ML22046A241
| ML22046A241 | |
| Person / Time | |
|---|---|
| Site: | 07109386 |
| Issue date: | 02/16/2022 |
| From: | Pierre Saverot Storage and Transportation Licensing Branch |
| To: | Geoffrey Miller Division of Fuel Management |
| P SAVEROT NRC/NMSS/DFM/STLB 3014157505 | |
| Shared Package | |
| ML22046A240 | List: |
| References | |
| EPID L-2021-NEW-0009 | |
| Download: ML22046A241 (7) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 February 16, 2022 MEMORANDUM TO: Geoffrey Miller, Acting Deputy Director Division of Fuel Management Office of Nuclear Material Safety and Safeguards Signed by Saverot, Pierre FROM: Pierre Saverot, Project Manager on 02/16/22 Storage and Transportation Licensing Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards
SUBJECT:
SUMMARY
OF FEBRUARY 10, 2022, MEETING WITH NATIONAL NUCLEAR SECURITY ADMINISTRATION
Background
On February 10, 2022, an Observation Public Meeting was held by teleconference between the U.S. Nuclear Regulatory Commission (NRC) staff and representatives from the National Nuclear Security Administration (NNSA), Holtec International (Holtec), Tennesse Valley Authority (TVA),
Savannah River Site (SRS), U.S. Department of Energy (DOE), and Pacific Northwest National Laboratory (PNNL) to discuss a partial request for supplemental information (RSI) for the Model No. HI-STAR PBT package. Pre-application meetings were held on August 20, 2019, March 31 and August 31, 2021. NNSA submitted an application for a Certificate of Compliance by letter dated October 13, 2021 (Agencywide Documents Access and Management System [ADAMS]
Accession No. ML21287A133).
This Observation Public Meeting was noticed on January 24, 2022 (ADAMS Accession No. ML22024A175). The attendance list and the publicly available presentation slides are provided as Enclosure Nos. 1 and 2, respectively.
Discussion The Model No. HI-STAR PBT package will be used for road transport of Tritium Producing Burnable Absorber Rods (TPBAR) from the Watts Bar Units 1 and 2 to the Tritium Extraction Facility at the Savannah River site CONTACT: Pierre Saverot, NMSS/DFM 301-415-7505
G. Miller 2 By letter dated January 27, 2022 (ADAMS Accession No. ML22026A527), NNSA received the results of staffs partial acceptance review which was focused on any supplemental need for physical testing of the new impact limiter design.
Staff started the meeting by quoting 10 CFR 71.41(a), which states that a package must be evaluated by subjecting a specimen or scale model to a specific test, or by another method of demonstration acceptable to the Commission, as appropriate for the particular feature being considered. The staff has never accepted a new design without it being tested (the HI-STAR 100 and the HI-STAR ATB-1T are perfect examples of new designs by Holtec that were physically tested at staffs request). As stated in 10 CFR 71.41(a), the staff also could determine that an approach through LS-DYNA modeling only (another method of demonstration) could be acceptable for packages of similar designs because of: (i) the high degree of similarity between the geometry and materials of construction of new impact limiter designs (e.g., HI-STAR 180, HI-STAR 180D, HI-STAR 190, HI-STAR 100MB) referencing a previously tested and approved impact limiter (e.g., HI-STAR 100), and (ii) because the applicant had a complete set of physical testing data for the previously tested, reviewed, and approved impact limiter design (HI-STAR 100 in that case).
The NNSA application that was submitted does not meet the threshold of providing benchmarking that would generate analytical results consistent with actual physical testing results. The applicant used test results, from the 1980s, for the NUPAC-125B package, a totally geometrically dissimilar package, for the end drop only, coupled with test results of a non-NRC certified HI-STAR 63 package for a very limited range of drop orientations, along with manufacturers tests for foam specimens (1-inch cubes). As such, the application does not provide a full set of test data - as required - that could be used in selected benchmarking tests and does not provide, with a reasonable level of confidence, all relevant behavior data for the proposed foam impact limiter of the HI-STAR PBT package. Staff also expressed concerns on the lack of data pertaining to the PBT impact limiter stainless steel skin seam welds and the extent of seam splitting occurrence. Staff also said that the application, through the reports cited on foam data, does not provide an accurate representation of the foam material properties and their connection to the thermal analyses, as well as the description in the safety analysis report (SAR) was lacking. Since results from hypothetical accident conditions (HAC) structural analyses and testing have an impact on HAC thermal analyses and testing, staff said that it cannot verify the thermal model of the impact limiter material, as presented, while fire test results of a full-scale foam impact limiter would best demonstrate the behavior of the foam.
Staff cautioned the applicant on its proposed resolution of the RSIs, i.e., an approach that would not involve testing of this new impact limiter design. While the approach presented by Holtec is not unreasonable at face value (although with additional material testing), the key required attribute of a similarity argument and a link to representative tests to benchmark a highly similar design (like it was the case between the HI-STAR 100 and the HI-STAR 180 for example) would still be missing.
Staff reiterated that any new design requires testing because, during testing, something unexpected will happen (i.e., good or bad) that is never seen in LS-DYNA. An applicant always learns something from testing its new package design that was not anticipated or expected: in this case, it is clear that the internal structure (absence of radial stiffener) of the HI-STAR PBT impact limiter is different from those previously benchmarked and one cannot compare impact limiters of different shapes; testing is also required to determine how much seam splitting occurs
G. Miller 3 and improving the geometry of the weld, as proposed by Holtec, will never properly capture such phenomena.
Staff said that there is still substantial work needed for this application to be accepted for review:
(i) there are currently gaps in the required structural testing, (ii) gaps in the current thermal analysis (assumptions made for the analyses are not justified or supported in the application, generic or exact material specifications or range of properties, references presented are not appropriate for modeling, incomplete descriptions in the calculation packages), and (iii) gaps in understanding Part 71 regulations.
Full scale testing is a direct path to qualification of the package as it will provide benchmarking with analytical results consistent with results produced in a physical test, address the strain rate effects of the foam, and the effect of confining the foam material in a stainless-steel skin. Staff said that, in the currently Holtec proposed resolution without testing, the burden will always remain on the applicant to prove that their model can be verified; linking test results of geometrically dissimilar designs to a new design will require several iterations to put all pieces together and obtain alignment for staff to perform a regulatory determination.
Staff reiterated the need for a quality submittal as a prerequisite for an efficient review to be performed in a timely manner and said that the applicant needs to assess the most expedient path forward for regulatory certainty.
No regulatory commitments were made during this meeting.
Docket No. 71-9386 EPID L-2021-NEW-0009
Enclosures:
- 1. Meeting Attendees
- 2. Presentation Slides
G. Miller 4
SUBJECT:
SUMMARY
OF FEBRUARY 10, 2022, MEETING WITH NATIONAL NUCLEAR SECURITY ADMINISTRATION. DOCUMENT DATE:
February 16, 2022 Distribution:
SHelton, NMSS ADimitriadis, RI BDesai, RII DHills, RIII GWarnick, RIV ADAMS No.: ML22046A240 (Pkg) ML22046A241 (Ltr w Enc1) ML22046A242 (Enc2_
OFC NMSS/DFM NMSS/DFM NMSS/DFM NAME PSaverot SFigueroa YDiaz-Sanabria DATE 02/11/2022 5/16/2022 2/16/2022 OFFICIAL RECORD COPY
Meeting Between National Nuclear Security Administration and the Nuclear Regulatory Commission (NRC)
February 10, 2022 Meeting Attendees NRC/Office of Nuclear Materials Safety and Safeguards (NMSS)/ Division of Fuel Management (DFM)
Shana Helton Pierre Saverot Patrick Koch JoAnn Ireland Jason Piotter Loren Howe Darrell Dunn HOLTEC INTERNATIONAL Prabhah Venkat Kishore Gangadharan Chuck Bullard John Zhai Daniel Thomas Chuck Bullard Raja Maheedhara Abrar Mohammad Brian Seawright Kimberly Manzione Debu Majumdar Myron Kaczmarsky Ryan Konop Pacific Northwest National Laboratory (PNNL)
Laurie Martin Randall Storms Harold Adkins Laura Hay Brian Koeppel Dean Paxton National Nuclear Security Administration (NNSA)
Kathy Schwendenman Becky Sipes Urszula Christner Audrey Nguyen Nanette Founds Samina Shaikh Maureen Holloway Samantha Winkle Enclosure 1
U.S. Department of Energy (DOE)
James Shuler Lawrence Gelder Tennessee Valley Authority (TVA)
Jaycen West Carla Borelli Kimberly Moncus Jeffrey McGuire Savannah River Site (SRS)
Louis Boone Bob Snyder Kevin Sessions Public Carlyn Greene Enclosure 1
ML22046A240; Memo ML22046A241 OFFICE NMSS/DFM/STLB NMSS/DFM/STLB NMSS/DFM/STLB NMSS/DFM/STLB NAME PSaverot PS SFigueroa SF YDiaz-Sanabria YD PSaverot PS DATE Feb 15, 2022 Feb 16, 2022 Feb 16, 2022 Feb 16, 2022