ML20037B588

Submits Request for Addl Info Re Proposed Change to Permit Installation of ECCS & Submittal of Proposed Augmented Inservice Insp Program to Provide Addl Assurance of Continued Primary Coolant Sys Integrity

ML20037B588
Person / Time
Site:	Dresden
Issue date:	07/22/1971
From:	Morris P US ATOMIC ENERGY COMMISSION (AEC)
To:	Stiede W COMMONWEALTH EDISON CO.
References
NUDOCS 8010210883
Download: ML20037B588 (3)

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I Dockst No. 50-10 JUL 2 21971 i

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Courc:Taealth Edison Co pany i

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it'. Yayne L. Stiede l

I Nuclear Licensing Adninistrator

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72 West Adn n Street Chicago, Illincia 60690 t

Gentleren:

Ue have under review three proposed chances to the Technical Specifications of facility License No. DP?e-2 for the Dresden Unit 1 facility:

(1) Your peed change to pemit instn11ntion of an emergency core cooling system (Proposed Change No. 17) dated October 10, 1968, supplenented by Ictters of September 17, 1970, and March 26, 1971, (2) Your proposed chanEes in effluent limits dated January 18,1971 (Pmposed Chance no. 21),

and (3) Proposed changes dated March 3,1971, related to prirar/ systen leak detection, administrative controls, containrent leak rate tests and the emergency condenser cysten. In several discussions refarding inadequacies in each of the above submittals, Conrrnwealth Edison perecnnel have indicated that supplerental infomation regardire each proposed chance would be submitted prorptly. Since your supplerents have not yet been Inceived, we have prepared the enclosed request for additional inferration, based on tae description and analysis in your subtittals.

'Ihe additional $nfomation should be subnitted in three signed plus forty additional copies.

On June 19, 1971, the AEC adopted interim acceptance criteria for the perfomance of ercreency core cooling systers (ECCS) for light-water nuclear power plants. A copy of the Co mission's interic policy staterent on this ratter is enclosed for ycur infonration. In accord nce with Section 1Y.C l(b) of the policy staterent, you are requested to sitrit cnalyces of the pco fort nce of the ECCS preposed for installatica in Dresden Unit 1, usinc rethods equivalent to the evaluaticn I:cdel $n Appendix A, Tcrt 2 of the policy stateccnt as soon as practicable, but not later tnan Januca 1, if 72.

to determine the extent cf cogliance with the criteria of Secticns IV./.

and B of the statenent.

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E' Corrcmrealth Edison Company Jr 2 2 @

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1-Tne infortaticn ire need regarding these analyses is cutlire:d belou.

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Provide curves of peak clad terperature and percent clad metal-water ij reaction as a function of break size for the various ccrbinations of ECC subsysters evaluated by applying the single failure criterion to iz the active corponents involved in the erergency cooling process. A discussica should be included shovdng the justification for the ECC

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subsystem corbinations used in the evaluation.

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For several breaks that typify small, intemediate and large breaks,

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provide curves of (a) peak fuel clad tenperature for var 1ous fuel rod groups within a fuel bundle, (b) core coolant flow, (c) fuel channel inlet and outlet quality, (d) heat transfer coefficients, (e) reactor

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vessel water level, and (f) rdnirarn critical heat flux ratio (MCE),

all as functions of tire. Indicate the tire that rated core cooling i

flow is initiated, the tire the fuel channel becores wetted based upon item 4 of Appendix A, Part 2, and the tire that the temperature transient is teminated.

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3 For the analyses perforced in 1 and 2 above, discuss the range o peaking factors studied and the basis for selecting the combinatica I

that resulted in the rest severe theImal transient. Curves of peak i

clad terperature vs time for the range of peaking factors studied should be included.

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4.. Discuss in detail any deviations in the evaluation rodel used in the foregoing studies from that described in Appendix A, Farc 2 of the Ccerdssicn's interim policy statement.

i In the event these analyses show that Dresden Unit 1 will not be in l-cocpliance idth the criteria of Section IV.A and B following installation 5

of the proposed ECCS, you are requested to submit a program of irprovements and a schedule for effecting them prior to July 1,1974, together vdth

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cnticipated perfomance infomation on the irproved system as indicated in i

iters 1-4 above, as soon as practicable but not later than July 1,1972.

You are requested to make, as scan as practicable, such interim irp m vo-rents in operating techniques as are practical and worthwhile in ig.rcrinc emergency ccm cooling system perfonmnce or ruliebility. Plecse info m us of cny such actions taken.

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i R 22 3 Corrorucalth Edison Cc pany !

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r In additicn, in acccrdcnce with Iterrs IV.C.l(b)(3) cnd (4) of the state-unt, you am requested to submit a proposed augrented inservice inspection program to provide additional assurance of continued primary coolant system integrity, to propose appmpriate additions to your prirg/

t system leakage detection system to provide at least two different methods of detecticn, and to propose -technical specifications that mduce allowable rates of identified and unidentified leakage to the lowest prcctical

'Ibese interim neasures should be effected pronptly cnd reported t.-

values.

to the AEC not later than October 1, 1971.

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Knen each of the infon:ation itens mquested has been prepamd, please hhen we have corpleted our review of your analysis for send us 60 copies.

the Dresden Unit 1 ECCS, we will contact you regardirc the results of our l

i evaluation.

Sincerely, I.

Peter A. Forris, Director Division of lieactor Licensing j

Enclosures:

1.

Fequest for Additional Infomation 2.

AEC Interin Policy Statemnt Arthur C. Ge r, Esq.

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i Isham, Lincoln & Beale 72 West Adams Street Chicago, Illinois 60690 DISTEIEUTIO:!

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