ML25093A237
| ML25093A237 | |
| Person / Time | |
|---|---|
| Site: | 07109378 |
| Issue date: | 04/03/2025 |
| From: | Holtec |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML25093A235 | List: |
| References | |
| 5026012 | |
| Download: ML25093A237 (1) | |
Text
Attachment 1 to Holtec Letter 5026012 Amendment Request 9379-3
SUMMARY
OF PROPOSED CHANGES All changes to the CoC and SAR are marked in the subsequent attachments. Changes that have occurred as part of prior applications are not marked as changes.
Proposed Change #1 Introduce the HI-STAR 100MB Version MSC which changes the layered design of lead, steel and Holtite to a monolithic shield cylinder (MSC) design similar to the HI-STAR 180.
Reason for Proposed Change #1 The HI-STAR 100MB Version MSC is identical to the base design, but has greater structural capacity to withstand the licensing basis impactive and impulsive loadings of Part 71.
Justification for Proposed Change #1 The HI-STAR 100MB Version MSC is a new variant of the HI-STAR 100MB cask, which aligns with previously licensed similar transport cask designs (HI-STAR 180). This cask design is demonstrated to meet all requirements of Part 71 in the newly added Supplement I to the HI-STAR 100MB SAR. This supplement provides licensing drawings and full qualification information for the cask variant.
Proposed Change #2 Include MPC-32M, MPC-24, MPC-32, MPC-68, MPC-68M, MPC-32MCBS, MPC-68M CBS, Diablo Canyon MPC-32, F-32M CBS basket, and F-24M CBS basket as allowable fuel package types.
Reason for Proposed Change #2 The listed MPC types have been certified for storage in the HI-STORM 100 docket, and some have been qualified for transport in the HI-STAR 100 cask. However, all of these MPCs may be stored with high burnup fuel, and therefore are added as contents to the HI-STAR 100MB. The F-32M CBS and F-24M CBS baskets are new designs of the continuous basket shim (CBS) style needed for transportation.
Justification for Proposed Change #2 All the new MPC and basket types are only allowable for use with the HI-STAR 100MB MSC and are therefore included in Supplement I to the HI-STAR 100MB SAR. As with the cask design in proposed change #1, this supplement provides licensing drawings and full qualification information for these MPCs and baskets within the transportation cask.
Proposed Change #3 Inclusion of approaches similar to those approved in Topical Reports for storage casks related to loading flexibility for shielding and thermal patterns.
Reason for Proposed Change #3 The previous approvals for the HI-STAR 100MB included specific, discrete loading patterns for thermal and shielding requirements. The cask can continue to meet safety requirements for a multitude of patterns. To improve licensing efficiency, this application asks for NRC approval of a methodology and acceptance criteria, rather than continued individual applications for discrete patterns.
to Holtec Letter 5026012 Amendment Request 9379-3
SUMMARY
OF PROPOSED CHANGES Justification for Proposed Change #3 The methodology and acceptance criteria laid out in the shielding and thermal chapters provides the identical level of safety as the existing discrete patterns. The cask must continue to meet all requirements and therefore the proposed approach ensures the cask continues to maintain compliance with NRC requirements. Similar approaches have been submitted for storage systems, including the HI-STORM 100 which contains the same canisters being added in proposed change 2, and therefore, this approach maintains consistency between the Part 72 and Part 71 casks.
Editorial Changes The previously named MPC-32M has been renamed as MPC-32M-T to identify it as a design that is only licensed for transportation. The version of MPC-32M added in Proposed Change #2 is a different design that is dual certified design for storage and transportation.