ML18136A231

Ro:On 791110,condenser Cooling Water Outlet Temp Exceeded Temp Change Rate of 3 F/H While Unit 1 Was at 100% Power & Unit 2 Was in Cold Shutdown.Caused by Valve Misalignment Permitting Sodium Fluid to Enter Sys

ML18136A231
Person / Time
Site:	Surry
Issue date:	11/26/1979
From:	Stallings C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Eisenhut D Office of Nuclear Reactor Regulation
References
NUDOCS 7911290295
Download: ML18136A231 (1)

Text

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e VIRGINIA. ELECTRIC A.ND POWER COMP.A.NY RIOHMOND,VIRGINIA 23261 November 26, 1979 Mr. Darrell G. Eisenhut, Acting Director Serial .No. 965 Division of Operating Reactors PO/RMT:baw Office of Nuclear Reactor Regulation Docket Nos.: 50-280 U. S. Nuclear Regulatory Commission 50-281 Washington, D. C. 20555 License Nos . : DPR-32 DPR-37

Dear Mr. Eisenhut:

This letter report is furnished in accordance with the provisions of Surry Power Station Technical Specification 4.14.C.l.

During the period from 1330 to 1430 on November 10, 1979, the condenser cooling water outlet temperature exceeded a temperature change rate of 3°F/hr. which is the maximum permitted by Technical Specification 4.14.A.3.

Unit 1 was operating at 100% power and Unit 2 was in cold shutdown during the occurrence.

This event occurred when an unusually high sodium content was noted in the condenser. This sometimes indicates a tube rupture. In the process of removing the suspected water box from service to isolate the problem, the temperature rate of change reached 3.4°F/hr. It was later discovered that there were no tube ruptures but rather that a valve misalignment was permitting the fluid containing the sodium to enter this system from another source.

A search conducted to determine if the temperature change had affected the river environment revealed no detrimental evidence.

Very truly yours,

a. Jn ~d.d ~ayv C. M. Stallings Vice-President-Power Supply and Production Operations cc: Mr. James P. O'Reilly Aoo/

.S.

171 791129oa.c,s