ML24029A069
| ML24029A069 | |
| Person / Time | |
|---|---|
| Site: | 07109377 |
| Issue date: | 01/30/2024 |
| From: | Pierre Saverot Storage and Transportation Licensing Branch |
| To: | Shaw D TN Americas LLC |
| References | |
| EPID L-2021-NEW-0010 | |
| Download: ML24029A069 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 January 30, 2024 Don Shaw, Licensing Manager TN Americas LLC 7160 Riverview Drive, Suite 200 Columbia, MD 21046
SUBJECT:
SECOND REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE MODEL NO. TN-32B PACKAGE
Dear Don Shaw:
By letter dated August 19, 2021 (Agencywide Documents Access and Management System Package Accession No. ML21231A189), TN Americas LLC submitted an application for approval of the Model No. TN-32B package. The application was accepted for review on October 21, 2021. On June 14, 2023, TN Americas LLC submitted its responses to the U.S.
Nuclear Regulatory Commission staffs request for additional information (RAI) letter dated May 22, 2022 (ML22137A289).
The staff has determined that further information is needed to complete its technical review.
The information requested is listed in the enclosure to this letter. We request you to provide this information by February 14, 2024.
Please reference Docket No. 71-9377 and Enterprise Project Identifier (EPID) No. EPID L-2021-NEW-0010 in future correspondence related to this request.
Sincerely, Pierre M. Saverot, Project Manager Storage and Transportation Licensing Branch Division of Fuel Management Office of Nuclear Material Safety and Safeguards Docket No. 71-9377 EPID L-2021-NEW-0010
Enclosure:
RAI Signed by Saverot, Pierre on 01/30/24
ML24029A069 OFFICE NMSS/DFM NMSS/DFM NMSS/DFM NAME PSaverot YKim TBoyce DATE 01/23/2024 1/29/2024 1/29/2024 OFFICE NMSS/DFM NMSS/DFM NMSS/DFM NAME WWheatley YDiaz-Sanabria SHelton DATE 1/30/2024 1/30/2024 1/30/2024
Enclosure Second Request for Additional Information Docket No. 71-9377 Model No. TN-32B Package By letter dated August 19, 2021 (Agencywide Documents Access and Management System Package Accession No. ML21231A189), TN Americas LLC submitted an application for approval of the Model No. TN-32B package. The application, which is for a one-time transportation of the U.S. Department of Energy - Electric Power Research Institute High Burnup (HBU) Demonstration Project Cask, was accepted for review on October 21, 2021 (ML21291A263).
On August 19, 2022, and subsequently on June 14, 2023, TN Americas LLC submitted its responses to the U.S. Nuclear Regulatory Commission staffs request for additional information (RAI) letter dated May 22, 2022 (ML22137A289).
This second RAI identifies information needed by the staff to complete its review of the application.
Each individual RAI describes information needed by the staff to complete its review of the application and to determine whether the applicant has demonstrated compliance with the regulatory requirements of Title 10 of the Code of Federal Regulations (10 CFR) Part 71.
CHAPTER 2 STRUCTURAL AND MATERIALS REVIEW:
2-1 Justify the property changes made to the wood materials in the LS-DYNA package models.
The changes to the balsa wood material model made in response to RAI 2-3 were acceptable. However, multiple other changes (unrelated to the RAI) were made to the redwood and balsa wood *MAT_MODIFIED_HONEYCOMB material models for the hypothetical accident conditions (HAC) cold package drop models. The approach and justification for these additional changes are not adequately described.
The full compaction (lockup) strains are 60% and 80% of the strain, at which wood material is fully compressed and lost its ability to absorb more impact energy, for redwood and balsa wood, respectively, as identified in section 2.12.9.2.6 and Assumption 4 in section 2.12.9.3. The SAR Rev 0c indicates that the relative volume at full compaction VF was varied in the models to match the g-loads from the TN-40 physical drop tests as described briefly in section 2.12.9.2.6, but changing this value is inconsistent with the basic material definition. The VF value was changed to 0.01 for all wood materials in the cold end drop, but three different values were used with the cold side drop.
Additional property changes were also simultaneously made without explanation or justification. If changes were made selectively for different drop orientations to better match the TN-40 test accelerations, such model changes could be in a non-conservative direction that may not capture the actual maximum accelerations of the TN-32B package (due to any inherent design differences) at each orientation. The changes included:
assignment of the perpendicular-to-grain and parallel-to-grain load curves for the cold balsa (Material #12) and cold redwood (Material #17) was updated, but the material would be expected to have only a single direction assigned for the parallel-to-grain load curve (which is significantly stronger than the other directions) as described in section 2.12.9.2.6, no basis is provided for the 50% shear strain element erosion criteria used for the balsa and redwood in the cold end drop model, no basis is provided for reducing the maximum strengths of the redwood load curves, and no basis is provided for the material changes to the redwood with grain parallel to package axis (Material #17) in the cold end drop (i.e., reduced fully-compressed elastic modulus, zero fully-compressed Poisson ratio, yield stress of 5400 psi).
Additionally, acceleration values for the TN-40 Scaled Drop Test Results in Table RAI 2-3-2 match the results for the Test column of Table 2.12.9-17 in the Rev 0c SAR changes, but no explanation is provided why these differ from the Test column in Table 2.12.9-17 in the Rev 0a SAR changes.
Explain the process used to vary the material properties for the redwood and balsa in the LS-DYNA models, provide justification for the values changed, and provide an explanation of the TN-40 test values used for benchmarking.
This information is needed by the staff to determine compliance with 10 CFR 71.73(c)(1).
2-2.
Justify the change of allowable for the impact limiter tie-rods.
The change to the tie-rod modeling approach made in response to RAI 2-5 was acceptable. The tie-rod allowable stress value used in the Rev 0c SAR was changed to show that the majority of tie-rods do not fail (section 2.12.9.6.11). Previously, the limit was 87.5 ksi based on American Society of Mechanical Engineers (ASME) Level D service limits of a bolted joint (section 2.12.9.6.11, SAR Rev 0a), but the updated calculation uses the ultimate strength of 125 ksi.
Provide a justification for use of the ultimate strength versus the more conservative ASME allowable.
This information is needed by the staff to determine compliance with 10 CFR 71.73(c)(1).