ML19347D100
| ML19347D100 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 03/02/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19347D099 | List: |
| References | |
| NUDOCS 8103110028 | |
| Download: ML19347D100 (2) | |
Text
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UNITED STATES E
w [',i NUCLEAR REGULATORY COMMISSION
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s-SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SHIPPING CASK LIFTING DEVICE VERMONT YANKEE NUCLEAR POWER CORPORATION VERft0NT YANKEE NUCLEAR POUER STATION DOCKET N0. 50-271 Introduction Our letter dated January 28, 1977, which transmitted Technical Specification changes and our Safety Evaluation concerning the Vernont Yankee Nuclear Power Station (VYNPS) reactor building crane codifications stated that, prior to any cask movement, a description and evaluation of the cask lifting devices should be submitted for our review and approval. On February 11, 1981, the Vernont Yankee Nuclear Power Corporation (VYNPC) submitted a description and evaluation' of a lifting device to be used with the Chem-Nuclear System, Inc. CNS 4-45 cask.
Evalua tion Paragraphs '3.12 and 4.12 of Goerating License DPR-28 for the VYNPS require that when the Reactor Building crane is used to lift a load over the fuel pool, redundancy of the lifting device should be provided such that the loac will not be dropped in the event of a single failure in the lifting system.
The plant is planning to dispose of sone activated reactor components. The Chem-Nuclear System Inc. CNS 4-45 cask will be used to contain those reactor components, and the Reactor Building crane and the proposed lifting device will be used to transfer the cask and its contents across the fuel pool.
The lifting device of the Reactor Building crane is compatible with both the CNS 4-45 cask and the redundant crane hook. The cask is equipped with four lifting trunnions, two at-the top and two at the bottom. The lifting
- device consists of two lifting rigs. The primary lifting rig couples the
. top cask trunnions to one hook of the reactor building crane while the secondary lifting rig couples the bottom cask trunnions to a second hook J
of the reactor building crane. The crane.is single failure proof, it is equipped with redundant blocks.
Each of the two lifting. rigs is designed to handle 210,000 lbs. based on the' yield. point strength, and will te tested preoperationally by a load of 87,500'1bs. The loaded cask will weigh 67,050-lbs.
During the lif ting,
.both rigs will share the cask load.
In the event of the failure of one rig, the.other one will be able to take up the additional load with capacity to spare. There would be no load displacement.
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- 2 Conclusion t
The proposed lifting device, when coupled with the reactor building crane, provides two independent load carrying paths. Each of the two paths is capable of handling 210,000 lbs. based on yield point strength, and has been successfully tested at 87,500 lbs. Since the cask with its contents weighs 67,500 lbs. and will be handled by the two loa-J carrying paths together, the entire load carrying and lif ting set-up is single failure proof. -The use of this proposed lifting device for the disposal of the reactor components over the fuei pool, as in the YYliPC letter dated February 11,~1981, is acceptable.
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