Regulatory Guide 1.26: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(StriderTol Bot change)
 
(3 intermediate revisions by the same user not shown)
Line 1: Line 1:
{{Adams
{{Adams
| number = ML13038A086
| number = ML21319A023
| issue date = 09/30/1974
| 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 =  
| author name =  
| author affiliation = US Atomic Energy Commission (AEC)
| author affiliation = NRC/ACRS
| addressee name =  
| addressee name =  
| addressee affiliation =  
| addressee affiliation =  
| docket =  
| docket =  
| license number =  
| license number =  
| contact person =  
| contact person = Jim Steckel
| document report number = RG-1.026, Rev. 1
| case reference number = RG-1.026, Rev 6
| document type = Regulatory Guide
| document type = Meeting Briefing Package/Handouts, Slides and Viewgraphs
| page count = 3
| page count = 13
}}
}}
{{#Wiki_filter:iVgGY C0 Revision 1.U.S. ATOMIC ENERGY COMMISSION
{{#Wiki_filter:NRC Regulatory Guide 1.26, Revision 6 Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste- Containing Components of Nuclear Power Plants NRC Staff ACRS Presentation November 16, 2021
September
1974 REGULATORY
GUIDE qrrs "i DIRECTORATE
OF R EGULATORY
STANDARDS REGULATORY
GUIDE 1.26 QUALITY GROUP CLASSIFICATIONS
AND STANDARDS
FOR WATER-, STEAM-, AND RADIOACTIVE-WASTE-CONTAIN
ING COMPONENTS
OF NUCLEAR POWER PLANTS


==A. INTRODUCTION==
NRC Staff Team Members for RG 1.26 Revision
General Design Criterion
* James Steckel, RGPMB/DE/RES
1, "Quality Standards and Records," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, "Licensing of Production and Utilization Facilities," 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.
* 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


Section 50.55a,"Codes and Standards," of 10 CFR Part 50 requires that components of the reactor coolant pressure boundary be designed, fabricated, erected, and tested in accordance with the requirements for Class 1 components of Section III of the ASME Boiler and Pressure Vessel Code or equivalent quality standards.
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


This guide describes a quality classification system related to specified national standards that may be used to determine quality standards acceptable to the Regulatory staff for satis-fying General Design Criterion I for other safety-related components containing
Key Changes
'radioactive material, water, or steam in water-cooled nuclear power plants.
* 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.


==B. DISCUSSION==
* Updated NRC staff position on classification of Quality Group C components to reflect latest guidance on systems that contain radioactive material.
After reviewing a number of applications for con-struction permits and operating licenses and after dis-cussions with representatives of professional societies and industry, the AEC Regulatory staff has developed a quality classification system for safety-related com-ponents containing radioactive material, water, or steam in water-cooled nuclear power plants. The system consists of four quality groups, A through D, methods Editions prior to 1971 of the ASME Boiler and Pressure Vessel Code, Section III, "Nuclear Power Plant Components," use the term Class A in lieu of Class 1.for assigning components to these quality groups, and the specific quality standards applicable to each quality group. The initial, portion of this system is described in§50.55a of 10 CFR Part 50, which requires that components of the reactor coolant pressure boundyry be designed, fabricated, erected, and tested to the highest available national standards;
this corresponds to the quality standard required for quality Group A of the AEC system. This guide describes a method for deter-mining acceptable quality standards for the remaining safety-related components containing radioactive material, water, or steam, i.e., quality Group B, C, and D components.


Other systems not covered by this guide, such as instrument and service air, diesel engine and its generators and auxiliary support systems, diesel fuel, emergency and normal ventilation, fuel handling, and fire protection systems using other than water, should be designed, fabricated, erected, and tested to quality standards commensurate with the safety function to be performed.
* NRC staff improved proposed Revision 6 to RG 1.26 in response to public comments.


C. REGULATORY
4
POSITION I. The group B quality standards given in Table I 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 part of the reactor coolant pressure boundary defined in §50.2(v) but excluded from the requirements of §50.55a 2 pursuant to footnote 2 of that section or not part of the reactor coolant pressure boundary but part of: 2 Group A quality standards that are required for pressure-containing components of the reactor coolant pressure bound-ary are specified in Section 50.55a of 10 CFR Part 5


===0. USAEC REGULATORY ===
Appendix A to Revision 6 to RG 1.26
GUIDES Regulatory Guides are issued to describe and make available to the public methods acceptable to the AEC Regulatory staff of implementing specific parts of the Commission's regulations, to delineate techniques
* 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
.~ed by the staff in evaluating specific problems or postulated accidents, or to provide guidance to Sapplicants.
* ANSI/ANS-58.14 scope is broader than RG 1.26 to apply to pressure integrity for water, steam, or radioactive material components
* 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
* Based on terminology differences, ANSI/ANS-58.14 users should consider full scope of 10 CFR Part 50, Appendix A
                                                              5


Regulatory Guides are not substitutes for regulations and compliance with them is not required.
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)
* 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


Methods and solutions different from those set out in the guides will be acceptable if they provide a basis for the findings requisite to the issuance or continuance of a permit or license by the Commission.
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.


Published guides will be revised periodically, as appropriate, to accommodate comments and to reflect new information or experience.
7


Copies of published guides may be obtained by request indicating the divisions desired to the US. Atomic Energy Commission, Washington.
Response to Public Comments
* Comment: Include 10 CFR 50.54 and 10 CFR 50.55 in list of regulatory requirements.


D.C. 20545, Attention:  
- Response: Complete
Director of Regulatory Standards.
* Comment: Clarify applicability of ANSI/ANS-58.14 and 10 CFR 50.69
  - Response: Added detailed footnote to Table 1 in RG 1.26 discussing 10 CFR 50.69
                                                    8


'Comments and suggestions for improvements in these guides are encouraged and should be sent to the Secretary of the Commission, U.S. Atomic Energy Commission, Washington, D.C. 20545, Attention:  
Response to Public Comments (continued)
Docketing and Service Section The guides are issued in the following ten broad divisions:
* Comment: Add technical basis for including important to safety items in Quality Group C or delete
1. Power Reactors 6. Products 2. Research and Test Reactors
  - 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


===7. Transportation===
NRC Response to Public Comments (continued)
3. Fuels and Materials Facilities
* Comment: Explain change to threshold for classification of systems containing radioactive material as Quality Group C
8. Occupational Health 4. Environmental and Siting 9. Antitrust Review 5. Materials and Plant Protection
  - Response: RG 1.26 updated to clarify reason for change to threshold for classification of systems containing radioactive material
10. General a. Systems or portions of systems 3 important to safety that are designed for (1) emergency core cooling,`.2) postaccident containment heat removal, or (3) post-:cident fission product removal.b. Systems or portions of systems 3 important to safety that are designed for (1) reactor shutdown or (2) residual heat removal.c. Those portions of the steam systems of boiling water reactors extending from the outermost contain-ment isolation valve up to but not including the turbine stop valves 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.
* 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


Alternatively, for boiling water reactors con-taining a shutoff valve (in addition to the two contain-ment isolation valves) in the main steam line and in the main feedwater line, Group B quality standards should be applied to those portions of the steam and feedwater systems extending from the outermost containment isolation valves up to and including the first valve that is either normally closed or capable of automatic closure during all modes of normal reactor operation.
High Temperature Reactor Quality Group Classification
* 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.


d. Those portions of the steam and feedwater sys-tems of pressurized water reactors extending from and including the secondary side of steam generators up to and including the outermost containmenrt isolation valves and connected piping up to and including the first valve (including a safety or relief valve) that is either yormally closed or capable of automatic closure during\ modes of normal reactor operation.
* 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.


e. Systems or portions of systems 3 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.2. The group C quality standards given in Table 1 of this guide should be applied to water-, steam-, and radioactive-waste-containing pressure vessels, heat ex-changers (other than turbines and condensers), storage tanks, piping, pumps, and valves not part of the reactor coolant pressure boundary or included in quality Group B but part of: a. Cooling water and auxiliary feedwater systems or portions of these systems 3 important to safety that are'The system boundary includes those portions of the system required 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.'Components in influent lines may be classified as Group D provided they are capable of being isolated from the reactor coolant pressure boundary by an additional valve which has high leak-tight integrity.
* DG-1380 discussed with ACRS on July 20, 2021.


designed for (1) emergency core cooling, (2) post-accident containment heat removal, (3) postaccident containment atmosphere cle,.up, or (4) residual heat removal from the reactor and from the spent fuel storage pool (including primary and secondary cooling systems).Portions of these systems that are required for their safety functions and that either do not operate during any mode of normal reactor operation or cannot be tested adequately should be classified as Group B.b. Cooling water and seal water, systems or portions of these systems3 important to safety that are designed for functioning of components and systems important to safety, such as reactor coolant pumps, diesels, and control room.c. Systems or portions of systems 3 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 closure.4 d. Radioactive waste treatment, handling, and dis-posal systems, except those portions of these systems whose postulated failure would not result in conserva-tively calculated potential offsite doses that exceed 0.5 rem to the whole body or its equivalent to any part of the body. For those systems located in Seismic Category I structures, only single component failures need be assumed. (However, no credit for automatic isolation from other components in the system or for treatment of released material should be taken 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.)
* RG 1.26 relies on DG-1380 for high-temperature reactor quality group classification.
Parts of these systems beyond the pro-cessing steps (such as monitoring tanks) may be classi-fied as Group D if the plant Technical Specifications limit inventories to levels which, if released, would not result in conservatively calculated potential offsite doses that exceed 0.5 rem to the whole body or its equivalent to any part of the body.e. Other systems, not covered by items 2.a. through 2.d. above, that contain or may contain radioactive material and whose postulated failure would result in conservatively, calculated potential offsite doses that exceed 0.5 rem to the whole body or its equivalent to any part of the body. For those systems located in Seismic Category I structures, only single component failures need be assumed. (However, no credit for automatic isolation from other components in the system or for treatment of released material should be taken 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,)
@4 4.1.26-2
3. The Group D quality standards given in Table 1 of this guide should be applied to water- and steam-containing components not part of the reactor coolant pressure boundary or included in quality Groups B or C but part of systems or portions of systems that contain or may contain radioactive material.


==D. IMPLEMENTATION==
11
The purpose of this section is to provide guidance to applicants regarding implementation of the quality group classifications and standards described in Section C of this guide.1. The quality group classifications and standards described in Section C of this guide for quality Groups B, C, and D' should be applied to the appropriate systems and components of all plants for which the docket date of the application for construction permit is subsequent to January 1, 1975.2. The quality group ,classifications and standards described in Section C of this guide may be applied, at the designer's option, to systems and components of plants for which the docket date of the application is prior to January 1, 1975.3. Other methods for determining acceptable quality standards for systems and components not in quality Group A may be proposed to the Commission by applicants and may be determined to be acceptable if they provide a comparable level of safety.sAcceptable standards for quality Group A components are described in §50.55a of 10 CFR Part 50.TABLE 1 QUALITY STANDARDS Components Quality B Quality C Quality D Pressure Vessels ASME Boiler and Pressure ASME Boiler and Pressure ASME Boiler and Pressure Vessel Code, Section II I, Vessel CodeSection II I, Vessel Code, Section VIII"Nuclear Power Plant Com- "Nuclear Power Plant Coin- Division 1 ponents," a, b, c Class 2 ponents," a, b, c Class 3 Piping As above As above ANSI B 31.1.0 Power Piping I Pumps As above As above Manufacturers standards Valves As above As above ANSI B31.1.0 Atmospheric As above As above AP1-650, AWWA D 100, or Storage Tanks ANSI B 96.1 0-15 psig As above As above API-620 Storage Tanks aSee Section 50.55a for guidance with regard to the Code and Addenda to be applied.bASME Code N- symbol need not be applied.CThe specific applicability of code cases will be covered separately in other regulatory guides or in Commission regulations, where appro-priate. 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.1.26-3}}
 
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
                                                    12
 
QUESTIONS?
          13}}


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

Latest revision as of 12:18, 18 January 2022

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

NRC Staff Team Members for RG 1.26 Revision

  • James Steckel, RGPMB/DE/RES
  • Edward Stutzcage, DRCB/DRA/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

10

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.

11

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

12

QUESTIONS?

13


Retrieved from "https://kanterella.com/w/index.php?title=Regulatory_Guide_1.26&oldid=3403351"