PNO-II-85-121, on 851221,safety Equipment in Southeast Diagonal Room of Reactor Bldg Flooded W/Torus Water.Caused by Open Flow Path Through Disassembled RHR Pump Suction Valve.Water Removed & Rooms Decontaminated

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PNO-II-85-121:on 851221,safety Equipment in Southeast Diagonal Room of Reactor Bldg Flooded W/Torus Water.Caused by Open Flow Path Through Disassembled RHR Pump Suction Valve.Water Removed & Rooms Decontaminated
ML20138R412
Person / Time
Site: Hatch Southern Nuclear icon.png
Issue date: 12/23/1985
From: Panciera V, Verrelli D
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-85-121, NUDOCS 8512310267
Download: ML20138R412 (1)


E December 23, 1985 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-85-121 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verifi-cation' or evaluation, and is basically all that is known by the Region II staff on this date.

FACILITY: Georgia Power Company Licensee Emergency Classification:

Hatch Unit 1 Notification of Unusual Event Docket No. 50-321 Alert Baxley, Georgia Site Area Emergency General Emergency X Not Applicable

SUBJECT:

FLOODING OF SAFETY EQUIPMENT Georgia Power Company will begin work shortly to restore to operability several pieces of safety equipment which were flooded on Saturday, December 21, when an isolation valve opened, permitting torus water to flow .through a disassembled pump into the southeast diagonal room of the reactor building. Hatch Unit I has been shut down since November 27 for refueling, and is completely defueled.

The incident occurred about 1:20 a.m. (EST) on Saturday as an emergency diesel generator was being tested and while a residual heat removal (RHR) pump suction valve was disas-sembled for maintenance. When a 4160-volt bus providing off-site power was de-energized for the diesel generator test -- as provided by procedure -- it caused the isolation valve to open. Because the RHR pump suction valve was disassembled, there was a direct path of torus water to the southeast diagonal room of the reactor building.

Before the water fluw was stopped, the southeast room had 14 feet of water on the floor.

Later action to remove this water caused accumulation of three feet of water in the north-east diagonal room and two feet of water in the high pressure coolant injection (HDCI) pump room. This flooding submerged two RHR pumps, one core spray pump, and a room unit cooler in the southeast room; an RHR jockey pump in the northeast room; and some flooding of the HPCI barometric condenser. The HPCI pump unit and turbine were unaffected because they are mounted on a base plate. No contaminated water was released offsite; no personnel were contaminated.

Water has been pumped out of the rooms, which are now being decontaminated. Georgia Power intends to begin restoration of the flooded equipment later this week. Region II will send a team of inspectors to the site on December 26 to review operational a.6d maintenance aspects of this incident as well as to monitor equipment restoration measures being taken.

The event had no effect on Hatch Unit 2, which is operating at 100 percent power.

Georgia Power is prepared to respond to media inquiries.

The State of Georgia has been informed.

This information is current as of 2:00 p.m. , today.

Contact:

V. Panciera, 242-5525 or David M. Verrelli, 242-5526.

DISTRIBUTION: (See page 2) 8512310267 851223 PDR I&E PNO-IT- -

121 PDR _

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