PNO-V-93-004, on 930121,automatic Reactor Scram Received Due to Low Level in Reactor Pressure Vessel.Licensee Estimates That Plant Will Be Shut Down for Repairs & Maint for 3 to 5 Days.Inspector Onsite During Event.Press Release Issued

PNO-V-93-004:on 930121,automatic Reactor Scram Received Due to Low Level in Reactor Pressure Vessel.Licensee Estimates That Plant Will Be Shut Down for Repairs & Maint for 3 to 5 Days.Inspector Onsite During Event.Press Release Issued

ML20127P672
Person / Time
Site:	Columbia
Issue date:	01/21/1993
From:	Johnson P, Perkins K, David Proulx NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
References
PNO-V-93-004, PNO-V-93-4, NUDOCS 9302020038
Download: ML20127P672 (2)

C January 21, 1993 PREllMINARY NOTIFICATION OF EVENT OR UNUSUAL, OCCURRENCE PNO-V-93-004-  !

This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially--

received without verification or evaluation and is basically all that'is known by Region V staff on this date.

Eac_ilit y L i cen s en_ Eme ro ency cl a s s i fi c a t i on  !

Washington Public Power Supply System Notification of Unusual Event 1 Washington Nuclear Project 2 (WNP-2) Alert i Richland, Washington Site Area Emergency Docket No. 50-397 General Emergency ,

X Not Applicable

]

SUBJECT:

AUTOMATIC REACTOR SCRAM DUE TO FEEv PUMP TRIP  !

At 0946 PST on 1-21-93, an automatic reactor scram was received-due to low level (Level 3 at +13 inches) in the reactor pressure vessel (RPV). 1 A trip of the "A" Reactor Feed Pump coupled with an apparent- failure of' the- H "A" Recirculation Flow ..ntrol (RFC) valve to runback to minimum per design was the apparent cause of the reactor vessel low water level trip. 1 1

At 0946 PST, with the reactor at 100% power, operators' received a fire alarm' 4 in the "A" reactor feed pump (RFP) room. This alarm.was followed shortly by "High Vibration" and "High Thrust Bearing Wear" alarms for the "A" RFP. The "A" RFP subsequently tripped. However, following the trip of the-RFP, the'"B"-  ;

P.FC valve ran back to minimum but the "A" RFC valve ran back-to 82% and stopped in that position. Due to the feed flow / steam flow mismatch, RPV level f decreased to +13 inches and an automatic reactor scram occurred. The emergency i operating procedures (EOPs) were entered based on going below +13: inches in the reactor vessel. Reactor Vessel water level reached a minimum of inches and operators recovered RPV level with the Reactor Core-Isolatioh Cooling-(RCIC) system. All safety systems responded as expected following the scram. - The plant is stable and a controlled cooldown to Mode 4 (cold shutdown) is in progress. -

Licensee preliminary investigation indicated that an employee accidentally.

actuated the fire protection manual " deluge pull station" in the "A";RFP room, causing the sprinkler system to actuate. This sprayed water on the "A" RFP' vibration monitoring panel ~, resulting in the above alarms and feed pump trip. '

The licensee is still investigating the cause of the failure of the "A"RFC ~

valve to runback to minimum.

The licensee estimates that the plant will-be shut downffor repairs and other routine maintenance for three to five days.

The NRC resident inspector was onsite.during the event and respunded to the control room upon notification, and is monitoring the licensee actions.

The licensee plans to issue a press release.

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