ML20204F922

Ro:On 860729,manual Reactor Trip Initiated When Large Quantity of Steam Found Rising Over Turbine Bay Area.Caused by Leak from Moisture Separator Reheater Drain Line 2A to High Pressure Feedwater Heater 5B.Drain Lines Repaired

ML20204F922
Person / Time
Site:	Ginna
Issue date:	07/29/1986
From:	Kober R ROCHESTER GAS & ELECTRIC CORP.
To:	NRC OFFICE OF ADMINISTRATION (ADM)
References
NUDOCS 8608070002
Download: ML20204F922 (2)

Text

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ROCHESTER GAS AND ELECTRIC CORPORATION e 89 EAST AVENUE, ROCHESTER, N.Y. 14649-0001  :

E tur Trtre ost Et.EcTmc r. STEAM PRODUCTION Apt A CODE M 6 546 2700 July 29, 1996 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Subject:

Follow-up Summary of Unusual Event at R.S. Ginna Nuclear Power Plant on July 29, 1986 Docket No. 50-244 In accordance with the NUREG-0654 reporting requirements, which require a written summary of closeout or class reduction conditions, the following is submitted for the Unusual Event declared at R.E. Ginna Nuclear Power Plant on July 29, 1986:

On July 29, 1986 at 0351 hours0.00406 days <br />0.0975 hours <br />5.803571e-4 weeks <br />1.335555e-4 months <br /> with the reactor at 100%

power, a loud noise was heard in the Control Room with no unusual Main Control Board alarms or indications immediately evident.

The Shift Supervisor immediately opened the Control Room Door #51 to the Turbine Building and observed a large quantity of steam rising over the north side of the Turbine (area of Turbine Bay) where upon he returned to the Control Room and ordered a manual reactor trip. The Head Control Operator tripped the reactor and verifMd that all control rods inserted and all turbine stop valves closed. The Main Steam Isolation valves were manually closed approximately 15 seconds after the reactor trip.

At 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br />, the Shift Supervisor declared an Unusual Event in accordance with SC-100, Ginna Station Event Evaluation and Classification for rapid depressurization of steam system j indicated on PI-484 (Steam Header Pressure Indicator).

Shortly thereafter, the leakage was terminated due to the closure of the Main Steam Isolation Valves. By 0410 hours0.00475 days <br />0.114 hours <br />6.779101e-4 weeks <br />1.56005e-4 months <br /> PI-484 indicated 0 psig. Subsequent investigation determined the leak was from the 2A Moisture Separator Reheater Drain Line to 5B High Pressure l Feedwater Heater.

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! Following the Manual Reactor Trip and Main Steam Isolation l

Valve closure, the plant was stabilized in hot shutdown with no l compromise to plant safety.

8608070002 860729 PDR ADOCK 05000244 ~

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. l ROCHESTER GAS AND ELECTRIC CORP. SHEET NO. 2 DATE July 29, 1986 To U.S. Nuclear Ibguhitory Cmmission I

With Superintendent-Ginna Production and plant staff approval, the Shift Supervisor declared, the Unusual Event terminated at 0514 hours0.00595 days <br />0.143 hours <br />8.498677e-4 weeks <br />1.95577e-4 months <br />, in accordance with SC-110, Ginna Station Event Evaluation For Reducing The Classification.

Proposed corrective action being implemented include the following:

1. The removal of insulation and the non-destructive examination of all similar drain lines and the affected drain line.

2. Repairs of all similar drain lines including the affected drain line that indicate significant degra-dation of pipe wall thickness.

V truly yours, O jt -

Rog(gr W. Kober kW xc: U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406

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