ML19214A127
| ML19214A127 | |
| Person / Time | |
|---|---|
| Site: | 07109377 |
| Issue date: | 08/08/2019 |
| From: | Pierre Saverot Spent Fuel Licensing Branch |
| To: | Christopher Regan Spent Fuel Licensing Branch |
| Saverot P | |
| Shared Package | |
| ML19214A126 | List: |
| References | |
| EPID L-2019-LRM-0029 | |
| Download: ML19214A127 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 8, 2019 MEMORANDUM TO: Christopher M. Regan, Deputy Director Division of Spent Fuel Management Office of Nuclear Material Safety and Safeguards FROM: Pierre Saverot, Project Manager /RA John McKirgan Acting for/
Spent Fuel Licensing Branch Division of Spent Fuel Management Office of Nuclear Material Safety and Safeguards
SUBJECT:
SUMMARY
OF JULY 30, 2019 MEETING WITH TN AMERICAS LLC
Background
On July 30, 2019, a Category 1 public meeting was held at the U.S. Nuclear Regulatory Commission (NRC) headquarters in Rockville, MD, between the NRC staff and representatives from TN Americas LLC (TN), Orano Federal Services, DOMINION ENERGY, and EPRI to discuss the licensing of the TN-32B HBU cask selected to support the U.S. Department of Energy (DOE)/EPRI high burnup cask research and development project. The July 30, 2019, meeting was noticed on May 29, 2019 (Agencywide Documents Access and Management System Accession No. ML19165A078).
The meeting attendance list and the presentation are provided as Enclosure Nos. 1 and 2, respectively.
Discussion The TN-32B HBU cask has been loaded with 32 PWR high burn up spent fuel assemblies, with four different cladding types, and placed in storage in November 2017, under certificate of compliance (CoC) No. 72-1021. Fuel assembly temperatures are monitored by thermocouples installed through the closure lid. TN Americas, LLC will be submitting, in the 3rd quarter of 2020, an application for a Part 71 CoC to support a one-time shipment of this TN-32B HBU cask in the 2027 timeframe. There are unique conditions specific to this demonstration cask, including the effect of thermocouple lance assemblies on the structural, thermal, and shielding evaluations, the criticality evaluation with new, i.e., not burnable, poison rod assemblies, etc.; but the meeting discussions focused on the impact limiters that have to be designed and manufactured, and the metallic containment boundary leakage rate test results to support compliance with regulations.
CONTACT: Pierre Saverot, NMSS/DSFM 301-415-7505
C. Regan TN is proposing to benchmark an LSDYNA model to the TN-40 1/3 scale wood impact limiter free drop tests to design an impact limiter with foam for the TN-32B package; TN claims the work done on foam impact limiters for the TRUPACT III package and a fresh fuel MOX package can be applicable and would provide temperature dependent compression curves and materials data with test results in the application to support the structural model. Staff questioned this approach noting that (i) LSDYNA was not used for the TN-40 modeling and, therefore, benchmarking may not be applicable from a quasi-static model to a 1/3 scale model, (ii) using foam in the impact limiters raises both characterization and materials questions, e.g., TN will need to characterize and demonstrate foam behavior in the hypothetical accident condition (HAC) fire test, and assess how the overall performance of the package is affected, (iii) TN will have to show, through materials testing, the similarity of the material properties of the foam and the wood with respect to stress-strain curves and strain rate effects, (iv) TN would have to show that the remaining portion of the impact limiter does not affect the foams performance; if any optimization of the internal structure of the impact limiter has to be done, this question would remain unanswered. Staff also indicated that the design of a foam impact limiter for a spent fuel package may be difficult to derive from data obtained from the TRUPACT III, a totally different package, that the impact limiter may bottom out and lock up, and that such modeling is likely to be challenging to justify by the applicant.
The input provided by the applicant on the metallic containment boundary leakage rate test results was well received. However, staff requested a number of clarifications on: (i) the impact of the 30-foot drop and puncture test on the integrity of the welds or containment boundary, (ii) the thermocouple lance assembly as being part of the containment boundary and the details on the sealing of the thermocouple lance assembly penetration, (iii) the modifications made on the closure lid and the portions that are part of the containment boundary, (iv) the inclusion of the 2-inch thick puncture resistant steel plate as part of the containment boundary and the type of material for this plate, (v) the sealing of the two drilled holes that penetrate the containment boundary, (vi) the measurement of helium during the tests when there is no helium in the cavity, and (vii) the tests which did or did not have helium in the cavity.
Staff noted that, if published prior to the submittal of the application, the applicant should consider the release fractions in NUREG-2224, Dry Storage and Transportation of High Burnup Spent Nuclear Fuel, and not those of NUREG/CR-6487 as indicated in the presentation. Staff said also that the TN-32B closure bolts are the subject of an ongoing review of North Annas 10 CFR 72.48 evaluation to remove ASME fracture toughness requirements for those bolts (for the storage license). The bolts, which had failed the ASME toughness criteria, continue to perform all their design functions, but are considered nonconforming by staff until additional testing and a revision of the 10 CFR 72.48 evaluation are both completed. Dominion Energy confirmed that a new material will be tested at higher temperatures and the minimum service temperature will be confirmed.
Staff expressed the view that, while structural data (vibration) exists for shipments, there is no thermal data during transport of high burnup fuel. While staff has a high level of confidence that what happens thermally during transport can be well predicted, it would be very helpful to obtain such empirical data to bridge the knowledge gap between temperature data before and after shipments. Staff said that the public at large will perceive that DOE has been willing to do all it could to obtain thermal data that, up to now, does not exist.
The TN-32B HBU cask demonstration project is a unique and challenging case as it encompasses many elements that are outside the ordinary. Staff said it will remain open to some outside the box proposals from the applicant and that it could commit to also do some
C. Regan outside the box thinking to come to a satisfactory safety finding for this Part 71 licensing action. Staff made no regulatory commitment during the meeting.
Docket No. 71-9377 EPID L-2019-LRM-0029
Enclosures:
- 1. Meeting Attendees
- 2. Presentation
C. Regan
SUBJECT:
SUMMARY
OF JULY 30, 2019 MEETING WITH TN AMERICAS LLC, DOCUMENT DATE: August 8, 2019 DISTRIBUTION: SFST r/f, M. Layton, RPowell, RI BBonser, RII MKunowski, RIII JKatanic, RIV G:\SFST\Saverot\71-9377 TN-32\meeting summary July2019.doc; NRC HBU Meeting 7-30-19 final.pdf ADAMS Package No.: ML19214A126 Memo: ML19214A127 OFC: SFM E SFM C SFM NAME: PSaverot SFigueroa JMcKirgan DATE: 07/31/2019 08/02/2019 08/08/2019 OFFICIAL RECORD COPY
Meeting Between TN Americas LLC and the Nuclear Regulatory Commission July 30, 2019 Meeting Attendees NRC/NMSS/DSFM Pierre Saverot Antonio Rigato JoAnn Ireland Chris Bajwa Jimmy Chang David Tang Ricardo Torres Jorge Solis EPRI Jeremy Renshaw Keith Waldrop Orano Federal Services Gary Clark Don McGee John McEntire Dominion Energy David Tomlinson Brian Vitiello Eric Jones TN Americas Don Shaw Peter Vescovi Enclosure 1