ML25043A295
| ML25043A295 | |
| Person / Time | |
|---|---|
| Site: | 07109235 |
| Issue date: | 02/12/2025 |
| From: | Baldner H NAC International |
| To: | Office of Nuclear Material Safety and Safeguards, Document Control Desk |
| References | |
| ED20250026 | |
| Download: ML25043A295 (1) | |
Text
ED20250026 Atlanta Corporate Headquarters 2 Sun Court, Suite 220 Peachtree Corners, GA 30092 Phone 770-447-1144 www.nacintl.com February 12, 2025 U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852-2738 Attn: Document Control Desk
Subject:
Supplement to NAC¶s Request for a Revision for the Certificate of Compliance (CoC) No. 9235 for the NAC-STC Docket No. 71-9235
References:
- 1. Model No. NAC-STC Package, U.S. Nuclear Regulatory Commission (NRC)
Certificate of Compliance (CoC) No. 9235, Revision 25, April 17, 2024
- 2. Safety Analysis Report (SAR) for the NAC Storage Transport Cask (NAC-STC), Revision 21, NAC International, November 2023
- 3. ED20240097, NAC¶s Request for a Revision to Certificate of Compliance (CoC) No. 9235 for the NAC-STC, July 31, 2024
- 4. ED20240122, Supplement to NAC¶s Request for a Revision to Certificate of Compliance (CoC) No. 9235 for the NAC-STC, August 22, 2024
- 5. ED20240120, Supplement to NAC¶s Request for a Revision to Certificate of Compliance (CoC) No. 9235 for the NAC-STC, August 29,2024
- 6. ED20240144, Supplement to NAC¶s Request for a Revision to Certificate of Compliance (CoC) No. 9235 for the NAC-STC, September 18, 2024
- 7. ED20240153, Supplement to NAC¶s Request for a Revision to Certificate of Compliance (CoC) No. 9235 for the NAC-STC, October 23, 2024 NAC International (NAC) hereby submits a request to revise the NAC-STC Certificate of Compliance (CoC) No. 9235, Revision 25 (Reference 1). This submittal contains SAR replacement page 4.2-14, correcting an editorial error in Note 2 of Table 4.2-3. The changes contained herein are common to the proprietary and non-proprietary versions of the NAC-STC SAR.
This proposed SAR revision is numbered to uniquely identify the applicable changed page.
Revision bars mark the SAR text change on the Revision STC-25A page found in Enclosure.
The header of the SAR page indicates Revision 25A and the submittal month and year. In accordance with NAC¶s administrative practices, upon final acceptance of this application, 24A, 24B 24C, 24D and 25A changed pages will be reformatted and incorporated into the next revision of the NAC-STC SAR.
ED20250026 Atlanta Corporate Headquarters 2 Sun Court, Suite 220 Peachtree Corners, GA 30092 Phone 770-447-1144 www.nacintl.com U.S. Nuclear Regulatory Commission February 12, 2025 Page 2 of 2 If you have any comments or questions, please contact me on my direct line at 678-328-1236.
Sincerely, Heath Baldner Director, Licensing Engineering
Enclosures:
+/-SAR Replacement Page, NAC-STC SAR, Supplement 05, Revision 25A to ED20250026 Page 1 of 1 ED20250026 LOEP and SAR Changed Pages NAC-STC SAR, Supplement 05, Revision 25A Docket No 71-9235 NAC International February 2025
NAC-STC SAR February 2025 Docket No. 71-9235 Revision 25A 4.2-14 Table 4.2-3 Leak Rate and Leak Test Sensitivity: Normal Conditions Leak Rate (cm3/sec)
Contents O-rings Vol. Activity (TBq/cm3)
Allowable (L)
Air Reference (LR)
Test Sensitivity LBU Viton 4.8E-06 8.8E-05 9.4E-051 4.7E-051 HBU Viton 6.3E-06 2.7E-06 2.6E-062 1.3E-062
- 1. The corresponding helium test leak rates and leak test sensitivities for directly loaded LBU fuel are 1.1 10-4 cm3/sec and 5.7 10-5 cm3/sec, respectively, at standard conditions.
- 2. The corresponding helium test leak rates and leak test sensitivities for directly loaded HBU fuel are 4.0 10-6 cm3/sec and 2.0 10-6 cm3/sec, respectively, at standard conditions.
Table 4.2-4 Cask Free Volumes and Pressures: Normal and Accident Conditions Contents LBU, 26 Assemblies HBU, 20 Assemblies Cask Operating Condition Normal Accident1 Normal Accident1 Free Gas Volume (liters)2 7440 7540 7200 7280 Pressure (atm)2 1.79 5.18 1.76 5.33 Average Gas Temperature (K) 505.0 675.0 505.0 675.0
- 1. The accident condition for this analysis is 100% rod failure in combination with a fire accident that raises the cask temperature. This hypothetical dual-failure accident conservatively maximizes both available releasable material and cask pressure.
- 2. Bounding values were chosen for free volume (minimum) and pressure (maximum). This conservatively minimizes free volume and capillary diameter.