ML20148F285

Diiscusses Util 740913 & 1105 Evaluation Results of Postulated Spent Fuel Shipping Cask Drop Accidents.Addl Info Required Re Yard Crane Sys Mods Final Details by 750328,to Complete Review of Proposed Approach of Sys Upgrading

ML20148F285
Person / Time
Site:	Yankee Rowe
Issue date:	02/07/1975
From:	Goller K Office of Nuclear Reactor Regulation
To:	Andognini G YANKEE ATOMIC ELECTRIC CO.
References
NUDOCS 8011040742
Download: ML20148F285 (3)

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, , FEB 7 1975 1

Docket No. 50-29 i

.j Yankee Atomic Electric Company

ATT't : Mr. G. Carl Andognini, Assistant

to the Vice President THIS DOCUMENT CONTAINS 20 Turnpike Road POOR QUAUTY PAGES

}j Westboro, Maspachusetts 01581 s

i Gentlenen:

l Your letters dated September 13 and November 5, 1974, presented the results of Yankee's evaluation of postulated spent fuel shipping cask drop accidents at Yankee-Rowe, to determina the possible damage to safety related features and to assess the probability of occurrence

_z of these postulated events. ,

A Your evaluation has shown that if the spent fuel shipping cask were assumed to drop in the spent fuel pool, damage to the pool floor could occur that would cause loss of pool vator at a greater rate than the available pool water makeup capability. The existing yard crane system provided for handling the cask does not have the necessary features to preclude a cask drop and the .issociated unacccptable consequences.

Therefore, in lieu of adding features to the spent fuel pool to provide assurance that the pool could withstand the loads generated by a cask drop, you propose to modify the yard crane system in a manner that will provide a high level of confidence that the likelihood of a cask drop vill be negligible.

We have reviewed your proposed plan for modifying the yard crane system which includes: (1) replacement of the existing trolley with a 100 ton capacity trolley designed to a safety factor of 5, (2) derating of this trolley to 50 tons in conjunction with the use of a replacement bridge to provide a safety f actor of 10 for the hoisting machinery handling the 32 ton spent fuel shipping cask, (3) redundant brakes and other features that would make the crane single failure proof, and (4) limit switches that will preclude movement of the trolley and the bridge over stored spent fuel. In addition, as a result of recent discussions with members of your staff, during which we provided guidance on current crana design criteria, you will make other modifications to further upgrade the yard crance system to the extent practicable.

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l Yankee Atomic Electric Company FEB 7 1975 .

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Based on our review of the information you have provided in your letters.

q of September 13 and November 5,1974, and the discussion.a with members of '

q your staff, wo find that your pinnned approach of upgrading of the yard crane U. system in lieu of structural modifications would be an acceptable approach to resolve the safety issues associated with the Handling of the spent fuel shipping cash at Yankop-Rowe; however, additional information is necessary.

Therefore, to complete our evaluation of your submittal we nood information

. on the final details of the modifications to the yard crane system including preoperational testing.

i In order to meet our review schedule we will need a response to this request

! .by March 28, 1975.

j Sincerely, I

j Original signed by

.{ EarlIL GoUer j Karl R. Coller, Assistant Director for Operating Reactors

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) Division of Reactor Licens,ing

'j- cc: Mr. Donald C. Allen, President Yankee Atomic Electric Company 20 Yurnpike Road l Westboro, Massachusetts 01581 i

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i SEE PREVIOUS YELLOW FOR CONCURRENCES AND DISTRIBUTION

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.._,.3 Yankee Atomic. Electric Company '

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- Based our review of the information you have provided in your 1ctters of Septe r 13 and November 5,1974, and the discussions with tienbers of your staff,'we f d that your planned approach of upgrading of the 7ard crane system

-in lieu of stI%ptural modifications would be an acceptable approach to reco1ve U 'the safety issuo asuociatedwiththehandlingofthespent/uelchippingcash at Yankee-Rowe, ho *ver, additional-information is necessary. Therefore, to

- c, complete our evaluatibn of your submittal va need infore ion on the final ll details of the modificahons to.the yard crane system i luding preoperational

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testing.

'i' In order to meet our review se edule we will nee.d a Tesponse to this request g by February 23, 1975. \

\ Sincerely, si 1

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i Kar R. Go1}cr, Assistant Director or Operat'ing Reactors vision of Rhetor Licensing ,

ces Mr. Donald C. A11ca, President Yankee Atomic Electric Compan 20 Turnpike Road

. Westboro, Massachusetts 0 81

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