ML23313A117

October 26, 2023 Summary of Holtec International Pre-decisional Enforcement Conference

ML23313A117
Person / Time
Site:	Holtec
Issue date:	11/21/2023
From:	Tomeka Terry NRC/NMSS/DFM/IOB
To:	Shana Helton Division of Fuel Management
Shared Package
ML23313A116	List: ML23313A117 ML23320A228
References
Download: ML23313A117 (9)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 21, 2023 MEMORANDUM TO: Shana Helton, Director Division of Fuel Management Office of Nuclear Material Safety and Safeguards Signed by Terry, Tomeka FROM: Tomeka Terry, Project Manager on 11/21/23 Inspection and Oversight Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards

SUMMARY

OF OCTOBER 26, 2023, HOLTEC INTERNATIONAL PRE-DECISIONAL ENFORCEMENT CONFERENCE On October 26, 2023, the U.S. Nuclear Regulatory Commission (NRC) staff held a Pre-decisional Enforcement Conference (PEC) hybrid public meeting between the NRC and Holtec International (Holtec) staff. The PEC was requested by Holtec following the issuance of the NRCs Choice Letter EA-23-044. The apparent violations involved: (1) Holtecs failure to obtain certificate of compliance (CoC) amendments prior to implementing proposed design changes to multi-purpose canister (MPC) continuous basket shims (CBS) for four spent fuel cask designs (i.e., MPC 68M-CBS, MPC 32M-CBS, MPC 89-CBS, and MPC 37-CBS basket variants) that resulted in a departure from the method of evaluations described in the HI-STORM 100 and HI-STORM Flood/Wind (FW) final safety analysis reports (FSARs) (as updated) used in establishing the design bases as required by Title 10 of the Code of Federal Regulations (10 CFR) 72.48(c)(2)(viii), Changes, test, and experiments; (2) Holtecs failure to maintain records of changes that included written evaluations that provided an adequate bases for the determination that changing to the MPC CBS basket variants did not require CoC amendments pursuant to 10 CFR 72.48(c)(2), as required by 10 CFR 72.48(d)(1), Changes, tests, and experiments; and (3) Holtecs failure to subject design changes for the MPC 68M-CBS, MPC 32M-CBS, MPC 89-CBS, and MPC 37-CBS basket variants to design control measures commensurate with those applied to the original design, as required by 10 CFR 72.146(c), Design control.

CONTACT: Tomeka Terry, NMSS/DFM 301-415-1488

S. Helton 2 The Choice Letter EA-23-044 was dated September 12, 2023, and is available from the NRCs website, www.nrc.gov, under the Agencywide Documents Access and Management System (ADAMS) Accession No. ML23145A175. A brief summary of the PEC proceedings is enclosed.

Docket No. 72-1014

Enclosures:

1. Pre-decisional Enforcement Conference Summary

2. Meeting Attendees

ML23313A116 (Pkg); ML23313A117 (Meeting Summary);

ML23307A107 (Meeting Transcript); ML23297A232 (NRC Presentation Slides);

ML23297A261 (Holtec Presentation Slides); ML23320A228 (NRC Follow up email)

OFFICE NMSS/DFM NMSS/DFM NMSS/DFM NMSS/MSST NMSS/DFM NMSS/DFM NMSS/DFM NAME TTerry WWheatley ELove MBurgess ARivera-Varona SHelton TTerry DATE 11/15/2023 11/16/2023 11/17/2023 11/17/2023 11/18/2023 11/21/2023 11/21/2023 PREDECISIONAL ENFORCEMENT CONFERENCE

SUMMARY

Certificate of Compliance Holder: Holtec International Facility: Holtec International Advanced Manufacturing Division in Camden, New Jersey Docket No.: 72-1014 EA-23-044 On September 12, 2023, the NRC issued Holtec a Choice Letter EA-23-044 ADAMS Accession No. ML23145A175 describing three apparent violations under consideration for escalated enforcement action in accordance with the NRC Enforcement Policy. The apparent violations involved: (1) Holtecs failure to obtain CoC amendments prior to implementing proposed design changes to MPC CBS for four spent fuel cask designs (i.e., MPC 68M-CBS, MPC 32M-CBS, MPC 89-CBS, and MPC 37-CBS basket variants) that resulted in a departure from the method of evaluations described in the HI-STORM 100 and HI-STORM FW FSARs (as updated) used in establishing the design bases as required by 10 CFR 72.48(c)(2)(viii), Changes, test, and experiments; (2) Holtecs failure to maintain records of changes that included written evaluations that provided an adequate bases for the determination that changing to the MPC CBS basket variants did not require CoC amendments pursuant to 10 CFR 72.48(c)(2), as required by 10 CFR 72.48(d)(1), Changes, tests, and experiments; and (3) Holtecs failure to subject design changes for the MPC 68M-CBS, MPC 32M-CBS, MPC 89-CBS, and MPC 37-CBS basket variants to design control measures commensurate with those applied to the original design, as required by 10 CFR 72.146(c), Design control.

The letter provided Holtec with the opportunity to address the apparent violations identified in the report by either: (1) responding in writing to the apparent violations addressed in the inspection report within 30 days of the date of the letter, (2) request to participant in a Pre-decisional Enforcement Conference (PEC), or (3) participating in an Alternative Dispute Resolution session prior to the NRCs final enforcement decision. In an email dated on September 18, 2023, Holtec requested a PEC.

On October 26, 2023, the PEC was convened at the NRC Headquarters. The purpose was to provide an opportunity for Holtec to provide any information that they would like the NRC to consider in the final enforcement determination, including determining whether an enforcement action is necessary.

The NRC staff provided a presentation on the NRC enforcement process and the apparent violations identified by the NRC staff, which was followed by Holtecs presentation. NRCs presentation is publicly available in ADAMS Accession No. ML23297A232, and Holtecs presentation is also publicly available in ADAMS Accession No. ML23297A261. The NRCs Enclosure 1

official transcript for this meeting is publicly available in ADAMS Accession No. ML23307A107.

A list of the meeting attendees is in Enclosure 2.

Based on Holtecs presentation, the NRC staff asked the following questions and clarifications, and provided Holtec two weeks from the issuance of the transcript to provide answers that the NRC staff could take into consideration as it makes its final determination on the apparent violations. The NRC staff transmitted an electronic copy of the transcript and the questions to Holtec on November 6, 2023 (ADAMS Accession No. ML23320A228).

• QUESTION 1: So, relating to Slide 10, this is your response to Item 1. While there were geometric changes to the model, the first example of Apparent Violation A was that Holtec changed an element of a methods of evaluation (MOE) by using a new modeling assumption to model the bolts with nodal constraints. Is Holtec suggesting that the use of nodal constraints is a geometric change, or a dimensional change or an input change and not an element change? If so, could you elaborate on that?

• QUESTION 2: My next question relates to Slide 12, which is Holtec's response to Item 2. While welds for the previous basket design with the extruded version of the shims are not welded to the shims, the second example of apparent violation A was that Holtec used a new or different MOE by assuming the impact load is directly transferred between the shims and the basket without inducing load in the bolts. Is Holtec suggesting that this assumption is not a new MOE because of the weld location in the previous design? If so, could you elaborate?

• QUESTION 3: My next question also relates to Slide 12. Holtec states that a separate analysis was performed as necessary to demonstrate bolt suitability for the solid shims. Could you explain what that analysis was and what bolt suitability entails? When you say, as necessary, how did you determine when that analysis was necessary? In cases when this analysis was determined to be unnecessary, what was the justification for this? Were these analyses and the decision on whether to perform them part of an MOE approved by the NRC for this application?

• QUESTION 4: My next question relates to Slide 15. That is your response to Item

3. Holtec states that the analysis of both canisters is the same. Which canisters is Holtec referring to? In which analyses? HI-2188448 for MPC-32M, and supplement 79 of HI-20127874 for MPC-68M-CBS? Sorry, that was a question. That was me suggesting that those are maybe the two analyses that you're referring to but seeking clarification for that.

• QUESTION 5: It is the Staff's understanding that MPC-68M-CBS was analyzed as a basket slice in ANSYS while MPC-32M was analyzed as a half-symmetry model in LS-DYNA, among other differences. Is this incorrect? How does Holtec view these analyses as the same?

• QUESTION 6: My next question also relates to Slide 15. Where was the previously approved method for calculating a bilinear material model for MPC-32M discussed? Is it Appendix B of HI-2188448 Revision 0? Which amendment added MPC-32M? Was the FSAR updated to reflect the change in material model for the shims? Why was a bilinear material model developed for MPC-32M shims? Did 2

these shims exceed the yield stress?

• QUESTION 7: My next questions also relate to Slide 15. Holtec mentions performing a finite element analysis with the CBS using an elastic material model.

Did the shim remain in the elastic region in the finite element analysis? If so, why was the bilinear material model needed previously? If not, how is an elastic material model valid for characterizing the behavior of the shims in the finite element analysis? Which results are essentially the same between the elastic CBS model, the bilinear CBS model, and the model for the previous design? And finally, did the elastic and bilinear CBS models include any other changes from the model for the previous design?

• QUESTION 8: My next questions relate to slide 17, which is Holtec's response to Item 4. Did Holtec demonstrate that the primary stresses in the CBS basket shims remain below the yield strength? If so, where is that documented? In the FSAR or Supplement 79 of HI-2012787? If not, which demonstration is referred to in the sub-bullet that is not replaced by the peak stress comparison? Is this how the previous design was analyzed, meaning, did the analysis of the standard shims demonstrate that only the primary stresses were below yield?

• QUESTION 9: More questions on Slide 17. What does Holtec mean by peak stresses in this context? How is Holtec categorizing the stresses as peak or primary, and is that different than the stress categorization in the previous analysis? Why was the peak stress comparison performed?

• QUESTION 10: My next question relates to Slide 19. That's Holtec's response to Item 5. Holtec states that the results for ANSYS Rev. 17 have been shown to be essentially the same. Which results from Rev. 17 were shown to the same as which other results?

• QUESTION 11: My next questions relate to Slide 21. That's Holtec's response to Item 6. Sorry, I don't have new questions here. These would basically be, as Holtec points out, this item is very similar to Item 2, so I would have the same questions for Item 2. This is just related to the FW, whereas Item 2 was for the HI-STORM 100. Then also on Slide 24, as Holtec points out, this item is related to Item 1, so I would have the same questions as I did for Item 1, which were my questions on Slide 10.

• QUESTION 12: So, my next question is for Slide 26. That relates to Holtec's response to Item 8. For the CBS results, were plastic strains limited to areas beyond the active fuel region? What were the structural basket criteria, and how has Holtec demonstrated the CBS baskets meet these criteria?

• QUESTION 13: My next questions relate to Slide 29. This is Holtec's response to Item 9. Was the allowance for basket-to-shell interference added as part of an amendment to the HI-STORM FW system? In which revision of the FSAR was the allowance for basket-to-shell interference added? In which revision to the FSAR was the CBS design added? Which non-CBS baskets have basket-to-shell interference? How did Holtec address this interference, and where is this documented?

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• QUESTION 14: Just one more question, which is in relation to Slide 12 in the presentation. Holtec mentioned the oversized holes in discussing the assumption that the shims aren't in the load path. Were these oversized holds depicted in the drawings or the FSAR at the time of the inspection?

• QUESTION 15: And I have one final question, which relates to Slide 33. Which is Holtec's response to apparent violation C. In Holtec's view, is the tip-over analysis part of the licensing basis for HI-STORM 100 or HI-STORM FW? In Holtec's view, what is the purpose for the tip-over analysis? Why has Holtec submitted a tip-over analysis as part of the FSAR, and where has Holtec demonstrated that no credible events could cause a tip-over?

At the conclusion of the meeting the members of the public were afforded the opportunity to ask questions of the NRC staff or make comments about the issues discussed during the business portion of the meeting (refer to the meeting transcript for questions posed and comments made by the public along with NRC responses). During the question and answer period, a member of the public asked the NRC staff which independent spent fuel storage installation licensees have already loaded spent fuel into canisters with the basket designs discussed in the PEC. The NRC staff committed to include that information in the PEC meeting summary. As of November 20, 2023, the NRC is aware that the following sites have loaded the baskets discussed during the PEC: Arkansas Nuclear One, Browns Ferry, Calvert Cliffs, Clinton, Dresden, FitzPatrick, Hatch, Hope Creek, LaSalle, Limerick, Nine Mile Point, Oyster Creek, Peach Bottom, Perry, Quad Cities, Sequoyah, South Texas Project, Susquehanna, VC Summer, Waterford, and Watts Bar.

The NRC did not actively solicit comments towards regulatory decisions at this meeting.

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Meeting Attendees Name Affiliation Shana Helton U.S. Nuclear Regulatory Commission (NRC)

Jacob Zimmerman NRC Aida Rivera-Varona NRC Earl Love NRC Michele Burgess NRC Patrick Koch NRC Sara Kirkwood NRC Tomeka Terry NRC David Jones NRC Raju Patel NRC Tom Boyce NRC Marlone Davis NRC Zackery Helgert NRC Jeremy Tapp NRC Linda Howell NRC Yen-Ju Chen NRC Yoira Diaz-Sanabria NRC Christian Jacobs NRC Chris Speer NRC Jeremy Smith NRC Jimmy Chang NRC Paula Cooper NRC Mark Henrion NRC Logan Crevelt NRC Norma Garcia-Santos NRC Majorie McLaughlin NRC Aaron Kostick NRC Andrew Hastings NRC Matthew Learn NRC Thomas Winkel NRC Binoy Desai NRC Miranda Ross NRC Zee St. Hillaire NRC Briana DeBoer NRC Jean Fleming Holtec International (Holtec)

Charles Bullard Holtec Kimberly Manzione Holtec Susan Shapiro LEAF of Hudson Valley Carlyn Greene UxC, LLC Michel Lee Council on Intelligent Energy and Conservation Policy Enclosure 2

Name Affiliation Kenn Hunter Constellation Kimberly Hobbs Constellation Christian Williams Constellation Brian Gutherman Gutherman Technical Services, LLC Tammy Morin PSEG Nuclear LLC Mark Oswald South Texas Project Nuclear Operating Company (STP)

Zhilin Dong STP Zita Martin Tennessee Valley Authority (TVA)

Brian Cupp TVA William Andrew Whitener TVA William McCoy TVA Suzanne Leblang Entergy Patricia Cardona Southwest Alliance for a Safe Future Scott Shaeffer Consultant for Holtec International Gabriel Grant Southern Nuclear Company Heath Baldner Member of Public Kalene Walker Member of Public Jacquelyn Drechsler Member of Public SD Smith Member of Public 2