ML19322A145
| ML19322A145 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 12/29/1978 |
| From: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7901030049 | |
| Download: ML19322A145 (4) | |
Text
Poiers.Axn GicxicitAn. I?i.1: critic Coxiuxv i
121 S. W. S A L M O N S T R E ET PORTLAND, OREGON 97204 CH ARLES GOODWIN,.J R.
ass,vant v.ca possunt Decembe r 29, 1978 Trojan Nuclear Plant Docket 50-344 License NPF-1 Director of Nuclear Reactor Regulation ATTN:
Mr. A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors 4
U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Sir:
In a letter dated April 12, 1978 we advised that Westinghouse had notified Portland General Electric Company (PSE) of a logic inconsistency in the Loss-of-Coolant Accident Emergency Core Cooling System (ECCS) evaluation for the Trojan Nuclear Plant. At that time, we committed to provide a schedule for submitting for NRC approval a corrected ECCS calculation as soon as Westinghouse and the NRC had agreed upon an acceptable model. On December 20, 1978 the NRC issued an exemption to PGE to permit interim operation of Trojan until a corrected ECCS evaluation has been submitted and approved.
It is our understanding that either of two approaches are acceptable to the NRC.
Namely, the improved " February 1978" Westinghouse ECCS evaluation model can be used, or, alternatively, the previous " October 1975" model can be used if it is appropriately corrected for the zirconium-water reac-tion error identified above. Westinghouse has advised PCE that their sensi-tivity studies indicate the " February 1978" ECCS evaluation model applied to Trojan would accommodate a teral peaking factor (Fq) of 2.32 with a peek cladding temperature (Pc"3 ices than the 10 CFR 50.46 limit of 2200*F.
. In contrast, preliminary results of the Trojan analyses using the " October 1975" model corrected for the zirconium-water reaction error indicate that a peaking factor of 2.25 results in a PCT of 2142*F; with Fq = due to the 2.32 the PCT would exceed 2200*F. The difference in the two results is fact that the." February 1978" model has been refined in several areas over
. the " October 1975" model.
NN f
PORTLAND OENERAL CLECTRIC COMPANY Mr. A. Schwencer December 29, 1978 Page two PGE has elected to submit' an ECCS evaluation using the " October 1975" Westinghouse ECCS evaluation model corrected for the zirconium-watur i
reaction error. We will submit this analysis for NRC review and a request for license amendment for the F Technical Specification l
be fore April 1, ' 19 78.
In the interim uOtil the NRC has reviewed the revised Trojan." October 1975" model ECCS analyses and issued an amend-
)
ment, PGE will administratively limit the allowable Fq to 2 25, as l
illustrated in the attached marked up Trojan Technical Specifications.
l Sincerely, L
/
C. Goodwin, Jr.
Assistant Vice President Tharmal Plant Operation and i
Maintenance CG/
/4crw2A18 c:
Director State of Oregon Department of Energy l
i
+
4 i
l i
..,,,... ~. _ - -