy, program, or alternative is in place and can assist in the decision about whether resources should be allocated to that alternative.

21 applicants may voluntarily choose to adopt without an alternative request if the Code Cases are approved through incorporation by reference in the NRCs regulations. Finally, endorsement of the ASME Code and Code Cases is consistent with the NTTAA, inasmuch as the NRC has determined that sound regulatory reasons exist for establishing regulatory requirements for design, maintenance, ISI, and IST and examination by rulemaking.

In a typical incorporation of Code Cases, the NRC endorsements can involve hundreds, if not thousands, of individual provisions. Evaluating the benefit in relation to the cost of each individual provision in this regulatory analysis would be prohibitive, and such an exercise would have limited value. Thus, this regulatory analysis does not evaluate individual requirements of the consensus standards.

5.1 Public Health (Accident)

Industry practice to adopt ASME BPV and OM Code Cases through incorporation by reference into the regulations may incrementally reduce the likelihood of a radiological accident in a positive, but not easily quantifiable, manner. Pursuing Alternative 2 would continue to meet the NRCs goal of maintaining safety by still providing the NRCs approval of new ASME Code Cases to allow licensees to gain experience with new technology before its incorporation into the ASME Code. Alternative 2 would also permit licensees to use advances in ISI and IST, provide alternative examinations for older plants, respond promptly to user needs, and offer a limited and clearly focused alternative to specific ASME Code provisions. Improvements in ISI and IST may also result in the earlier identification of material degradation that, if undetected, could lead to further degradation that eventually causes a plant transient. For these reasons, Alternative 2 maintains the same level of, or may provide an incremental improvement in, safety when compared to the regulatory baseline.

5.2 Occupational Health (Accident and Routine)

The NRCs practice of reviewing ASME BPV and OM Code Cases, determining their acceptability, and specifying its finding in RGs that are incorporated by reference into the regulations ensures that the mandated ASME Code requirements and approved Code alternatives result in an acceptable level of quality and safety. Pursuing Alternative 2 (the rule alternative) would continue to meet the NRCs goal of maintaining safety, permitting licensees to use ISI and IST advancements, providing alternative examinations, responding to user needs, and offering alternatives to ASME Code provisions. The NRC expects that licensees and applicants voluntary use of NRC-approved Code Cases would reduce occupational radiation exposure in a positive, but not easily quantifiable, manner. For example, the NRC staff expects that the use of the approved Code Cases would result in an incremental decrease in the likelihood of an accident and would reduce worker radiological exposures during routine inspections or testing when compared to the regulatory baseline.

22 The rule alternative would allow licensees and applicants to voluntarily apply NRC-approved Code Cases, sometimes with NRC-specified conditions. The NRC lists the approved Code Cases in three RGs that are incorporated by reference in 10 CFR 50.55a.

5.3 Industry Implementation This attribute accounts for the projected net economic effect on the affected licensees as a result of implementing the proposed regulatory changes (conditions on the ASME Code Editions). Additional costs above the regulatory baseline are negative, and cost savings and averted costs are positive.

5.3.1 Additional Materials for Subsection NF, Class 1, 2, 3, and Metal Containment Supports Fabricated by Welding The first condition on Code Case N-71-19 is identical to the first condition on Code Case N-71-18, which the NRC first approved in Revision 33 of RG 1.84 in August 2005. The condition stated the following:

The maximum measured ultimate tensile strength (UTS) of the component support material must not exceed 170 Ksi in view of the susceptibility of high-strength materials to brittleness and stress corrosion cracking.

Code Case N-71-19 does not address the reasons for imposing this condition; therefore, Revision 38 of RG 1.84 would retain this condition.

The second condition on Code Case N-71-19 is an update to the third condition in Revision 18 of the Code Case. This condition has been modified so that it references the correct sentence and paragraph of the revised Code Case and now refers to paragraph 5.2 of the Code Case, instead of paragraph 5.5 to cite the following:

5.3.2.3, Alternative Atmosphere Exposure Time Periods Established by Test, of the American Welding Society D1.1 Code for the evidence presented to and accepted by the Authorized Inspector concerning exposure of electrodes for a longer period of time.

The basis for this change is that the paragraph of the Code Case identified by this condition has been renumbered and is now 5.2. Code Case N-71-19 does not address the reasons for imposing this condition; therefore, Revision 38 of RG 1.84 will retain this condition.

The third condition on Code Case N-71-19 is substantively the same as the fourth condition on Code Case N-71-18, which the NRC first approved in Revision 33 of RG 1.84 in August 2005, except that it now references the renumbered paragraphs of the revised Code Case. The condition now reads as follows:

23 Paragraph 16.2.2 of Code Case N-71-19 is not acceptable as written and must be replaced with the following: When not exempted by 16.2.1 above, the post weld heat treatment must be performed in accordance with NF-4622 except that ASTM A-710 Grade A Material must be at least 1000°F (540°C) and must not exceed 1150°F (620°C) for Class 1 and 2 material and 1175°F (640°C) for Class 3 material.

Code Case N-71-19 does not address the reasons for imposing this condition; therefore, Revision 38 of RG 1.84 will retain this condition.

The fourth condition on Code Case N-71-19 is identical to the fifth condition on Code Case N-71-18, which the NRC first approved in Revision 33 of RG 1.84 in August 2005. The condition stated the following:

The new holding time-at-temperature for weld thickness (nominal) must be 30 minutes 1/2 inch or less, 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months per inch of thickness for welds over 1/2 inch to 5 inches, and for thicknesses over 5 inches, 5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months plus 15 minutes for each additional inch over 5 inches.

Code Case N-71-19 does not address the reasons for imposing this condition; therefore, Revision 38 of RG 1.84 will retain this condition.

The fifth condition on Code Case N-71-19 is identical to the sixth condition on Code Case N-71-18, which the NRC first approved in Revision 33 of RG 1.84 in August 2005. The condition stated, The fracture toughness requirements as listed in this Code Case apply only to piping supports and not to Class 1, 2 and 3 component supports. Code Case N-71-19 does not address the reasons for imposing this condition; therefore, Revision 38 of RG 1.84 will retain this condition.

The sixth condition is a new condition, which states that, when welding P-Number materials listed in the Code Case, the corresponding S-Number welding requirements shall apply. This Code Case revision, as well as all previous revisions, not only provides for the use of materials not listed in ASME Code Section II, Part D, but also provides exemptions to postweld heat treatment requirements listed in Section III, Article NF-4622, for materials up to 10.16 centimeters (4 inches) in thickness. Therefore, if a user applies this Code Case as written and uses a P-Number material listed in the tables that was previously assigned an S-Number, the user does not have to follow the special welding requirements unless it wishes to be exempted from the postweld heat treatment requirements listed in NF-4622. Using materials assigned an S-Number in the Code Case would still require the user to follow all special welding requirements regardless of whether postweld heat treatment is exempted. The staff believes that these special welding requirements should apply to P-Number materials whether the user wants to be exempted from postweld heat treatment or not, given that the materials have not changed. An additional condition on the use of this Code Case is warranted to address the

24 above. This new condition would not impose any additional restrictions on the use of this Code Case from those placed on the previous revisions.

The NRC estimates that no incremental industry implementation costs result from these identical, substantively identical, or administrative conditions.

5.3.2 Underwater Welding,Section XI, Division 1 RG 1.147 conditionally accepted the previously approved revision of this Code Case, N-516-3, to require that licensees obtain NRC approval in accordance with 10 CFR 50.55a(z) regarding the technique to be used in the weld repair or replacement of irradiated material underwater.

The rationale for this condition was the knowledge that materials subjected to high neutron fluence could not be welded without cracking. However, the condition applied to Code Case N-516-3 did not provide any guidance on what level of neutron irradiation could be considered a threshold for weldability.

The technical basis for imposing conditions on the welding of irradiated materials is that neutrons can generate helium atoms within the metal lattice through transmutation of various isotopes of boron or nickel. At high temperatures, such as those that occur during welding, these helium atoms rapidly diffuse though the metal lattice, forming helium bubbles. In sufficient concentration, these helium atoms can cause grain boundary cracking in the fusion zones and heat affected zones during the heatup/cooldown cycle.

During rulemaking for the 2009-2013 Editions of the ASME Code, in Final Regulatory Analysis for Final Rule: Incorporation by Reference of American Society of Mechanical Engineers Codes and Code Cases, issued April 2017 (NRC, 2017c), the NRC adopted conditions that should be applied to Section XI, Article IWA-4660, for underwater welding on irradiated materials. These conditions provide guidance on what level of neutron irradiation or helium content would require approval by the NRC because of the impact of neutron fluence on weldability, with separate criteria for three generic classes of material: ferritic material, austenitic material other than P-Number 8 (e.g., nickel-based alloys), and P-Number 8 austenitic material (e.g., stainless steel alloys). These conditions are currently listed in 10 CFR 50.55a(b)(2)(xii), and while they apply to underwater welding performed in accordance with IWA-4660, they do not apply to underwater welding performed in accordance with Code Case N-516-4.

Therefore, the staff proposes to approve Code Case N-516-4 with the following conditions for underwater welding. The first condition captures the 10 CFR 50.55a(b)(2)(xii) requirement for underwater welding of ferritic materials and states that licensees must obtain NRC approval in accordance with 10 CFR 50.55a(z) regarding the welding technique to be used before they perform welding on ferritic material exposed to fast neutron fluence greater than 1 x 1017 n/cm2 (E > 1 MeV). The second condition captures the 10 CFR 50.55a(b)(2)(xii) requirement for underwater welding of austenitic materials that are not P-Number 8 and states that licensees must obtain NRC approval in accordance with 10 CFR 50.55a(z) regarding the welding technique to be used before performing welding on austenitic material other than P-Number 8

25 material exposed to thermal neutron fluence greater than 1 x 1017 n/cm2 (E < 0.5 eV). The third condition captures the 10 CFR 50.55a(b)(2)(xii) requirement for underwater welding of austenitic P-Number 8 materials and states that licensees must obtain NRC approval in accordance with 10 CFR 50.55a(z) regarding the welding technique to be used before performing welding on P-Number 8 austenitic material exposed to thermal neutron fluence greater than 1 x 1017 n/cm2 (E < 0.5 eV) and measured or calculated helium concentration of the material greater than 0.1 atomic parts per million.

Because these conditions capture existing requirements, the NRC estimates that they result in no incremental costs for industry implementation.

5.3.3 Evaluation of Pipe Wall Thinning,Section XI The conditions on N-597-3 are all carryovers from the previous version of code case N-597-2; however the staff made revisions to clarify the intent of the conditions. The first condition on Code Case N-597-3 addresses the NRCs concerns regarding how the corrosion rate and associated uncertainties will be determined when N-597-3 is applied to evaluate the wall thinning in pipes for degradation mechanisms other than flow accelerated corrosion. Therefore, the NRC is proposing a condition that requires the corrosion rate be reviewed and approved by the NRC prior to the use of the Code Case.

The second condition on Code Case N-597-3 has two parts, that allow the use of this Code Case to mitigate flow accelerated corrosion, but only if both of the requirements of the condition are met. Due to the difficulty inherent in calculating wall thinning, the first part of Condition 2 requires that the use of N-597-3 on flow-accelerated corrosion piping must be supplemented by the provisions of EPRI Nuclear Safety Analysis Center Report 202L-2, Recommendations for an Effective Flow Accelerated Corrosion Program, April 1999, which contain rigorous provisions to minimize wall thinning.

The first part of Condition 2 (i.e. (2)(a)) on Code Case N-597-3) is identical to the first condition on Code Case N-597-2 that was first approved by the NRC in Revision 15 of RG 1.147 in October, 2007. The condition stated that Code Case must be supplemented by the provisions of EPRI Nuclear Safety Analysis Center Report 202L-2, Recommendations for an Effective Flow Accelerated Corrosion Program (Ref. 6), April 1999, for developing the inspection requirements, the method of predicting the rate of wall thickness loss, and the value of the predicted remaining wall thickness. As used in NSAC-202L-R2, the term should is to be applied as shall (i.e., a requirement). The NRCs reasons for imposing this condition are not addressed by Code Case N-597-3, and therefore this condition will be retained in Revision 19 of RG 1.147.

The second part of Condition 2 (i.e. (2)(b)) on Code Case N-597-3 is identical to the second condition on Code Case N-597-2 that was first approved by the NRC in Revision 15 of RG 1.147 in October, 2007. The condition stated that Components affected by flow-accelerated corrosion to which this Code Case are applied must be repaired or replaced in accordance with

26 the construction code of record and owners requirements or a later NRC approved edition of Section III, Rules for Construction of Nuclear Power Plant Components, of the ASME Code prior to the value of tp reaching the allowable minimum wall thickness, tmin, as specified in -3622.1(a)(1) of this Code Case. Alternatively, use of the Code Case is subject to NRC review and approval per § 50.55a(z). The NRCs reasons for imposing this condition are not addressed by Code Case N 597-3, and therefore this condition will be retained in Revision 19 of RG 1.147.

The third condition on Code Case N-597-3 is identical to the fourth condition on Code Case N-597-2 that was first approved by the NRC in Revision 15 of RG 1.147 in October, 2007. The condition stated that for those components that do not require immediate repair or replacement, the rate of wall thickness loss is to be used to determine a suitable inspection frequency so that repair or replacement occurs prior to reaching allowable minimum wall thickness. The NRCs reasons for imposing this condition are not addressed by Code Case N 597-3, and therefore this condition will be retained in Revision 19 of RG 1.147.

The fourth condition on Code Case N-597-3 is updated from the sixth condition on Code Case N-597-2 that was first approved by the NRC in Revision 17 of RG 1.147 in August, 2014. This condition allows the use of Code Case N-597-3 to calculate wall thinning for moderate-energy Class 2 and 3 piping (using criteria in Code Case N-513-2) for temporary acceptance (until the next refueling outage). The NRCs reasons for imposing this condition are not addressed by Code Case N 597-3, and therefore this condition will be retained in Revision 19 of RG 1.147.

The fifth condition is also updated from the sixth condition on Code Case N-597-2 that was first approved by the NRC in Revision 17 of RG 1.147 in August, 2014 and prohibits the use of this Code Case in evaluating through-wall leakage conditions. The NRC finds it difficult to authorize the use of this Code Case for evaluation of through wall leakage in high energy piping.

due to the consequences and safety implications associated with pipe failure.

Because all of the conditions on N-597-3 are either identical or substantively identical to conditions on N-597-2, the NRC estimates that these conditions will result in no incremental industry implementation costs.

5.3.4 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique for Boiling-Water Reactor Control Rod Drive Housing/Stub Tube Repairs The condition on Code Case N-606-2 is identical to the condition on Code Case N-606-1, which the NRC first approved in Revision 13 of RG 1.147 in January 2004. The condition states the following:

Prior to welding, an examination or verification must be performed to ensure proper preparation of the base metal, and that the surface is properly contoured so that an acceptable weld can be produced. This verification is to be required in the welding procedure.

27 Code Case N-606-2 does not address the reasons for imposing this condition; therefore, Revision 19 of RG 1.147 will retain this condition. The NRC estimates no incremental industry implementation costs associated with this identical condition.

5.3.5 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique The condition on Code Case N-638-7 is identical to the condition on Code Case N-638-6, which the NRC first approved in Revision 18 of RG 1.147 in the August 2017 final rule (NRC, 2017f).

The condition states, demonstration for ultrasonic examination of the repaired volume is required using representative samples which contain construction type flaws. Code Case N-638-7 does not address the reasons for imposing this condition; therefore, Revision 19 of RG 1.147 will retain this condition. The NRC estimates no incremental industry implementation costs associated with this identical condition.

5.3.6 Alternative Requirements for Inner Radius Examinations of Class 1 Reactor Vessel Nozzles,Section XI The NRC is proposing one condition for this Code Case related to preservice inspections. The condition on N-648-2 is that this Code Case shall not be used to eliminate the preservice or inservice volumetric examination of plants with a combined license pursuant to 10 CFR Part 52, Licenses, Certifications, and Approvals for Nuclear Power Plants, or a plant that receives its operating license after October 22, 2015.

The staff position on this Code Case is that the required preservice volumetric examinations should be performed on all vessel nozzles for comparison with later volumetric examinations if indications are found. Eliminating the volumetric preservice or inservice examination is based on the good operating experience of the existing fleet, which has not found any inner radius cracking in the nozzles within the scope of the Code Case. At this time, the new reactor designs have no inspection history or operating experience available to support eliminating the periodic volumetric examination of the nozzles in question. Use of Code Case N-648-2 would not eliminate preservice examinations for the existing fleet since all plants have already completed a preservice examination.

A condition on N-648-1 already prohibits preservice examinations. The NRC estimates no incremental implementation costs associated with this condition for industry, but does estimate incremental industry operation costs for this condition in Section 5.4.6.

5.3.7 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface Code Case N-695-1 provides alternative rules for ultrasonic inspections of dissimilar metal welds from the inner and outer surfaces. Code Case N-695 was developed to allow for

28 inspections from the inner surface in ASME Code Section XI editions before 2007. However, no inspection vendor was able to meet the depth-sizing requirements of 0.125-inch root mean square error. The NRC staff has granted relief to several licensees to allow the use of alternate depth-sizing requirements. The NRC reviewed the depth-sizing results at the Performance Demonstration Institute for procedures able to achieve a root mean square error over 0.125 inches but less than 0.25 inches. The review found that the inspectors tend to oversize small flaws and undersize deep flaws. The flaws sized by the inspectors as 50-percent though-wall or less were accurately or conservatively measured. There were, however, some instances of very large flaws being measured as significantly smaller than the true state, but they were not measured as less than 50-percent through-wall.

Code Case N-695-1 changes the depth sizing requirements for inner-surface examinations of test blocks of 2.1 inches or greater thickness to 0.25 inches. This change is in line with the granted relief requests and with the NRC staff review of the Performance Demonstration Institute test results.

The depth-sizing capabilities of the inspections do not provide sufficient confidence in the ability of an inspector qualified using a 0.25-inch root mean square error to accurately measure the depth of deep flaws. The NRC proposes a condition on Code Case N-695-1 stating that any surface-connected flaw sized over 50-percent through-wall should be considered to be of indeterminate size.

The NRC proposes to approve Code Case N-695-1 with the following condition:

Inspectors qualified using the 0.25 root mean square error for measuring the depths of flaws using N-695-1 are not qualified to depth-size inner diameter (ID) surface breaking flaws greater than 50% through-wall in dissimilar metal welds 2.1 inches or greater in thickness. When an inspector qualified using N-695-1 measures a flaw as greater than 50% through-wall in a dissimilar metal weld from the inner diameter, the flaw shall be considered to have an indeterminate depth.

The NRC estimates that this condition will result in no incremental industry implementation costs, but does estimate incremental operation costs to industry as a result of relief requests, which are discussed in Section 5.4.7.

5.3.8 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface Code Case N-696-1 provides alternative rules for ultrasonic inspections of Supplement 2, 3, and 10 welds from the inner and outer surfaces. The justifications and condition for N-696-1 are the same as for N-695-1 above.

29 The NRC estimates that this condition will result in no incremental industry implementation costs, but does estimate incremental operation costs to industry as a result of relief requests, which are discussed in Section 5.4.8.

5.3.9 Alternative Requirements for Boiling-Water Reactor Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1 The NRC previously accepted with conditions Code Case N-702 in RG 1.147, Revision 18. For Revision 19 of RG 1.147, the NRC proposes revisions to the conditions on N-702. The original conditions in RG 1.147, Revision 17, were consistent with the established review procedure for all applicants before August 2014 for the original 40 years of operation. The conditions were required to ensure that the probability of vessel nozzle failure meets the NRC safety goal.

During the 40 years of operation, past reviews by the NRC have indicated that all licensees evaluated the condition adequately and that future NRC review is not needed. For the period of extended operation, applications are prohibited, so that licensees could submit relief requests based on BWRVIP-241, Appendix A, BWR Nozzle Radii and Nozzle-to-Vessel Welds Demonstration of Compliance with the Technical Information Requirements of the License Renewal Rule (10 CFR 54.21), approved on April 26, 2017, or plant-specific probabilistic fracture mechanics analyses. Therefore, the NRC proposes to revise the RG 1.147, Revision 17, condition to reflect the changes stated in this paragraph.

Consistent with the safety evaluations for all prior ASME Code Case N-702 applicants, a condition on visual examination is added to reaffirm that the NRC is not relaxing the licensees practice on Visual Test (VT)-1 on nozzle inner radii.

The revised conditions on Code Case N-702 state the following:

The applicability of Code Case N-702 for 40 years of operation must be demonstrated by satisfying the criteria in Section 5.0 of NRC Safety Evaluation regarding BWRVIP-108 dated December 18, 2007 (ADAMS Accession No. ML073600374) or Section 5.0 of NRC Safety Evaluation regarding BWRVIP-241 dated April 19, 2013 (ADAMS Accession No. ML13071A240). The use of Code Case N-702 for the period of extended operation is prohibited.

Additionally, if VT-1 is used, it shall utilize ASME Code Case N-648-2, Alternative Requirements for Inner Radius Examination of Class 1 Reactor Vessel Nozzles,Section XI Division 1, with the associated required conditions specified in Regulatory Guide 1.147.

The NRC estimates no incremental implementation costs to industry as a result of these conditions, which are consistent with the approach used by licensees before the Code Case existed.

30 5.3.10 Evaluation Criteria for Temporary Acceptance of Degradation in Moderate-Energy Class 2 or 3 Vessels and Tanks The NRC previously accepted Code Case N-705 in RG 1.147, Revision 16, issued October 2010, without conditions, and the revised Code Case in Supplement 11 contains only editorial changes. However, the staff has identified an area of concern. Paragraph 1(d) of Code Case N-705 states that the evaluation period is the operational time for which the temporary acceptance criteria are satisfied (i.e., evaluation period tallow ) but not greater than 26 months from the initial discovery of the condition. The staff finds the 26-month duration unacceptable. The Code Case applies to the temporary acceptance of degradation, which could be a through-wall leak and would permit a vessel or tank to leak coolant for 26 months without repair or replacement. The staff finds it is unacceptable for plant safety to permit a through-wall leak in vessels or tanks for 26 months without an ASME Code repair. Therefore, the NRC proposes the following condition on Code Case N-705:

The ASME Code repair or replacement activity temporarily deferred under the provisions of this Code Case shall be performed during the next scheduled refueling outage. If a flaw is detected during a scheduled shutdown, an ASME code repair is required before plant restart.

The NRC estimates no incremental industry implementation costs associated with this condition, but does estimate incremental operation costs to industry as discussed in Section 5.4.10.

5.3.11 Alternative Examination Coverage Requirements for Examination Category B-F, B-J, C-F-1, C-F-2, and R-A Piping Welds Code Case N-711 was first listed as unacceptable for use by the NRC in Revision 3 of RG 1.193, ASME Code Cases Not Approved for Use, in October 2010 (NRC, 2010). ASME created Code Case N-711-1 to incorporate several NRC conditions for the use of Code Case N-711. This Code Case provides requirements for determining an alternative required examination volume. This alternative volume is defined as the volume of primary interest based on the postulated degradation mechanism in a particular piping weld.

The NRC finds Code Case N-711-1 acceptable with one condition:

The Code Case shall not be used to redefine the required examination volume for preservice examinations or when the postulated degradation mechanism for piping welds is primary water stress corrosion cracking, intergranular stress corrosion cracking, or crevice corrosion degradation mechanisms.

There is no degradation method during preservice; therefore, the Code Case would not apply.

For primary water stress-corrosion cracking, the staff finds that the examination volume must meet the requirements of ASME Code Case N-770-1, with the conditions in 10 CFR 50.55a(g)(6)(ii)(F). For intergranular stress-corrosion cracking and crevice corrosion,

31 the Code Case does not define a volume of primary interest, and therefore, it cannot be used for these degradation mechanisms. The Code Case requires selection of an alternative inspection location within the same risk region or category if it will improve the examination coverage of the volume of primary interest. Further, the Code Case refers to the owners program for intergranular stress-corrosion cracking.

The licensees 90-day postoutage report of activities must identify the use of the Code Case, as well as the examination category, weld number, weld description, and percent coverage and a description of limitation. The NRC staff determined that the Code Case provides a suitable process for determining the appropriate volume of primary interest based on the degradation mechanism postulated by the degradation mechanism analysis except as noted in the proposed condition. The NRC estimates no incremental implementation costs to industry associated with this condition.

5.3.12 Optimized Structural Dissimilar Metal Weld Overlay for Mitigation of Pressurized-Water Reactor Class 1 Items The NRC proposes to approve Code Case N-754-1 with three conditions. Code Case N-754 concerns the use of optimized structural weld overlays as an alternative to full-structure overlays for mitigation of flaws in large-diameter piping. The first condition on Code Case N-754-1 is the same as the first condition on Code Case N-754, which the NRC first approved in Revision 18 of RG 1.147 in January 2018. The condition stated the following:

The conditions imposed on the optimized weld overlay design in the NRC safety evaluation for MRP-169, Revision 1-A (Agencywide Document Access and Management System Nos. ML101620010 and ML101660468) must be satisfied.

Code Case N-754-1 does not address the reasons for imposing this condition; therefore, Revision 19 of RG 1.147 will retain this condition.

The second condition on Code Case N-754-1 is the same as the second condition on Code Case N-754, which was first approved by the NRC in Revision 18 of RG 1.147 in January 2018.

The condition stated that 2) The preservice and inservice inspections of the overlaid weld must satisfy 10 CFR 50.55a(g)(6)(ii)(F). Code Case N-754-1 does not address the reasons for imposing this condition; therefore, Revision 19 of RG 1.147 will retain this condition.

The third condition on Code Case N-754-1 is new and states that the weld overlay in this Code Case can be installed on an Alloy 82/182 weld only when the outer 25 percent of weld wall thickness does not contain indications that are greater than 1/16 inch in length or depth. The optimized weld overlay is designed with the structural support from the outer 25 percent of the existing weld metal (i.e., the base metal) intact. For this reason, the outer 25 percent of the weld metal needs to be free of degradation before the overlay installation. The Code Case is not clear with regard to the condition of the outer 25 percent of the Alloy 82/182 weld before the overlay installation, instead stating that the weld overlay must be capable of compliance.

32 Therefore, the NRC staff proposes this condition to ensure that the outer 25 percent of the base metal (the weld) has no indications greater than 1/16 inch so that the structural integrity of the repaired weld is maintained, clarifying what is meant by capable of compliance.

The NRC estimates no incremental implementation costs to industry associated with these essentially identical and clarifying conditions.

5.3.13 Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of Pressurized-Water Reactor Full-Penetration Circumferential Nickel Alloy Dissimilar Metal Welds in Class 1 Items Code Case N-766-1 contains provisions for repairing nickel-based Alloy 82/182 dissimilar metal butt welds in Class 1 piping using weld inlay and onlay. The Code Case provides adequate requirements for the design, installation, pressure testing, and examinations of the inlay and onlay. The weld inlay and onlay using the Code Case provides reasonable assurance that the structural integrity of the repaired pipe will be maintained. However, certain provisions of the Code Case are inadequate, and therefore the NRC proposes five conditions.

The first condition on Code Case N-766-1 is new and prohibits the reduction of inspection requirements of this Code Case for inlays or onlays applied to Alloy 82/182 dissimilar metal welds, which contain an axial indication that has a depth of more than 25 percent of the pipe wall thickness and a length of more than half the axial width of the dissimilar metal weld, or a circumferential indication that has a depth of more than 25 percent of the pipe wall thickness and a length of more than 20 percent of the circumference of the pipe. Paragraph 1(c)(1) of the Code Case states the following:

Indications detected in the examination of 3(b)(1) that exceed the acceptance standards of IWB-3514 shall be corrected in accordance with the defect removal requirements of IWA-4000. Alternatively, indications that do not meet the acceptance standards of IWB-3514 may be accepted by analytical evaluation in accordance with IWB-3600.

The above alternative would allow a flaw with a maximum depth of 75-percent through-wall to remain in service in accordance with the ASME Code Section XI, IWB-3643. Even if the inlay or onlay will isolate the dissimilar metal weld from the reactor coolant to minimize the potential for stress-corrosion cracking, the NRC staff finds that having a 75-percent flaw in the Alloy 82/182 weld does not provide reasonable assurance of the structural integrity of the pipe. The NRC staff finds that the indication in the Alloy 82/182 weld needs to be limited in size to ensure structural integrity of the weld.

The second condition on Code Case N-766-1 is new and modifies the Code Case to require that pipe with any thickness of inlay or onlay must be evaluated for weld shrinkage, pipe system flexibility, and additional weight of the inlay or onlay. Paragraph 2(e) of the Code Case states the following:

33 If the inlay or onlay deposited in accordance with this Case is thicker than 1/8t, where t is the original nominal DMW [Dissimilar Metal Weld] thickness, the effects of any change in applied loads, as a result of weld shrinkage from the entire inlay or onlay, on other items in the piping system (e.g., support loads and clearances, nozzle loads, and changes in system flexibility and weight due to the inlay or onlay) shall be evaluated. Existing flaws previously accepted by analytical evaluation shall be evaluated in accordance with IWB-3640.

The NRC staff finds that a pipe with any thickness of inlay or onlay must be evaluated for weld shrinkage, pipe system flexibility, and the additional weight of the inlay or onlay. This is a clarification of the expected welding process and not a new requirement in that sense.

The third condition on Code Case N-766-1 is new. The third condition sets reexamination requirements for inlay or onlay when applied to Alloy 82/182 dissimilar metal welds with any indication that it exceeds the acceptance standards of IWB-3514 and is accepted for continued service in accordance with IWB-3132.3 or IWB-3142.4. This condition states that the subject weld must be inspected in three successive examinations after the installation of the inlay or onlay. The NRC has concerns about the Code Case permitting indications exceeding IWB-3514 to remain in service after inlay or onlay installation, based on analytical evaluation of IWB-3600. IWB-2420 requires three successive examinations for indications that are permitted to remain in service per IWB-3600. The Code Case does not discuss the three successive examinations. If an inlay or onlay is applied to an Alloy 82/182 dissimilar metal weld that contains an indication that exceeds the acceptance standards of IWB-3514 and is accepted for continued service in accordance with IWB-3132.3 or IWB-3142.4, the subject weld must be inspected in three successive examinations after inlay or onlay installation. The NRC staff proposes this condition to ensure performance of the three successive examinations.

The fourth condition on Code Case N-766-1 is new and prohibits an inlay or onlay from remaining in service when eddy current testing during acceptance examinations discovers a detectable subsurface indication. Operational experience has shown that subsurface flaws on Alloy 52 welds for upper heads may be very near the surface. However, these flaws are undetectable by liquid dye penetrant, as there are no surface-breaking aspects during initial construction. Nevertheless, in multiple cases, after a plant goes through one or two cycles of operation, these defects become exposed to the primary coolant. The exposure of these subsurface defects to primary coolant challenges the effectiveness of the Alloy 52 weld mitigation of only 3 millimeters in total thickness. In the upper head scenario, these welds are inspected during each outage. To allow the extension of the inspection frequency to that defined by 10 CFR 50.55a(g)(6)(ii)(F), the NRC found that all subsurface indications detectable by eddy current examination should be removed from the Alloy 52 weld layer. This is a clarification of the expected welding process and not a new requirement in that sense.

The fifth condition on Code Case N-766-1 is new and requires that the flaw analysis of paragraph 2(d) of the Code Case shall also consider primary water stress-corrosion cracking

34 growth in the circumferential and axial directions, in accordance with IWB-3640. The postulated flaw evaluation in the Code Case requires only a fatigue analysis. Conservative generic analysis by the NRC staff has raised the concern that a primary water stress-corrosion crack could potentially grow through the inner Alloy 52 weld layer and into the highly susceptible Alloy 82/182 weld material, to a depth of 75-percent through-wall, within the period of reexamination frequency required by 10 CFR 50.55a(g)(6)(ii)(F). Therefore, users of this Code Case will verify, for each weld, that a primary water stress-corrosion crack will not reach a depth of 75-percent through-wall within the required reinspection interval because of primary water stress-corrosion cracking. This is a clarification of the expectations of paragraph 2(d) of the Code Case, resulting in no additional burden.

The NRC estimates no incremental implementation costs to industry as a result of these conditions. However, the first condition does result in incremental operation costs to industry, which are estimated in Section 5.4.13.

5.3.14 Ultrasonic Examination of Cast Austenitic Piping Welds from the Outside Surface,Section XI, Division 1 Code Case N-824 is a new Code Case for the examination of cast austenitic piping welds from the outside surface. The NRC, using NUREG/CR-6933, Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods, issued March 2007 (NRC, 2007), and NUREG/CR-7122, An Evaluation of Ultrasonic Phased Array Testing for Cast Austenitic Stainless Steel Pressurizer Surge Line Piping Welds, issued March 2012 (NRC, 2012), has determined that inspections of cast austenitic stainless steel (CASS) materials are very challenging, and sufficient technical basis exists to add conditions to the Code Case to bring it into agreement with the NUREG/CR reports. These reports also show that CASS materials produce high levels of coherent noise. The noise signals can be confusing and mask flaw indications.

The use of dual-element, phased-array search units showed the most promise in obtaining meaningful responses from flaws. For this reason, the NRC is adding a condition to require the use of dual, transmit-receive, refracted longitudinal wave, multielement phased-array search units when utilizing Code Case N-824 for the examination of CASS components.

NUREG/CR-6933 and NUREG/CR-7122 describe the optimum inspection frequencies for examining CASS components of various thicknesses. For this reason, the NRC is proposing to add a condition to require that ultrasonic examinations performed to implement ASME BPV Code Case N824 on piping greater than 1.6 inches thick shall use a phased-array search unit with a center frequency of 500 kHz with a tolerance of +/- 20 percent.

NUREG/CR-6933 shows that the grain structure of CASS can reduce the effectiveness of some inspection angles (i.e., angles including, but not limited to, 30 to 55 degrees with a maximum increment of 5 degrees). Because the NRC is requiring the use of a phased-array search unit, the staff finds that the use of the phased-array search unit must be limited so that the unit is

35 used at inspection angles that would provide acceptable results. For this reason, the NRC is proposing to add a condition to require that ultrasonic examinations performed to implement ASME BPV Code Case N-824 shall use a phased-array search unit that produces angles including, but not limited to, 30 to 55 degrees with a maximum increment of 5 degrees.

Therefore, the NRC finds Code Case N-824 acceptable with the following proposed conditions:

Instead of paragraph 1(c)(1)(-c)(-2), licensees shall use a phased-array search unit with a center frequency of 500 kHz with a tolerance of +/- 20 percent.

Instead of paragraph 1(c)(1)(-d), the phased-array search unit must produce angles including, but not limited to, 30 to 55 degrees with a maximum increment of 5 degrees.

The NRC approved these conditions under 10 CFR 50.55a in a previous ASME Code Editions final rule (NRC, 2017f).

Because these conditions were previously approved and the costs were estimated at that time in the final regulatory analysis (NRC, 2017f), the NRC estimates no incremental industry implementation costs as a result of the conditions.

5.3.15 Austenitic Stainless Steel Cladding and Nickel-Base Cladding Using Ambient Temperature Machine GTAW Temper Bead Technique Code Case N-829 is a new Code Case for the use of automatic or machine gas tungsten arc welding (GTAW) temper bead technique to repair stainless steel cladding and nickel-base cladding without the specified preheat or postweld heat treatment in Section XI, paragraph IWA-4411.

The NRC finds the Code Case acceptable on the condition that the provisions of Code Case N-829, paragraph 3(e)(2) or 3(e)(3), may be used only when it is impractical to use the direct interpass temperature measurement methods described in Code Case N-829, paragraph 3(e)(1), such as in situations where the weldment area is inaccessible (i.e., internal bore welding) or when there are extenuating radiological conditions. The NRC has determined that interpass temperature measurement is critical to obtaining acceptable corrosion resistance, notch toughness, or both in a weld. Only in areas that are totally inaccessible to temperature measurement devices or when there are extenuating radiological conditions shall alternate methods be allowed, such as the calculation method from Section 3(e)(2) or the weld coupon test method shown in Section 3(e)(3) of Code Case N-829.

The staff estimates that the temperature measurement techniques of the Code Case do not differ significantly in cost and, therefore, estimates no incremental implementation costs to industry as a result of this condition.

36 5.3.16 Direct Use of Master Fracture Toughness Curve for Pressure-Retaining Materials of Class 1 Vessels The 2013 edition of the ASME Code introduced Code Case N-830. This Code Case outlines the use of a material specific master curve as an alternative fracture toughness curve for crack initiation, KIC, in Section XI, Division 1, Appendices A and G, for Class 1 pressure-retaining materials other than bolting.

The NRC finds the Code Case acceptable with one condition to prohibit the use of the provision in paragraph (f) of the Code Case that allows for the use of an alternative to limiting the lower shelf of the 95-percent lower tolerance bound master curve toughness, KJC-lower 95%, to a value consistent with the current KIC curve. Code Case N-830 contains provisions for using the KJC-lower 95% curve and the master curve-based reference temperature To as an alternative to the KIC curve and the nil-ductility transition reference temperature RTNDT in Appendices A and G of the ASME Code Section XI. The reference temperature To is determined in accordance with ASTM International Standard E 1921, Standard Test Method for the Determination of Reference Temperature, To, for Ferritic Steels in the Transition Range, from direct fracture toughness testing data. The RTNDT is determined in accordance with the ASME BPV Code,Section III, NB-2330, Test Requirements and Acceptance Standards, from indirect Charpy V-notch testing data, and Regulatory Guide 1.99, Revision 2, Radiation Embrittlement of Reactor Vessel Materials, issued May 1988. Considering the entire test data at a wide range of T-RTNDT (-400°F to 100°F), the NRC staff found that the current KIC curve also represents approximately a 95-percent lower tolerance bound for the data. Thus, using the KJC-lower 95%

curve based on the master curve is acceptable. However, because paragraph (f) provides a significant deviation from the KJC-lower 95% curve for (T - To) below -115°F in a nonconservative manner without justification, the NRC staff determined that paragraph (f) of Code Case N-830 must not be applied.

The NRC estimates no incremental industry implementation costs due to this condition, which is a clarification to ensure a single curve is used in the analysis.

5.3.17 Ultrasonic Examination in Lieu of Radiography for Welds in Ferritic Pipe Code Case N-831 is a new Code Case, which provides an alternative to radiographic testing when it is required by the construction code for Section Xl repair and replacement activities.

This Code Case describes the requirements for inspecting ferritic welds for fabrication flaws using ultrasonic testing as an alternative to the current requirements to use radiography. The Code Case describes the scanning methods, recordkeeping, and performance demonstration qualification requirements for the ultrasonic procedures, equipment, and personnel.

The NRC finds the Code Case acceptable with the condition that it is prohibited for use in new reactor construction. History has shown that the combined use of radiographic testing for weld fabrication examinations followed by the use of ultrasonic testing for preservice inspections and inservice inspections ensures that workmanship is maintained (with radiographic testing) while

37 potentially critical planar fabrication flaws are not put into service (with ultrasonic testing). Until studies are completed that demonstrate the ability of ultrasonic testing to replace radiographic testing (repair and replacement activity), the NRC will not generally allow the substitution of ultrasonic testing for radiographic testing in weld fabrication examinations. In addition, ultrasonic examinations are not equivalent to radiographic examinations as they use different physical mechanisms to detect and characterize discontinuities. These differences in physical mechanisms result in several key differences in sensitivity and discrimination capability. As a result of these differences, as well as in consideration of the inherent strengths of each of the methods, the two methods are not considered to be interchangeable, but instead are complementary. Therefore, the NRC determined that this Code Case is not acceptable for use on new reactor construction.

This condition will require new reactors under construction to use radiography, but the NRC estimates no incremental implementation costs to industry compared to existing methods because the time required to set up and perform these examinations is approximately equal.

Additionally, new reactors under construction would not incur any incremental costs to shut down or extend an outage to perform the radiography.

5.3.18 Flaw Tolerance Evaluation of Cast Austenitic Stainless Steel Piping,Section XI, Division 1 The NRC staff proposes to approve Code Case N-838 with the following condition: Code Case N-838 shall not be used to evaluate flaws in CASS piping where the delta ferrite content exceeds 25 percent.

Code Case N-838 contains provisions for performing a postulated flaw tolerance evaluation of ASME Class 1 and 2 CASS piping with delta ferrite exceeding 20 percent. The Code Case provides a recommended target flaw size for the qualification of nondestructive examination methods, along with an approach that may be used to justify a larger target flaw size, if needed.

The Code Case is intended for the flaw tolerance evaluation of postulated flaws in CASS base metal adjacent to welds, in conjunction with license renewal commitments. The NRC staff notes that the Code Case is limited in application and provides restrictions so that it will not be misused. For example, the Code Case is applicable to portions of Class 1 and 2 piping made of SA-351 statically or centrifugally cast Grades CF3, CF3A, CF3M, CF8, CF8A, and CF8M base metal with delta ferrite exceeding 20 percent and niobium or columbium content not greater than 0.2 weight percent. This Code Case is limited to application to the thermally aged CASS material types mentioned above with normal operating temperatures between 500°F and 662°F.

The Code Case is not applicable to the evaluation of detected flaws. Section 3 of the Code Case provides specific analytical evaluation procedures for the pipe mean radius-to-thickness (R/t) ratio greater and less than 10. Tables 1 through 4 of the Code Case provide the maximum tolerable flaw depth-to-thickness ratios for circumference and axial flaws.

However, the staff finds that paragraph 3(c) of the Code Case is inadequate. Paragraph 3(c) specifies that for delta ferrite exceeding 25 percent, or pipe mean R/t ratio exceeding 10, the

38 flaw tolerance evaluation shall be performed, except that representative data shall be used to determine the maximum tolerable flaw depths applicable to the CASS base metal and R/t ratio instead of Tables 1 through 4 of the Code Case.

The staff notes that the open source literature provides insufficient fracture toughness data for CASS that contains more than 25 percent delta ferrite. Thus, the staff needs to review flow tolerance evaluations to ensure that the flaw tolerance evaluations are adequately conservative.

Therefore, the staff proposes a condition to prohibit the use of this Code Case when delta ferrite in CASS piping exceeds 25 percent. The NRC estimates no incremental implementation costs to industry as a result of this condition, but estimates there will be industry operation costs as a result of relief requests, as discussed in Section 5.4.18.

5.3.19 Alternative Pressure Testing Requirements Following Repairs or Replacements for Class 1 Piping between the First and Second Inspection Isolation Valves,Section XI, Division 1 Code Case N-843 is consistent with alternatives granted by the NRC. The staff originally voted against this Code Case because of the inclusion of return lines, which could have allowed significantly lower pressures to be used on Class 1 portions of return lines. Therefore, the staff proposes the following condition to ensure that the injection lines are tested at the highest pressure of the lines intended safety function.

The proposed condition on Code Case N-843 states that if the portions of the system requiring pressure testing are associated with more than one safety function, the pressure test and visual examination VT-2 shall be performed during a test conducted at the higher of the operating pressures for the respective system safety functions. This clarifying condition represents good engineering practice and does not impose additional requirements beyond those typical for pressure testing. Therefore, the NRC estimates no incremental implementation costs to industry from this condition.

5.3.20 In Situ VT-3 Examination of Removable Core Support Structures without Removal Code Case N-849 is a new Code Case introduced in the 2013 Edition of the ASME BPV Code.

This Code Case is meant to provide guidelines for allowing the VT-3 inspection requirements of Table IWB-2500-1 for preservice or inservice inspections of the core support structures to be performed without the removal of the core support structure. The NRC finds the Code Case acceptable with two proposed conditions.

The first condition limits the use of Code Case N-849 to plants that are designed with accessible core support structures to allow for in situ inspection. Code Case N-849 allows the performance of VT-3 preservice or inservice visual examinations of removable core support structures in situ using a remote examination system. A provision of the Code Case is that all surfaces accessible for examination when the structure is removed shall be accessible when the structure is in situ, except for load bearing and contact surfaces, which would be inspected only

39 when the core barrel is removed. Designs for new reactors, such as small modular reactors, may include accessibility of the annulus between the core barrel and the reactor vessel. Unlike newly designed reactors, currently operating plants were not designed to allow in situ VT-3 examinations. There are no industry survey results of the current fleet to provide an evaluation of operating plant inspection findings. Therefore, the applicability of the Code Case to the designs of currently operating plants has not been satisfactorily addressed. Furthermore, because this condition represents the intent of the Code Case as it moved through committee, it is a clarifying condition.

The second condition on Code Case N-849 requires that before initial plant startup, the VT-3 preservice examination must be performed with the core support structure removed, as required by ASME Section XI, IWB-2500-1. The NRC has concerns that a preservice examination would not be performed on the load bearing and contact surfaces even though the surfaces would be accessible before installation of the core support structure. There is also no evidence that the in situ examination will achieve the same coverage as the examination with the core support structure removed. This clarifying condition reflects existing Code requirements.

The NRC estimates no incremental implementation costs to industry as a result of these clarifying conditions.

5.4 Industry Operation This attribute accounts for the projected net economic effect of routine and recurring activities required by the proposed alternative for all affected licensees. Under Alternative 2, a nuclear power plant licensee would not need to submit an alternative request under the new 10 CFR 50.55a(z) or a relief request under 10 CFR 50.55a(f) or (g) to receive permission to use a later edition or addenda of the ASME Codes (as an alternative to the ASME Code provisions) that provides a net benefit (i.e., averted cost) to the licensee.

The use of later editions and addenda of the ASME BPV and OM Codes would benefit NRC nuclear power plant licensees and applicants for several reasons. Later editions and addenda may introduce the use of advanced techniques, procedures, and measures. Alternative 2 has the advantage that, on implementation of the proposed rule, licensees and applicants would be able to voluntarily ask to use a more recent edition or addenda of the ASME BPV and OM Codes under the provisions in 10 CFR 50.55a(f)(4)(iv) and (g)(4)(iv).6 Submission of an alternative request to the NRC is not a trivial matter. Once ASME issues a Code Edition, the licensee or applicant must determine the applicability of the Code Edition to its facility and the benefit derived from its use. If the licensee or applicant determines that use of 6

Regulations in 10 CFR 50.55a(f)(4) and (g)(4) establish the effective ASME Code edition and addenda to be used by licensees in performing IST of pumps and valves and ISI of components (including supports),

respectively. NRC Regulatory Issue Summary 2004-12, Clarification on Use of Later Editions and Addenda to the ASME OM Code and Section XI, dated July 28, 2004 (NRC, 2004), clarified the requirements for IST and ISI programs when using later editions and addenda of the ASME OM Code.

40 the Code would be beneficial but the NRC has not approved the Code Edition, the licensee or applicant must prepare a request for the use of the Code alternative, and appropriate levels of licensee or applicant management must review and approve the request before submission to the NRC. A review of Code alternative requests submitted to the NRC over the last 5 years found that these submittals ranged from a few pages to several hundred pages, with an average of approximately 32 pages of average technical complexity.

Therefore, the NRC estimates that a Code alternative submittal requires an average of 280 hours0.00324 days 0.0778 hours 4.62963e-4 weeks 1.0654e-4 months of effort to develop the technical justification and an additional 100 hours0.00116 days 0.0278 hours 1.653439e-4 weeks 3.805e-5 months to research, review, approve, process, and submit the document to the NRC for the use of alternatives under 10 CFR 50.55a(z) (for a total of 380 hours0.0044 days 0.106 hours 6.283069e-4 weeks 1.4459e-4 months per submittal). The NRC assumes that licensees or applicants would decide whether to request the use of an alternative by weighing the cost against the benefit to be derived. In some cases, licensees may decide to forfeit the benefits of using newer ASME Code, whether in terms of radiological considerations or burden reduction.

A review of past submittals of Code alternative requests has determined that plant owners submit Code alternative requests that cover multiple units and multiple plant sites. Based on annual Code Case relief request submissions before and after ASME final rules are published, the staff estimated that if Alternative 2 is not adopted, operating sites would submit 24 relief requests annually for the Code Cases in this proposed rule. Under Alternative 2, a nuclear power plant licensee would no longer need to submit the aforementioned Code alternative requests under the new 10 CFR 50.55a(z), which would provide a net benefit (i.e., averted cost) to the licensee. As shown in Table 6, the implementation of Alternative 2 would avert 24 additional Code alternative submittals (and their associated preparation) each year under the new 10 CFR 50.55a(z). The NRC estimates the industry operation averted costs for operating nuclear power plants to range from $5.80 million (7-percent NPV) to $6.35 million (3-percent NPV), yielding a net positive savings for Alternative 2.

Table 6 Industry OperationAverted Costs for Code Alternative Requests Undiscounted 7% NPV 3% NPV 2019 Code Case relief request preparation and submission 24 380

$127

$1,137,000

$1,137,000 2020 Code Case relief request preparation and submission 24 380

$127

$1,137,000

$1,063,000

$1,104,000 2021 Code Case relief request preparation and submission 24 380

$127

$1,137,000

$993,000

$1,072,000 2022 Code Case relief request preparation and submission 24 380

$127

$1,137,000

$928,000

$1,041,000 2023 Code Case relief request preparation and submission 24 380

$127

$1,137,000

$867,000

$1,010,000 2024 Code Case relief request preparation and submission 24 380

$127

$1,137,000

$811,000

$981,000 Total:

$6,822,000

$5,799,000

$6,345,000 Year Activity Cost Labor Hours Weighted Hourly rate Relief Requests per Year

41 5.4.1 Additional Materials for Subsection NF, Class 1, 2, 3, and Metal Containment Supports Fabricated by Welding The NRC estimates that there are no incremental operation costs to industry associated with the conditions of this Code Case, which are either identical or substantively identical to existing conditions or administrative in nature.

5.4.2 Underwater Welding,Section XI, Division 1 The NRC estimates that there are no incremental operation costs to industry associated with the conditions of this Code Case, which are clarifications of the existing condition.

5.4.3 Evaluation of Pipe Wall Thinning,Section XI The NRC estimates that there are no incremental operation costs to industry associated with the conditions of this Code Case, which are either identical or substantively identical to existing conditions.

5.4.4 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique for Boiling-Water Reactor Control Rod Drive Housing/Stub Tube Repairs The NRC estimates that there are no incremental operation costs to industry associated with the condition of this Code Case, which is identical to the existing condition.

5.4.5 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique The NRC estimates that there are no incremental operation costs to industry associated with the condition of this Code Case, which is identical to the existing condition.

5.4.6 Alternative Requirements for Inner Radius Examinations of Class 1 Reactor Vessel Nozzles,Section XI This condition prevents the Code Case from allowing new pressurized-water reactors (PWRs) and boiling-water reactors (BWRs) to use visual testing instead of ultrasonic testing on their first reactor vessel nozzle inservice inspection, which would occur during the lifetime of this Code Case. Per nozzle, the ultrasonic testing takes approximately 16 more hours than the visual testing, and the staff estimates that this condition would affect two PWRs and three BWRs.

PWRs have approximately 8 nozzles, while BWRs have approximately 25 nozzles, and the inspection must cover at least 25 percent but not more than 50 percent of the nozzles. As shown in Table 7, this results in costs ranging from ($48,400) at a 7-percent NPV to ($55,800) at a 3-percent NPV.

42 Table 7 N-648-2 Reactor Nozzle Ultrasonic Test Inspection 5.4.7 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface The staff expects that industry will operate in accordance with this condition in most cases, based on over 15 years of operating experience in which this condition would not have altered industry actions. For this cost estimate, the staff has assumed that the condition would affect one licensee over the lifetime of this Code Case. This condition would result in a verbal review of the licensees maintenance issue, taking approximately 190 hours0.0022 days 0.0528 hours 3.141534e-4 weeks 7.2295e-5 months for industry to perform. As shown in Table 8, the estimated costs range from ($20,000) at a 7-percent NPV to ($22,000) at a 3-percent NPV.

Table 8 N-695-1 Piping Examination Relief Request 5.4.8 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface The staff expects that industry will operate in accordance with this condition in most cases, based on over 15 years of operating experience in which this condition would not have altered industry actions. For this cost estimate, the staff has assumed that the condition would affect one licensee over the lifetime of this Code Case. This condition would result in a verbal review of the licensees maintenance issue, taking approximately 190 hours0.0022 days 0.0528 hours 3.141534e-4 weeks 7.2295e-5 months for industry to perform. As shown in Table 9, the estimated costs range from ($20,000) at a 7-percent NPV to ($22,000) at a 3-percent NPV.

Table 9 N-696-1 Piping Examination Relief Request 5.4.9 Alternative Requirements for Boiling-Water Reactor Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1 Undiscounted 7% NPV 3% NPV 2023 Additional cost of UT instead of VT for Reactor Nozzles at New PWRs 2

16 0.4 8

$127

($11,000)

($8,400)

($9,800) 2023 Additional cost of UT instead of VT for Reactor Nozzles at New BWRs 3

16 0.4 25

$127

($52,000)

($40,000)

($46,000)

($63,000)

($48,400)

($55,800)

Year Activity Number of Affected Entities Cost Hours per Nozzle Ratio of Nozzles Inspected Weighted Hourly rate Number of Nozzles Total:

Undiscounted 7% NPV 3% NPV 2022 Verbal relief request 1

190

$127

($24,000)

($20,000)

($22,000)

($24,000)

($20,000)

($22,000)

Total:

Year Activity Number of Affected Labor Hours Weighted Hourly rate Cost Undiscounted 7% NPV 3% NPV 2022 Verbal relief request 1

190

$127

($24,000)

($20,000)

($22,000)

($24,000)

($20,000)

($22,000)

Year Activity Number of Affected Labor Hours Weighted Hourly rate Cost Total:

43 The NRC estimates that there are no incremental operation costs to industry associated with the conditions of this Code Case, which are consistent with the approach used by licensees before the Code Case existed.

5.4.10 Evaluation Criteria for Temporary Acceptance of Degradation in Moderate-Energy Class 2 or 3 Vessels and Tanks The staff expects that licensees would incur incremental costs when the condition on N-705 causes a licensee to repair a tank earlier than the 26-month allowable timeframe of the Code Case (during the next refueling outage or before startup). The staff estimated these costs by calculating the NPVs (undiscounted, 7-percent, 3-percent) of the tank repair at 26 months and at a time ranging from 1 to 2 years earlier based on the condition and then calculating the cost of the condition based on the difference between these two repair costs. The undiscounted cost of the tank repair is estimated at $46,700, and the staff expects this condition to affect one licensee per year. For this cost estimate, the undiscounted column represents the situation in which the time value of money is not considered so that there is no difference in cost. The 7-percent NPV and 3-percent NPV calculations show the impact of the time value of money for performing the earlier repair. As shown in Table 10, these calculations result in costs ranging from ($17,000) at a 7-percent NPV to ($9,000) at a 3-percent NPV.

Table 10 N-705-1 Tank Weld Repairs 5.4.11 Alternative Examination Coverage Requirements for Examination Category B-F, B-J, C-F-1, C-F-2, and R-A Piping Welds Undiscounted 7% NPV 3% NPV 2019 Difference in cost resulting from maintenance at next refuel / prior to restart 1

$40,303

$0

($3,310)

($1,536) 2020 Difference in cost resulting from maintenance at next refuel / prior to restart 1

$40,303

$0

($3,094)

($1,491) 2021 Difference in cost resulting from maintenance at next refuel / prior to restart 1

$40,303

$0

($2,891)

($1,448) 2022 Difference in cost resulting from maintenance at next refuel / prior to restart 1

$40,303

$0

($2,702)

($1,405) 2023 Difference in cost resulting from maintenance at next refuel / prior to restart 1

$40,303

$0

($2,525)

($1,365) 2024 Difference in cost resulting from maintenance at next refuel / prior to restart 1

$40,303

$0

($2,360)

($1,325)

Total:

$0

($17,000)

($9,000)

Increase in Cost due to earlier schedule Cost to repair at 26 months Year Activity Number of Affected Entities

44 The NRC estimates that there are no incremental operation costs to industry associated with this condition, which is a clarification of language used in the Code Case.

5.4.12 Optimized Structural Dissimilar Metal Weld Overlay for Mitigation of Pressurized-Water Reactor Class 1 Items The NRC estimates that there are no incremental operation costs to industry associated with the conditions of this Code Case, which are either identical to existing conditions or clarifications of language used in the Code Case.

5.4.13 Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of Pressurized-Water Reactor Full-Penetration Circumferential Nickel Alloy Dissimilar Metal Welds in Class 1 Items The staff expects that licensees would incur incremental costs when the first condition on N-766-1 prevents the use of the Code Case on a weld. Licensees would submit relief requests in this circumstance, which is expected to occur about once per year. As shown in Table 11, these relief requests are estimated to take approximately 380 hours0.0044 days 0.106 hours 6.283069e-4 weeks 1.4459e-4 months to produce, resulting in costs ranging from ($245,000) at a 7-percent NPV to ($268,000) at a 3-percent NPV.

Table 11 N-766-1 Inlay and Onlay Repair Relief Requests 5.4.14 Ultrasonic Examination of Cast Austenitic Piping Welds from the Outside Surface,Section XI, Division 1 The NRC estimates that there are no incremental operation costs to industry associated with the conditions of this Code Case, which have already been incorporated by reference into 10 CFR 50.55a. The costs have already been estimated in the latest final regulatory analysis for the ASME Code Editions rulemaking (NRC, 2017f).

Undiscounted 7% NPV 3% NPV 2019 Relief request when condition prevents use of N-766-1 1

380

$127

($48,000)

($48,000) 2020 Relief request when condition prevents use of N-766-1 1

380

$127

($48,000)

($45,000)

($47,000) 2021 Relief request when condition prevents use of N-766-1 1

380

$127

($48,000)

($42,000)

($45,000) 2022 Relief request when condition prevents use of N-766-1 1

380

$127

($48,000)

($39,000)

($44,000) 2023 Relief request when condition prevents use of N-766-1 1

380

$127

($48,000)

($37,000)

($43,000) 2024 Relief request when condition prevents use of N-766-1 1

380

$127

($48,000)

($34,000)

($41,000)

($288,000)

($245,000)

($268,000)

Year Activity Number of Affected Entities Cost Total:

Labor Hours Weighted Hourly rate

45 5.4.15 Austenitic Stainless Steel Cladding and Nickel-Base Cladding Using Ambient Temperature Machine GTAW Temper Bead Technique The NRC estimates that there are no incremental operation costs to industry associated with this condition because there is not an appreciable cost difference between the temperature measurement techniques in the referenced paragraphs.

5.4.16 Direct Use of Master Fracture Toughness Curve for Pressure-Retaining Materials of Class 1 Vessels The NRC estimates that there are no incremental operation costs to industry associated with this clarifying condition.

5.4.17 Ultrasonic Examination in Lieu of Radiography for Welds in Ferritic Pipe The NRC estimates that there are no incremental operation costs to industry associated with this condition because new reactors can use radiography instead of this Code Case, with no cost impact.

5.4.18 Flaw Tolerance Evaluation of Cast Austenitic Stainless Steel Piping,Section XI, Division 1 The staff expects that licensees would incur incremental costs when the condition on N-838 prevents the use of the Code Case to evaluate a CASS flaw. Licensees would submit relief requests in this circumstance, which is expected to occur about once per year. As shown in Table 12, these relief requests are estimated to take about 380 hours0.0044 days 0.106 hours 6.283069e-4 weeks 1.4459e-4 months to produce, resulting in costs ranging from ($245,000) at a 7-percent NPV to ($268,000) at a 3-percent NPV.

Table 12 N-838 CASS Flaw Tolerance Evaluation Relief Requests Undiscounted 7% NPV 3% NPV 2019 Relief request when condition prevents use of N-838 1

380

$127

($48,000)

($48,000) 2020 Relief request when condition prevents use of N-838 1

380

$127

($48,000)

($45,000)

($47,000) 2021 Relief request when condition prevents use of N-838 1

380

$127

($48,000)

($42,000)

($45,000) 2022 Relief request when condition prevents use of N-838 1

380

$127

($48,000)

($39,000)

($44,000) 2023 Relief request when condition prevents use of N-838 1

380

$127

($48,000)

($37,000)

($43,000) 2024 Relief request when condition prevents use of N-838 1

380

$127

($48,000)

($34,000)

($41,000)

($288,000)

($245,000)

($268,000)

Cost Total:

Labor Hours Year Activity Number of Affected Entities Weighted Hourly rate

46 5.4.19 Alternative Pressure Testing Requirements Following Repairs or Replacements for Class 1 Piping between the First and Second Inspection Isolation Valves,Section XI, Division 1 The NRC estimates that there are no incremental operation costs to industry associated with this clarifying condition.

5.4.20 In Situ VT-3 Examination of Removable Core Support Structures without Removal The NRC estimates that there are no incremental operation costs to industry associated with these clarifying conditions.

5.5 Total Industry Costs Table 13 shows the total industry costs, separated by implementation and operation costs, for the requirements under Alternative 2. These total industry costs represent averted costs of

$5.20 million at a 7-percent NPV and $5.70 million at a 3-percent NPV.

Table 13 Total Industry Costs Note: Total costs are rounded to three significant figures.

5.6 NRC Implementation The NRC will incur implementation costs for the stages of the rulemaking process. As shown in Table 14, the NRC costs include final rulemaking changes and issuance of the final rule.

Proposed rulemaking costs are considered sunk costs at this stage of the rulemaking process.

The staff estimates 1,840 hours0.00972 days 0.233 hours 0.00139 weeks 3.1962e-4 months for development of the final rule package and 920 hours0.0106 days 0.256 hours 0.00152 weeks 3.5006e-4 months for the finalization of the regulatory guides. This results in a cost estimate of ($362,000).

Table 14 NRC Implementation Costs 5.6.1 Additional Materials for Subsection NF, Class 1, 2, 3, and Metal Containment Supports Fabricated by Welding Undiscounted 7% NPV 3% NPV

$0

$6,140,000

$5,200,000

$5,700,000

$6,140,000

$5,200,000

$5,700,000 Total Industry Cost:

Implementation Costs:

Operation Costs:

Attribute Undiscounted 7% NPV 3% NPV 2019 Develop and issue final regulatory guides 1

920

$131

($121,000)

($121,000) 2019 Develop and issue final rule 1

1840

$131

($241,000)

($362,000)

Year Activity Number of Actions Hours Weighted Hourly rate Total:

Cost

47 The NRC estimates that there are no incremental NRC implementation costs associated with the conditions of this Code Case, which are either identical or substantively identical to existing conditions or administrative in nature.

5.6.2 Underwater Welding,Section XI, Division 1 The NRC estimates that there are no incremental NRC implementation costs associated with the conditions of this Code Case, which are clarifications of the existing condition.

5.6.3 Evaluation of Pipe Wall Thinning,Section XI The NRC estimates that there are no incremental NRC implementation costs associated with the conditions of this Code Case, which are either identical or substantively identical to existing conditions.

5.6.4 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique for Boiling-Water Reactor Control Rod Drive Housing/Stub Tube Repairs The NRC estimates that there are no incremental NRC implementation costs associated with the condition of this Code Case, which is identical to the existing condition.

5.6.5 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique The NRC estimates that there are no incremental NRC implementation costs associated with the condition of this Code Case, which is identical to the existing condition.

5.6.6 Alternative Requirements for Inner Radius Examinations of Class 1 Reactor Vessel Nozzles,Section XI The NRC estimates that there are no incremental NRC implementation costs for inservice inspections associated with the condition of this Code Case.

5.6.7 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface The NRC estimates that there are no incremental NRC implementation costs associated with the condition of this Code Case, because the resulting relief request is an operation cost.

5.6.8 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface

48 The NRC estimates that there are no incremental NRC implementation costs associated with the condition of this Code Case, because the resulting relief request is an operation cost.

5.6.9 Alternative Requirements for Boiling-Water Reactor Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1 The NRC estimates that there are no incremental NRC implementation costs associated with the conditions of this Code Case, which are consistent with the approach used by licensees before the Code Case existed.

5.6.10 Evaluation Criteria for Temporary Acceptance of Degradation in Moderate-Energy Class 2 or 3 Vessels and Tanks The NRC estimates that there are no incremental NRC implementation costs from the tank repairs associated with the condition of this Code Case.

5.6.11 Alternative Examination Coverage Requirements for Examination Category B-F, B-J, C-F-1, C-F-2, and R-A Piping Welds The NRC estimates that there are no incremental NRC implementation costs associated with this condition, which is a clarification of language used in the Code Case.

5.6.12 Optimized Structural Dissimilar Metal Weld Overlay for Mitigation of PWR Class 1 Items The NRC estimates that there are no incremental NRC implementation costs associated with the conditions of this Code Case, which are either identical to existing conditions or clarifications of language used in the Code Case.

5.6.13 Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of Pressurized-Water Reactor Full-Penetration Circumferential Nickel Alloy Dissimilar Metal Welds in Class 1 Items The NRC estimates that there are no incremental NRC implementation costs associated with the conditions of this Code Case, because the resultant relief requests are operation costs.

5.6.14 Ultrasonic Examination of Cast Austenitic Piping Welds from the Outside Surface,Section XI, Division 1 The NRC estimates that there are no incremental NRC implementation costs associated with the conditions of this Code Case, which have already been incorporated by reference into 10 CFR 50.55a, and the costs have already been estimated in the final regulatory analysis for the latest ASME Code Editions rulemaking (NRC, 2017f).

49 5.6.15 Austenitic Stainless Steel Cladding and Nickel-Base Cladding Using Ambient Temperature Machine GTAW Temper Bead Technique The NRC estimates that there are no incremental NRC implementation costs associated with this condition.

5.6.16 Direct Use of Master Fracture Toughness Curve for Pressure-Retaining Materials of Class 1 Vessels The NRC estimates that there are no incremental NRC implementation costs associated with this clarifying condition.

5.6.17 Ultrasonic Examination in Lieu of Radiography for Welds in Ferritic Pipe The NRC estimates that there are no incremental NRC implementation costs associated with this condition, which causes new reactors to use radiography instead of this Code Case, with no cost impact.

5.6.18 Flaw Tolerance Evaluation of Cast Austenitic Stainless Steel Piping,Section XI, Division 1 The NRC estimates that there are no incremental NRC implementation costs associated with the conditions of this Code Case, because the resultant relief requests are operation costs.

5.6.19 Alternative Pressure Testing Requirements Following Repairs or Replacements for Class 1 Piping between the First and Second Inspection Isolation Valves,Section XI, Division 1 The NRC estimates that there are no incremental NRC implementation costs associated with this clarifying condition.

5.6.20 In Situ VT-3 Examination of Removable Core Support Structures without Removal The NRC estimates that there are no incremental NRC implementation costs associated with these clarifying conditions.

5.7 NRC Operation When the NRC receives an alternative request, the staff requires additional time to evaluate the alternative request submittals acceptability relative to the criteria currently approved by the agency. Under Alternative 2, the additional seven alternative request submittals per year would not be required. By incorporating by reference the ASME Code Editions in the Code of Federal Regulations, a nuclear power plant licensee could use a more current ASME Code edition or addenda without submitting an alternative request for NRC review.

50 As discussed in the Section 5.4, the staff expects Alternative 2, the proposed rule alternative, to avert approximately 24 relief requests per year. As shown in Table 15, the NRC estimates that each submittal would require 143 hours0.00166 days 0.0397 hours 2.364418e-4 weeks 5.44115e-5 months of staff time to perform the technical review (including resolving technical issues), document the evaluation, and respond to the licensees request.

The absence of these submittals would result in an NRC averted cost that ranges from

$2.11 million based on a 7-percent NPV to $2.40 million based on a 3-percent NPV. Therefore, this alternative would provide a net benefit (i.e., averted cost).

Table 15 NRC Operation CostsReviews of Averted Code Alternative Requests (Operating and New Reactors)

The NRC review costs for any ASME Code alternative requests submitted to the NRC before the effective date of the proposed rule are considered sunk costs, and this regulatory analysis does not address them further.

5.7.1 Additional Materials for Subsection NF, Class 1, 2, 3, and Metal Containment Supports Fabricated by Welding The NRC estimates that there are no incremental NRC operation costs associated with the conditions of this Code Case, which are either identical or substantively identical to existing conditions or administrative in nature.

5.7.2 Underwater Welding,Section XI, Division 1 The NRC estimates that there are no incremental NRC operation costs associated with the conditions of this Code Case, which are clarifications of the existing condition.

5.7.3 Evaluation of Pipe Wall Thinning,Section XI Undiscounted 7% NPV 3% NPV 2020 Review Code Case relief request submittal and issue safety evaluation 24 143

$131

$443,000

$414,000

$430,000 2021 Review Code Case relief request submittal and issue safety evaluation 24 143

$131

$443,000

$387,000

$418,000 2022 Review Code Case relief request submittal and issue safety evaluation 24 143

$131

$443,000

$362,000

$405,000 2023 Review Code Case relief request submittal and issue safety evaluation 24 143

$131

$443,000

$338,000

$394,000 2024 Review Code Case relief request submittal and issue safety evaluation 24 143

$131

$443,000

$316,000

$382,000 2025 Review Code Case relief request submittal and issue safety evaluation 24 143

$131

$443,000

$295,000

$371,000

$2,658,000

$2,112,000

$2,400,000 Total:

Year Activity Number of Actions Hours Weighted Hourly rate Cost

51 The NRC estimates that there are no incremental NRC operation costs associated with the conditions of this Code Case, which are either identical or substantively identical to existing conditions.

5.7.4 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique for Boiling-Water Reactor Control Rod Drive Housing/Stub Tube Repairs The NRC estimates that there are no incremental NRC operation costs associated with the condition of this Code Case, which is identical to the existing condition.

5.7.5 Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique The NRC estimates that there are no incremental NRC operation costs associated with the condition of this Code Case, which is identical to the existing condition.

5.7.6 Alternative Requirements for Inner Radius Examinations of Class 1 Reactor Vessel Nozzles,Section XI The NRC estimates that there are no incremental NRC operation costs from the resultant inservice inspections associated with the condition of this Code Case.

5.7.7 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface The NRC estimates that there are incremental NRC operation costs associated with the condition of this Code Case because of the resulting relief request. The staff would need to approve the relief request submitted by a licensee, resulting in estimated costs ranging from

($20,000) at a 7-percent NPV to ($23,000) at a 3-percent NPV, as shown in Table 16.

Table 16 N-695-1 Piping Examination Relief Request Review 5.7.8 Qualification Requirements for Mandatory Appendix VIII Piping Examination Conducted from the Inside Surface The NRC estimates that there are incremental NRC operation costs associated with the condition of this Code Case because of the resulting relief requests. The staff would need to approve the relief request submitted by a licensee, resulting in estimated costs ranging from

($20,000) at a 7-percent NPV to ($23,000) at a 3-percent NPV, as shown in Table 17.

Undiscounted 7% NPV 3% NPV 2022 Verbal relief request 1

190

$131

($25,000)

($20,000)

($23,000)

($25,000)

($20,000)

($23,000)

Cost Total:

Year Activity Number of Affected Labor Hours Weighted Hourly rate

52 Table 17 N-696-1 Piping Examination Relief Request Review 5.7.9 Alternative Requirements for Boiling-Water Reactor Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1 The NRC estimates that there are no incremental NRC operation costs associated with the conditions of this Code Case, which are consistent with the approach used by licensees before the Code Case existed.

5.7.10 Evaluation Criteria for Temporary Acceptance of Degradation in Moderate-Energy Class 2 or 3 Vessels and Tanks The NRC estimates that there are no incremental NRC operation costs from the tank repairs associated with the condition of this Code Case.

5.7.11 Alternative Examination Coverage Requirements for Examination Category B-F, B-J, C-F-1, C-F-2, and R-A Piping Welds The NRC estimates that there are no incremental NRC operation costs associated with this condition, which is a clarification of language used in the Code Case.

5.7.12 Optimized Structural Dissimilar Metal Weld Overlay for Mitigation of Pressurized-Water Reactor Class 1 Items The NRC estimates that there are no incremental NRC operation costs associated with the conditions of this Code Case, which are either identical to existing conditions or clarifications of language used in the Code Case.

5.7.13 Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of Pressurized-Water Reactor Full-Penetration Circumferential Nickel Alloy Dissimilar Metal Welds in Class 1 Items The NRC expects to incur costs associated with the review of N-766-1 relief requests submitted by licensees. As shown in Table 18, the staff estimates receiving one review request per year, requiring approximately 143 hours0.00166 days 0.0397 hours 2.364418e-4 weeks 5.44115e-5 months per review, resulting in costs ranging from ($98,000) at a 7-percent NPV to ($105,000) at a 3-percent NPV.

Undiscounted 7% NPV 3% NPV 2022 Verbal relief request 1

190

$131

($25,000)

($20,000)

($23,000)

($25,000)

($20,000)

($23,000)

Total:

Year Activity Number of Affected Labor Hours Weighted Hourly rate Cost

53 Table 18 N-766-1 Relief Request Reviews 5.7.14 Ultrasonic Examination of Cast Austenitic Piping Welds from the Outside Surface,Section XI, Division 1 The NRC estimates that there are no incremental NRC operation costs associated with the conditions of this Code Case, which have already been incorporated by reference into 10 CFR 50.55a. The costs have already been estimated in the final regulatory analysis for the latest ASME Code Editions rulemaking (NRC, 2017f).

5.7.15 Austenitic Stainless Steel Cladding and Nickel-Base Cladding Using Ambient Temperature Machine GTAW Temper Bead Technique The NRC estimates that there are no incremental NRC operation costs associated with this condition.

5.7.16 Direct Use of Master Fracture Toughness Curve for Pressure-Retaining Materials of Class 1 Vessels The NRC estimates that there are no incremental NRC operation costs associated with this clarifying condition.

5.7.17 Ultrasonic Examination in Lieu of Radiography for Welds in Ferritic Pipe The NRC estimates that there are no incremental NRC operation costs associated with this condition, which causes new reactors to use radiography instead of this Code Case, which has no cost impact.

Undiscounted 7% NPV 3% NPV 2019 Review relief request when condition prevents use of N-766-1 1

143

$131

($19,000)

($19,000) 2020 Review relief request when condition prevents use of N-766-1 1

143

$131

($19,000)

($18,000)

($18,000) 2021 Review relief request when condition prevents use of N-766-1 1

143

$131

($19,000)

($17,000)

($18,000) 2022 Review relief request when condition prevents use of N-766-1 1

143

$131

($19,000)

($16,000)

($17,000) 2023 Review relief request when condition prevents use of N-766-1 1

143

$131

($19,000)

($14,000)

($17,000) 2024 Review relief request when condition prevents use of N-766-1 1

143

$131

($19,000)

($14,000)

($16,000)

($114,000)

($98,000)

($105,000)

Year Activity Number of Actions Hours Weighted Hourly rate Total:

Cost

54 5.7.18 Flaw Tolerance Evaluation of Cast Austenitic Stainless Steel Piping,Section XI, Division 1 The NRC expects to incur costs associated with the review of N-838 relief requests submitted by licensees. As shown in Table 19, the staff estimates receiving one review request per year, requiring approximately 143 hours0.00166 days 0.0397 hours 2.364418e-4 weeks 5.44115e-5 months per review, resulting in costs ranging from ($98,000) at a 7-percent NPV to ($105,000) at a 3-percent NPV.

Table 19 N-838 Relief Request Reviews 5.7.19 Alternative Pressure Testing Requirements Following Repairs or Replacements for Class 1 Piping between the First and Second Inspection Isolation Valves,Section XI, Division 1 The NRC estimates that there are no incremental NRC operation costs associated with this clarifying condition.

5.7.20 In Situ VT-3 Examination of Removable Core Support Structures without Removal The NRC estimates that there are no incremental NRC operation costs associated with these clarifying conditions.

5.8 Total NRC Costs Table 20 shows the total NRC costs broken down between implementation and operation costs for Alternative 2. These total NRC costs represent averted costs (savings) and are estimated to range from $1.52 million at a 7-percent discount rate to $1.78 million at a 3-percent discount rate.

Undiscounted 7% NPV 3% NPV 2019 Review relief request when condition prevents use of N-838 1

143

$131

($19,000)

($19,000) 2020 Review relief request when condition prevents use of N-838 1

143

$131

($19,000)

($18,000)

($18,000) 2021 Review relief request when condition prevents use of N-838 1

143

$131

($19,000)

($17,000)

($18,000) 2022 Review relief request when condition prevents use of N-838 1

143

$131

($19,000)

($16,000)

($17,000) 2023 Review relief request when condition prevents use of N-838 1

143

$131

($19,000)

($14,000)

($17,000) 2024 Review relief request when condition prevents use of N-838 1

143

$131

($19,000)

($14,000)

($16,000)

($114,000)

($98,000)

($105,000)

Year Activity Number of Actions Hours Weighted Hourly rate Cost Total:

55 Table 20 Total NRC Costs 5.9 Total Costs Table 21 shows the total averted costs (benefits/savings) broken down between implementation and operation for the industry and the NRC under Alternative 2. These total averted costs are estimated to range from million at a 7-percent discount rate to $7.48 million at a 3-percent discount rate.

Table 21 Total Costs 5.10 Improvements in Knowledge Alternative 2 compared to the regulatory baseline (Alternative 1) would improve the knowledge of industry and the NRC staff by allowing them to gain experience with new technology before its incorporation into the ASME Code and by permitting licensees to use advances in ISI and IST. Developing greater knowledge and common understanding of the ASME Code, as well as eliminating unnecessary work, better enables industry and the NRC staff to produce desired on-the-job results, which leads to pride in performance and increased job satisfaction.

5.11 Regulatory Efficiency Alternative 2, compared to the regulatory baseline, would increase regulatory efficiency because licensees that want to use NRC-approved ASME Code Cases would not need to submit requests for alternatives to the NRCs regulations. This would give licensees flexibility and decrease their uncertainty when modifying or preparing to perform ISI or IST. Further, Alternative 2 is consistent with the provisions of the NTTAA, which encourages Federal regulatory agencies to consider adopting voluntary consensus standards as an alternative to de novo agency development of standards affecting an industry. Alternative 2 is also consistent Undiscounted 7% NPV 3% NPV

($360,000)

$2,380,000

$1,880,000

$2,140,000

$2,020,000

$1,520,000

$1,780,000 Total NRC Cost:

Total NRC Implementation Cost:

Attribute Total NRC Operation Cost:

NRC Costs Undiscounted 7% NPV 3% NPV Industry Implementation

$0

$0 Industry Operation

$6,130,000

$5,200,000

$5,700,000 Total Industry Cost

$6,130,000

$5,200,000

$5,700,000 NRC Implementation

($360,000)

NRC Operation

$2,380,000

$1,880,000

$2,140,000 Total NRC Cost

$2,020,000

$1,520,000

$1,780,000 Net

$8,150,000

$6,720,000

$7,480,000 Attribute Total Averted Costs (Costs)

56 with the NRCs policy of evaluating the latest versions of consensus standards in terms of their suitability for endorsement by regulations and RGs. Finally, Alternative 2 is consistent with the NRCs goal of harmonizing with international standards to improve regulatory efficiency for both the NRC and international standards groups.

5.12 Other Considerations 5.12.1 National Technology Transfer and Advancement Act of 1995 Alternative 2 is consistent with the provisions of the NTTAA and its implementing guidance in OMB Circular A-119, Federal Participation in the Development and Use of Voluntary Consensus Standards and in Conformity Assessment Activities, dated January 27, 2016 (OMB, 2016), which encourage Federal regulatory agencies to consider adopting voluntary consensus standards as an alternative to de novo agency development of standards affecting an industry.

5.12.2 Continued NRC Practice of Incorporation by Reference of ASME Code Editions and Addenda into the Code of Federal Regulations Alternative 2 would continue the NRCs practice of establishing requirements for the design, construction, operation, ISI, and IST of nuclear power plants by approving the use of new ASME BPV and OM Code Cases in 10 CFR 50.55a.

Given the existing data and information, Alternative 2 is the most effective way to implement the updated ASME Code Cases. The updates would amend 10 CFR 50.55a to incorporate by reference the latest revisions to RGs 1.84, 1.147, and 1.192, which list Code Cases published by ASME and approved by the NRC.

5.12.3 Increased Public Confidence Alternative 2 incorporates the current ASME Code Cases for the design, construction, operation, ISI, and IST of nuclear power plants by approving the use of later ASME BPV and OM Code Cases in 10 CFR 50.55a. This alternative would allow licensees to use risk-informed, performance-based approaches and the most current methods and technology to design, construct, operate, examine, and test nuclear power plant components while maintaining NRC oversight of these activities, which increases public confidence.

5.12.4 Reliable Assessment of Cast Austenitic Stainless Steel Materials The ability to reliably assess CASS materials is important for life extension and license renewal activities. There remains a level of concern with CASS components because of the possibility of thermal embrittlement over time and the limitations of current volumetric inspection techniques. Establishing a robust aging management approach for CASS components would improve the knowledge of the material condition of those components exposed to reactor

57 coolant environments and improve the current state of knowledge, which is constrained by a lack of data, operating experience, and proven nondestructive engineering solutions.

5.13 Uncertainty Analysis The staff completed a Monte Carlo sensitivity analysis for this regulatory analysis using the specialty software @Risk. The Monte Carlo approach answers the question, What distribution of net benefits results from multiple draws of the probability distribution assigned to key variables?

5.13.1 Uncertainty Analysis Assumptions As this regulatory analysis is based on estimates of values that are sensitive to plant-specific cost drivers and plant dissimilarities, the staff provides the following analysis of the variables with the greatest uncertainty. To perform this analysis, the staff used a Monte Carlo simulation analysis using the @Risk software program.7 Monte Carlo simulations involve introducing uncertainty into the analysis by replacing the point estimates of the variables used to estimate base-case costs and benefits with probability distributions. By defining input variables as probability distributions instead of point estimates, the influence of uncertainty on the results of the analysis (i.e., the net benefits) can be effectively modeled.

The probability distributions chosen to represent the different variables in the analysis were bounded by the range-referenced input and the staffs professional judgment. When defining the probability distributions for use in a Monte Carlo simulation, summary statistics are needed to characterize the distributions. These summary statistics include the minimum, most likely, and maximum values of a program evaluation and review technique (PERT) distribution,8 the minimum and maximum values of a uniform distribution, and the specified integer values of a discrete population. The staff used the PERT distribution to reflect the relative spread and skewness of the distribution defined by the three estimates.

Table 22 identifies the data elements, the distribution and summary statistic, and the mean value of the distribution that were used in the uncertainty analysis.

7 Information about this software is available at http://www.palisade.com.

8 A PERT distribution is a special form of the beta distribution with specified minimum and maximum values.

The shape parameter is calculated from the defined most likely value. The PERT distribution is similar to a triangular distribution in that it has the same set of three parameters. Technically, it is a special case of a scaled beta (or beta general) distribution. The PERT distribution is generally considered superior to the triangular distribution when the parameters result in a skewed distribution, as the smooth shape of the curve places less emphasis in the direction of skew. Similar to the triangular distribution, the PERT distribution is bounded on both sides and therefore may not be adequate for modeling purposes that need to capture tail or extreme events.

58 Table 22 Uncertainty Analysis Variables Data Element Mean Estimate Distribution Low Estimate Best Estimate High Estimate N-695-1 and N-696-1 Piping Examinations Verbal relief request (industry)

Weighted hourly rate for relief request (industry)

$126.89 PERT

$101.17

$127.10

$151.73 Hours to produce relief request 190.0 PERT 50 190 330 Number of relief requests (per Code Case) 1 PERT 1

1 1

Verbal relief request (NRC)

Weighted hourly rate (NRC)

$131.00 PERT

$131

$131 Hours to approve relief request 190.0 PERT 50 190 330 Number of relief requests (per Code Case) 1 PERT 1

1 1

N-705-1 Tank Weld Repair Condition that replaces 26-month timeframe with next refueling/before startup Cost to repair leaking tank

$46,666.67 PERT

$20,000

$40,000

$100,000 Number of years earlier for repair due to condition 1.0 PERT 0

1 2

Number of repairs per year for all plants 1.0 PERT 0

1 2

N-766-1 Inlay and Onlay Repair Condition that prevents Code Case use in certain situations (industry)

Weighted hourly rate for relief request (industry)

$126.89 PERT

$101.17

$127.10

$151.73 Hours to produce N-766-1 relief request 380.0 PERT 100 380 660 Number of N-766-1 relief requests produced per year 1.0 PERT 0

1 2

Condition that prevents Code Case use in certain situations (NRC)

Weighted hourly rate (NRC)

$131.00 PERT

$131

$131 Hours to approve relief request 143.3 PERT 120 140 180 Number of N-766-1 relief requests approved per year 1.0 PERT 0

1 2

N-838 Flaw Tolerance Evaluation of CASS Condition that prevents Code Case use in certain situations (industry)

Weighted hourly rate for relief request (industry)

$126.89 PERT

$101.17

$127.10

$151.73 Hours to produce N-838 relief request 380.0 PERT 100 380 660 Number of N-838 relief requests (total, all reactors) 1.0 PERT 0

1 2

59 Data Element Mean Estimate Distribution Low Estimate Best Estimate High Estimate Condition that prevents Code Case use in certain situations (NRC)

Weighted hourly rate (NRC)

$131.00 PERT

$131

$131 Hours to approve relief request 143.3 PERT 120 140 180 Number of relief requests per year 1.0 PERT 0

1 2

N-648-2 nozzle inspection (new reactors only)

Hourly rate for technical staff

$126.89 PERT

$101.17

$127.10

$151.73 Hours per nozzle (UT vs VT) 16.0 PERT 12 16 20 Number of nozzles (BWR) 25.0 PERT 22 25 28 Number of nozzles (PWR) 8.0 PERT 6

8 10 Inspection time after reactor placed into service 2.8 PERT 2

3 3

Percentage of nozzles inspected 0.4 PERT 25%

35%

50%

Number of new PWRs 2

PERT 1

2 2

Number of new BWRs 3

PERT 2

3 3

Averted Code Case relief request costs Weighted hourly rate for relief request (engineer)

$126.89 PERT

$101.17

$127.10

$151.73 Relief request preparation and submission (hours) 380.0 PERT 100 380 660 Number of relief requests per year 23.6 PERT 16.5 22.5 35.0 Develop and issue final rule (NRC)

Hourly rate for NRC

$131.00 PERT

$131

$131 Hours to develop 1840.0 PERT 1440 1600 3200 Number of years 1.0 PERT 1

1 1

Develop and issue final regulatory guide changes (NRC)

Hourly rate for NRC

$131.00 PERT

$131

$131 Hours to develop 920.0 PERT 720 800 1600 Number of years 1.0 PERT 1

1 1

Averted review of Code alternative request (NRC)

Hourly rate for NRC

$131.00 PERT

$131

$131 Hours to review 143.3 PERT 120 140 180 Number of actions (this is a recurring averted cost) 23.6 PERT 16.5 22.5 35.0 5.13.2 Uncertainty Analysis Results The NRC performed the Monte Carlo simulation by repeatedly recalculating the results 10,000 times. For each iteration, the values identified in Table 22 were chosen randomly from the probability distributions that define the input variables. The values of the output variables

60 were recorded for each iteration, and these values were used to define the resultant probability distribution.

For the analysis shown in each figure below, 10,000 simulations were run in which the key variables were changed to assess the resulting effect on costs and benefits. Figure 1, 2, and 3 display the histograms of the incremental costs and benefits from the regulatory baseline (Alternative 1). The analysis shows that both the industry and the NRC would benefit if this rule is issued.

Figure 1 Total industry costs (7-percent NPV)Alternative 2 5.0%

90.0%

5.0%

2.33 8.56 0

2 4

6 8

10 12 14 Values in Millions ($)

Total Industry Cost - 7%

Minimum

$610,000 Maximum

$13,170,000 Mean

$5,207,695 Std Dev

$1,913,732 5%

$2,330,000 95%

$8,560,000

61 Figure 2 Total NRC costs (7-percent NPV)Alternative 2 Figure 3 Total costs (7-percent NPV)Alternative 2 Table 23 presents descriptive statistics for the uncertainty analysis. The 5-percent and 95-percent values (i.e., the bands marked 5.0% on either side of the 90.0% confidence interval 5.0%

90.0%

5.0%

0.990 2.140 0.50 1.00 1.50 2.00 2.50 3.00 Values in Millions ($)

Total NRC Cost - 7%

Minimum

$620,000 Maximum

$2,930,000 Mean

$1,516,874 Std Dev

$350,991 5%

$990,000 95%

$2,140,000 5.0%

90.0%

5.0%

3.61 10.37 0

2 4

6 8

10 12 14 16 Values in Millions ($)

Total Cost - 7%

Minimum

$1,750,000 Maximum

$15,700,000 Mean

$6,724,569 Std Dev

$2,076,622 5%

$3,610,000 95%

$10,370,000

62 in Figure 1 and Figure 2) that appear as numerical values on the top of the vertical lines in Figure 1, 2, and 3 are reflected in Table 23 (rounded) as the 0.05 and 0.95 values, respectively.

Table 23 Descriptive Statistics for Uncertainty Results (7-Percent NPV)

Uncertainty Result Incremental Cost-Benefit (2017 million dollars)

Min Mean Std Dev Max 0.05 0.95 Total Industry Cost

$0.61

$5.21

$1.91

$13.2

$2.33

$8.56 Total NRC Cost

$0.62

$1.52

$0.35

$2.93

$0.99

$2.14 Total Cost

$1.75

$6.72

$2.08

$15.7

$3.61

$10.4 Examining the range of the resulting output distribution in Table 23, it is possible to more confidently discuss the potential incremental costs and benefits of the proposed rule. This table displays the key statistical results, including the 90-percent confidence interval in which the net benefits would fall between the 5-percent and 95-percent values.

Figure 4 shows a tornado diagram that identifies the key variables whose uncertainty drives the largest impact on total costs (and averted costs) for this proposed rulemaking. This figure ranks the variables based on their contribution to cost uncertainty. One key variablethe number of hours required for Code relief request preparation and submissionaccounts for the most uncertainty in the costs. The remaining key variables show diminishing variation.

Figure 4 Top eight variables for which uncertainty drives the largest impact on total costs (7-percent NPV)Alternative 2 3,966,860.00 9,576,580.00 4,923,000.00 8,955,640.00 6,076,980.00 7,533,820.00 6,477,410.00 7,059,820.00 6,485,510.00 6,891,480.00 6,568,860.00 6,955,890.00 6,531,680.00 6,913,370.00 6,537,030.00 6,908,100.00 3

4 5

6 7

8 9

10 Total Cost - 7%

Values in Millions Percentage of Nozzles inspected Number of N-838 relief requests (total, all reactors)

Hours to produce N-766-1 relief request Hours to produce N-838 relief request Hours to review code alternative relief request Weighted Hourly Rate for Relief Request (Engineer)

Number of code case relief requests per site Hours for relief request preparation and submission Input High Input Low Baseline = 6,724,569.00

63 5.13.3 Summary of Uncertainty Analysis The simulation analysis shows that the estimated mean benefit (i.e., positive averted costs or savings) for this proposed rule is $6.72 million with a 90-percent confidence interval that the benefit is between $3.61 million and $10.4 million at a 7-percent discount rate. A reasonable inference from the uncertainty analysis is that proceeding with the proposed rule represents an efficient use of resources and averted costs for the NRC and the industry. The rule is deemed cost beneficial both to industry and to the NRC when they are considered separately.

5.14 Disaggregation To comply with the guidance in Section 4.3.2 of NUREG/BR-0058 on criteria for the treatment of individual requirements, the NRC performed a screening review to determine whether any of the individual requirements (or set of integrated requirements) of the final rule would be unnecessary to achieve the objectives of the rulemaking. The NRC determined that the objectives of the rulemaking are to incorporate RGs by reference and to make conforming changes. Furthermore, the NRC concludes that each of the final rules requirements would be necessary to achieve one or more objectives of the rulemaking. Table 24 provides the results of this review.

Table 24 Disaggregation Regulatory Goals for Proposed Rule (1) Approve Use of the New Code Cases in Each of the RGs (2) Make Incorporation by Reference Conforming Changes 10 CFR 50.55a(a)(3)(i), NRC RG 1.84, Revision 38 (DG-1342)

X X

10 CFR 50.55a(a)(3)(ii), NRC RG 1.147, Revision 19 (DG-1343)

X X

10 CFR 50.55a(a)(3)(iii), NRC RG 1.192, Revision 3 (DG-1345)

X X

5.15 Summary This regulatory analysis identified both quantifiable and nonquantifiable costs and benefits that would result from incorporating NRC-approved ASME BPV and OM Code Cases by reference into the Code of Federal Regulations. Although quantifiable costs and benefits appear to be more tangible, the staff urges decisionmakers not to discount costs and benefits that cannot be quantified. Such benefits or costs can be as important as or even more important than benefits or costs that can be quantified and monetized.

5.15.1 Quantified Net Benefit As shown in Table 21 above, the estimated quantified incremental averted costs for Alternative 2, compared to the regulatory baseline (Alternative 1) over the 6 years the Code

64 Cases will be effective range from approximately $6.72 million (7-percent discount rate) to

$7.48 million (3-percent discount rate). Table 21 shows that Alternative 2 would also be cost beneficial for the NRC and the industry when they are considered separately.

5.15.2 Nonquantified Benefits In addition to the quantified costs discussed in this regulatory analysis, the attributes of public health (accident), improvements in knowledge, regulatory efficiency, and other considerations would produce a number of nonquantified costs and benefits for the industry and the NRC.

These benefits are summarized below.

5.15.2.1 Advances in Inservice Inspection and Inservice Testing Advances in ISI and IST may incrementally decrease the likelihood of a radiological accident, the likelihood of postaccident plant worker exposure, and the level of plant worker radiological exposures during routine inspections or testing. The NRCs approval of later editions and addenda of the ASME BPV and OM Codes and associated Code Cases may contribute to plant safety by providing alternative examination methods that may result in the earlier identification of material degradation that, if undetected, could result in further degradation and lead to a plant transient. These alternative methods may increase assurance of plant safety system readiness and may prevent, through inspection and testing, the introduction of a new failure mode or common-cause failure mode not previously evaluated.

5.15.2.2 Reduction in Public Health Radiation Exposures The industrys practice of adopting the ASME BPV and OM Code Cases that are incorporated by reference into the regulations may incrementally reduce the likelihood of a radiological accident in a positive, but not easily quantifiable, manner. Pursuing Alternative 2 would continue to meet the NRC goal of maintaining safety by still providing NRC approval of later editions and addenda of the ASME Code and associated Code Cases to permit licensees to use advances in ISI and IST, provide alternative examinations for older plants, respond promptly to user needs, and provide a limited and clearly focused alternative to specific ASME Code provisions. Improvements in ISI and IST may also result in the earlier identification of material degradation that, if undetected, could lead to further degradation that eventually causes a plant transient. As such, Alternative 2 would maintain the same level of safety, or possibly an incremental improvement in safety, which may result in an incremental decrease in public health radiation exposures when compared to the regulatory baseline.

5.15.2.3 Reduction in Worker Radiation Exposures The NRCs approval of later editions and addenda of the ASME BPV and OM Codes and associated Code Cases may reduce occupational radiation exposures in a positive, but not easily quantifiable, manner. For example, the advances in ISI and IST may result in an incremental decrease in the likelihood of an accident resulting in worker exposure when

65 compared to the regulatory baseline. The occupational exposure resulting from the condition the NRC proposes to add in 10 CFR 50.55a(b)(2)(xxxix) on ASME Code Section XI, Appendix III, Supplement 2, results in costs from dose calculated in Section 5.4 of this regulatory analysis.

5.15.2.4 Improvements in Inservice Inspection and Inservice Testing Knowledge The NRC approval of later editions and addenda of the ASME BPV and OM Codes and associated Code Cases would improve knowledge by enhancing the ability of the industry and the staff to gain experience with new technology before its incorporation into the ASME Codes and by permitting licensees to use advances in ISI and IST. Improved ISI and IST may result in the earlier identification of material degradation that, if undetected, could lead to further degradation that eventually causes a plant transient.

5.15.2.5 Consistent with National Technology Transfer and Advancement Act of 1995 and Implementing Guidance Alternative 2 is consistent with the provisions of the NTTAA and its implementing guidance in OMB Circular A-119, which encourage Federal regulatory agencies to consider adopting voluntary consensus standards as an alternative to de novo agency development of standards affecting an industry.

5.15.2.6 Continued NRC Practice of Incorporation by Reference of ASME Code Editions and Addenda into the Code of Federal Regulations Alternative 2 would continue the NRCs practice of establishing requirements for the design, construction, operation, ISI, and IST of nuclear power plants by approving the use of later editions and addenda of the ASME BPV and OM Codes in 10 CFR 50.55a.

5.15.2.7 Increased Public Confidence Alternative 2 would incorporate the current ASME Code edition, addenda, and Code Cases for the design, construction, operation, ISI, and IST of nuclear power plants by approving the use of editions and addenda of the ASME BPV and OM Codes in 10 CFR 50.55a. This alternative would allow licensees to use risk-informed, performance-based approaches and the most current methods and technology to design, construct, operate, examine, and test nuclear power plant components, while maintaining NRC oversight of these activities.

The timely incorporation by reference of current addenda and editions of the ASME BPV and OM Codes into the Code of Federal Regulations and the review and approval of associated Code Cases would help the NRC remain an effective industry regulator. This role would be

66 undermined if outdated material remains incorporated by reference in the Code of Federal Regulations.

5.15.2.8 Increased Cast Austenitic Stainless Steel Material Component Reliability The ability to reliably assess CASS materials is important for life extension and license renewal activities. There remains a level of concern with CASS components because of the possibility of thermal embrittlement over time and the limitations of current volumetric inspection techniques. Establishing a robust aging management approach for CASS components would increase knowledge of the material condition of those components exposed to reactor coolant environments over the current state of knowledge, which is constrained by a lack of data, operating experience, and proven nondestructive engineering solutions.

5.15.3 Nonquantified Costs The staff believes that incorporating by reference the most recent ASME BPV and OM Code editions and addenda and associated NRC-approved Code Cases into the Code of Federal Regulations would decrease industry and NRC operation costs. If the staff has underestimated the number or the complexity of these eliminated submittals, then the averted costs would increase proportionally, causing the quantified net cost of Alternative 2 to decrease toward a more net-beneficial determination.

5.16 Safety Goal Evaluation The proposed rule alternative would allow licensees and applicants to apply the most recent ASME BPV and OM Code Cases approved by the NRC, sometimes with NRC-specified conditions. The NRCs safety goal evaluation applies only to regulatory initiatives considered to be generic safety enhancement backfits subject to the substantial additional protection standard at 10 CFR 50.109(a)(3). The NRC does not regard the incorporation by reference of NRC-approved ASME Code Cases to be backfitting or to represent an inconsistency with any issue finality provisions in 10 CFR Part 52. The Federal Register notice of proposed rulemaking states the basis for this determination.

5.16.1 Section A: Incorporation by Reference of Later Editions and Addenda of Section III, Division 1, of the ASME BPV Code Incorporation by reference of the Code Cases of Section III, Division 1, of the ASME BPV Code is prospective in nature. Incorporation of the Code Cases would not affect a plant that has received a construction permit, an operating license, or a combined license, or a design that has been approved. This is because the Code Cases of the ASME BPV Code to be used in constructing a plant are, by rule, determined based on the date of the construction permit or the combined license and are not changed, except voluntarily by the licensee with the approval of

67 the NRC. Thus, incorporation by reference of later Code Cases of Section III, Division 1, of the ASME BPV Code would not constitute a backfitting as defined in 10 CFR 50.109(a)(1).

5.16.2 Section B: Incorporation by Reference of Later Editions and Addenda of Section XI, Division 1, of the ASME BPV and OM Codes Incorporation by reference of later Code Cases of Section XI, Division 1, of the ASME BPV Code and of the ASME OM Code would affect the ISI and IST programs of operating reactors.

However, the Backfit Rule generally does not apply to incorporation by reference of later Code Cases of Section XI of the ASME BPV Code and the ASME OM Code for the following reasons:

The NRCs longstanding policy has been to incorporate later versions of the ASME Codes into its regulations; thus, licensees know when receiving their operating licenses that such updating is part of the regulatory process. This is reflected in 10 CFR 50.55a, which requires licensees to revise their ISI and IST programs every 120 months to the latest edition and addenda of Section XI of the ASME BPV Code and of the ASME OM Code incorporated by reference into 10 CFR 50.55a that are in effect 12 months before the start of a new 120-month ISI and IST interval. Thus, when the NRC endorses a later version of an ASME Code, it is implementing this longstanding policy.

ASME BPV and OM Codes are national consensus standards developed by participants with broad and varied interests, in which all interested parties including the staff and nuclear utility personnel, participate. This consideration is consistent with both the intent and spirit of the Backfit Rule (i.e., the NRC provides for the protection of public health and safety but does not unilaterally impose undue burden on applicants or licensees).

5.16.3 Other Circumstances in Which the NRC Does Not Apply the Backfit Rule to the Endorsement of a Later Code The NRC does not apply the Backfit Rule to the endorsement of a later code in the following other circumstances:

When the NRC takes exception to a later ASME BPV or OM Code provision and merely retains the current existing requirement, prohibits the use of the later Code provision, or limits the use of the later Code provision, the Backfit Rule would not apply because the NRC is not imposing new requirements. However, the NRC provides the technical or policy bases, or both, for taking exceptions to the code in the Statement of Considerations for the rule.

When an NRC exception relaxes an existing ASME BPV or OM Code provision but does not prohibit a licensee from using the existing code provision, the Backfit Rule would not apply.

68 5.16.4 Safety Goal Evaluation Result Based on the reasons described, a safety goal evaluation is not appropriate for this regulatory analysis.

5.17 Results for the Committee to Review Generic Requirements This section addresses regulatory analysis information requirements for rulemaking actions or staff positions subject to review by the Committee to Review Generic Requirements (CRGR).

All information called for by the CRGR charter (NRC, 2011) is presented in this regulatory analysis or in the Federal Register notice for the proposed rule. Table 25 provides a cross-reference between the relevant information and its location in this document or the Federal Register notice.

Table 25 Specific CRGR Information Requirements for Regulatory Analysis CRGR Charter Citation (NRC, 2011)

Information Item To Be Included in a Regulatory Analysis Prepared for CRGR Review Where Item Is Discussed Appendix C, (i)

The new or revised generic requirement or staff position as it is proposed to be sent out to licensees or issued for public comment.

Proposed rule text in Federal Register notice for the proposed rule.

Appendix C, (ii)

Draft papers or other documents supporting the requirements or staff positions.

Federal Register notice for the proposed rule.

Appendix C, (iii)

The sponsoring offices position on each proposed requirement or staff position as to whether the proposal would modify, implement, or relax or reduce existing requirements or staff positions.

Regulatory Analysis, Section 5, and Backfitting and Issue Finality,Section XIII, Federal Register notice for the proposed rule.

Appendix C, (iv)

The proposed method of implementation.

Regulatory Analysis, Section 7.

Appendix C, (vi)

Identification of the category of power reactors, new reactors, or nuclear materials facilities or activities to which the proposed generic requirement or staff position applies.

Regulatory Analysis, Section 4.2.2.

Appendix C, (vii)-(viii)

If the proposed action involves a power reactor backfit and the exceptions at 10 CFR 50.109(a)(4) are not applicable, the items required at 10 CFR 50.109(c) and the required rationale at 10 CFR 50.109(a)(3).

Backfitting and Issue Finality,Section XIII, Federal Register notice for the proposed rule.

69 CRGR Charter Citation (NRC, 2011)

Information Item To Be Included in a Regulatory Analysis Prepared for CRGR Review Where Item Is Discussed Section III For proposed generic relaxations or decreases in current requirements or staff positions, a determination, along with the rationale that (a) the public health and safety and the common defense and security would be adequately protected if the proposed relaxations were implemented and (b) the cost savings attributed to each action would be significant enough to justify the action.

Federal Register notice for the proposed rule.

Appendix C, (xi)

An assessment of how the proposed action relates to the Commissions Safety Goal Policy Statement.

Regulatory Analysis, Section 5.16.

6. Decision Rationale Table 26 provides the quantified and qualified costs and benefits for Alternative 2. The quantitative analysis used best-estimate values.

Table 26 Summary of Totals Net Monetary Savings or (Costs)Total Present Value Nonquantified Benefits or (Costs)

Alternative 1: No Action

$0 None Alternative 2: Incorporate by reference RG 1.84, Design, Fabrication, and Materials Code Case Acceptability, ASME Section III, Revision 38 (DG-1342); RG 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, Revision 19 (DG-1343); and RG 1.192, Operation and Maintenance Code Case Acceptability, ASME OM Code, Revision 3 (DG-1345)

Industry: (all provisions)

$5.20 million using a 7% discount rate

$5.70 million using a 3% discount rate NRC: (all provisions)

$1.52 million using a 7% discount rate

$1.78 million using a 3% discount rate Benefits:

Advances in ISI and IST: May incrementally decrease the likelihood of a radiological accident, the likelihood of postaccident plant worker exposure, and the level of plant worker radiological exposures during routine inspections or testing.

Public Health (Accident): May incrementally reduce the likelihood of a radiological accident in a positive, but not easily quantifiable, manner. Pursuing Alternative 2 would continue to meet the NRC goal of maintaining safety by still providing NRC approval of the use of later editions and addenda of the ASME BPV and OM Codes and applicable Code Cases to permit licensees to use

70 Net Monetary Savings or (Costs)Total Present Value Nonquantified Benefits or (Costs)

Net Benefit (Cost): (all provisions)

$6.72 million using a 7% discount rate

$7.48 million using a 3% discount rate advances in ISI and IST, provide alternative examinations for older plants, respond expeditiously to user needs, and provide a limited and clearly focused alternative to specific ASME Code provisions. Improvements in ISI and IST may also result in the earlier identification of material degradation that, if undetected, could lead to further degradation that eventually causes a plant transient. As such, Alternative 2 would maintain the same level of safety or possibly an incremental improvement in safety when compared to the regulatory baseline, which may result in an incremental decrease in public health radiation exposures.

Occupational Health (Accident and Routine): The use of later editions and addenda of the ASME BPV and OM Code and applicable Code Cases may reduce postaccident occupational radiation exposures in a positive, but not easily quantifiable, manner. The advances in ISI and IST may result in an incremental decrease in the likelihood of an accident resulting in worker exposure when compared to the regulatory baseline.

Improvements in Knowledge: Staff would gain experience with new technology and ISI and IST advances.

On-the-job learning would increase worker satisfaction. Eliminating unnecessary work would better enable the staff to produce desired on-the-job results, which lead to pride in performance and increased job satisfaction.

71 Net Monetary Savings or (Costs)Total Present Value Nonquantified Benefits or (Costs)

Consistent with the NTTAA and Implementing Guidance: Alternative 2 is consistent with the provisions of the NTTAA and implementing guidance in OMB Circular A-119, which encourage Federal regulatory agencies to consider adopting voluntary consensus standards as an alternative to de novo agency development of standards affecting an industry. Furthermore, the ASME Code consensus process is an important part of the regulatory framework.

Costs:

Nonquantified Costs: If the staff has underestimated the number or the complexity of these eliminated submittals, then the averted costs would increase proportionally, causing the quantified net costs of Alternative 2 to decrease.

The industry and the NRC would benefit from the proposed rulemaking Alternative 2 because of the averted costs of licensees not needing to submit and the NRC not needing to review and approve ASME Code Case relief requests on a plant-specific basis under the new 10 CFR 50.55a(z). As shown in Table 26, Alternative 2 compared to the regulatory baseline would result in a net benefit (averted cost) to industry that ranges from $5.20 million (7-percent NPV) to $5.70 million (3-percent NPV). The NRCs net benefit would range from $1.52 million (7-percent NPV) to $1.78 million (3-percent NPV). Thus, the total quantitative net averted costs of the rulemaking would range from $6.72 million (7-percent NPV) to $7.48 million (3-percent NPV).

Alternative 2 would also have the qualitative benefit of meeting the NRC goal of ensuring the protection of public health and safety and the environment through the NRCs approval of the use of later ASME BPV and OM Code Cases. It would also allow for the use of the most current methods and technology. This alternative would also support the NRCs goal of maintaining an open regulatory process, because approving ASME Code Cases would demonstrate the agencys commitment to participating in the national consensus standards process and maintain the NRCs role as an effective regulator.

The NRC has had a decades-long practice of approving or mandating, or both, the use of certain of these ASME Code Cases in 10 CFR 50.55a through the rulemaking process of incorporation by reference. Retaining the practice of approving or mandating the ASME

72 Codes would continue the regulatory stability and predictability provided by the current practice.

Retaining the practice would also ensure consistency across the industry and assure the industry and the public that the NRC will continue to support the use of the most updated and technically sound techniques developed by ASME to provide adequate protection to the public.

In this regard, these ASME Codes are voluntary consensus standards developed by participants with broad and varied interests, and they have already undergone extensive external review before being evaluated by the NRC. Finally, the NRCs use of the ASME Codes is consistent with the NTTAA, which directs Federal agencies to adopt voluntary consensus standards instead of developing Government-unique standards (i.e., those developed by Federal agencies), unless inconsistent with applicable law or otherwise impractical.

Based solely on quantified costs and benefits, the regulatory analysis shows that the rulemaking is justified because the total quantified benefits of the proposed rule regulatory action would exceed the costs of the proposed action, for all discount rates up to 7 percent. Certainly, if the qualitative benefits (including the safety benefit, regulatory efficiency, and other nonquantified benefits) are considered together with the quantified benefits, then the benefits would outweigh the identified quantitative and qualitative impacts.

Considering nonquantified costs and benefits, the regulatory analysis shows that the rulemaking is justified because the number and significance of the nonquantified benefits outweigh the nonquantified costs. The uncertainty analysis shows a net benefit (averted cost) for all simulations with a range of averted cost from $1.75 million to $15.7 million (at a 7-percent NPV).

Therefore, integrating both quantified and nonquantified costs and benefits, the benefits of the proposed rule outweigh the identified quantitative and qualitative impacts attributable to the proposed rule.

7. Implementation Schedule The final rule for this proposed rule will become effective 30 days after its publication in the Federal Register.

8. References Code of Federal Regulations, Title 10, Energy, Part 50, Domestic Licensing of Production and Utilization Facilities.

U.S. Department of Labor, Bureau of Labor Statistics (BLS), NAICS Code: North American Industry Classification System Code, January 2017a. Available at http://www.bls.gov/bls/naics.htm; last accessed on April 3, 2018.

BLS, CPI Detailed Report, December 2017, Table 24, Historical Consumer Price Index for All Urban Consumers (CPI-U): U.S. City Average, All-Items, December 2017b. Available at http://www.bls.gov/cpi/tables.htm; last accessed on April 3, 2018.

73 BLS, Databases, Tables & Calculators by

Subject:

CPI Inflation Calculator, January 2018, accessible at http://www.bls.gov; last accessed on April 3, 2018.

Congressional Budget Office, The Budget and Economic Outlook: 2017 to 2027, January 2017. Available at https://www.cbo.gov/sites/default/files/115th-congress-2017-2018/reports/52370-outlookonecolumn.pdf; last accessed on April 10, 2018.

Electric Power Research Institute, Nuclear Safety Analysis Center Report (NASC)-202L-2, Recommendations for an Effective Flow-Accelerated Corrosion Program, April 1999.

U.S. Nuclear Regulatory Commission (NRC), A Handbook for Value-Impact Assessment, NUREG/CR-3568, December 1983 (ADAMS Accession No. ML062830096).

NRC, Regulatory Analysis Technical Evaluation Handbook, NUREG/BR-0184, January 1997 (ADAMS Accession No. ML050190193).

NRC, Regulatory Issue Summary 2004-12, Clarification on Use of Later Editions and Addenda to the ASME OM Code and Section XI, July 28, 2004 (ADAMS Accession No. ML042090436).

NRC, Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods, NUREG/CR-6933, March 2007.

NRC, Regulatory Guide 1.193, ASME Code Cases Not Approved for Use, Revision 3, October 2010 (ADAMS Accession No. ML101800540).

NRC, Charter: Committee to Review Generic Requirements, Revision 8, March 2011.

Available at https://www.nrc.gov/about-nrc/regulatory/crgr/charter.html (ADAMS Accession No. ML110620618).

NRC, An Evaluation of Ultrasonic Phased Array Testing for Cast Austenitic Stainless Steel Pressurizer Surge Line Piping Welds, NUREG/CR-7122, March 2012.

NRC, Regulatory Guide 1.84, Design, Fabrication, and Materials Code Case Acceptability, ASME Section III, Revision 37, March 2017a (ADAMS Accession No. ML16321A335).

NRC, Regulatory Guide 1.192, Operation and Maintenance Code Case Acceptability, ASME OM Code, Revision 2, March 2017b (ADAMS Accession No. ML16321A337).

NRC, Final Regulatory Analysis for Final Rule: Incorporation by Reference of American Society of Mechanical Engineers Codes and Code Cases, April 2017c (ADAMS Accession No. ML16130A522).

NRC, Regulatory Analysis Guidelines of the U.S. Nuclear Regulatory Commission, NUREG/BR-0058, draft Revision 5, April 2017d (ADAMS Accession No. ML17100A480).

NRC, Incorporation by Reference of American Society of Mechanical Engineers Codes and Code Cases; Final Rule, June 2017e (ADAMS Accession No. ML16130A530).

NRC, Approval of American Society of Mechanical Engineers Code Cases; Final Rule, August 2017f (ADAMS Accession No. ML16285A012).

74 NRC, 2017-2018 Information Digest, NUREG-1350, Volume 29, Revision 1, December 2017g (ADAMS Accession No. ML18037A641).

NRC, Regulatory Guide 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, Revision 18, January 2018a (ADAMS Accession No. ML16321A336).

NRC, Draft Regulatory Guide, DG-1342, Design, Fabrication, and Materials Code Case Acceptability, ASME Section III, proposed Revision 38, March 2018b (ADAMS Accession No. ML18114A225).

NRC, Draft Regulatory Guide, DG-1343, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, proposed Revision 19, March 2018c (ADAMS Accession No. ML18114A226).

NRC, Draft Regulatory Guide, DG-1345, Operation and Maintenance Code Case Acceptability, ASME OM Code, proposed Revision 3, March 2018d (ADAMS Accession No. ML18114A228).

Office of Management and Budget (OMB), Circular No. A-4, Regulatory Analysis, September 2003. Available at https://www.whitehouse.gov/omb/circulars_a004_a-4/.

OMB, Circular No. A-119, Federal Participation in the Development and Use of Voluntary Consensus Standards and in Conformity Assessment Activities, January 27, 2016. Available at https://www.federalregister.gov/documents/2016/01/27/2016-01606/revision-of-omb-circular-no-a-119-federal-participation-in-the-development-and-use-of-voluntary.

National Technology Transfer and Advancement Act of 1995, as amended, Public Law 104-113, accessible at http://www.gpo.gov/fdsys/pkg/PLAW-104publ113/pdf/PLAW-104publ113.pdf.

A-1 Appendix A Major Assumptions and Input Data Table A-1 Major Assumptions and Input Data Data Element Best Estimate Unit Source or Basis of Estimate Key analysis dates Proposed rule effective date 2019 year NRC input Analysis base year 2019 year NRC input Average new reactor unit first year of commercial operation 2020 year Assumption of the average commercial operation commencement date of the four new reactor units. Information on the scheduled commercial operation dates of each new reactor unit obtained from http://www.southerncompany.com/about-us/our-business/southern-nuclear/home.cshtml, https://www.scana.com/investors/investor-news#nuclear-development, and https://www.tva.gov/Energy/Our-Power-System/Nuclear. These Web sites were last accessed on April 14, 2016.

Number of entities Number of currently operating reactor units in 2019 98 units Calculation. Based on NUREG-1350, Appendix A (NRC, 2017g). Available at ADAMS Accession No. ML18037A641.

Number of forecasted operating reactor units in 2024 91 units Assumption. Based on NUREG-1350, Appendix A (NRC, 2017g). Available at ADAMS Accession No. ML18037A641. Pilgrim Nuclear Power Station closing in 2019, based on the announcement by Entergy Nuclear Operations, Inc. (see http://www.entergy.com), and Oyster Creek Nuclear Generating Station closing in 2019 based on Exelon Corporations announcement (http://www.exeloncorp.com). Vogtle Electric Generating Plant,

A-2 Data Element Best Estimate Unit Source or Basis of Estimate Units 3 and 4, beginning operation in 2021 and 2022, based on the NRCs Combined License Applications for New Reactors at http://www.nrc.gov/reactors/new-reactors/col.html with data current as of September 15, 2017 (last accessed on April 3, 2018).

Number of new reactor units under construction in 2018 2

units Assumption. Based on the NRCs Combined License Applications for New Reactors at http://www.nrc.gov/reactors/new-reactors/col.html with data current as of February 18, 2016 (last accessed on April 14, 2016). The construction of Vogtle Electric Generating Plant, Unit 3, is expected to be completed in 2021. The construction of Vogtle Unit 4 is expected to be completed in 2022.

Number of Sites Number of sites with currently operating reactors in 2019 59 sites Calculation: [total number of sites with operating reactors] +

[sites with construction completed in 2017] - [sites with units closed in 2017]. Information on operating reactor sites was obtained from the NRCs Operating Nuclear Power Reactors (by Location or Name) at http://www.nrc.gov/info-finder/reactor/

with data current as of January 10, 2017 (last accessed on May 24, 2017).

Number of sites forecasted with currently operating reactors in 2024 52 sites Calculation: [total number of sites with operating reactors] +

[sites with construction completed in years 2017 through 2020] -

[sites with units closed in years 2017 through 2020].

Information on operating reactor sites was obtained from the NRCs Operating Nuclear Power Reactors (by Location or Name) http://www.nrc.gov/info-finder/reactor/ with data current as of January 10, 2017 (last accessed on May 24, 2017).

Proposed rule applicability period (years)

A-3 Data Element Best Estimate Unit Source or Basis of Estimate Proposed rule applicability term 6

years Code Cases last 3 years and are typically renewed once, for a total of 6 years.

Labor Rates Industry engineer or plant supervisor

$132 Dollars per hour Labor rates used are from the Bureau of Labor Statistics Employer Costs for National Compensation Survey dataset, 2017 values. These hourly rates were inflated to 2019 dollars using values of the Consumer Price Index for All Urban Consumers. A multiplier of 2.4, which includes fringe and indirect management cost, was then applied and resulted in the displayed labor rates.

Managers

$152 Dollars per hour BLS tables Technical staff

$111 Dollars per hour BLS tables Administrative staff

$82 Dollars per hour BLS tables Licensing staff

$148 Dollars per hour BLS tables Industry plant technician

$105 Dollars per hour BLS tables NRC engineer

$131 Dollars per hour NRC, Rulemaker@nrc.gov, NRC Labor Rates for Use in Regulatory Analyses, 2017.

ML18099A054

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2.1 Background

Subject:

Subject:

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