ML20006B316
| ML20006B316 | |
| Person / Time | |
|---|---|
| Site: | 07109183 |
| Issue date: | 01/29/1990 |
| From: | Wells A NAC INTERNATIONAL INC. (FORMERLY NUCLEAR ASSURANCE |
| To: | Macdonald C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| Shared Package | |
| ML20006B317 | List: |
| References | |
| AHW-90-12EDS, NUDOCS 9002010356 | |
| Download: ML20006B316 (3) | |
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Suite 200 No ross Georgia 30092 FX 4 4) 74797 i.,%.,,.....
8 Zunch, Switzerland Tek: 5727s January 29, 1990 AHW/90/12/EDS
- VIA FEDERAL EXPRESS---
Mr. Charles E. MacDonald, Chief Transportation Branch NMSS:SGTB, Mail Stop WF4E4 U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852
Dear Mr. MacDonald:
Nuclear Assurance Corporation hereby requests an amendment to the NAC 1/NFS-4 cask, Certificate of Comnliance 9183, Revision 9, to update the design of the cask basket (liner) and containers for failed metallic fuel rods.
The NAC 1 is currently licensed to carry up to ten encapsulated (defective) rods.
NAC has determined that only six failed rods at most can be inserted into the fuel basket because of space requiremants caused by bowing of the rods.
The revision requested does not change any other fuel parameters. NAC requests that the Certificate be modified to limit the cask contents to six failed rods or less in sealed canisters shipped in either the six failed rod configuration or three failed rod configuration. Drawings of the two canister types and the associated two basket types are attached.
The container used to ship the fuel will be a sealed, dry aluminum canister.
The fuel is loaded in the canister under water, and the water is blown out with dry compressed air. The canister is vacuum dryed after the water is blown out and the canister is backfilled with dry air. A check valve is used at tre bottom-of the can to prevent water from re-entering the can once it is dry.
A sealed plug is ) laced over the check valve after the drying operation to insure that the chec( valve cannot open inadvertantly during shipment.
These precautions are employed to insure that fuel material will not escape the container if the cladding is badly failed, and to insure that the cask cavity is not contaminated.
The dryed, sealed canisters are dry-loaded into the NAC-1/NFS 4 cask via a transfer cask in the reactor facility in the same fashion as intact fuel.
Two fuel basket designs have been prepared to accept the failed fuel: a six rod capacity version and a three rod capacity version. The three rod version allows a larger diameter sealed canister for badly failed fuel. The check valve and plug arrangement, as well as the handling and drying procedures, are identical for the smaller and larger diameter canisters. Only one rod is placed in one canister, regardless of the type of container used.
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January 29, 1990 Page 2 A check for $150.00 is enclosed for -this amendment in accordance with 100FR170.31. Please contact me if you have any questions or require additional information.
Sincerely.-
NOCLEAR ASSURANCE CORPORATION Alan H. Wells, PF0 Chief Engineer Engineering Design Services AHW/kt enclosure-l i
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