ML19095A270
| ML19095A270 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 04/07/1978 |
| From: | Stallings C Virginia Electric & Power Co (VEPCO) |
| To: | Case E, Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| Download: ML19095A270 (2) | |
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- vepco VIRGINIA ELECTRIC ANO POWER COMPANY, Rt-CHMONO, ~GINIA 23261 Mr. Edson G. Case Office of ?..~clear Re.actor Regulation Attn:
Mr. Albe.rt Scbwencer,. Chief Operating B.e.aetors Branch No. 1 Dirlsiou of Reac1:0r Liei!nsillg U. s. Nuclear R.egul.at.ory Commi.asion w'ashingtoc., D. C.
20555 Dear Mr. Case t April 7, 1978
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Serial No:*;. f97 n./111.B : er l ~~
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Docket Nos.s so-2sg:,
50-281 License Nos. DPR-32 DPR-37
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Pursuant to the provisions of the Surry Units No.land 2 Technical Specifications, the NRC Region II was-notified on Mal:'ch 23t 1978 of an error in the currently al)plic.able UlCA-ECCS analy9is.
The error found was in the ra1>resent.ation of the heat release £Tom the metal-water reaction 1n the NRC approved Westinghouse LOCA-ECCS evaluation model.
The impact of this error is to increase. the peak clad temperatura obtained during a postulate-d tOCA over that reported in the currently ap9licable LOCA-ECCS analysi~.
To con-servatively aco:i1Bm0date the ~ct. of this err1'T,. the LOCA-ECCS limiting he.at £1ux.ho1: cham:lel. factor ('F~) has* been administratively reduced from its present* Techrdcal Specifications limit of l.85 to 1.81 (or t.o l.79 when additional steam geuerattlr tuba plugging is required).
These new FQ limits have been. conservative.ly selected in order to ensure that the LOCA-ECCS acceptance criteria delineated in 10 en.. 50.46 is me1:.
The bases for the new FQ limits are provided in the Attachmen:.
Compl.ianc:e with the new FQ limit will.. be. ensured by* the* performance of a:d al power d.iatrlbution S111itcring (.A.P'DM) as described in the TedmicaJ.
Specif !cations.
Admini st-rative i.t2Structions have been.. im:plemented that require
.:U'DM surveillance fer p<CWer operation above 82% for Unit 1 and 85% for Uuit 2.
Additionally~ the ~I o-perating itmits (for operation outside of the constant axial offset ccutrol target band) have been revised in order eo ensure a cou-sistent basis becween consumt axial offse-c control Of the core and the Pq sur-veillance r.equirenents.. These ad:min.istn.tiva restrtctious will re323ain. in effect until. a nev LOCA-ECCS analysis and associated changes to the Tachnieal Sp.ecifica-tiou.s are approved.
Th~ new LOCA-ECCS analysis wiU. ~ performed as soon as possible with an acceptable i;.,estinghouse LOCA-ECCS evaluation model.
This naw analysis will be in compliance with 10 en 50, Appendix :I and meet the acceptance criteria of 10 en so.46.
Mr. c.aae 2
Should you ha-ve questions, we would like to meet with you at your earliest convenience.
Attachment cc:
Mr. James P. O'Railly, Director Office of !ns~eeticu and Enforcement Regi..ou II
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._..,C. M. Stalling& !
Vice President - Power Supply and Production Operations