ML21235A011
| ML21235A011 | |
| Person / Time | |
|---|---|
| Issue date: | 12/14/2021 |
| From: | Thomas Scarbrough NRC/NRR/DEX/EMIB |
| To: | |
| Steckel J | |
| Shared Package | |
| ML20224A372 | List: |
| References | |
| DG-1371 RG-1.026, Rev 6 | |
| Download: ML21235A011 (7) | |
Text
Response to Public Comments on Proposed Revision 6 to Regulatory Guide (RG) 1.26 - Draft Regulatory Guide (DG)-1371 Regulatory Guide Title Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste-Containing Components of Nuclear Power Plants Commenters On May 7, 2021 the U.S. Nuclear Regulatory Commission (NRC) published a notice in the Federal Register (85 FRN 24672-24673) that Draft Regulatory Guide DG-1371, a proposed regulatory guide revision, was available for public comment. The Public Comment Period ended on July 6, 2021; the NRC received comments from the following:
Norbert Carte1 ADAMS Accession No. ML21141A186 U.S. Nuclear Regulatory Commission Washington, DC 20852-0001 Victoria K. Anderson for Nuclear Energy Institute ADAMS Accession No. ML21182A118 1201 F St NW, Suite 1100 Washington, DC 20004 Mark W. Shaver for NuScale Power, LLC ADAMS Accession No. ML21201A055 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330 Comments are in ADAMS at their accession numbers, or Docket Number PROJ0689, and their proposed resolutions are in the following Public Comment Resolution table:
Public Comments and Their NRC Resolutions to Proposed Revision 6 of Regulatory Giude 1.26: Draft Regulatory Guide DG-1371 Table of Comments and Their Resolution Commenter Section of DG- Specific Comments NRC Resolution 1371 Carte A, C CARTE_1 There were two The NRC staff agrees with regulatory requirements not the comment . These two list[ed] in the DG. Please add references to NRCs the following two regulatory regulations, as reproduced requirements or explain why below, are added to the they are not applicable. Applicable Regulations list in RG 1.26, Revision 6.
10 CFR 50.54 Conditions of licenses. (jj) Structures, 10 CFR 50.54, Conditions systems, and components of licenses, paragraph (jj),
subject to the codes and states Structures, systems, standards in 10 CFR 50.55a and components subject to must be designed, fabricated, the codes and standards in erected, constructed, tested, 10 CFR 50.55a must be and inspected to quality designed, fabricated, standards commensurate with erected, constructed, tested, the importance of the safety and inspected to quality function to be performed. standards commensurate with the importance of the 1
Mr. Carte indicated in his comment submission that the comments were submitted by the NRC. The comments were submitted in his personal capacity only.
Commenter Section of DG- Specific Comments NRC Resolution 1371 10 CFR 50.55 Conditions of safety function to be construction permits, early performed.
site permits, combined licenses, and manufacturing 10 CFR 50.55, Conditions licenses. (i) Structures, of construction permits, systems, and components early site permits, combined subject to the codes and licenses, and manufacturing standards in 10 CFR 50.55a licenses, paragraph (i),
must be designed, fabricated, states Structures, systems, erected, constructed, tested, and components subject to and inspected to quality the codes and standards in standards commensurate with 10 CFR 50.55a must be the importance of the safety designed, fabricated, function to be performed. erected, constructed, tested, and inspected to quality standards commensurate with the importance of the safety function to be performed.
NEI A, C NEI_1 In our review, we The NRC staff agrees with noted that the draft regulatory the comment that additional guide revision could be discussion of 10 CFR 50.69 would be helpful in RG enhanced by better clarifying 1.26. Therefore, the the separation between the following footnote to Table 1 applicability of the ANSI will be included in RG 1.26:
standard and the implementation of 50.69, For nuclear power plant particularly in the introduction licensees that have and conclusion. Additionally, implemented 10 CFR 50.69, in Table 1 of Appendix A, Q Risk-informed Group B requires ASME categorization and Section III Class 2; this would treatment of structures, not be the case for plants with systems and components 50.69 implemented. If a for nuclear power reactors, component is categorized as the classification of structures, systems, and LSS, it is out of scope of the components (SSCs) may O&M codes and alternative not correspond to the treatments can be applied. classification in Table 1.
We recommend clarifying that For additional guidance on Table 1 of Appendix A is not the categorization of SSCs applicable to plants with under 10 CFR 50.69, 50.69. please refer to Regulatory Guide 1.201, Guidelines for Categorizing Structures, Systems, and Components in Nuclear Power Plants According to Their Safety Significance. In the Federal Register notice (69 FR 68008) for the 10 CFR 50.69 rule, the Commission stated that RISC-3 (safety-related low safety significant) and RISC-4 (nonsafety-related low safety significant) structures, systems, and components (SSCs) will be exempt from the special treatment requirements (STRs) for qualification methods for environmental conditions and effects and seismic conditions. The 2
Commenter Section of DG- Specific Comments NRC Resolution 1371 Commission stated that RISC-3 SSCs continue to be required to be capable of performing their safety-related functions under applicable environmental conditions and effects and seismic conditions, albeit at a lower level of confidence as compared to RISC-1 (safety-related safety significant) SSCs. The Commission direction in the Federal Register notice for 10 CFR 50.69 regarding the capability of RISC-3 SSCs to be able to perform their safety functions under applicable environmental and seismic conditions is clear for licensees who have received a license amendment to implement a 10 CFR 50.69 program.
See 69 FR 68008 for more information.
NuScale General NuSc_1 The technical basis Appendix A, Alternative for elevating all important to Classification for safety (ITS) items to Quality Components in Light-Water-Group C is unclear. Cooled Nuclear Power Plants, to RG 1.26 accepts Proposed Resolution: Add the guidance provided in technical basis for the reason American Nuclear Society why ITS items need to be (ANS)/American National Quality Group C, or remove Standards Institute (ANSI) requirement. 58.14-2011, Safety and Pressure Integrity Classification Criteria for Light Water Reactors, as an alternative to the method described in RG 1.26 for classification of components in light-water-cooled nuclear power plants. The NRC has the responsibility to evauate consensus standards for reference in performing nuclear power plant activities. Appendix A to RG 1.26 states that among the Class 3 components, a user of ANSI/ANS-58.14-2011 should include those components that are important to safety but do not necessarily accomplish safety-related functions, such as primary and secondary residual heat removal systems for spent fuel storage pools.
Applicants and licensees can propose a different classification method if the 3
Commenter Section of DG- Specific Comments NRC Resolution 1371 methods described in RG 1.26 and its Appendix A are not considered appropriate for their specific nuclear power plant. No change has been made to RG 1.26 and its Appendix A in response to this comment.
NuScale General NuSc_2 The term important The NRC staff has to safety is ambiguous. evaluated the need to specify a prescriptive set of Proposed Resolution: criteria for important to Consider defining this term for safety in 10 CFR 50.2, clarity to ensure proper Definitions. The NRC staff scoping and implementation. has determined that there is not a safety need to include the term important to safety in 10 CFR 50.2 at this time. No change has been made to RG 1.26 in response to this comment.
NuScale Section A, NuSc_3 There is an extra Change made to RG 1.26.
Introduction bullet under Applicable Thank you for identifying Regulations and at the top of the typographical error.
page 2, between Section III, Rules for Construction of Nuclear Facility and Components, of Proposed Resolution:
Remove bullet.
NuScale Section B, NuSc_4 This section The proposed change is Discussion, contains the statements, acceptable and will be Key Safety A user of RG 1.26 made in RG 1.26. The Principles should be aware of NRC staff will consider the differences in the improvements to RG 1.201 safety classification when that RG is updated.
process inRG 1.201 when 10 CFR 50.69 will be implemented.
An applicant or licensee may request the application of 10 CFR 50.69 as part of an alternative classification system for componentsin its nuclear power plant, as described in Appendix A to this RG.
RG 1.26, Appendix A, seemingly now includes information that should be contained in RG 1.201.
Proposed Resolution:
Rewrite to state, An applicant or licensee may request the application of 10 4
Commenter Section of DG- Specific Comments NRC Resolution 1371 CFR 50.69 as part of an alternative classification system for components in its nuclear power plant, as described in Appendix A to RG 1.201.
RG 1.201 describes a method that the NRC staff considers acceptable for usein complying with the Commissions requirements in §50.69 with respect to the categorization of SSCs that are considered in risk-informing special treatment requirements.
NuScale Section C, NuSc_5 Both Item C.2.d RG 1.26 up to Revision 5 Paragraphs 2.d and Item C.3.c make use of did not include and or or and 3.c the word and indicating in Item C.2 or C.3 for the that all conditions need to scope of Quality Group B be met to meet the and C components.
classification requirements Revision 5 to RG 1.26 of the respective quality added and to Items C.2 group. and C.3. It is agreed that the recent addition of and (C.2.d) those might cause confusion by portions of the RG 1.26 users. The term steam and or also might cause feedwatersystems confusion regarding the of pressurized- scope of Quality Group B water reactors and C components. In extending from response to this comment, and including the the term and will be secondary side of removed to match the early steam generators versions of RG 1.26.
up to and including the outermost containment isolation valves, and connected piping up to and including the first valve (includinga safety or relief valve) that is either normally closed or capable of automatic closure during all modes of normal reactor operation; and (C.3.c) systems or portions of systems that are connected to the reactor coolant pressure boundary and are capable of being isolated from that boundary 5
Commenter Section of DG- Specific Comments NRC Resolution 1371 during all modes of normal reactor operation by two valves, each of which is either normally closed or capable of automatic closure; and Proposed Resolution:
Change these instances of and to or.
NuScale Section C, NuSc_6 The draft guidance The staff agrees with the Paragraph 3d, revises the threshold for comment and will update Quality Group classification of systems Section B, Reason for C containing radioactive Revision to include the material as Quality Group C reason for the changes to from 0.5 rem to the whole the dose criteria.
body or its equivalent to any part of the body to 0.1 rem The criteria of 0.5 rem to total effective dose the whole body or its equivalent. The basis is equivalent to any part of the unclear for changing the dose body was consistent with criteria. the annual public radiation dose limit prior to 1994, Proposed Resolution: which was revised to 0.1 Revise requirement to 0.5 rem total effective dose rem total effective dose equivalent (TEDE) in equivalent, or provide brief 1994. Subsequent to the explanation for the change in rule change, several other Sec B Reason for Revision. guidance documents that had originally used the 0.5 rem whole body dose criteria for a design criteria and for evaluating radiological design basis accidents, have been revised to the 0.1 rem TEDE criteria. This includes guidance on the postulated radioactive releases due to a gaseous radwaste system leak or failure and the failure of liquid containing tanks (currently contained in NUREG-0800, Chapter 11, Branch Technical Positions 11-5 and 11-6) and the standard review plan guidance for meeting the radiological criteria for the design of radwaste systems using RG 1.143, Revision 2 (see Chapter 11 for additional information). Therefore, the revision is to provide a dose criteria that is consistent with the current public dose limit and to provide consistent radiological guidance for the design of components containing radioactive material (that 6
Commenter Section of DG- Specific Comments NRC Resolution 1371 are within the scope of RG 1.26) whose failure could result in a significant radiological release but are not otherwise assigned to Quality Groups A, B, or C.
Therefore, Section B, Reason for Revision will be revised, as follows:
This revision of the RG (Revision 6) includes an appendix that provides guidance for alternative quality classification systems for components in LWR nuclear power plants. In addition, this revision updates the staff position on the classification of Quality Group C components to incorporate current public radiation dose criteria and reflect the latest guidance on systems that contain radioactive material.
NuScale Appendix NuSc_7 RG 1.26, Appendix A to RG 1.26 Section A-12, Appendix A, seemingly now accepts the classification Risk-Informed includes information that approach in ANS/ANSI Categorization should be contained in RG 58.14-2011 with specific and Treatment 1.201. discussin of its use. It is of Structures, considered best to maintain Systems, and Proposed Resolution: the discussion regarding Components Keep the special ANS/ANSI 58.14-2011 in for Nuclear treatment and Appendix A to RG 1.26 Power classification of without including discussion Reactors information contained in of ANS/ANSI 58.14-2011 in RG 1.201 rather than RG 1.201. No change has scattering it across been made to RG 1.26 in multiple RGs. response to this comment.
RG 1.201 describes a method that the NRC staff considers acceptable for use in complying with the Commissions requirements in §50.69 with respect to the categorization of SSCs that are considered in risk-informing special treatment requirements.
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