ML19239A016

NEI Comments on IMC 0609, Appendix a and Attachment 1 August 2019

ML19239A016
Person / Time
Site:	Nuclear Energy Institute
Issue date:	08/27/2019
From:	Slider J Nuclear Energy Institute
To:	Alex Garmoe Office of Nuclear Reactor Regulation
Govan T, 415-6197, NRR/DIRS
References
Download: ML19239A016 (5)

Text

From: SLIDER, James To: Garmoe, Alex Cc: Govan, Tekia; Lewin, Aron

Subject:

[External_Sender] Comments on Draft Appendix A and Attachment 1 Date: Monday, August 26, 2019 4:47:59 PM Attachments: Comments on Draft Appendix A and Attachment 1 20190826.docx Alex/Tekia/Aron, Attached are comments on the draft revisions of Appendix A and Attachment 1 provided to the public in conjunction with the July 31, 2019 public meeting. We will be glad to answer any questions the staff may have on our comments during the August 28 public meeting.

Best regards, Jim James SLIDER l Technical Advisor, Regulatory Affairs 1201 F Street, NW, Suite 1100 l Washington, DC 20004 P: 202.739.8015 nei.org This electronic message transmission contains information from the Nuclear Energy Institute, Inc. The information is intended solely for the use of the addressee and its use by any other person is not authorized. If you are not the intended recipient, you have received this communication in error, and any review, use, disclosure, copying or distribution of the contents of this communication is strictly prohibited. If you have received this electronic transmission in error, please notify the sender immediately by telephone or by electronic mail and permanently delete the original message. IRS Circular 230 disclosure: To ensure compliance with requirements imposed by the IRS and other taxing authorities, we inform you that any tax advice contained in this communication (including any attachments) is not intended or written to be used, and cannot be used, for the purpose of (i) avoiding penalties that may be imposed on any taxpayer or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein.

Sent through www.intermedia.com

NEI Comments on Draft Revision of IMC-0609, Appendix A and Attachment 4 1 Introduction 2 Following are comments from NEI on behalf of its member companies on two documents related to the 3 NRCs Significance Determination Process (SDP). The documents are: (1) Draft revision of Inspection 4 Manual Chapter (IMC) 0609, Appendix A, The Significance Determination Process for Findings At-5 Power, [ADAMS ML9198A183] and (2) Draft revision of IMC-0609, Attachment 04, Initial Characteriza-6 tion of Findings [ADAMS ML19198A195]. Both documents were provided to external stakeholders just 7 prior to the July 31, 2019 public meeting on the Reactor Oversight Process (ROP).

8 9

10 Comments on Draft Revised Appendix A 11 1. Overarching Comment: We continue to disagree with the staff on the merits of merging the Appen-12 dix O SDP (for mitigating strategies) into Appendix A, as attempted in the draft revision provided for 13 public comment. We believe the appropriate action on Appendix O would be to merge it and Ap-14 pendix L (the B.5.b SDP) into a single Beyond-Design-Basis SDP. The detailed comments provided 15 below highlight the problems created by the staffs chosen alternative, attempting to merge FLEX 16 considerations into the At-Power SDP of Appendix A.

17 2. Basis for the Changes: The draft IMC-0609 Appendix A revision was released to the public without 18 an accompanying update of the basis document (IMC-0308, Attachment 3, Appendix A, last issued 19 June 19, 2012, ADAMS ML11222A063). When the ROPTF inquired about this at the July 31, 2019 20 public meeting, the staff responded that, in lieu of updating the basis document, the staff provided 21 equivalent information in the Background section of draft revised IMC-0609, Appendix A.

22 23 This does not solve the problem of the missing basis document update. This means that many of 24 the changes shown in the draft revision of Appendix A are provided without explanation or basis.

25 This undermines the principle of Clarity that is essential to good regulation. Citing various NRC inter-26 nal Feedback Forms in the documents revision history does not suffice. The internal Feedback 27 Forms are rarely made public, so the contents and internal deliberations on the staffs feedback 28 forms is unavailable to external stakeholders. The public is left with no opportunity to understand 29 the problem the proposed revision is intended to solve, nor the data and analysis that informs the 30 staffs decision on how to solve that problem through the proposed revision.

31 32 The commingling of basis information and background information in the body of the draft revision 33 also deviates from the best practice of maintaining the basis document as the primary source of in-34 formation on why the SDP is what it is. Instead, this draft revision of Appendix A mixes the proce-35 dural how of this SDP with the narrative why behind this SDP.

36 3. Guidance Section Provides No Meaningful Guidance: Section 0609A-02, Background, gives the 37 history of pre-solved tables and advent of SAPHIRE, but little information to address the contents of 38 this SDP. The subsequent section, 0609A-03, labeled Guidance in the Table of Contents but not 39 labeled in the draft provided on July 31, 2019, consists of three sentences. The value this guid-40 ance adds to the document is not apparent.

41 4. Reference to SDP Basis Document: Section 0609A-04, Screening, presents a new third paragraph 42 that discusses screening and ends with declarative statement to See IMC 0308, Attachment 3 for 43 additional information on the basis of the SDP. This statement could appear anywhere in Appendix 44 A, so its appearance in this spot seems intended to have the user look for additional instruction in 45 the text of Attachment 3 that applies to screening. The five mentions of screening in IMC 0308, 46 Attachment 3 do not appear to provide much additional information to help the user of Appendix A.

Page 1 of 4 Revised 20190826

NEI Comments on Draft Revision of IMC-0609, Appendix A and Attachment 4 1 Does the staff intend the user of Appendix A should refer to a specific section of IMC 0308, Attach-2 ment 3 that applies to screening? If so, it would be helpful to specify that section, rather than make 3 a general reference to the entire Attachment 3 in this particular section of Appendix A.

4 5. Basis for Expanded Guidance on LOCA Initiators: The text added to page 3 on the definition of 5 LOCA Initiators appears substantial. If this addition represents long-standing NRC practice, it 6 should be identified as such. If it is documenting a relatively new NRC practice, the basis for this ad-7 dition should be cited. There is no citation or reference given at the point of the added text, leaving 8 the outside reader to guess which of the Feedback Forms or other sources cited in the Revision His-9 tory table addresses this gap.

10 6. Basis for Expanded Guidance on Support System Initiators: As in the comment above on LOCA Ini-11 tiators, in Section 04.01.c of Appendix A, substantially revised and expanded text on Support System 12 Initiators is added without mention of a source, citation or basis.

13 7. Basis for Expanded Guidance on Mitigating Systems: As in the comment above on LOCA Initiators, 14 in Section 04.02 of Appendix A, substantially revised and expanded text on Mitigating Systems is 15 added without mention of a source, citation or basis.

16 8. Definition of Mission Time: In Section 04.02, bottom of page 4, the term mission time is intro-17 duced. The new text on mission time should make clear that the PRA mission time is not the same 18 as the mission time used in Inspection Manual Chapter 0326 for operability determinations and 19 functionality assessments.

20 9. Change in Time Duration for Risk Significant Outage Times: In Section 04.02.a, first full paragraph 21 on top of page 5, new text addresses allowed outage times. The time duration for loss of function of 22 risk significant, non-Technical Specification systems, structures and components (SSCs) is changed 23 from 14 days to three days. What is the basis for this change? This section also says, RICTs [risk-24 informed completion times] may not be applied in retrospect after a degraded condition occurs.

25 This text warrants explanation.

26 10. FLEX Implementation Plan: New item e, Flexible Coping Strategies (FLEX), on page 5 of the draft 27 revision adds a new paragraph describing the origin and three phases of FLEX. The paragraph ends 28 with This information can be found in the licensees FLEX implementation plan. This should refer 29 to the licensees FLEX final integrated plan.

30 11. Basis for Expanded Guidance on Barrier Integrity: As in the comment above on LOCA Initiators, in 31 Section 04.03 of Appendix A, substantially revised and expanded text on Barrier Integrity is added 32 without mention of a source, citation or basis. In particular, Fuel Cladding Integrity is a new topic in 33 this section. What is the basis for the text added here?

34 12. Questions Transferred from Appendix O are Substantially Different: In Exhibit 2, Mitigating Sys-35 tems Screening Questions, the new questions E.2 and E.3 are substantially different from the word-36 ing of questions 2 and 3 in IMC-0609, Appendix O, from which they are derived. In proposing to 37 merge Appendix O into Appendix A, the staff conveyed to external stakeholders in public meetings 38 this spring that the merger would involve merely a copy-and-paste transfer of the Appendix O ques-39 tions into Appendix A. The staff has not documented or explained why it was necessary to funda-40 mentally change the Appendix O questions at this time.

41 a. Partial Loss Added to Scope: The new questions add the term partial loss to the term com-42 plete loss in the original version. This term introduces ambiguity and uncertainty and substan-43 tially expands the scope of issues that might not screen to Green and would be directed to a de-44 tailed risk evaluation. There are already programmatic controls for timely restoration of the Page 2 of 4 Revised 20190826

NEI Comments on Draft Revision of IMC-0609, Appendix A and Attachment 4 1 +1 component. Entering a detailed risk evaluation for loss of the +1 component would be 2 comparable to performing a detailed risk evaluation for every entry into a technical specification 3 condition that has an allowable completion time already determined to be of low risk.

4 b. Resources Applied to Detailed Risk Evaluations: If answered Yes, questions 2 and 3 direct the 5 staff to perform a detailed risk evaluation (per Section 0609A-05). It is not clear why a detailed 6 risk evaluation is necessary for analysis of FLEX equipment that is provided to mitigate beyond 7 design basis events. Additionally, the resorting to a detailed risk evaluation will consume NRC 8 resources to analyze beyond design basis scenarios that are, by definition, very low risk events.

9 In turn, the NRCs initiation of a detailed risk evaluation will trigger a like response from the li-10 censees PRA teams. The result will be a cascade of NRC and licensee resources directed to the 11 analysis of a very low risk situation and away from more safety-significant work, and an out-12 come that adds little or no benefit to public health and safety.

13 13. Model: What model will NRC use to perform a detailed significance evaluation? SPAR models typi-14 cally address only internal events (with limited fire modeling capability). From industrys perspec-15 tive, the SPAR models contain pessimistic reliability and HEP inputs, which could strongly influence 16 the SPAR results involving FLEX issues. Many stations have not incorporated FLEX into their PRA 17 models of record yet, making it difficult to cross-check the SPAR results.

18 14. Why Default to a Detailed Risk Evaluation?: Although plant-specific, FLEX credit in base models 19 generally has a small risk impact. In an engineering condition assessment (e.g., an SDP case), FLEX 20 may have a bigger impact, especially in cases where Station Blackout and loss of power scenarios 21 dominate. Nonetheless, FLEX unavailability (even for a full year) would not reach even a moderate 22 safety significance result.

23 Even in a seismic PRA (SPRA) model, where FLEX is being credited for a beyond design basis external 24 event, the components are not risk significant. This is because seismic importance is generally 25 driven by common cause issues (i.e., correlated failures). By design, FLEX equipment is located and 26 installed to limit the impact of the initiating event (seismic, flood, wind) associated with this hazard.

27 15. FLEX Unavailability: Attempting to quantify FLEX unavailability in the detailed risk evaluation ap-28 pears to be of very low value. Therefore, any screening or significance analysis should be limited to 29 a qualitative analysis (i.e., industry should not be prompted to a science project to quantify).

30 16. Fuel Clad Integrity Called Out in Exhibit 3: Why is Fuel Cladding Integrity called out in three new 31 questions in Exhibit 3?

32 33 34 Comments on Draft Revised Attachment 4 35 1. Missing Basis Information: As above in the comments on Appendix A, Attachment 4 suffers from 36 the same lack of explicit bases for the proposed changes. A raft of internal Feedback Forms is pro-37 vided in the Revision History table, but these non-public sources are no help in explaining why the 38 staff is proposing the changes shown in the proposed revision of Attachment 4.

39 2. Why FLEX in New Item E? In IMC 0609, Attachment 4, revised Table 2, FLEX is called out specifically 40 in the Mitigating Systems Cornerstone column (item E on page 7) but there is already an External 41 Events Mitigating Systems category (Item B on page 6). Why is FLEX singled out as a new item E? It 42 should either be incorporated into Item B or be a subset of item B.

43 In the Initiating Events cornerstone, the external events of interest are limited to fire and internal 44 flooding. Other external events, in the context of the Initiating Events cornerstone, are not Page 3 of 4 Revised 20190826

NEI Comments on Draft Revision of IMC-0609, Appendix A and Attachment 4 1 applicable because the licensee does not have control over these events (e.g., tornado, hurricane).

2 However, the licensee does have control over the systems used to mitigate an external event and 3 that is covered in the Mitigating Systems section (Exhibit 2).

4 3. Mitigating External Hazards Perspective: Any quantitative evaluation of a FLEX issue must be con-5 sidered part of the Mitigating Systems cornerstone, which consists primarily of Internal Events (in-6 cluding internal flooding) and Fire modeling. FLEX was designed and implemented to mitigate Exter-7 nal Hazards (extreme beyond design basis events) and should be evaluated from that perspective, 8 not from the perspective of internal events or fire.

9 4. Logic in Table 3, A.1: The logic of Table 3, Section A, Question 1 is unclear. Why does Question 1 10 direct the user to Appendix A for findings involving defueled conditions or fuel handling issues?

11 5. Logic in Table 3, A.2: Why is the reference to RHR [Residual Heat Removal] replaced with the longer 12 and more ambiguous term the system used to remove residual heat in the Note below Question 13 A.2?

Page 4 of 4 Revised 20190826