ML19319C158

Requests Addl Info Re Evaluation of Potential Consequences of Refueling Accident Inside Containment Bldg in Fsar. Questions Encl

ML19319C158
Person / Time
Site:	Davis Besse
Issue date:	03/10/1977
From:	Stolz J Office of Nuclear Reactor Regulation
To:	Roe L TOLEDO EDISON CO.
References
NUDOCS 8001310518
Download: ML19319C158 (6)

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.s WAR 101977 Cocket in: 50-346 Icleco Euicon Cc: ecny I".1 :

P.r. Lowell E. Foo Vice President, Facilities Development Edison Plaza 300 P.adison Avenue Toleco, Cnio 42652 Centiccen sci.U CT: DVEL H.'O.rLI'G ACCICDC - (CAVIS 3 ESSE, U? LIT 1)

..e are la tne crocess of evaluating a refueling accident inside the ccntaumnt cuilding since it may not nava been 2dccuataly cenai.: area in the licensing review.

3aseu on our pralininary review, octantial site cocr.dary r viiation ex-posures uce to such an accident at y0ur facility wuld ce wil within the excesure gaicellnes of 10 CFR Part 100 even 1;cu11rq no isolatica of centainacnt.

In order to confirm these resulta and detar::ine if the acceptance criteria of Standard Feview Plan 15.7.4 ar2 mt, and to docuacnt the factors involved in the ovaluatica, we regest tnat you provido a detailed evaluation of tne cctential consecuar.cas cc sucn an accident at ycur facility in your FSA3. Your analysia Onculd utilize as;tections ccc.paraale to these given in ic,ulatory Guide 1.25, "Assumcticas Ucca f 0r Evaluating the Fctential Tx.iolcgical Ccacecuences cf a Fuel

!iandling Accie.;cnt in tne fuel 1:andling rd S_or:ge ?acilit'/ for Sciling r.c Preasuri:cd,Jater Feactors," assuming the erst ; ingle failuro. It acceld censiJer, in a ecnservative. winner, any mixing in tne contai. tent

tmosencra wnica would delay release of material, any filtration of effluent which wuld reduce releases, and any autcoatic isolation of the centainment wnich would limit releaces. Your analysis snould utilize para cterc (e.g., =axi,uai allowable valve closure times) as limited by tne propeced technical specificaticns. Clearly indicate any credit taken in the analyses for nonsafety grado equi;r:ent and provide acgro-priate justification for this credit. Octailed gestions wnich should cc addressed in your response ara enclosed.

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• NRC FORM 31s (9 ?6) NRCM 024 fr us s. oovenmuswr eniarine orncs. sete -saa.4a4 800133o M

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N 101977 Toledo D31 son Cocpany You snould cor: pare procesed tecnnical specifications (e.g., valve closure times, filter-testirg) with results of tne abcve analyses to snow that parameters irportant in the evaluation are :.aintained at levels whien will assure that cosmervatively calculated offsite cun-sequences are well within the exposure guidelines of 10 CFR Part 100 cver the plant li2cti1ce.

Senait your analysis within 60 days from the date of this letter.

'ntis request for generic information was apcroved by GM under a clanket cleara:x:e nuct:er B-180225 (20072).

his clearance expires July 31,1977.

Sincerely, Ori;;I M SI acd L[

bh:1 F. Stoir Jonn P. Stolz, Chief Lignt Water Faacters 2rancn.1o.1 Division of Project ::anagement Office of Nuclear Ecactor F+7ulatica

Enclosure:

Information Nec<.!cd to Evaluate Centainrent Fafueling Iccident cc w/cnclosures I

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NRC PORM 318 (9-76) NRCM 0240

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Mr. Donald H. Hauser, Esq.

The Cleveland Electric Illuminating Company P. O. Box 5000 Cleveland, Ohio 44101 Gerald Charnoff, Esq.

Shaw, Pittman, Potts and Trowbridge 1800 M Street, N. W.

Washington, D. C.

20036 Leslie Henry, Esq.

Fuller, Seney, Henry and Hodge 300 Madison Avenue Toledo, Ohio 43604 l

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I*tFOR;fATION NEEDED TO F"AIJATE r.y' TAI * "E':T T50LAT!O CPMIT ?TY I

DL'RIrG PEFFEI:'IC ACCIntrT 1

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1) Describe all instrumentation which would detect a fuel-handling accident (FHA) i 1

inside containment. Your response shculd include the follow'ing information:

I a) instrumentation function, e.g.,

cicse containment isolation valves; 4.

b) type of instruments and setpoints, e.g., nr/hr, and normal background reading; I

c) safety class, redundanqy, power sources, and technical specification requirements; d) a description of instrument response folicwing a FHA taking into acccunt

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instrument location; e) response time for the instrument to signal containment isclation af:er the FHA.

2) Describe the response of the containment isoldtion and ventilation valves i

following the FHA.

Include valve closure times including expected valve elesure j

time as well as technical specification requirements.

3) Provide the transit ti=e from the point where a enitor can respond to a release 1

frem the THA to the inboard isolation valve based on the maximum air velocity (peak centerline velocity) at maximum exhaust flow. Also include the trarsit l

time based on average velocity and normally expected air fleus. Conserva:ively assume that the FHA is a puff release feca the poci at a point closes: te an

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exhaust grill.

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Provide drawinge of the containcent which cicarly show the 1scation of the radiation monitors relative to the ventilation exhaus: system including all exhaust inists, filters, dampers, and duct arrangement up to the cutboard isolatien valves.

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If the summation of the instrument response tino (cuestien 1.e) and valve damners closu a tine (question 2) is greater than the gas transit tire (cuestion 3),

p re-an analysis as to the volume and amount of radioactive exhaust air whicn eculJ be released. Your respense should include the followine:

a) duct sizes; b) maximum (peak) air velocity; c) average air velocity; di containment isolation valve closure characteristics; e) exhaust systen flow rates; f) methodolecy used to calculate gas transit times frem the pool surface to the exhaust systen; g) air velocity profiles over the pcol surface. You shculd consider the effects of pool water temperature on air ficw trajectories.

6)

Describe any charcoal filters which would mitigate the censecuence of the F*iA.

If so, include the folicwinz informatien: type (e.g.,

kidne:n, redundancy, power sources, safety grade, technical specification requirements.

In responding to the above, reference can be made to specific pazes er figures in the Safety Analysis Report.

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