ML24136A192
| ML24136A192 | |
| Person / Time | |
|---|---|
| Site: | HI-STORM 100 |
| Issue date: | 04/18/2024 |
| From: | Holtec |
| To: | Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML24136A188 | List: |
| References | |
| 5021076 | |
| Download: ML24136A192 (1) | |
Text
NRC FORM 651 U.S. NUCLEAR REGULATORY COMMISSION (3-1999) 10 CFR 72 CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Supplemental Sheet Certificate No.
1040 Amendment No.
54 Page 2
of 4
DESCRIPTION (continued)
There are two types of MPCs permitted for storage in HI-STORM UMAX VVM: the MPC-37 and MPC-89. The number suffix indicates the maximum number of fuel assemblies permitted to be loaded in the MPC. The MPC-37 also has an alternative design called the MPC-37 Type 1. Both MPC models have the same external diameter.
The HI-TRAC VW transfer cask provides shielding and structural protection of the MPC during loading, unloading, and movement of the MPC from the cask loading area to the VVM. The transfer cask is a multi-walled (carbon steel/lead/carbon steel) cylindrical vessel with a neutron shield jacket attached to the exterior and a retractable bottom lid used during transfer operations.
The HI-STORM UMAX VVM utilizes a storage design identified as an air-cooled vault or caisson. The HI-STORM UMAX VVM relies on vertical ventilation instead of conduction through the fill material around the VVM, as it is essentially a below-grade storage cavity. For all UMAX designs, aAir inlets and an air outlet allow air to circulate naturally through the cavity to cool the MPC inside except for Version B2 which has no air inlets.
The subterranean steel structure is seal welded to prevent ingress of any groundwater in the MPC storage cavity from the surrounding subgrade, and it is mounted on a stiff foundation. The surrounding subgrade and a top surface pad provide significant radiation shielding. A loaded MPC is stored within the HI-STORM UMAX VVM in a vertical orientation.
HI-STORM UMAX Version MSE is a structurally strengthened embodiment of the VVM engineered for deployment at sites with its Design Basis Earthquake with ZPA in excess of 2.12Gs (resultant horizontal) and up to 1.0G (vertical).
CONDITIONS
- 1. OPERATING PROCEDURES Written operating procedures shall be prepared for handling, loading, movement, surveillance, and maintenance. The users site-specific written operating procedures shall be consistent with the technical basis described in Chapter 9 of the FSAR.
- 2. ACCEPTANCE TESTS AND MAINTENANCE PROGRAM Written acceptance tests and a maintenance program shall be prepared consistent with the technical basis described in Chapter 10 of the FSAR. At completion of welding the MPC shell to baseplate, an MPC confinement weld helium leak test shall be performed using a helium mass spectrometer. This test shall include the base metals of the MPC shell and baseplate. A helium leakage test shall also be performed on the base metal of the fabricated MPC lid. The confinement boundary welds leakage rate test shall be performed in accordance with ANSI N14.5 to leaktight criterion. If a leakage rate exceeding the acceptance criteria is detected, then the area of leakage shall be determined and the area repaired per ASME Code Section III, Subsection NB, Article NB-4450 requirements. Re-testing shall be performed until the leakage rate acceptance criterion is met.
Attachment 3 to Holtec Letter 5021076 Attachment 3 to Holtec Letter 5021076
Programs 5.0 Certificate of Compliance No. 1040 Amendment No. 5 Appendix A 5.0-3 5.0 ADMINISTRATIVE CONTROLS AND PROGRAMS (continued) 5.3 Radiation Protection Program 5.3.1 Each cask user shall ensure that the Part 50 radiation protection program appropriately addresses dry storage cask loading and unloading, as well as ISFSI operations, including transport of the loaded TRANSFER CASK outside of facilities governed by 10 CFR Part 50. The radiation protection program shall include appropriate controls for direct radiation and contamination, ensuring compliance with applicable regulations, and implementing actions to maintain personnel occupational exposures As Low As Reasonably Achievable (ALARA). The actions and criteria to be included in the program are provided below.
5.3.2 As part of its evaluation pursuant to 10 CFR 72.212(b)(5)(iii), the licensee shall perform an analysis to confirm that the dose limits of 10 CFR 72.104(a) will be satisfied under the actual site conditions and ISFSI configuration, considering the planned number of casks to be deployed and the cask contents.
5.3.3 Based on the analysis performed pursuant to Section 5.3.2, the licensee shall establish individual cask surface dose rate limits for the TRANSFER CASK and the VVM to be used at the site. Total (neutron plus gamma) dose rate limits shall be established at the following locations:
- a.
The top of the VVM.
- b.
The side of the TRANSFER CASK
- c.
The outlet vents on the VVM (applicable only for VENTILATED VVM) 5.3.4 Notwithstanding the limits established in Section 5.3.3, the measured dose rates on a loaded VVM or TRANSFER CASK shall not exceed the following values:
- a.
HI-STORM UMAX Standard Lid: 66 mrem/hr (gamma + neutron) on the closure lid of the VVM (see 5.3.8(a) for location description)
HI-STORM UMAX Version B Lid: 22 mrem/hr (gamma + neutron) on the closure lid of the VVM (see 5.3.8(a) for location description)
- b.
3500 mrem/hr (gamma + neutron) on the side of the TRANSFER CASK 5.3.5 The licensee shall measure the TRANSFER CASK and lid VVM surface neutron and gamma dose rates as described in Section 5.3.8 for comparison against the limits established in Section 5.3.3 or Section 5.3.4, whichever Attachment 3 to Holtec Letter 5021076 Attachment 3 to Holtec Letter 5021076