ML19095A220
| ML19095A220 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 05/26/1978 |
| From: | Stallings C Virginia Electric & Power Co (VEPCO) |
| To: | Case E, Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| Serial No. 303 | |
| Download: ML19095A220 (2) | |
Text
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v1it\\i\\liJ~R1c AND POWER COMPANY, RICHMOND, VIRGINIA 232s1 Mr. Edson G. Case, Acting Director Office of Nuclear Reactor Regulation Attn:
Mr. Albert Schwencer, Chief Operating Reactors Branch No. 1 Division of Reactor Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. Case:
May 26, 1978' Serial N~:.*: 303 FR/MLB: c~J:'-~:. "
Dock~t'.No~ 50-280 P. 50-2~
License,Nos. DPR-SQ DPR-37 In our letter of April 7, 1978 (Serial No. 197), we indicated that we had administratively reduced the LOCA-ECCS limiting heat flux hot channel factor (FQ) from 1. 85 to 1. 81 (or to 1. 79 when additional steam generator tube plugging is required) for Surry Units No. 1 and 2.
This reduction was intended to conservatively accommodate an error in the representation of the heat release from the metal-water reaction in the currently approved:version (October 1975) of the Westinghouse LOCA Evaluation Model~
Our letter of April 7, 1978 (Serial No. 197) also indicated that a new LOCA-ECCS analysis would be performed with an acceptable Westinghouse LOCA Evaluation Model (i.e., in compliance with 10 CFR 50, Appendix K) and meet the acceptance criteria of 10 CFR 50.46.
Your letter of April 28, 1978 confirmed this approach through the issuance of an Order.for Modification of License for Surry Unit No. 2.
Subsequent to our April 7, 1978. (Serial No. 197) letter, additional LOCA-ECCS analysis has been performed.with a corrected version (i.e., the full effect of the*m.eta.1-water reaction is incorporated) of the October 1975 version of the Westinghouse LOCA.. Evaluation Model.
This analysis also reflects plant specific fuel and ECCS containment response input parameters, as well as more recently* available FLECHT data, and indicates that the.. FQ value(s) provided in our letter of April 7, 1978 (Serial No. 197) are extremely conservative.
There-fore, we would like to update the information contained in our letter of April 7, 1978 with the analysis provided in Attachment 1 which.will conservatively support a limiting FTB value of 1. 94 with m.8:rgin to the* acceptance criteria de-lineated in 10 CFR 5.46.
Since the use of new FLECHT data is still under review by the NRC, theNRC procedure for use of the new FLECHTdata (as documented in the NRC safety evaluation supporting the April 28, 1978-0rder for Modification of License for Surry Unit No. 2) was followed.
As a result, the attached analysis is submitted for the purpose of supporting the-.1.94 F~ limit on an interim basis only.
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.e V1Ra1N1A ELECTRIC AND PowER CoMPANv TO Mr. Case*
- SHEET No. 2 Compliance withthenew*F~ limit of 1.94:will be ensured by the per.:..
formance of axial power distribution monitoring (APDM) as currently_described in the Technical Specifications-for both Surry_Units No. 1 and 2. Administra-tive restrictions will be implemented t0 ensure that the limiting value of FQ, as well as the accumulator water volume,* assumed in the attached analysis are not exceeded 'during Condition I operation.
These administrative*. restric-tions will*rema.in in effect until a new LOCA-ECCS reanalysis (and associated changes* to*the Technical Specifications)*has been deterininedtobein complete compliance with 10 CFR 50, Appendix Kand meet the acceptance criteria of lO*CFR 50.46 *
. Your expeditious review of.the above :i::'equest:*to* change the interim LOCA-ECCS limiting value of Fq.to 1.94,. and the accumulator water volume to 975. ft3* would be greatly appreciated*. in order* to* maintain our schedule to restlllle full power operation of Surry Unit.No. lby*June 27, 1978.
Should you have questions, *.we* would like to meet with you at your earliest convenience
- Attachment cc:. Mr. James. P. O'Reilly,* Director Office of Inspection and Enforcement
. Region II
. Very truly yours,*
ZP.m.0~
C. M. Stallings
- Vice*President - Power Supply and Production Operations