ML20128L918

Ro:On 850701,containment Vessel Sump Pump Actuation Interval Decreased Significantly from Normal.Caused by Svc Water Leak.Fan Cooler Inspected & Repaired

ML20128L918
Person / Time
Site:	Ginna
Issue date:	07/12/1985
From:	Kober R ROCHESTER GAS & ELECTRIC CORP.
To:	NRC OFFICE OF ADMINISTRATION (ADM)
References
NUDOCS 8507250147
Download: ML20128L918 (4)

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R'n.)7!$['Edc';;;q d7f y ' Mef ROCHESTER SAS AND ELECTRIC CORPORATION e 89 EAST AVENUE, ROCHESTER, N.Y.14645 b001 Y:l ROGER W KOBER ELE M PRODUCTION A.E 4 CODE 7 6 546 2700 July 12, 1985 4

U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Subject:

Service Water Leak Inside Containment R.E. Ginna Nuclear Power Plant Docket No. 50-244 In accordance with the requirements of IE Bulletin No. 80-24

" Prevention of Damage Due to Water Leakage Inside Containment",

the attached 14 days written report is hereby submitted.

V ry truly yours, hr !klA R r W. Kober RWK/eeg- a i

xc: U.S. Nuclear Regulatory Commission Region I j 631 Park Avenue King of Prussia, PA 19406 nr2ms myir .

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SERVICE WATER LEAK INSIDE CONTAINMENT At 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br /> on July 1, 1985, while Ginna Station was operating at 100% power and following completion of PT-2.7 " Service Water System" test,-the Containment Vessel "A" Sump Pump actuation interval decreased significantly from normal. This sump is located at the bottom of the reactor vessel cavity area and is the lowest elevation of the Containment Vessel. (See attached drawing)

An investigation for determination of the cause of leakage inside containment was immediately initiated. No changes were observed on radiation monitors R-ll and R-12, Containment Air Particulate Monitor and Containment Radiogas Monitor respectively, no changes in containment dewpoint, no indication of Reactor Coolant System Leakage increase was observed and no significant increases in actuation of the Containment Vessels Recirculation Fan Coolers condensate Collection System dump valves to Sump "A".

The leakage rate to the Sump "A" was calculated to be, through the actuation of the sump pump and by use of the cump level indication chart recorder, approximately 4 to 5 gpm. This was also verified by the Waste Holdup Tank level increase, the receiving tank of Sump "A" discharge located outside containment.

A Service Water Leak was suspected.

Operations personnel requested the Health Physics and Chemistry section to take a sample of Sump "A" water and to initiate required actions for containment entry as per Administrative Procedure A-3 " Containment Vessel Access Requirements", a non-emergency entry. A group of personnel consisting of Operations, Maintenance, Quality Control, and Health Physics was designated to make the entry to investigate and repair the leak.

i 1 To expedite the identification of the service water leak, while preparations were made for containment entry, Operations personnel at 1056 hours0.0122 days <br />0.293 hours <br />0.00175 weeks <br />4.01808e-4 months <br /> initiated the sequence for service water isolation to selected containment Vessel (CV) Recirculation Fan Coolers using maintenance procedure M-11.34.2 " Containment Recirculation Fan Cooler Maintenance".

The "B" CV Recirculation Fan Cooler and motor cooler was isolated

first by closing the manual inlet and outlet service water valves j and by pulling-to-stop the fan motor switch thus rendering it inoperable. At 1142 hours0.0132 days <br />0.317 hours <br />0.00189 weeks <br />4.34531e-4 months <br /> the "B" CV Fan was returned to service

, since no decrease in leakage was observed.

At 1143 hours0.0132 days <br />0.318 hours <br />0.00189 weeks <br />4.349115e-4 months <br />, the same sequence was initiated for the "D" CV Recirculation Fan Cooler, with its return to service at 1201 hours0.0139 days <br />0.334 hours <br />0.00199 weeks <br />4.569805e-4 months <br /> since again no decrease in leakage was observed.

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At 1203 hours0.0139 days <br />0.334 hours <br />0.00199 weeks <br />4.577415e-4 months <br /> the same sequence was initiated for the "A" CV Recirculation Fan Cooler. Since the post accident charcoal filter is part of this fan cooler system the isolation rendered inoperable both the fan cooler and the post accident charcoal filter. This time the actuation of Sump "A" pump decreased significantly. The inspection and repair team was instructed which fan cooler to inspect and repair. The group's entry in containment was made at approximately 1220 hours0.0141 days <br />0.339 hours <br />0.00202 weeks <br />4.6421e-4 months <br />.

Inspection of the 1A Containment Fan Cooler revealed that a 1/8" diameter threaded motor cooler drain plug had become displaced during PT-2.7. The drain plug was replaced and the remaining three plugs in the cooler were inspected per maintenance procedure M-11.34.2. In addition, the motor cooler drain plugs on the 1B, 1C, and 1D CV Pecirculation Fans were inspected at this time and found acceptable. At the completion of the repair work the "A" CV Recirculation Fan Cooler and its associated post accident charcoal filter was restored to service at 1440 hours0.0167 days <br />0.4 hours <br />0.00238 weeks <br />5.4792e-4 months <br />.

As a preventive measure, inspection of all drain plugs will be performed each Refueling Outage. The total leakage into Sump "A" and eventual transfer to the Waste Holdup Tank was calculated to have been approximately 1100 gallons.

The NRC was notified via telephone at 1323 hours0.0153 days <br />0.368 hours <br />0.00219 weeks <br />5.034015e-4 months <br /> on the same date and the NRC Resident Inspector was also notified and appraised of the situation.

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