ML21292A289

Comment (3) of Mark A. Richter on Acceptability of ASME Code Section III, Division 5, High Temperature Reactors

ML21292A289
Person / Time
Site:	Nuclear Energy Institute
Issue date:	10/19/2021
From:	Richter M Nuclear Energy Institute
To:	Office of Administration
References
86FR46888 00003, DG-1380, NRC-2021-0117
Download: ML21292A289 (9)

Text

10/19/21, 3:21 PM blob:https://www.fdms.gov/43c0af5a-da75-4ee2-95cd-810a0e24351c SUNI Review Complete As of: 10/19/21 3:21 PM Template=ADM-013 Received: October 19, 2021 PUBLIC SUBMISSION E-RIDS=ADM-03 Status: Pending_Post ADD: Robert Roche- Tracking No. kuy-7v41-2dq0 Rivera, Bridget Curran, Kyle Song, Mary Neely Comments Due: October 19, 2021 Comment (3) Submission Type: API Publication Date:

8/20/2021 Docket: NRC-2021-0117 Citation: 86 FR 46888 Acceptability of ASME Code Section III, Division 5, High Temperature Reactors Comment On: NRC-2021-0117-0001 Acceptability of ASME Code Section III, Division 5, High Temperature Reactors Document: NRC-2021-0117-DRAFT-0006 Comment on FR Doc # 2021-17916 Submitter Information Email: kme@nei.org Organization: Nuclear Energy Institute General Comment Comments on Draft Regulatory Guide (DG), DG-1380 Attachments 10-19-21_NEI_Comments on NRC DG-1380 blob:https://www.fdms.gov/43c0af5a-da75-4ee2-95cd-810a0e24351c 1/1

MARK A. RICHTER, PH.D.

Technical Advisor, Decommissioning & Used Fuel 1201 F Street, NW, Suite 1100 Washington, DC 20004 P: 202.739.8106 mar@nei.org nei.org October 19, 2021 Office of Administration ATTN: Program Management, Announcements and Editing Staff Mail Stop: TWFN-7-A60M U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Comments on Draft Regulatory Guide (DG), DG-1380 (proposed Revision 2 to Regulatory Guide

[RG] 1.87), Acceptability of ASME Code Section III, Division 5, High Temperature Reactors, and accompanying draft NUREG-2245, Technical Review of the 2017 Edition of ASME Section III, Division 5, High Temperature Reactors [Docket ID NRC-2021-0117]

Project Number: 689 Submitted via Regulations.gov

Dear Program Management,

Announcements and Editing Staff:

On behalf of the Nuclear Energy Institutes (NEI) 1 members (hereinafter referred to as industry), we appreciate the opportunity, as requested in an August 20, 2021 Federal Register Notice (86 FR 46888), to provide comments on the U.S. Nuclear Regulatory Commissions (NRC) draft regulatory guide (DG), DG-1380 (proposed Revision 2 to Regulatory Guide [RG] 1.87), Acceptability of ASME Code Section III, Division 5, High Temperature Reactors, and accompanying draft NUREG-2245, Technical Review of the 2017 Edition of ASME Section III, Division 5, High Temperature Reactors. The draft NUREG provides the technical basis for DG-1380 and documents the NRC staffs review of the 2017 Edition of ASME Section III, Division 5, certain portions of the 2019 Edition, and associated Code Cases N-861 and N-862.

1 The Nuclear Energy Institute (NEI) is responsible for establishing unified policy on behalf of its members relating to matters affecting the nuclear energy industry, including the regulatory aspects of generic operational and technical issues. NEIs members include entities licensed to operate commercial nuclear power plants in the United States, nuclear plant designers, major architect and engineering firms, fuel cycle facilities, nuclear materials licensees, and other organizations involved in the nuclear energy industry.

Program Management, Announcements and Editing Staff October 19, 2021 Page 2 We agree with the action that NRC is taking because the current version of RG 1.87 (Revision 1) does not reflect the changes and updates with respect to modern design, fabrication, inspection, testing, and overpressure provisions (among others) addressed by the aforementioned Code iterations, research, and operating experience. This revision (Revision 2) updates the guidance to endorse with conditions, the 2017 Edition of ASME Code Section III, Division 5, certain portions of the 2019 Edition, and associated Code Cases N-861 and N-862 as a method acceptable to the staff for the materials, mechanical/structural design, construction, testing, and quality assurance of mechanical systems and components and their supports of high temperature reactors.

Industry encourages the NRC to consider additional opportunities to gain new regulatory efficiencies that improve safety focus. To that end, the attached documents provide several general comments as well as a number of detailed comments which identify specific opportunities to improve or clarify the Draft RG and associated NUREG.

Again, we appreciate the opportunity to provide these comments for NRC consideration. If you have any questions or require additional information, please contact me at 202-439-0954, mar@nei.org.

Sincerely, Mark A. Richter Attachments c: Jeffrey Poehler, Office of Nuclear Regulatory Research, NRC Robert Roche-Rivera, Office of Nuclear Regulatory Research, NRC Jordan Hoellman, Office of Nuclear Reactor Regulation, NRC

NEI/Industry Comments on DG-1380 Affected Section Comment/Basis Recommendation

1. General Section III, Should add a statement that Code Cases may be Revise/Add Division 5, Code implemented upon ASME Committee approval.

Cases

2. General Section III, Should add a statement that deviations from Code Case Revise/Add Division 5, Code may be made with appropriate 50.59 analysis or Cases equivalent analysis.

3. Section 1 p. 12 (y) HGB-3224, Level C Service Limits (1): When extrapolating Extrapolation to determine the allowable time for t ib using Figures HBB-I-14.4A through HBB-I-14.4E to use-fractions is an intended use of the Code, both obtain t ib in accordance with HGB-3224(d), the maximum to obtain t ib in HGB-3224(d) and in other portions t ib value for any stress and temperature combination of the Code, including those referenced by the staff should not exceed 300,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> or the end of the curve in the discussion of NUREG-2245 page 3-193.

for the temperature of interest, whichever is less. Extrapolation is not prohibited elsewhere in the Code; the Code is silent on extrapolation in the Basis Text referenced paragraphs, which does not prohibit NUREG-2245 Basis Text NUREG-2245 (from page 3-192 extrapolation as indicated in the Foreword to the line 43 to 3-193 line 14) Code, the Code does not address all aspects of these activities and those aspects that are not HGB-3224 Level C Service Limits specifically addressed should not be considered prohibited.

Paragraph HGB-3224 serves the same purpose and is technically equivalent to paragraph HBB-3224, except for Prohibiting extrapolation for determining allowable HGB-3224(d) as described below. HGB-3224(d) indicates, times may place an economic penalty on designs by in part, that it is permissible to extrapolate the allowable restricting component design life or requiring stress intensity at temperature curve (Figures HBB-I- significant overdesign to obtain the required life. It 14.3A through HBB-I-14.3E and Figures HBB-I-14.4A is noted that HGB-1124 restricts the time at through HBB-I-14.4E) to determine time value (t ib ) when elevated temperature to the maximum time computing use-fractions, and that any such extrapolation associated with S mt ; extrapolation does not permit and the method used should be reported in the Design increasing the operating time at elevated Report (ASME Code, NCA-3551.1). The staff notes that temperature beyond the restriction of HGB-1124, Figures HBB-I-14.3A through HBB-I-14.3E provide S mt but rather allows for calculation of the use-fraction values while Figures HBB-I-14.4A in conditions of low operating stress relative to the allowables.

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Affected Section Comment/Basis Recommendation 3-193through HBB-I-14.4E provide S t values, and that Restricting extrapolation for a component with a the procedure described in HGB-3224(d) only uses the S t specified 300,000-hour design life at elevated values. The staff also notes that extrapolation is not temperature results in a use-fraction of greater permitted for the procedure of HGB-3224(b) to determine than or equal to 1.0 regardless of the specified the use-fraction associated with primary membrane Service Loadings; this would occur because the stresses, nor is it approved in the corresponding denominator in the use-fraction summation would paragraph in HBB-3224 for the time fractions associated always be less than or equal to 300,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />. To with primary membrane stresses and primary membrane achieve a time fraction of 1.0 in this case, all plus bending stresses. Since the creep test data were Service Level A, B, and C loadings would be generally already extrapolated by a factor of required to have a stress less than or equal to S t at approximately 3 to 5 to obtain the allowable stresses in 300,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> at the appropriate temperature, Figures HBB-I-14.4A-E, the staff is concerned that even if the Service Loading duration was much allowing extrapolation as permitted by HGB-3224(d) shorter, with higher stresses permitted by HGB-could result in nonconservative t ib values. Therefore, the 3224(c) equation (10).

staff finds HGB-3224 acceptable with the following The most significant contributors to the use-fraction limitation: summation will be Service Loadings where the stresses are relatively high, and the allowable times

• When extrapolating t ib using Figures HBB-I- have limited or no extrapolation. The Code margins 14.4A through HBB-I-14.4E to obtain t ib in accordance for these Service Loadings are not at risk of being with HGB-3224(d), the maximum t ib value for any stress degraded by extrapolation. Lower stress Service and temperature combination should not exceed 300,000 Loadings, where t ib is extrapolated to longer times, hours or the end of the curve for the temperature of would be smaller overall contributions to the use-interest, whichever is less. fraction summation since the total duration of all elevated temperature service loadings is limited to the time associated with S¬mt. Since the low stress Service Loadings would have small overall contribution to the use-fraction, extrapolation error in these cases would not have a significant impact on the overall margins.

4. Appendix A - General There are numerous places within Appendix A that are See comments below for specific examples of Comment inconsistent with 10 CFR 50.69. where Appendix A is inconsistent with 10 CFR 50.69.

5. A-2, Safety It is important to point out that in RG1.26 Quality Group The first two full paragraphs should be combined Classification D is applied only to water- and steam-containing into one paragraph and re-written as shown below.

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Affected Section Comment/Basis Recommendation Categories - components that are not part of the reactor coolant Traditional Approach, pressure boundary or included in Quality Groups B or C Proposed New paragraph:

Page 19 of 26, but are part of systems or portions of systems that SSCs that are NSR may function to prevent a Paragraphs 1 & 2 contain or may contain radioactive material. radiological release to the public by ensuring that no dose to the public is beyond the regulatory limits of 0.1 rem total effective dose equivalent (TEDE) set by 10 CFR Part 20, Domestic Licensing of Production and Utilization Facilities, (Ref. A-5).

While such SSCs do not meet the criteria for an SR SSC, there is still a need to ensure component integrity. RG 1.26 assigns Quality Group D to components that contain or may contain radioactivity but are not part of the reactor coolant pressure boundary or included in Quality Groups B or C. Refer to RG 1.26 for more information on this traditional approach. RG 1.143, Design Guidance for Radioactive Waste Management Systems, Structures, and Components Installed in Light-Water-Cooled Nuclear Power Plants, (Ref. A-10) provides information related to the classification of radioactive waste management systems that fall within the scope of that RG. SSCs that are NSR and do not meet the criteria for special treatment are left to the applicant to specify any standards for design and fabrication.

6. A-2, Safety Last full paragraph states: NSR mechanical components Change to: NSR mechanical components that need Classification that need special treatment, such as for systems special treatment, such as for systems containing Categories - containing high levels of radioactive material high levels of radioactive material as this part of Traditional Approach, section A-2 only applies to the Traditional Page 19 of 26, last Approach for Safety Classification Categories.

full paragraph 3

Affected Section Comment/Basis Recommendation

7. A-2, Safety Second full paragraph is inconsistent with 10 CFR 50.69. Needs to be re-written so that for RISC-2 Classification components the owner has the flexibility allowed by Categories - Risk 10 CFR 50.69 and that for RISC-3 components, Informed Approach, Section III and Appendix B are not required.

Page 20 of 26, Paragraph 2

8. Pages 22 & 23 (A-4, Should be re-written to be consistent with 10 CFR 50.69 Should be re-written to be consistent with 10 CFR Quality Group (i.e., for Group B and C the owner defines these 50.69 (i.e., for Group B and C the owner defines Classifications) requirements). For Group B the owner also needs to these requirements). For Group B the owner also provide reasonable confidence. For Group C, the needs to provide reasonable confidence. For requirements need to be consistent with the Group C, the requirements need to be consistent categorization process. with the categorization process.

9. Page 24 (Table A-1, Should be re-written to be consistent with 10 CFR 50.69 Should be re-written to be consistent with 10 CFR Classification and (i.e., for Group B and C the owner defines these 50.69 (i.e., for Group B and C the owner defines Standards Applicable requirements / applicable codes and standards). For these requirements / applicable codes and to Advanced Reactors Group B the owner also needs to provide reasonable standards). For Group B the owner also needs to for Quality Groups A, confidence. For Group C, the requirements need to be provide reasonable confidence. For Group C, the B, C, and D) consistent with the categorization process. requirements need to be consistent with the categorization process.

10. Appendix A (Table A- Table A-1 is not consistent with 10 CFR 50.69. The Table A-1 should be re-written.

1) interpretation of Table A-1 is such that the user is required to use the codes and standards as defined in the table for the specified quality groups. However, there may be alternative design and construction codes Class A and B applicable and acceptable for Quality Group A, B, C and D components.

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NEI/Industry Comments on NUREG-2245 Affected Section Text Comment/Recommendation

1. NUREG-2245 3-107 The NRC staff is not endorsing Mandatory Appendix HBB- As the basis for the above restriction, NUREG-2245 lines 16-20 I-14 for: (a) Type 304 stainless steel (Type 304 SS) Sections 3.7.5, 3.7.6, and 3.7.9 utilized values of Smt, St, and Sr for temperatures greater than comparisons in ANL/AMD-21/1, Tables 3 and 4. The 1300 °F or 700 °C. staff proposed a cutoff at temperatures where the difference is -10% or greater. Review of Tables 3 and 4 of ANL/AMD-21/1 indicates that typically the difference does not reach -10% until longer times, for example at 725°C St in Table 3 does not drop below the 10% criteria until 100,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />. Has the staff considered use of both temperature and time to set this limit and allow short duration conditions at temperatures greater than 1300 °F or 700 °C, where the 2017 Code allowable stresses meet the 10% criteria?

2. NUREG-2245 3-107 The NRC staff is not endorsing Mandatory Appendix HBB- As the basis for the above restriction, NUREG-2245 lines 21-22 I-14 for: (b) Type 316 stainless steel (Type 316 SS) Sr Section 3.7.9 utilized comparisons in ANL/AMD-values for temperatures greater than 1300 °F or 700 °C. 21/1 Table 6. The staff proposed a cutoff at temperatures where the difference is -10% or greater. Review of Tables 6 of ANL/AMD-21/1 indicates that typically the difference does not reach -10% until longer times, for example, at 725°C Sr in Table 6 does not drop below the 10%

criteria until 1,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />. Has the staff considered use of both temperature and time to set this limit and allow short duration conditions at temperatures greater than 1300°F or 700°C, where the 2017 Code allowable stresses meet the 10% criteria?

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Affected Section Text Comment/Recommendation

3. NUREG-2245 3-107 The NRC staff is not endorsing Mandatory Appendix HBB- As the basis for the above restriction, NUREG-2245 lines 24-25 I-14 for: (c) 2-1/4Cr-1Mo material Smt, St, and Sr values Sections 3.7.5, 3.7.6, and 3.7.9 utilized for temperatures greater than 950 °F or 510°C. comparisons in ANL/AMD-21/1, Tables 10 and 11 and Figure 4. Review of Tables 10 and 11 indicates that the 2017 Code allowable stresses were conservative at 100,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> up to 550°C. Has the staff considered use of both temperature and time to set this limit and allow short duration conditions at temperatures greater than 950 °F or 510°C?

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