ML18180A136

Comment (4) of Andrew N. Mauer on Behalf of Nuclear Energy Institute on Draft Letter to the Regarding the Clarification of Regulatory Paths for Lead Test Assemblies

ML18180A136
Person / Time
Site:	Nuclear Energy Institute
Issue date:	06/27/2018
From:	Mauer A Nuclear Energy Institute
To:	May Ma Rules, Announcements, and Directives Branch
References
83FR26503 00004, NRC-2018-0109
Download: ML18180A136 (8)

Text

PUBLIC SUBMISSION Docket: NRC-2018-0109 As of: 6/28/18 7:27 AM Received:

June 27, 2018 Status: Pending_Post Tracking No. lk2-93yi-uuf7 Comments Due: June 27 , 2018 Submission Type: Web Draft Letter to the Nuclear Energy Institute Regarding the Clarification of Regulatory Paths for Lead Test Assemblies Comment On: NRC-2018-0109-0001 Draft Letter to the Nuclear Energy Institute Regarc:ling the Clarification of Regulatory Paths for Lead Test Assemblies Document:

NRC-2018-0109-DRAFT-0004 Comment on FR Doc# 2018-12276 Submitter Information Name: Andrew Mauer Submitter's Representative:

Allison Borst Organization:

Nuclear Energy Institute General Comment See attached file( s) Attachments 06-27-18_NRC_NEI Comments on Draft Letter re Clarification of Regulatory Paths for Lead Test Assemblies SUNS! Review Complete Template=

ADM-013 E RIDS=ADM-03 ADD= Sihan Ding, Kimberly Green & Jan Burkhardt COMMENT (4) PUBLICATION DATE: 6/7/2018 CITATION # 83 FR 26503 ANDREW N. MAUER Technical Advisor I 1201 F Street, NW, Suite 1100 Washington, DC 20004 NUCLEAR ENERGY INSTITUTE P: 202.739.8018 anm@nei.org nei.org June 27, 2018 Ms. May Ma Office of Administration Mail Stop: TWFN-7-A60M U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Submitted via Regulations.gov

Subject:

Submittal of NEI comments on Draft Letter to the Nuclear Energy Institute Regarding the Clarification of Regulatory Paths for Lead Test Assemblies, 83 Federal Register 26503, 06/7/2018 (Docket ID: NRC-2018-0109)

Project Number: 689 On behalf of the nuclear energy industry, the Nuclear Energy Institute (NEI)1 appreciates the opportunity to provide comments on the draft letter to NEI regarding the clarification of regulatory paths for lead test assemblies (LTAs). Industry appreciates and recognizes the NRC's commitment to providing this guidance and that it supersedes the June 29 2017 letter, "Response to Nuclear Energy Institute Letter Concerning the Regulatory Path for Lead Test Assemblies." The draft letter is a great step forward to provide a stable regulatory framework for addressing irradiation of LTAs, and we urge the NRC to move forward to issue the letter without delay. We agree with the NRC clarification that the final sentence in Standard Technical Specifications (STS) Section 4.2.1 can be read separate from the other sentences in STS Section 4.2.1. This final sentence is in part a qualifier on the other sentences in STS Section 4.2.1 for LTAs. NRC's clarifications of this sentence are consistent with current industry practice. We also agree with the clarification's impact on related topics such as: use of approved methods, LTA-specific guidance on 10 CFR 50.59, and exemptions from 10 CFR 50.46(a)(1)(i) for LTA campaigns.

The NRC's perspective on how to address the method of evaluation question in the 10 CFR 50.59 process for LTAs, where an approved method does not exist, is consistent with industry practice of using an approved code and method with a conservative evaluation and sound engineering judgement.

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

NUCLEAR. CLEAN AIR ENERGY Ms. May Ma June 27, 2018 Page 2 Industry has safely loaded LTAs for decades and appreciates the additional regulatory certainty provided by this letter, as we ramp up ATF development.

Attached are more specific comments for the NRC's consideration as the letter is finalized. Thank you for your time and attention on this important matter. If you have any questions, please contact me or Ben Holtzman (202-739-8031; bah@nei.org). Sincerely, Andrew Mauer Attachment c: Brian Holian, NRR , NRC Mirela Gavrilas, NRR/DSS, NRC Kathryn Brock, NRR/DORL, NRC M i chael King, NRR/DIRS, NRC Jennifer Whitman, NRR/DSS/SRXB, NRC Kimberly Green , NRR/D0RL/LPL3 , NRC NEI Comments on Clarification of Regulatory Paths for Lead Test Assemblies Comment# Location of Comment Comment/ ..... , -The paragraph should be revised as follows: II ... Licensees can demonstrate compliance with the STS LTA There are several concerns regarding this paragraph:

provision that LTAs are of 'limited 1) The second sentence could be read to mean number' and 'in nonllmlting core that the LTA analysis must conform to codes regions' through an evaluation of the and methods used to develop the UFSAR and L TAs using good engineering COLR limits; judgment and analytical codes and 2) The second sentence uses the term methods that reflect well-established

" invalidate" when the terms "applicable and engineering practices, and where 1 Page 3, Paragraph 2 bounding

are used later in the paragraph; uncertainties in input parameters and 3) The NRC expectations regarding the LTA models are conservatively addressed analysis approach appears across several using the current state of knowledge sentences in the remainder of the paragraph; and all available data to the extent and practical.

The NRC expects that 4) The language regarding limits being relevant licensees will confirm that the UFSAR to the LTAs is unclear. Chapter 15 transient and accident The restructuring of the sentences can make this analyses of the core with the LTAs paragraph more concise and clear. and the COLR limits remain applicable and bounding.

These evaluations are subject to verification through the Reactor Oversight Process (ROP)." Page 1 of 5 NEI Comments on Clarification of Regulatory Paths for Lead Test Assemblies Comment. Location 2 Page 3 , Paragraph 3 3 Page 4, Paragraph 2 The text "Historically , LTA campaigns have ranged from a few rods to 2 percent of the core, depending on the nature of the design and the degree of prior characterization of the LT As' performance

." The text as written does not translate into a percentage of a core easily since the sizes of cores vary. Two percent of the core in a 157 assembly core is -3 assemblies and for a 193 assembly core, this is -4 assemblies. However, it's not uncommon to have up to 8 LTAs allowing variability in discharge cycle to allow more detailed inspections and testing that cannot be completed during a refueling outage. There is no contextual information regarding the examples in the text. These examples may be rather unique compared to industry's currently planned LTAs, and context would help explain why these referenced LTA programs required a license amendment while other LTA programs did not. Page 2 of 5 Add a qualifying statement to confirm that the intent is not to require an upper limit. Additionally, revise the text to indicate " l=listoricallyTypically, LTA campaigns have ranged from a few rods to ~over 5 percent of the core , depending on the nature of the design and the degree of prior characterization of the LT As' performance

." Please change the text These LTA campaigns~

unusually large in size. scope or impact, and therefore impacted fundamental core dynamics ... "

4 NEI Comments on Clarification of Regulatory Paths for Lead Test Assemblies Page 5, Paragraph 2 The statement "In those instances, the licensee should perform a conservative evaluation of the LT As using the approved codes and methods for the core." A requirement to use the approved codes and methods for the core to evaluate the LTAs is inconsistent w i th the statement in paragraph 3 which allows the use of modifications to the approved codes and methods for the evaluation of the LT As. Furthermore, it is important that the phrase " for the core" is removed. Within the engineering judgement and good engineering practices allowance , there is a range of methods that could be used to demonstrate acceptability of the LT As. Page 3 of 5 Please change the text as follows: " In those i nstances , the licensee should perform a conservative evaluation of the LT As ~siRg tl=le a1313roveel coeles a Rel metl=loels for tl=le ffife.

Comment# 5 6 NEI Comments on Clarification of Regulatory Paths for Lead Test Assemblies Location of Comment Page 5, Paragraph 3 Page 6 , Paragraph 1 Comment/ ..... '. , The following excerpt implies that the use of unapproved codes/methods is only acceptable if modifying an existing approved code/method (vs. starting with any entirely new code/method):

The evaluation of LTA campaigns necessarily requires some engineering judgment due to incomplete representative data availability prior to irradiation of the LTAs, and evaluation may necessitate modifications to approved codes and methods or the use of such codes and methods outside the bounds for which they were explicitly approved.

These modifications, made solely for the evaluation of limited numbers of LTAs, may be acceptable for confirmation of the nonlimiting nature of the L TAs and the continued applicability of the core operating limits, which themselves are calculated using approved codes and methods." The NRC letter already states that it is an expectation that the licenses will use good engineering judgement and analytical codes and methods that reflect well-established engineering practices reflecting the current state of knowledge, including all available data (page 3). Therefore, the use of a code and/or method that has not previously been approved by the NRC but is based on wellestablished engineering practices should be reasonable under those expectations. The text 'must perform a 10 CFR 50.59 evaluation' can be confusing as it appears to assume a full 50.59 evaluation is required -however , that may not be the case as the 50.59 process may screen out this need. Page 4 of 5 Modify the cited text as follows: The evaluation of LTA campaigns necessarily requires some engineering judgment due to incomplete representative data availability prior to irradiation of the LTAs, and evaluation may necessitate the use of modified or different codes and methods in the form of: 1) modifications to approved codes and methods, et= n the use of 54:IEA codes and methods outside the bounds for which they were explicitly approved,.

or 3) the use of a code or method based on well-established engineering practices that has not been previously approved by the NRC. Use of t=Alese unapproved codes and methods MeEiifi6atieAs, ~solely for the evaluation of limited numbers of LTAs, may be acceptable for confirmation of the nonlimitlng nature of the LTAs and the continued applicability of the UFSAR and core operating limits, which ttleRtsewes are calculated using approved codes and methods." Please change to 'must follow the 10 CFR 50.59 process" NEI Comments on Clarification of Regulatory Paths for Lead Test Assemblies Comment# Location of Comment QNnmentJa..

~* .. *. ---, "; .-.. ;,.,t ..... . :~rt~. ' '*:.-C . .. . ,:t',;.,,*,.;i The following is the only sentence currently used to explicitly justify 10 CFR 50.59(c)(2)(viii) in the letter: "LTA campaigns that meet the STS LTA provision (i.e., Please add this text after the cited the COLR limits and Chapter 15 UFSAR analyses sentence:

remain applicable and bounding) will not affect the "Furthermore, any unapproved codes performance of safety-related SSCs and, therefore, that were used solely to confirm the the method of evaluation used in establishing the nonlimiting nature of the LTAs do not design bases will remain the same, and the licensee result In a 'departure from a method 7 Page 7, Paragraph 5 may not meet this criterion (and thereby would not of evaluation described in the FSAR need to request a license amendment due to this (as updated) used in establishing the criterion)." design bases or in the safety analyses' because they did not Although previous discussion in the letter (Page 5) impact any of the applicable design addresses the use of unapproved codes, it would limits (i.e. COLR limits and Chapter 15 significantly increase clarity if the use of unapproved UFSAR analyses)".

codes was explicitly discussed in this 10 CFR 50.59(c)(2)(viii) justification as well. 8 Page 8, Paragraph 5 Typo: " 4.21" should be "4.2.1" Change to '4.2.1' 9 Administrative Please change addressee of the letter to Joseph Pollock Change addressee of the letter to Joseph Pollock Page 5 of 5