ML20330A239
| ML20330A239 | |
| Person / Time | |
|---|---|
| Site: | 07201015 |
| Issue date: | 12/10/2020 |
| From: | Tomeka Terry NRC/NMSS/DFM/IOB |
| To: | Christopher Regan Division of Fuel Management |
| Terry T | |
| Shared Package | |
| ML20330A237 | List: |
| References | |
| Download: ML20330A239 (6) | |
Text
C. Regan UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 10, 2020 MEMORANDUM TO: Christopher M. Regan, Deputy Director Division of Fuel Management Office of Nuclear Material Safety and Safeguards FROM: Tomeka Terry, Project Manager Inspection and Oversight Branch Division of Fuel Management Tomeka Digitally signed by Tomeka L. Terry L. Terry 16:02:52 -05'00' Date: 2020.12.10 Office of Nuclear Material Safety and Safeguards
SUBJECT:
SUMMARY
OF OCTOBER 20, 2020, NAC INTERNATIONAL PREDECISIONAL ENFORCEMENT CONFERENCE On October 20, 2020, the U.S. Nuclear Regulatory Commission (NRC) staff held a Category 1 Pre-decisional Enforcement Conference (PEC) public webinar meeting between NRC and NAC International (NAC) staff. The PEC was requested by NAC following the issuance of the NRCs Choice Letter EA-20-066. The apparent violations involve: (1) NACs implementation of a design change for the MAGNASTOR Concrete Cask version 5 (CC5) cask without ensuring that design control measures were commensurate with those applied to the original design, as required by Title 10 of the Code of Federal Regulations (10 CFR) 72.146(c), Design control, and (2) NACs failure to obtain a certificate of compliance (CoC) amendment pursuant to 10 CFR 72.244 prior to implementing a proposed design change for the MAGNASTOR CC5 cask that resulted in a departure from the method of evaluation described in the FSAR (as updated),
as required by 10 CFR 72.48(c)(2)(viii), Changes, test, and experiments. The Choice Letter EA-20-066 was dated September 3, 2020, and is available from the NRCs website, www.nrc.gov, under the Agencywide Documents Access and Management System (ADAMS)
Accession No. ML20225A032. A brief summary of the PEC proceedings is enclosed.
Docket No. 72-1015
Enclosure:
PEC Summary CONTACT: Tomeka Terry, NMSS/DFM 301-415-1488
ML20330A237 (Pkg) ML20330A239 (Meeting Summary)
ML20330A238 (Meeting Transcript) E-mail*
OFFICE NMSS/DFM NMSS/DFM NMSS/DFM NMSS NMSS/DFM NMSS/DFM NAME TTerry* WWheatley* JWoodfield* RSun* LCuadrado* CRegan*
DATE 11/23/2020 12/02/2020 12/09/2020 12/10/2020 12/09/2020 12/10/2020 PREDECISIONAL ENFORCEMENT CONFERENCE
SUMMARY
Certificate of Compliance Holder: NAC International Facility: NAC International Corporate Office, located in Norcross, Georgia Certificate of Compliance No..: 1031 Docket No.: 72-1015 EA-20-066 On September 3, 2020, the NRC issued NAC International (NAC) a Choice Letter EA-20-066 (ADAMS Accession No. ML20225A032) describing two apparent violations under consideration for escalated enforcement action in accordance with the NRC Enforcement Policy. The apparent violations involve: (1) NACs implementation of a design change for the MAGNASTOR Concrete Cask version 5 (CC5) spent fuel cask without ensuring that design control measures were commensurate with those applied to the original design, as required by 10 CFR 72.146(c), Design control, and (2) NACs failure to obtain a certificate of compliance (CoC) amendment pursuant to 10 CFR 72.244 prior to implementing a proposed design change for the MAGNASTOR CC5 cask that resulted in a departure from the method of evaluation described in the FSAR (as updated), as required by 10 CFR 72.48(c)(2)(viii), Changes, test, and experiments.
The letter transmitting the inspection report provided NAC 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 11, 2020, (ADAMS Accession No. ML20269A456) NAC requested to participate in a PEC.
On October 20, 2020, a Category 1 PEC public webinar meeting was held between NRC and NAC. The purpose of the meeting was to provide an opportunity for NAC to provide any information that they would like NRC to consider in the final enforcement determination, including determining whether an enforcement action was necessary. The PEC focused on areas such as (1) a common understanding of the facts, root causes and (2) a common understanding of NACs corrective actions taken or planned. No decisions were reached or discussed during the conference. Also, NAC committed to provide NRC staff with additional technical information after the PEC.
The NRC staff provided a presentation on the NRC enforcement process and the apparent violations identified by the NRC staff, which was followed by NAC Internationals presentation.
NRCs presentation is publicly available in ADAMS Accession No. ML20293A403, and NACs presentation is also publicly available in ADAMS Accession No. ML20293A289. The NRCs transcript for this meeting is publicly available in ADAMS Accession No. ML20330A238. A list of the meeting attendees is included in this summary.
Enclosure
The NRC staff asked questions and clarifications based on NACs presentation to which NAC responded, that included the following:
- With regards to NAC presentation, slide 36, it is stated that NAC has performed LS-DYNA analyses explicitly for CC3, CC4, CC5, and CC6 and the resulting accelerations are essentially the same as FSAR CC1 and CC2. Were there any non-conservative results base on those analyses? For the standard and oversized pad?
- With regards to NAC presentation, slide 36, it is stated the NAC verified LS-DYNA was used for all subcontracted site-specific MAGNASTOR implementations. Clarify why LS-DYNA was not used initially for the tip-over evaluation at Palo Verde Generating Station?
- With regards to NAC presentation, slide 36, it is stated that NAC has reviewed earlier cask system designs (NAC-MPC and NAC-UMS) and found FSAR tip over analyses to be consistent with the current MAGNASTOR licensing basis. Clarify what is meant that the tip-over analyses are consistent with the current MAGNASTOR licensing basis?
- With regards to NAC presentation, slide 36, it is stated that NAC has performed an internal assessment of their 72.48 activities with respect to linear scaling or ratioing dispositions. Are the results of this assessment available?
- With regards to NAC presentation, slide 10, clarify why LS-DYNA, the MOE noted in the FSAR, was not run to calculate g-loads?
- With regards to NAC presentation, slide 20 describe what would constitute a significant difference in angular velocity, which would require a cask-specific LS-DYNA analysis?
- With regards to NAC presentation, slide 22, although hand calculations were used to determine the moment of inertia, clarify if LS-DYNA was used to calculate g-loads?
- Clarify when NAC conducted the 72.48 evaluations for CC-3 and CC-4, what was the conclusion of those 72.48 evaluations, and what were the results of the evaluations?
- With regards to NAC presentation, slide 11, explain how the g-load was obtained?
Following the questions and answers session of this meeting, in response to the NRC questions and clarifications sought, NAC committed to provide the following information in writing after the PEC:
- A table that would show the moment of inertia ratios of CC5 to CC1, including their individual magnitudes, when the moment of inertia is calculated assuming a uniform cylinder, LS-DYNA, and Autodesk Inventor method, and
- NACs LS-DYNA run results from analyses that explicitly evaluated CC3, CC4, CC5, and CC6 on the MAGNASTOR FSAR generic storage pad and soil, and
- NACs calculational results that investigated the sensitivity of the g-loads calculated in LS-DYNA when the input angular velocity is varied up or down by 3 percent.
LIST OF ATTENDEES Name Affiliation Christopher Regan U.S. Nuclear Regulatory Commission (NRC)
Leira Cuadrado NRC Jon Woodfield NRC Marlone Davis NRC Robert Sun NRC Lorraine Baer NRC Antonio Rigato NRC Yong Kim NRC Tom Boyce NRC David Jones NRC Haile Lindsay NRC Greg Warnick NRC Tomeka Terry NRC Lee Brookhart NRC Rhex Edwards NRC Linda Howell NRC Matt Learn NRC Earl Love NRC David McIntyre NRC Lorraine Baer NRC Tomeka Terry NRC Kent Cole NAC International (NAC)
Wren Fowler NAC George Carver NAC Marc Griswold NAC Ryan Bailey NAC Doug Jacobs NAC Heath Baldner NAC Robert Helfrich NAC Richard Hendrix NAC Laura Piscetta NAC Jim Puzan NAC Juan Subiry NAC George Vaughan NAC Tim Wilson NAC Carlyn Greene UXC Matt Keene Duke Energy Attachment
Name Affiliation Cheryl Olson Dairyland Power Paul Plante Three Yankees Robert Quinn Westinghouse Dan Stenger Hogan Lovells Jack Boshoven Areva Kevin Braico Pacific Gas & Electric Company 8 anonymous caller*
- Not all meeting attendees were identified by name, in some cases the only identifying information available was a phone number.