ML20207N391

Forwards Safety Evaluation Re Licensee 861110 & 1230 Requests to Reduce Void Vols in Defueling Canisters Prepared for Shipment in Nupac 125-B Casks.Reduction Acceptable. Measurements of Canister Gas Contents Requested

ML20207N391
Person / Time
Site:	Three Mile Island
Issue date:	01/07/1987
From:	Travers W Office of Nuclear Reactor Regulation
To:	Standerfer F GENERAL PUBLIC UTILITIES CORP.
Shared Package
ML20207N392	List: ML20207N391 ML20207N431
References
CON-NRC-TMI-87-003, CON-NRC-TMI-87-3 NUDOCS 8701140187
Download: ML20207N391 (2)

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LN 50-320 TMI Site r/f TMI HQ r/f Local PDR NRC PDR January 7, 1987 DCS NRC/THI 87-003 FMiraglia WDTravers MMasnik RHall Docket No. 50-320 JThomas CCowgill TMoslak Mr. F. R. Standerfer LChandler 4

m Vice President / Director, TH1-2 ACRS GPU fiuclear Corporation I&E P. O. Box 480 M-Town Office Middletown, PA 17057 Service List

Dear I:

r. Standerfer:

Subject:

Reduced Defueling Canister Void Volune

Reference:

(a) Letter 4410-86-L-0193, F. Standerfer to W. Travers, Canister Dewatering, dated Novenber 10, 1936

) (b) Letter 4410-86-L-0220, F. Standerfer to W. Travers, g.. Canister Dewatering, dated Dececher 30, 1986 9

References (a) and (b) requested HRC approval of a reduction in the required void volunes of the defueling canisters prepared for shipuent in the UUPAC 125-B shipping cask. The issues were further discussed in nectings between our technical staffs during the weeks of November 17 and December 15, 1986.

Pe have conpleted cur revicu of your proposal and based on the attached safety evaluation have concluded that the void volunes in the defueling canisters can be safely reduced to a level that assures exposure of a mininun of 25 grans of reewbiner catalyst in any possible canister orientation. This is equivalent to a volum of 25 porcent of the enpty canister void for a fuel canister, and a slightly larger percentage of the enpty volune for a filter or knockout canister. We have further concluded that the void voluaas can be reduced and still be in conforrance with the Certificate of Conpliance for the NVPAC 125-0 cask, thus na further licensing action is required as o result of this issue.

He have, however, deternined that confirnatory measurements of canister gas contents af ter shipping are desirable to further support the data already gathered on canister gas generation. This was discussed in a necting among GPU Nuclear, NRC, and EG&G Idaho staffs on January 7,1987.

We therefore approve your request to reduce the required canister void volune to 25 percent in the fuel canisters ed to leve's assuring exposure of 25

, grans of catalyst in filter and knockout canisters provided the folloutng conditicas are net:

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!!r F. P. Standerfer January 7,1937 a .

1) Canisters will be dewatered to the ocxinun extent practical under the curr:nt dewatering prograu.

2) After shipping, confinaatory gas neasurecents will be taken on one canister per shipnent (i.e., one of seven for a single cask shipnent, one of fourteen for a double cask shipment). A gas scn will be withdrawn and analyzed shortly af ter (uithin a few days) ple ret:cyal of the canister frota the shipping cask at the Idaho f:ational Engineering Laboratory. The canister will be stored in an unvented conditica for about six wecks and resetapled. The gas sample analysis is to be recorded cr.d used to confiru the conservatism in the projected allowable shipping window deternined by the sar.;ples withdrawn prior to shipping.

3) The sample results are to be uade available for HAC review on request.

This approval is contingent upon NRC approval of the associated precedures subject to Tcchnical Specification 6.8.2.

Sincerely,

• T*

DRIGWJ. MD y/miam D. Travers Willien D. Travers Director TilI-2 Cleanup Project Directorate Attachnent: As stated cc: T. F. Demitt R. E. P,ogan

. S. Levin J. E. Frew J. J. Byrne A. W. 1: iller Service Distribution List (see attached)

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