ML20236X459

Advises That Util Proposal to Operate Canister Decontamination Sys W/Nonborated Water Poses No Risk to Public Health Safety & Does Not Create Potential Environ Impacts Outside Bounds of Impacts Previously Analyzed

ML20236X459
Person / Time
Site:	Three Mile Island
Issue date:	12/04/1987
From:	Travers W Office of Nuclear Reactor Regulation
To:	Standerfer F GENERAL PUBLIC UTILITIES CORP.
References
CON-NRC-TMI-87-085, CON-NRC-TMI-87-85 NUDOCS 8712090217
Download: ML20236X459 (2)

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c. V DISTR IBUTIONi Central File DN 50-320 NRC PDR Local PDR TMI HQ r/f f

TMI Site r/f I Vecember 4,1987 BBoger URC/THI 87-085 EJordan JPartlow FSchroeder WTravers MMasnik JThomas Docket No. 50-320 TMoslak Service List fir. F. R. Standerfer Vice President / Director, TMI-2 GPU Huclear Corporation P. O. Box 480 Hiddletown, PA 17057

Subject:

Safety Evaluation Report For Use of Non-Berated Uater in the Canister Loading Decontenination Systen

References:

(c) Letter 4410-87-L-0180/0274, F. Stendtrfer to UStiP.C, Safety Evaluation Report for Use of. Han-Borated Water in the Canister Loading Decontamination Systen, dated Decenber 2,1937 (b) Letter NRC/THI 66-079, N. Travers to F. Stauderfer, Defueling Canister Technical Evaluation Report, dated Augu.,t 12, 1986 Reference (a) subaitted for NRC staff review and approval a safety evaluation in support of your request to use non-borated water for defueling canister decontamination. We have reviewed your .,ubaittal and determined that your proposed systen modifications are adequate to prevent inadvertent communication of the non-borated water source with the reactor coolant systen (RCS). Thus the probability of an RCS boron dilution transient as a result of the activity has not been increased. We have also evaluated the potential for inadvertent criticality in the ' A' spent fuel pool (SFP) due to baron j dilution. Reference (b) includes an analysis of the criticality safety of the defueling canisters. That analysis shows that defueling canisters stored in the design configuration in the SFP storage racks are subcritical even if a single can has experienced the worst case geometric defomation due to a drop accident, and the SFP has been completely deborated. The analysis also shows i.

that a leaded canister dropped on top of another loaded canister in the i

f. storage racks is cubcritical, provided the water in the SFP is borated. The l analysis does not support a critically safe configuration in this case in non-borated water. Even though this presents an extremely unlikely scenario, action is required to preclud2 such an ever,t. W have evaluated this event l based on the following considerations.

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!!r. F. R. Standerfer Decenber 4, 19H7 Cenister decentwination uses a volum of abaut 200 collons of mts p.2r canister. If two shipping cashs are loaded in one u5ck, & vclune et cbout 2G00 gallons of desincrolized watcr Utuld ba edded tu i.ha SFP per wack. This is snall in comparisca to the total volune of the SFP. Thus sufficient d;bastien to pre ..t a criticality hncrd is not likt.ly to occur during the weekly SFP sanpling intervels. Local deburatico, however, is a potential concern due to thc stagnant natura of the pool and ceacity difference of bulk pual u.er und heated non-boreted wat2r. Opar_ tion of the defueling water clenup sun (DUCS} ca the ma.it fu.*1 peal ;L suf ficient flew re tcs tu assure nixing of the water will preclude such a localizai debaration transient. ijoucver, in discussion with nanbors of your stafi, it wcs :tc Led that you do not intend to aptre.te DJCS csntinuousl,i durino calistar decoa tanin:: tinn. We will therefera requira d ily .locr.1 dip s mples of the SFP wter in the vicinity of the decents.ination statian to verify thct th; barco concentration is not reduced below tha Technical Specificn tion limits uhm the DUCS is not operating as discused cbove. U: understand b m d on discussions that this ir acceptable to your sw.f.

Based on the above, we have cuncluded that our prwui to eperate the  ;

cinis.tcr decatoniao tion spton wit.h vn-barsted water does ".ut pos; a significant risk to the public h alth scruty, ucr da.s it crectu pet % tiel enviror.n"utal inpacts cu; side th bounds of th.o " prtviously mlymd, z pravided the restrictions discussed ere inpased in accardance. with Lpproved udainistrative end operating proccJurcs.

Wt tharciore approve your Safety Evalu; tion for Up of Ncn-Bored Wter in the Canimr LNding Decontr,nin-tie systaa subject tc tha previuusly u:.ntioned restrictions.

Sincerelj, DRIGINAL SIGNED BY y/illiam D. Travers i.illi<a D. Truvers, Dioctor Tul-2 Cl;.mup Project Directorate cc: T. F. D a itt n

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NRC FORM 318 00-801 NRCM 0240 OFFICIAL RECORD COPY _ - _ -