Regulatory Guide 1.26: Difference between revisions

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{{Adams
{{Adams
| number = ML070290283
| number = ML21319A023
| issue date = 03/12/2007
| issue date = 11/16/2021
| title = Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste-Containing Components of Nuclear Power Plants
| title = Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste-Containing Components of Nuclear Power Plants
| author name = Hixon J
| author name =  
| author affiliation = NRC/RES/DFERR/DDME/FAITB
| author affiliation = NRC/ACRS
| addressee name =  
| addressee name =  
| addressee affiliation =  
| addressee affiliation =  
| docket =  
| docket =  
| license number =  
| license number =  
| contact person = Hixon, J B, RES/DFERR, (301) 415-5205
| contact person = Jim Steckel
| case reference number = DG-1152
| case reference number = RG-1.026, Rev 6
| document report number = RG-1.026, Rev. 4
| document type = Meeting Briefing Package/Handouts, Slides and Viewgraphs
| package number = ML070180354
| page count = 13
| document type = Regulatory Guide
| page count = 8
}}
}}
{{#Wiki_filter:1 In editions of the ASME Boiler and Pressure Vessel Code published before 1971, Section III uses the terms Class A,
{{#Wiki_filter:NRC Regulatory Guide 1.26, Revision 6 NRC Staff ACRS Presentation November 16, 2021 Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste- Containing Components of Nuclear Power Plants
Class B, and Class C in lieu of Class 1, Class 2, and Class 3.


The U.S. Nuclear Regulatory Commission (NRC) issues regulatory guides to describe and make available to the public methods that the NRC staff considers acceptable for use in implementing specific parts of the agencys regulations, techniques that the staff uses in evaluating specific problems or postulated accidents, and data that the staff need in reviewing applications for permits and licenses.  Regulatory guides are not substitutes for regulations, and compliance with them is not required.  Methods and solutions that differ from those set forth in regulatory guides will be deemed acceptable if they provide a basis for the findings required for the issuance or continuance of a permit or license by the Commission.
NRC Staff Team Members for RG 1.26 Revision
*
James Steckel, RGPMB/DE/RES
*
Ian Tseng, Acting Branch Chief, EMIB/DEX/NRR
*
Thomas Scarbrough, EMIB/DEX/NRR
*
Edward Stutzcage, DRCB/DRA/NRR
*
Timothy Lupold, UTB1/DANU/NRR
*
Nicholas Hansing, MSB/DFM/NMSS
*
Tuan Le, UNPO/DANU/NRR
2


This guide was issued after consideration of comments received from the public. The NRC staff encourages and welcomes comments and suggestions in connection with improvements to published regulatory guides, as well as items for inclusion in regulatory guides that are currently being developed.
Reason for Revision
* Revision 5 to RG 1.26 was an administrative update
* Proposed Revision 5 presented to ACRS in October 2016
* ACRS letter dated 10-17-2016 stated:
- Revision 5 to RG 1.26 should be issued
- Next revision to RG 1.26 should be broadened to include basic principles for assignment of components to each quality group
* EDO responded on 12-13-2016 that Revision 5 to RG 1.26 would be issued, and next revision to RG 1.26 would address ACRS recommendations
* NRC issued proposed Revision 6 to RG 1.26 (DG-1371)
for public comment in April 2021
3


The NRC staff will revise existing guides, as appropriate, to accommodate comments and to reflect new information or experience. Written comments may be submitted to the Rules and Directives Branch, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.
Key Changes
* New Appendix A, Alternative Classification for Components in Light-Water-Cooled Nuclear Power Plants, discusses component classification method described in American National Standards Institute (ANSI)/American Nuclear Society (ANS) Standard 58.14-
2011, Safety and Pressure Integrity Classification Criteria for Light Water Reactors.


Regulatory guides are issued in 10 broad divisions:  1, Power Reactors; 2, Research and Test Reactors; 3, Fuels and Materials Facilities;
* Updated NRC staff position on classification of Quality Group C components to reflect latest guidance on systems that contain radioactive material.
4, Environmental and Siting; 5, Materials and Plant Protection; 6, Products; 7, Transportation; 8, Occupational Health; 9, Antitrust and Financial Review;
and 10, General.


Requests for single copies of draft or active regulatory guides (which may be reproduced) should be made to the U.S. Nuclear Regulatory Commission, Washington, DC 20555, Attention: Reproduction and Distribution Services Section, or by fax to (301) 415-2289; or by email to Distribution@nrc.gov.
* NRC staff improved proposed Revision 6 to RG 1.26 in response to public comments.


Electronic copies of this guide and other recently issued guides are available through the NRCs public Web site under the Regulatory Guides document collection of the NRCs Electronic Reading Room at http://www.nrc.gov/reading-rm/doc-collections/ and through the NRCs Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html, under Accession No. ML070290283.
4


U.S. NUCLEAR REGULATORY COMMISSION
Appendix A to Revision 6 to RG 1.26
March 2007 Revision 4 REGULATORY GUIDE
* Applicant or licensee may propose use of the classification method in ANSI/ANS-58.14-2011 subject to considerations discussed in RG 1.26, Appendix A
OFFICE OF NUCLEAR REGULATORY RESEARCH
* ANSI/ANS-58.14 scope is broader than RG 1.26 to apply to pressure integrity for water, steam, or radioactive material components
REGULATORY GUIDE 1.26 (Draft was issued as DG-1152, dated November 2006)
* ANSI/ANS-58.14 does not include radiological criteria in RG 1.26 to complement application of ANSI/ANS-58.14 with RG 1.26
QUALITY GROUP CLASSIFICATIONS AND STANDARDS
* Based on terminology differences, ANSI/ANS-58.14 users should consider full scope of 10 CFR Part 50, Appendix A
FOR WATER-, STEAM-, AND
5
RADIOACTIVE-WASTE-CONTAINING COMPONENTS
OF NUCLEAR POWER PLANTS


==A. INTRODUCTION==
Appendix A to Revision 6 to RG 1.26 (continued)
General Design Criterion 1, Quality Standards and Records, as set forth in Appendix A,
* Specific guidance provided for ANSI/ANS-58.14 users in developing Class 1 to 4 (Quality Group A to D)
General Design Criteria for Nuclear Power Plants, to Title 10, Part 50, of the Code of Federal Regulations (10 CFR Part 50), Licensing of Production and Utilization Facilities (Ref. 1), requires that structures, systems, and components important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed.
* User should apply applicable ASME Boiler and Pressure Vessel Code, Section III, Subsection NF, for snubbers
* ANSI/ANS-58.14 users should review plant-specific design in comparison to RG 1.26 because specific RG 1.26 topics (such as spent fuel pool) not addressed in ANSI/ANS-58.14
* Users should ensure that containment penetration regulations are met
* Applicable users may include 10 CFR 50.69 (risk-informed categorization and treatment) as part of classification
6


Under 10 CFR 50.55a, Codes and Standards, certain systems and components of boiling- and pressurized-water-cooled nuclear power reactors must be designed, fabricated, erected, and tested in accordance with the standards for Class 1, 2, and 31 components given in Section III, Nuclear Power Plant Components, of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Ref. 2) or equivalent quality standards.  This guide describes a quality classification system related to specified national standards that may be used to determine quality standards acceptable to the staff of the U.S. Nuclear Regulatory Commission (NRC) for satisfying General Design Criterion 1 for other safety-related components containing water, steam, or radioactive material in light-water-cooled nuclear power plants.
Quality Group C
Modification in RG 1.26
*
Systems, other than radioactive waste management systems, not covered by Regulatory Positions 2.a through 2.c that contain or may contain radioactive material and whose postulated failure would result in conservatively calculated potential offsite doses that exceed 0.1 rem total effective dose equivalent; only single component failures need be assumed for those systems located in Seismic Category I structures, and no credit should be taken for automatic isolation from other components in the system or for treatment of released material, unless the isolation or treatment capability is designed to the appropriate seismic and quality group standards and can withstand loss of offsite power and a single failure of an active component.


2 Regulatory Guide 1.143, Design Guidance for Radioactive Waste Management Systems, Structures, and Components Installed in Light-Water-Cooled Nuclear Power Plants (Ref. 4), provides specific guidance on the classification of radioactive waste management systems.
7


Rev. 4 of RG 1.26, Page 2 This regulatory guide contains information collections that are covered by the requirements of 10 CFR Part 50 which the Office of Management and Budget (OMB) approved under OMB control number 3150-0011.  The NRC may neither conduct nor sponsor, and a person is not required to respond to, an information collection request or requirement unless the requesting document displays a currently valid OMB control number.
Response to Public Comments
* Comment:  Include 10 CFR 50.54 and 10 CFR 50.55 in list of regulatory requirements.


==B. DISCUSSION==
- Response:  Complete
In the early 1970s, the NRC staff developed a quality classification system to provide licensees with guidance for satisfying General Design Criterion 1. The system consists of four quality groups, A through D; methods for assigning components to those quality groups; and specific quality standards applied to each quality group. When the NRC issued Revision 2 of this guide in June 1975 and Draft Revision 3 for public comment in February 1976, 10 CFR 50.55a required only that components of the reactor coolant pressure boundary be designed, fabricated, erected, and tested to the highest available national standards; this corresponded to the quality standards for Quality Group A of the NRC
* Comment: Clarify applicability of ANSI/ANS-58.14 and 10 CFR 50.69
system. On March 15, 1984, the Commission published a final rule (Ref. 3) amending 10 CFR 50.55a to incorporate by reference the criteria in Section III of the ASME Code, as they relate to the design and fabrication of Class 2 and 3 components (Quality Group B and C components, respectively).
- Response: Added detailed footnote to Table 1 in RG 1.26 discussing 10 CFR 50.69
Because the quality group classification system is well-established, this Revision 4 of Regulatory Guide 1.26 retains the method described in previous versions for determining acceptable quality standards for Quality Group B, C, and D components.  Other systems not covered by this guide, such as instrument and service air, diesel engines and their generators and auxiliary support systems, diesel fuel, emergency and normal ventilation, fuel handling, and radioactive waste management systems,2 should be designed, fabricated, erected, and tested to quality standards commensurate with the safety function to be performed.
8


The evaluation to establish the quality group classification of these other systems should consider the guidance provided in Regulatory Positions 1 and 2 of this guide.
Response to Public Comments (continued)
 
* Comment: Add technical basis for including important to safety items in Quality Group C or delete
3 The regulations in 10 CFR 50.55a specify the Quality Group A standards for pressure-containing components of the reactor coolant pressure boundary.
- Response:  Explained ANSI/ANS-58.14 provides consensus recommendation for Class 3 components (Quality Group C) and that applicants/licensees may propose a different classification method for those components
 
* Comment:  Term important to safety is ambiguous
4 The system boundary includes those portions of the system necessary to accomplish the specified safety function and connected piping up to and including the first valve (including a safety or relief valve) that is either normally closed or capable of automatic closure when the safety function is required.
- Response: NRC staff does not consider a safety need to develop a specific definition of important to safety at this time
 
9
5 The turbine stop valve and turbine bypass valve, although not included in Quality Group B, should be subjected to a quality assurance program at a level generally equivalent to Quality Group B.
 
Rev. 4 of RG 1.26, Page 3
 
==C. REGULATORY POSITION==
1.
 
Quality Group B
The Quality Group B standards given in Table 1 of this guide should be applied to water- and steam-containing pressure vessels, heat exchangers (other than turbines and condensers), storage tanks, piping, pumps, and valves that are either (1) part of the reactor coolant pressure boundary defined in
10 CFR 50.2 but excluded from the requirements of 10 CFR 50.55a3 pursuant to paragraph (c)(2)
of that section, or (2) not part of the reactor coolant pressure boundary but part of the following:
(a)
systems or portions of systems4 important to safety that are designed for (i) emergency core cooling, (ii) postaccident containment heat removal, or (iii) postaccident fission product removal (b)
systems or portions of systems5 important to safety that are designed for (i) reactor shutdown or (ii) residual heat removal (c)
those portions of the steam systems of boiling-water reactors extending from the outermost containment isolation valve up to but not including the turbine stop and bypass valves,5 and connected piping up to and including the first valve that is either normally closed or capable of automatic closure during all modes of normal reactor operation; alternatively, for boiling-water reactors containing a shutoff valve (in addition to the two containment isolation valves)
in the main steamline and the main feedwater line, those portions of the steam and feedwater systems extending from the outermost containment isolation valves up to and including the shutoff valve or the first valve that is either normally closed or capable of automatic closure during all modes of normal reactor operation (d)
those portions of the steam and feedwater systems of pressurized-water reactors extending from and including the secondary side of steam generators up to and including the outermost containment isolation valves, and connected piping up to and including the first valve (including a safety or relief valve) that is either normally closed or capable of automatic closure during all modes of normal reactor operation (e)
systems or portions of systems5 that are connected to the reactor coolant pressure boundary and are not capable of being isolated from the boundary during all modes of normal reactor operation by two valves, each of which is either normally closed or capable of automatic closure
 
6 Components in influent lines may be classified as Quality Group D if they are capable of being isolated from the reactor coolant pressure boundary by an additional valve that has high leaktight integrity.
 
Rev. 4 of RG 1.26, Page 4
2.
 
Quality Group C
The Quality Group C standards given in Table 1 of this guide should be applied to water-, steam-,
and radioactive-waste-containing pressure vessels; heat exchangers (other than turbines and condensers);
storage tanks; piping; pumps; and valves that are not part of the reactor coolant pressure boundary or included in Quality Group B but part of the following:
(a)
cooling water and auxiliary feedwater systems or portions of those systems5 important to safety that are designed for (i) emergency core cooling, (ii) postaccident containment heat removal, (ii) postaccident containment atmosphere cleanup, or (iv) residual heat removal from the reactor and from the spent fuel storage pool (including primary and secondary cooling systems),
although Quality Group B includes portions of those systems that are required for their safety functions and that (i) do not operate during any mode of normal reactor operation and (ii) cannot be tested adequately (b)
cooling water and seal water systems or portions of those systems5 important to safety that are designed for the functioning of components and systems important to safety, such as reactor coolant pumps, diesels, and the control room (c)
systems or portions of systems5 that are connected to the reactor coolant pressure boundary and are capable of being isolated from that boundary during all modes of normal reactor operation by two valves, each of which is either normally closed or capable of automatic closure6 (d)
systems, other than radioactive waste management systems3, not covered by Regulatory Positions
2(a) through 2(c) (above) that contain or may contain radioactive material and whose postulated failure would result in conservatively calculated potential offsite doses [using meteorology as recommended in Regulatory Guide 1.3, Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss-of-Coolant Accident for Boiling-Water Reactors (Ref. 5),
and Regulatory Guide 1.4, Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss-of-Coolant Accident for Pressurized-Water Reactors (Ref. 6)]
that exceed 0.5 rem to the whole body or its equivalent to any part of the body; only single component failures need be assumed for those systems located in Seismic Category I structures, and no credit should be taken for automatic isolation from other components in the system or for treatment of released material, unless the isolation or treatment capability is designed to the appropriate seismic and quality group standards and can withstand loss of offsite power and a single failure of an active component
 
Rev. 4 of RG 1.26, Page 5
3.
 
Quality Group D
The Quality Group D standards given in Table 1 of this guide should be applied to water- and steam-containing components that are not part of the reactor coolant pressure boundary or included in Quality Groups B or C, but are part of systems or portions of systems that contain or may contain radioactive material.
 
Table 1 Components QUALITY STANDARDS
Quality Group B
Quality Group C
Quality Group D
Pressure Vessels ASME Boiler and Pressure Vessel Code, Section III,
Rules for Construction of Nuclear Facility Components,a,b Class 2 ASME Boiler and Pressure Vessel Code, Section III,
Rules for Construction of Nuclear Facility Components,a,b Class 3 ASME Boiler and Pressure Vessel Code, Section VIII,
Division 1, Rules for Construction of Pressure Vessels (Ref. 7)
Piping As above As above ASME B31.1 (Ref. 8)
Pumps As above As above Manufacturers standards Valves As above As above ASME B31.1 (Ref. 8)
Atmospheric Storage Tanks As above As above API-650 (Ref. 9),
AWWA D-100 (Ref. 10),
or ASME B96.1 (Ref. 11)
0-15 psig Storage Tanks As above As above API-620 (Ref. 12)
a See 10 CFR 50.55a for guidance regarding the ASME Code and addenda to be applied.
 
b Other regulatory guides or Commission regulations cover the specific applicability of code cases, where appropriate.
 
Applicants proposing the use of code cases not covered by guides or regulations should demonstrate that an acceptable level of quality and safety would be achieved.
 
Rev. 4 of RG 1.26, Page 6
 
==D. IMPLEMENTATION==
The purpose of this section is to provide information to applicants and licensees regarding the NRC staffs plans for using this regulatory guide. No backfitting is intended or approved in connection with the issuance of this guide.
 
Except in those cases in which an applicant or licensee proposes or has previously established an acceptable alternative method for complying with specified portions of the NRCs regulations, the NRC staff will use the methods described in this guide to evaluate (1) submittals in connection with applications for construction permits, standard plant design certifications, operating licenses, early site permits, and combined licenses; and (2) submittals from operating reactor licensees who voluntarily propose to initiate system modifications if there is a clear nexus between the proposed modifications and the subject for which guidance is provided herein.
 
REGULATORY ANALYSIS / BACKFIT ANALYSIS
The regulatory analysis and backfit analysis for this regulatory guide are available in Draft Regulatory Guide DG-1152, Quality Group Classifications and Standards for Water-, Steam-,
and Radioactive-Waste-containing Components of Nuclear Power Plants (Ref. 13).  The NRC issued DG-1152 in November 2006 to solicit public comment on the draft of this Revision 4 of Regulatory Guide 1.26.
 
7 All NRC regulations listed herein are available electronically through the Public Electronic Reading Room on the NRCs public Web site, at http://www.nrc.gov/reading-rm/doc-collections/cfr/part050.  Copies are also available for inspection or copying for a fee from the NRCs Public Document Room at 11555 Rockville Pike, Rockville, MD; the PDRs mailing address is USNRC PDR, Washington, DC 20555; telephone (301) 415-4737 or (800) 397-4209; fax (301)
415-3548; email PDR@nrc.gov.
 
8 Copies of ASME standards discussed herein may be obtained from the American Society of Mechanical Engineers, Three Park Avenue, New York, New York  10016-5990; telephone (800) 843-2763;
http://www.asme.org/Codes/Publications/.
9 All Federal Register notices listed herein were issued by the U.S. Nuclear Regulatory Commission.  Copies are available for inspection or copying for a fee from the NRCs Public Document Room at 11555 Rockville Pike, Rockville, MD; the PDRs mailing address is USNRC PDR, Washington, DC 20555; telephone (301) 415-4737 or (800) 397-4209; fax (301) 415-3548; email PDR@nrc.gov.


NRC Response to Public Comments (continued)
* Comment:  Explain change to threshold for classification of systems containing radioactive material as Quality Group C
- Response:  RG 1.26 updated to clarify reason for change to threshold for classification of systems containing radioactive material
* Comment:  Appendix A to RG 1.26 contains information that should be included in RG 1.201
- Response:  RG 1.26, Appendix A, revised to clarify reference to RG 1.201 with consideration of future improvements to RG 1.201
* Comment:  Specific editorial suggestions
- Response:  Complete
10
10
All regulatory guides listed herein were published by the U.S. Nuclear Regulatory Commissio
====n. Where an ADAMS====
accession number is identified, the specified regulatory guide is available electronically through the NRCs Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html.
All other regulatory guides are available electronically through the Electronic Reading Room on the NRCs public Web site, at http://www.nrc.gov/reading-rm/doc-collections/reg-guides/.  Single copies of regulatory guides may also be obtained free of charge by writing the Reproduction and Distribution Services Section, ADM, USNRC,
Washington, DC 20555-0001, or by fax to (301)415-2289, or by email to DISTRIBUTION@nrc.gov.  Active guides may also be purchased from the National Technical Information Service (NTIS) on a standing order basis.  Details on this service may be obtained by contacting NTIS at 5285 Port Royal Road, Springfield, Virginia 22161, online at http://www.ntis.gov, by telephone at (800) 553-NTIS (6847) or (703)605-6000, or by fax to (703) 605-6900.  Copies are also available for inspection or copying for a fee from the NRCs Public Document Room (PDR), which is located at 11555 Rockville Pike, Rockville, Maryland; the PDRs mailing address is USNRC PDR, Washington, DC 20555-0001.
The PDR can also be reached by telephone at (301) 415-4737 or (800) 397-4209, by fax at (301) 415-3548, and by email to PDR@nrc.gov.
Rev. 4 of RG 1.26, Page 7 REFERENCES
1.
U.S. Code of Federal Regulations, Title 10, Part 50, Domestic Licensing of Production and Utilization Facilities, U.S. Nuclear Regulatory Commission, Washington, DC.7
2.
ASME Boiler & Pressure Vessel Code, Section III, Nuclear Power Plant Components, American Society of Mechanical Engineers, New York, New York.8
3.
Codes and Standards for Nuclear Power Plants, U.S. Nuclear Regulatory Commission, Federal Register, Vol. 49, March 15, 1984, p. 9711.9
4.
Regulatory Guide 1.143, Design Guidance for Radioactive Waste Management Systems, Structures, and Components Installed in Light-Water-Cooled Nuclear Power Plants, U.S. Nuclear Regulatory Commission, Washington, DC.10
5.
Regulatory Guide 1.3, Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss-of-Coolant Accident for Boiling-Water Reactors, U.S. Nuclear Regulatory Commission, Washington, DC.10
6.
Regulatory Guide 1.4, Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss-of-Coolant Accident for Pressurized-Water Reactors, U.S. Nuclear Regulatory Commission, Washington, DC.10
11 Copies of API standards discussed herein may be obtained from the American Petroleum Institute , 1220 L Street, NW,
Washington, DC 20005-4070; telephone (800) 926-7337; http://www.api.org/Publications/.
12 Copies of AWWA standards discussed herein may be obtained from the American Water Works Association ,
6666 W. Quincy Ave., Denver, CO 80235 ; telephone (202) 682-8000;
http://www.awwa.org/bookstore/Category.cfm?cat=ALLSTD.
13 Draft Regulatory Guide DG-1152 is available electronically under Accession No. ML063100379 in the NRCs Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html.
Copies are also available for inspection or copying for a fee from the NRCs Public Document Room (PDR), which is located at 11555 Rockville Pike, Rockville Maryland; the PDRs mailing address is USNRC PDR, Washington, DC
20555-0001.  The PDR can also be reached by telephone at (301) 415-4737 or (800) 397-4209 by fax at (301) 415-3548, and by email to PDR@nrc.gov.
Rev. 4 of RG 1.26, Page 8
7.


ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, Rules for Construction of Pressure Vessels, American Society of Mechanical Engineers, New York, New York.8
High Temperature Reactor Quality Group Classification
8.
* Proposed Revision 2 to RG 1.87, Acceptability of ASME  
Code, Section III, Division 5, High Temperature Reactors, (DG-1380) issued for public comment in August 2021.


ASME B31.1, Power Piping, American Society of Mechanical Engineers, New York, New York.8
* Appendix A, High Temperature Reactor Quality Group Classification, in DG-1380 establishes quality group assignments for mechanical systems and components for non-light-water reactors.
9.


API-650, Welded Steel Tanks for Oil Storage, American Petroleum Institute, Washington, DC.11
* DG-1380 discussed with ACRS on July 20, 2021.
10.


AWWA D-100, Welded Steel Tanks for Water Storage, American Water Works Association, Denver, Colorado.12
* RG 1.26 relies on DG-1380 for high-temperature reactor quality group classification.
11.


ASME B96.1, Welded Aluminum-Alloy Storage Tanks, American Society of Mechanical Engineers, New York, New York.8
11
12.


API-620, Design and Construction of Large, Welded, Low-Pressure Storage Tanks, American Petroleum Institute, Washington, DC.11
Next Steps
13.
* NRC staff has distributed proposed Revision 6 to RG 1.26 for NRC management review
* NRC staff will address NRC management and ACRS recommendations when finalizing Revision 6 to RG 1.26
* NRC plans to issue Revision 6 to RG 1.26 by early
2022
12


Draft Regulatory Guide DG-1152, Quality Group Classifications and Standards for Water-,
QUESTIONS?
Steam-, and Radioactive-Waste-containing Components of Nuclear Power Plants, U.S. Nuclear Regulatory Commission, Washington, DC.13}}
13}}


{{RG-Nav}}
{{RG-Nav}}

Latest revision as of 03:51, 7 February 2025

Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste-Containing Components of Nuclear Power Plants
ML21319A023
Person / Time
Issue date: 11/16/2021
From:
Advisory Committee on Reactor Safeguards
To:
Jim Steckel
References
RG-1.026, Rev 6
Download: ML21319A023 (13)
v • d • e


NRC Regulatory Guide 1.26, Revision 6 NRC Staff ACRS Presentation November 16, 2021 Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste- Containing Components of Nuclear Power Plants

NRC Staff Team Members for RG 1.26 Revision

James Steckel, RGPMB/DE/RES

Ian Tseng, Acting Branch Chief, EMIB/DEX/NRR

Thomas Scarbrough, EMIB/DEX/NRR

Edward Stutzcage, DRCB/DRA/NRR

Timothy Lupold, UTB1/DANU/NRR

Nicholas Hansing, MSB/DFM/NMSS

Tuan Le, UNPO/DANU/NRR

2

Reason for Revision

  • Revision 5 to RG 1.26 was an administrative update
  • Proposed Revision 5 presented to ACRS in October 2016
  • ACRS letter dated 10-17-2016 stated:

- Revision 5 to RG 1.26 should be issued

- Next revision to RG 1.26 should be broadened to include basic principles for assignment of components to each quality group

  • EDO responded on 12-13-2016 that Revision 5 to RG 1.26 would be issued, and next revision to RG 1.26 would address ACRS recommendations
  • NRC issued proposed Revision 6 to RG 1.26 (DG-1371)

for public comment in April 2021

3

Key Changes

  • New Appendix A, Alternative Classification for Components in Light-Water-Cooled Nuclear Power Plants, discusses component classification method described in American National Standards Institute (ANSI)/American Nuclear Society (ANS) Standard 58.14-

2011, Safety and Pressure Integrity Classification Criteria for Light Water Reactors.

  • Updated NRC staff position on classification of Quality Group C components to reflect latest guidance on systems that contain radioactive material.
  • NRC staff improved proposed Revision 6 to RG 1.26 in response to public comments.

4

Appendix A to Revision 6 to RG 1.26

  • Applicant or licensee may propose use of the classification method in ANSI/ANS-58.14-2011 subject to considerations discussed in RG 1.26, Appendix A
  • ANSI/ANS-58.14 scope is broader than RG 1.26 to apply to pressure integrity for water, steam, or radioactive material components

5

Appendix A to Revision 6 to RG 1.26 (continued)

  • Specific guidance provided for ANSI/ANS-58.14 users in developing Class 1 to 4 (Quality Group A to D)
  • Users should ensure that containment penetration regulations are met
  • Applicable users may include 10 CFR 50.69 (risk-informed categorization and treatment) as part of classification

6

Quality Group C

Modification in RG 1.26

Systems, other than radioactive waste management systems, not covered by Regulatory Positions 2.a through 2.c that contain or may contain radioactive material and whose postulated failure would result in conservatively calculated potential offsite doses that exceed 0.1 rem total effective dose equivalent; only single component failures need be assumed for those systems located in Seismic Category I structures, and no credit should be taken for automatic isolation from other components in the system or for treatment of released material, unless the isolation or treatment capability is designed to the appropriate seismic and quality group standards and can withstand loss of offsite power and a single failure of an active component.

7

Response to Public Comments

- Response: Complete

- Response: Added detailed footnote to Table 1 in RG 1.26 discussing 10 CFR 50.69

8

Response to Public Comments (continued)

  • Comment: Add technical basis for including important to safety items in Quality Group C or delete

- Response: Explained ANSI/ANS-58.14 provides consensus recommendation for Class 3 components (Quality Group C) and that applicants/licensees may propose a different classification method for those components

  • Comment: Term important to safety is ambiguous

- Response: NRC staff does not consider a safety need to develop a specific definition of important to safety at this time

9

NRC Response to Public Comments (continued)

  • Comment: Explain change to threshold for classification of systems containing radioactive material as Quality Group C

- Response: RG 1.26 updated to clarify reason for change to threshold for classification of systems containing radioactive material

  • Comment: Appendix A to RG 1.26 contains information that should be included in RG 1.201

- Response: RG 1.26, Appendix A, revised to clarify reference to RG 1.201 with consideration of future improvements to RG 1.201

  • Comment: Specific editorial suggestions

- Response: Complete

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High Temperature Reactor Quality Group Classification

Code,Section III, Division 5, High Temperature Reactors, (DG-1380) issued for public comment in August 2021.

  • Appendix A, High Temperature Reactor Quality Group Classification, in DG-1380 establishes quality group assignments for mechanical systems and components for non-light-water reactors.
  • DG-1380 discussed with ACRS on July 20, 2021.
  • RG 1.26 relies on DG-1380 for high-temperature reactor quality group classification.

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Next Steps

  • NRC staff has distributed proposed Revision 6 to RG 1.26 for NRC management review
  • NRC staff will address NRC management and ACRS recommendations when finalizing Revision 6 to RG 1.26
  • NRC plans to issue Revision 6 to RG 1.26 by early

2022

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QUESTIONS?

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