ML22221A222
| ML22221A222 | |
| Person / Time | |
|---|---|
| Issue date: | 10/05/2022 |
| From: | Mohammad Sadollah NRC/RES/DE |
| To: | |
| Eudy M | |
| Shared Package | |
| ML22062A025 | List: |
| References | |
| RG-1.248, Rev 0 DG-1393 | |
| Download: ML22221A222 (14) | |
Text
Response to Public Comments on Draft Regulatory Guide (DG)-1393 Guide for Assessing, Monitoring, and Mitigating Aging Effects on Electrical Equipment Used in Nuclear Power Plants.
Proposed New Regulatory Guide (RG) 1.248 On February 3, 2022, the NRC published a notice in the Federal Register (87 FR 6204) that Draft Regulatory Guide, DG-1393 (Proposed New RG 1.248), was available for public comment. The Public Comment period ended on March 7, 2022. The NRC received comments from the organizations listed below. The NRC has combined the comments and NRC staff responses in the following table.
Comments were received from the following:
Comment Document 1 Comment Document 2 Comment Document 3 Carrie Fosaaen Alan Cox William Horin Director, Regulatory Affairs United States Nuclear Utility Group on Equipment NuScale Power, LLC acox@ct1.us Qualification - Winston & Strawn LLP 1100 NE Circle Blvd., Suite 200 ADAMS Accession No. ML22068A163 1901 L Street N.W.
Corvallis, Oregon 97330 Washington, DC, 20036-3506 ADAMS Accession No. ML22068A162 ADAMS Accession No. ML22068A164 Commenter Section of Specific Comments NRC Resolution DG-1393 Comment Document 1: ML22068A162 Carrie Section A Comment 1 The staff agreed with the comment and proposed Fosaaen The applicability section states the regulatory guide (RG) recommendation. The staff removed the reference to 10 is applicable to "holders of and applicants for combined CFR Part 52.137(a)(13) from DG-1393.
licenses, standard design certifications, standard design approvals..." The Applicable Regulations identify only 10 No additional changes were made to DG-1393 as a CFR 52.137(a)(13), which requires an applicant for a result of this comment.
standard design approval to provide the list of electric equipment that is important to safety as defined by 10 CFR 50.49(d), as establishing the applicability of this RG to applicants for design certifications (DCs) and standard May 2022
Commenter Section of Specific Comments NRC Resolution DG-1393 design approvals (SDAs) (the equivalent regulation for DC applicants is not listed).
The requirements for DC and SDA applicants to identify electric equipment that is important to safety does not necessitate the conduct of maintenance and aging management or the development of an aging management program at the design approval stage.
Accordingly, IEEE 1205-2014 and RG 1.248 are not applicable to SDA and DC applicants.
Recommendation Revise the applicability and applicable regulations to remove applicability to holders of and applicants for standard design certifications and standard design approvals.
Carrie Section C Comment 2 The staff did not agree with the comment and the Fosaaen Part C of the DG-1393 endorses IEEE 1205-2014 without proposed recommendation. The endorsement of IEEE any exception or clarification. The endorsement of IEEE 1205-2014 in DG-1393 constitutes an approach that is 1205-2014 should clarify the criteria comprising a acceptable to the NRC staff to meet regulatory significant aging mechanism (SAM). Absent clarification, requirements for assessing, monitoring, and mitigating the endorsement guidance and its references will contain the aging effects on electrical equipment. Other the following conflict: methods including those that are endorsed elsewhere
- ASME QME-1-2017, endorsed by RG 1.100, may be used and found acceptable. Additionally, as a provides that an aging mechanism is considered result of Comment 3, RG 1.89 was added to DG-1393 as significant if it satisfies any one of four criteria. related guidance on meeting the equipment qualification
- IEEE 1205-2014 provides a definition of (EQ) requirements of 10 CFR 50.49.
SAM as "An aging mechanism that, under normal and abnormal service conditions, Addressing variances between different revisions of causes degradation of equipment that other standards (e.g., IEEE 627-2010, and IEEE 627-2018) is outside the scope of this proposed RG.
progressively and appreciably renders the equipment vulnerable to failure to perform its specified function(s). IEEE 1205-2014 includes 2
Commenter Section of Specific Comments NRC Resolution DG-1393 undated IEEE 627 as a normative reference, i.e. No changes were made to DG-1393 as a result of this one that is "indispensable for the application of' comment.
- IEEE 627-2010, which was in effect at the time of issuing IEEE 1205-2014, includes the same definition of SAM as IEEE 1205-2014, and provides further that aging is significant if it satisfies "all of' the same four criteria as listed in QME-1-2017.
- IEEE 627-2018, the current version in effect, maintains the same SAM definition, but no longer provides the list of four criteria.
Thus, without clarification, the endorsed guidance will further an inconsistency as to whether and how the four SAM criteria apply. This discrepancy is essential to compliance with 10 CFR 50.49(e)(5), which requires that "consideration must be given to all significant types of degradation which can have an effect on the functional capability of the equipment," and therefore important to the implementation of RG 1.248. NRC's endorsement of IEEE- 1205-2014 should resolve this discrepancy with an exception to the standard, including a definition and discussion of the rationale The history, content, and context of the four SAM criteria indicate that the list was intended to be conjunctive, as originally provided in IEEE 627 up through IEEE 627-2010. Accordingly, RG 1.248 should provide the same conjunctive list.
Recommendation Revise the endorsement to IEEE 1205-2014 to include an exception defining and discussing the rationale for criteria 3
Commenter Section of Specific Comments NRC Resolution DG-1393 constituting a significant aging mechanism, as per IEEE 627-2010.
Carrie Section C Comment 3 The staff did not agree with the comment and proposed Fosaaen IEEE 1205-2014 brings up synergistic effects as a recommendation. RG 1.89 provides guidance on EQ "concern" yet the standard doesn't actually provide any and information on synergistic effects. Hence, staff did guidance on how to best address it. RG 1.89 R1 does not re-state those positions in this proposed RG.
indicate that any known synergistic effects should be However, the staff revised DG-1393 to add RG 1.89 as a addressed at the time when a qualification effort is reference in related guidance.
initiated (e.g., in the development of the test specification, test plan, & test procedure). No additional changes were made to DG-1393 as a result of this comment.
Recommendation Revise RG 1.248 to reflect the results of research on synergistic effects. This should include the basis and any actions needed to address the synergistic effects beyond those included in RG 1.89.
Carrie Section C Comment 4 The staff did not agree with the comment and the Fosaaen The list of references in IEEE 1205-2014 Annex that proposed recommendation. With the exception of covers the NRC sponsored research into aging and NUREG/CR-2877, the references mentioned in the synergisms is incomplete and should be supplemented by recommendation were not located and may no longer be RG 1.248. available as public documents. NUREG/CR-2877 is a limited focus study prepared in 1982. Other relevant Recommendation research documents are included in the respective Update references in RG 1.248 to include the following reference sections of documents mentioned in DG-1393, NRC sponsored research into aging and synergisms: such as NUREG 2191.
NUREG/CP-0036, NUREG/CR-0401, The staff believes that the additional references would NUREG/CR-0275 & -0276, not add significant value and no changes to DG-1393 NUREG/CR-2156 & -2157, and NUREG/CR-2877. were made as a result of this comment.
Carrie Secdtion Comment 5 The staff partially agreed with this comment and Fosaaen C.1.e Related Guidance does not list RG 1.89 or RG recommendation. RG 1.89 is relevant to this proposed RG, and therefore the staff revised the RG and added it 4
Commenter Section of Specific Comments NRC Resolution DG-1393 1.209. RG 1.89 and RG 1.209 should be listed as they are as a reference per Comment 3. RG 1.209 has a narrow relevant to aging of electrical equipment. focus applying to EQ of computer-based instrumentation and control systems and is already Recommendation referenced in RG 1.89 accordingly. The staff does not List RG 1.89 and RG 1.209 as related guidance. agree that RG 1.209 needs to be added to DG-1393.
No additional changes were made to DG-1393 as a result of this comment.
Carrie Section Comment 6 The staff did not agree with the comment and Fosaaen C.1.f 10 CFR 50.69 is not identified as an recommendation to include 10 CFR 50.69 in the Applicable Regulation. Aging effects are part of 10 CFR applicability section of DG-1393. RG 1.201 discusses 50.69 considerations for RISC-3 components. how to meet the requirements of 10 CFR 50.69 with respect to the categorization of structures, systems and Recommendation components that are considered in risk-informing Add language about applicability of 10 CFR 50.69. special treatment requirements. The staff does not agree that 10 CFR 50.69 and RG 1.201 are within the scope of DG-1393.
No changes were made to DG-1393 as a result of this comment.
Comment Document 2: ML22068A163 Alan Cox General Comment 7 See responses to Comments 8, 9, and 10 below.
I have over 20 years of experience preparing and supporting license renewal applications for US and international utilities.
Recommendation See attached file(s) for three comments to improve wording for the Reg. Guide.
Alan Cox Pg. 3/ Comment 8 The staff partially agreed with the comment and with the Section A. NUREG-1801, Generic Aging Lessons Learned (GALL) proposed recommendation. The staff prefers the Report, Revision 2, issued December 2010 (Ref. 10), addition of, managing the effects of aging to clarify 5
Commenter Section of Specific Comments NRC Resolution DG-1393 provides recommendations for aging management of in- the intent of the NUREG-1801. The description of scope SSCs for the initial renewal of an operating license. NUREG-1801 in DG-1393 was revised to read:
provides recommendations for managing the effects of Recommendation: aging on in-scope SSCs The license renewal rule discusses managing the effects of No additional changes to DG-1393 were made as a aging, not aging management of SSCs. This and the next result of this comment.
bullet would be made consistent with the rule if this was changed to read managing the effects of aging on in-scope SSCs.
Alan Cox Pg. 5/ Comment 9 The staff agreed with the comment and the proposed Section B. This RG provides guidelines and methods acceptable to recommendation to replace assessing with the NRC staff for assessing, monitoring, and mitigating managing. Using the term managing instead of aging effects on electrical equipment in nuclear generating assessing, is appropriate to clarify the intent of DG-stations. 1393. DG-1393 was revised to change this bullet to read: NRC staff for managing, monitoring, and Recommendation:
This would be simplified and made more consistent with the license renewal rule if replace with managing.
Alan Cox Pg. 7 / Comment 10 The staff agreed with the comment and proposed Section C. The NRC staff considers conformance with the recommendation to use the term provisions instead of requirements in IEEE Standard 1205-2014 to constitute requirements, which is more appropriate as to the an acceptable method for use in satisfying the intent and purpose of the subject standard. DG-1393was Commissions regulations with respect to maintenance and revised to change this bullet to read: conformance aging management of applicable SSCs subject to aging with the provisions in IEEE standard .
stressors, aging mechanisms, and aging effects to ensure facility safety throughout the period of initial license No additional changes to DG-1393 were made as a operation, extended operation, and subsequent extended result of this comment.
operation.
Recommendation:
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Commenter Section of Specific Comments NRC Resolution DG-1393 Previous paragraph indicates that the provisions of the IEEE standard are not requirements, but constitute an acceptable method for satisfying regulations. Therefore, seems it might be appropriate to say provisions rather than requirements.
Comment Document 3: ML22068A164 William All Comment 11 The staff did not agree with the comment and proposed Horin of The NRC Staff should consider delaying the issuance of recommendation. IEEE 1205-2014 as well as IEEE NUGEQ DG-1393 to endorse IEEE Std 1205-2014 because the 1205-2000 have been referenced in RG 1.218, NUREG-IEEE Subcommittee Working Group (WG) 3.4, Aging 1801, and NUREG-2191. NRC has committed to Assessment is currently in the process of revising that provide a formal position and endorsement for use by standard. the NRC staff as well as other stake holders. Industry standards are routinely revised and changed. Delaying According to the IEEE website (https://site.ieee.org/npec- DG-1393, as recommended, is not necessarily justified sc3/working- group-3-4-aging-assessment/), WG 3.4 met due to the unknown nature of all the standards potential in December 2021 to develop a Project Authorization changes, including the depth and nature of which are not Request (PAR) for the next revision IEEE 1205. A PAR is known at this time. The staff notes that versions of the means by which standards projects are started within IEEE 1205, are already widely used in license renewal, the IEEE A revision to IEEE 1205 is planned for therefore, an agency position on the standard should be publication in the 2023-2024 timeframe. As such, a delay formally explained in a RG. The impact of not in issuing DG- 1393 until the standard is revised is in endorsing the standard is that the associated agency keeping with the goal of Alternative 2 of the Regulatory position is not clearly delineated, even though the Analysis for DG-1393 to ensure that up-to-date standard is widely referenced in NRC documents.
regulatory guidance is available for use by licensees Further, the Regulatory Analysis (ML21288A112) and applicants, and that the guidance accurately reflects provides the staffs rationale for endorsing IEEE Std.
the staffs position. 1205-2014 at this time.
Recommendation There were no changes made to DG-1393 as a result of By delaying issuance of DG-1393 until IEEE completes it this comment.
revision to IEEE 1205, the Staff would better achieve its goal of afford[ing] value to the NRC staff, and agency licensees and future applicants, due to the benefits associated with enhanced efficiency and effectiveness in 7
Commenter Section of Specific Comments NRC Resolution DG-1393 using a common guidance document as the technical basis for maintenance practices and aging management of the subject SSCs for license applications and other interactions with the NRC. None of the cost saving for the industry with respect to Staff review times, responding to RAIs, etc., would be realized by endorsing an 8-year-old standard that is soon to be outdated.
William Section C Comment 12 See responses for each comment below (13 thru 17)
Horin of General Observation: The Staff Regulatory Guidance in NUGEQ Part C makes no specific clarification and takes no exceptions to the guidance in IEEE 1205-2014.
Should the staff decide to proceed with endorsement of IEEE 1205-2014, the following observations and comments are provided as suggested areas where specific clarification or exception is considered appropriate in the proposed new Regulatory Guide 1.248.
William Section Comment 13 The staff did not agree with the comment and the Horin of C.1.c General Observation: DG-1393 would be an appropriate proposed recommendation. See the NRC resolution to NUGEQ vehicle to address an industry recognized issue related to a Comment 2.
discrepancy in the criteria used by IEEE and ASME to identify significant aging mechanisms (SAM). We feel No changes to DG-1393 were made as a result of this that it is appropriate for a SAM to satisfy all four criteria comment.
from IEEE 627-2010.
The criteria for a SAM from IEEE 627-2010 states:
Aging is significant for the purpose of an aging program if it satisfies all of the following criteria:
a) In the normal service environments, an aging mechanism promotes the same failure mode as that resulting from exposure to abnormal or DBE service conditions.
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Commenter Section of Specific Comments NRC Resolution DG-1393 b) The aging mechanism adversely affects the ability of the equipment to perform its required function in accordance with its specification requirements.
c) The deterioration caused by the aging mechanism is not amenable to assessment by in-service inspection or surveillance activities that provide confidence in the equipments ability to function in accordance with its specification requirements during the intervals between surveillance.
d) In the normal service environment, the aging mechanism causes degradation during the design life of the equipment that is appreciable compared to degradation caused by the DBE. [Emphasis Added]
The NRC has previously used very similar criteria presented in Section 3.4.5 of Technical Evaluation Report TER-C5257-532, Implementation Guidance for New and Corrective Equipment Environmental Qualification dated 04/22/1983 [ML20244C266].
However, the criteria from Section QR-5310 of ASME QME-1-2017 (endorsed by RG 1.100 R4) is inconsistent with the definition of a SAM since it can identify an aging mechanism as being significant even if the degradation has no effect on the equipments ability to perform its required function.
Recommendation IEEE and ASME use the same four criteria for a SAM but differ in whether a SAM needs to meet all four criteria (e.g., IEEE position) or any one of the four criteria (e.g.,
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Commenter Section of Specific Comments NRC Resolution DG-1393 ASME position). Satisfying all four criteria is consistent with the definition of a significant aging mechanism provided in IEEE 1205- 2014. Section 3 of IEEE 1205-2014 defines a SAM as: An aging mechanism that, under normal and abnormal service conditions, causes degradation of equipment that progressively and appreciably renders the equipment vulnerable to failure to perform its specified function(s).
Having clear and consistent criteria on what constitutes a significant aging mechanism is directly related to the requirement in 10 CFR 50.49(e)(5) that consideration must be given to all significant types of degradation which can have an effect on the functional capability of the equipment.
DG-1393 should endorse the position that a SAM needs to satisfy all four criteria from IEEE 627-2010.
William Section C Comment 14 The staff did not agree with the comment and proposed Horin of IEEE 1205-2014 expanded the scope to include all recommendation. Applicants/licensees can apply risk NUGEQ electrical equipment instead of only Class 1E equipment. informed-categorization of electrical equipment per 10 DG-1393 should be specific as to the applicability of the CFR 50.69 and subsequently, the NRC staff will review staffs endorsement being limited to important to safety and evaluate on a site-specific basis accordingly. RG electrical equipment that has not been classified as RISC-3 1.201, Guidelines for Categorizing Structures, Systems, or RISC-4 under 10 CFR 50.69. and Components in Nuclear Power Plants According to Their Safety Significance, provides guidance on risk-Recommendation informed categorization. Addressing risk classification The scope of IEEE 1205-2014 goes beyond the scope of of electrical equipment is beyond the scope of the equipment subject to 10 CFR Part 50 (e.g., §50.49, §50.65, endorsement of IEEE 1205-2014 in DG-1363.
GDC-4 of 10 CFR 50 Appendix A), the important to safety equipment subject to 10 CFR Part 52, or the The scope of electrical equipment addressed in DG-electrical equipment subject to 10 CFR Part 54. 1363 is the electrical equipment subject to the regulations in the Applicable Regulations section.
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Commenter Section of Specific Comments NRC Resolution DG-1393 DG-1363 provides one acceptable method of meeting the regulations.
No changes were made to DG-1363 as a result of this comment.
William Section C Comment 15 The staff did not agree with the comment and proposed Horin of Part C of DG-1393 should clarify that Section C.5.a of RG recommendation. See the NRC resolution for Comment NUGEQ 1.89 R1 (or the equivalent section of the proposed revision 4. However, as a result of Comment 3, the staff has to RG 1.89 in DG- 1361) provides guidance on how to added a reference to RG 1.89, which contains address synergistic effects for equipment subject to 10 considerations in simulating an end-of-installed life.
CFR 50.49.
No additional changes to DG-1393 were made as a Section 4.1 Stressors of IEEE 1205-2014 (pg 4) states result of this comment.
the following:
Aging degradation due to a single stressor is often represented as a first-order relationship involving stressor intensity and time as described for thermal aging in 6.6.3, however, aging degradation due to a combination of more than one stressor may exceed the sum of the individual effects and may result in conditions that are not appropriately modeled by this simple representation.
Typically, the concern is associated with the potential for synergistic effects between temperature and radiation in some polymers.
DG-1393 is the appropriate place for the NRC to reference for consideration the results and conclusions from the NRCs research into aging and synergistic effects because Annex G of IEEE 1205-2014 only refers to references that should be consulted for additional information on this topic. Consistent with the resolution of the EQ TAP and GSI-168, this summary should specifically characterize 11
Commenter Section of Specific Comments NRC Resolution DG-1393 the significance of potential synergistic effects from the perspective of the overall uncertainties in simulating an end-of- installed life condition during a qualification/test program.
Recommendation There is no specific guidance in IEEE 1205-2014 on how to address synergistic effects instead it simply refers to references listed in Annex G that IEEE 1205 states should be consulted for additional information on this topic. The reference citations in Annex G are a partial listing of the NRCs research into aging and synergistic effects. DG-1393 should clarify that there are additional documents related to NRC sponsored research into aging and synergistic effects that are not currently cited in IEEE 1205-2014. Some examples include:
NUREG/CR-0401 NUREG/CR-0275 & 0276 NUREG/CR-2156 & -2157 NUREG/CR-2877 Additionally, DG-1393 should also expand on the information contained in some of the references in Annex G, such as NUREG/CR-6384 as well as identify those documents associated with EQ Task Action Plan (EQ-TAP) and the resolution of GSI-168 such as the June 28, 2002 Technical Assessment of Generic Safety Issue (GSI) 168, Environmental Qualification of Low-Voltage Instrumentation and Control (I&C) Cables (ML021790551).
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Commenter Section of Specific Comments NRC Resolution DG-1393 William Section C Comment 16 The staff did not agree with the comment and the Horin of IEEE 1205-2014 uses the term qualified life throughout proposed recommendation. RG 1.209 discusses NUGEQ the standard without being defined or providing any computer-based I&C systems. RG 1.89 addresses distinction or clarification between harsh or mild environmental qualification as well as qualified life and environment applications. The term qualified life is RG 1.89 is now referenced in DG-1393. Therefore, specific to equipment requiring qualification to harsh qualified life does not need to be addressed in this RG.
design basis accident conditions.
No changes to DG-1393 were made as a result of this DG-1393 should clarify or reinforce the position in RG comment.
1.209 that because of ready accessibility for monitoring and maintenance in mild environments, the need to establish a qualified life does not apply.
Recommendation This comment is intended to ensure consistency between RG 1.248 and RG 1.209.
William Section C Comment 17 The staff did not agree with the proposed Horin of DG-1393 should take exception or provide clarification to recommendation. Endorsement of IEEE Std. 1205-2014 NUGEQ Section 2 Normative references of IEEE 1205-2014 provides one method acceptable to comply with the such that the endorsement of IEEE 1205-2014 clearly regulations. The facilities current licensing basis indicates that the use of these normative references should determines the codes, standards, and regulatory guides a be as applicable and consistent with the current licensing facility conforms to and is plant-specific. The listing of basis of the plant. normative references in IEEE Std. 1205-2014 does not indicate that a plant must include those references in the The current wording in IEEE 1205-2014 indicates the licensing basis. A regulatory guide is one acceptable need to apply the latest edition of IEEE 323 and IEEE 627, method of meeting the regulations. Furthermore, which could conflict with the current licensing basis of the endorsing IEEE Std. 1205-2014 does not imply tacit plant. endorsement of IEEE 627 or IEEE Std 323 in this RG.
In addition, DG-1393 discusses the use of secondary Recommendation references in an endorsed standard at the end of Section Section 2 of IEEE 1205-2014 provides undated references B; and, licensees and applicants may consider and use to IEEE Std 323 and IEEE Std 672, which goes on to state information in the secondary references, if appropriately that these documents are indispensable for the justified, consistent with current regulatory practice, and 13
Commenter Section of Specific Comments NRC Resolution DG-1393 application of this document (i.e., they must be consistent with applicable NRC requirements. In understood and used: therefore, each referenced response to Comment 3, the staff added a reference to document is cited in text and its relationship to this RG 1.89, which contains staffs position on IEEE 323.
document is explained). For dated references, only the edition cited applies. For undated references, the latest No changes to DG-1393 were made as a result of this edition of the referenced document (including any comment.
amendments or corrigenda) applies.
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