ML24151A036
| ML24151A036 | |
| Person / Time | |
|---|---|
| Site: | 07201015 |
| Issue date: | 06/11/2024 |
| From: | Yoira Diaz-Sanabria Storage and Transportation Licensing Branch |
| To: | NAC International |
| References | |
| Download: ML24151A036 (5) | |
Text
NRC FORM 651 U.S. NUCLEAR REGULATORY COMMISSION CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Code of Federal Regulations CONDITIONS This certificate is conditioned upon fulfilling the requirements of 10 CFR Part 72, as applicable, the attached Appendix A (Technical Specifications) and Appendix B (Approved Contents and Design Features), and the conditions specified below:
- 1.
CASK
- a.
Model No. NAC-UMS The NAC-UMS system (the cask) consists of the following components: (1) transportable storage canister (TSC), which contains the spent fuel; (2) vertical concrete cask (VCC),
which contains the TSC during storage; and (3) a transfer cask, which contains the TSC during loading, unloading, and transfer operations. The cask stores up to 24 pressurized water reactor (PWR) fuel assemblies or 56 boiling water reactor (BWR) fuel assemblies.
- b.
Description The NAC-UMS system is certified as described in the Safety Analysis Report (SAR) and in NRCs Safety Evaluation Report (SER) accompanying the Certificate of Compliance. The cask comprises three discrete components: the TSC, the VCC, and the transfer cask.
NRC FORM 651A (3-1999) 10 CFR 72 U.S. NUCLEAR REGULATORY COMMISSION CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Supplemental Sheet 2
of Page
- 1.
- b.
Description (continued)
The TSC is the confinement system for the stored fuel. The TSC assembly consists of a right circular cylindrical shell with a welded bottom plate, a fuel basket, a shield lid, two penetration port covers, and a structural lid. The cylindrical shell, plus the bottom plate and lids, constitute the confinement boundary. The stainless steel fuel basket is a right circular cylinder configuration with either 24 (PWR) or 56 (BWR) stainless steel fuel tubes laterally supported by a series of stainless steel (PWR) or carbon steel (BWR) support disks. The square fuel tubes in the PWR basket include Boral sheets on all four sides for criticality control. The square fuel tubes in the BWR basket may include Boral sheets on up to two sides for criticality control. Aluminum heat transfer disks are spaced midway between the support disks and are the primary path for conducting heat from the spent fuel assemblies to the TSC wall for the PWR basket. A combination of the carbon steel support disks and aluminum heat transfer disks (in a ratio of 2.4 to 1, respectively) are the primary means of conducting heat from the spent fuel assemblies to the TSC wall for the BWR basket. There are three TSC configurations of different lengths for PWR contents and two TSC configurations of different lengths for BWR contents. All PWR and BWR spent fuel assemblies must be intact.
The VCC is the storage overpack for the TSC and provides structural support, shielding, protection from environmental conditions, and natural convection cooling of the TSC during long-term storage. The VCC is a reinforced concrete (Type II Portland cement) structure with a carbon steel inner liner. The VCC has an annular air passage to allow the natural circulation of air around the TSC. The air inlets and outlets take non-planar paths to the VCC cavity to minimize radiation streaming. The spent fuel decay heat is transferred from the fuel assemblies to the tubes in the fuel basket and through the heat transfer disks to the TSC wall. Heat flows by convection from the TSC wall to the circulating air, as well as by radiation from the TSC wall to the VCC inner liner. The heat flow to the circulating air from the TSC wall and the VCC liner is exhausted through the air outlets. The top of the VCC is closed by a shield plug, consisting of carbon steel plate (gamma shielding) and NS-4-FR (neutron shielding), and a carbon steel lid. The lid is bolted in place and has tamper indicating seals on two of the bolts. There are three VCC configurations of different lengths for PWR contents, and two VCC configurations of different lengths for BWR contents.
The transfer cask provides shielding during TSC movements between work stations, the VCC, or the transport cask. It is a multi-wall (steel/lead/NS-4-FR/steel) design and has a bolted top retaining ring to prevent a loaded canister from being inadvertently removed through the top of the transfer cask. Retractable (hydraulically operated) bottom shield doors on the transfer cask are used during loading and unloading operations. To minimize contamination of the TSC exterior and interior of the transfer cask, clean water is circulated in the gap between the transfer cask and the TSC during loading operations. A carbon steel extension ring can be bolted to the top of the transfer cask and used to extend the operational height of a transfer cask. This height extension allows a transfer cask designed for a specific TSC length to be used with the next longer TSC.
NRC FORM 651A (3-1999) 10 CFR 72 U.S. NUCLEAR REGULATORY COMMISSION CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Supplemental Sheet Page 3
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- 2.
OPERATING PROCEDURES Written operating procedures shall be prepared for cask handling, loading, movement, surveillance, and maintenance. The users site-specific written operating procedures shall be consistent with the technical basis described in Chapter 8 of the SAR.
- 3.
ACCEPTANCE TESTS AND MAINTENANCE PROGRAM Written cask acceptance tests and a maintenance program shall be prepared consistent with the technical basis described in Chapter 9 of the SAR.
- 4.
QUALITY ASSURANCE Activities in the areas of design, purchase, fabrication, assembly, inspection, testing, operation, maintenance, repair, modification of structures, systems and components, and decommissioning that are important to safety shall be conducted in accordance with a Commission-approved quality assurance program which satisfies the applicable requirements of 10 CFR Part 72, Subpart G, and which is established, maintained, and executed with regard to the cask system.
- 5.
HEAVY LOADS REQUIREMENTS Each lift of an NAC-UMS TSC, transfer cask, or VCC must be made in accordance with the existing heavy loads requirements and procedures of the licensed facility at which the lift is made. A plant-specific safety review (under 10 CFR 50.59 or 10 CFR 72.48 requirements, if applicable) is required to show operational compliance with existing plant-specific heavy loads requirements. Lifting operations outside of structures governed by 10 CFR Part 50 must be in accordance with Section 3.5 of Appendix B to this certificate.
- 6.
APPROVED CONTENTS Contents of the NAC-UMS system must meet the fuel specifications given in Appendix B to this certificate.
- 7.
DESIGN FEATURES Features or characteristics for the site, cask, or ancillary equipment must be in accordance with Appendix B to this certificate.
- 8.
CHANGES TO THE CERTIFICATE OF COMPLIANCE The holder of this certificate who desires to make changes to the certificate, which includes Appendix A (Technical Specifications) and Appendix B (Approved Contents and Design Features),
shall submit an application for amendment of the certificate.
NRC FORM 651A (3-1999) 10 CFR 72 U.S. NUCLEAR REGULATORY COMMISSION CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Supplemental Sheet Page of UMS UMS
NRC FORM 651A (3-1999) 10 CFR 72 U.S. NUCLEAR REGULATORY COMMISSION CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Supplemental Sheet Page of AUTHORIZATION YOIRA DIAZ-SANABRIA Digitally signed by YOIRA DIAZ-SANABRIA Date: 2024.06.11 13:28:55
-04'00' Attachments:
- 1. Appendix A
- 2. Appendix B June 11, 2024