PNO-I-99-019, on 990420,Limerick Unit 1 Automatically Shutdown from 100% Power on Low Rwl Due to Loss of Mfw. Normal Feedwater Sys Has Been Restored,Which Allowed for Securing of RCIC & HPCI Systems.Licensee Issued Pr

PNO-I-99-019:on 990420,Limerick Unit 1 Automatically Shutdown from 100% Power on Low Rwl Due to Loss of Mfw. Normal Feedwater Sys Has Been Restored,Which Allowed for Securing of RCIC & HPCI Systems.Licensee Issued Pr

ML20205S055
Person / Time
Site:	Limerick
Issue date:	04/21/1999
From:	Cowgill C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-99-019, PNO-I-99-19, NUDOCS 9904260069
Download: ML20205S055 (1)

April 21, 1999 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-I-99-019 i

This preliminary notification constitutes EARLY notice of events of POSSIBLE i cafety or public interest significance. The information is as initially l received withou,t verification or evaluation, and is basically all that is j known by Regidh I staff in King of Prussia, Pennsylvania on this date. J l

Facility Licensee Emeroency Classification !

Psco Energy Company. Notification of Unusual Event j Limerick 1 Alert  !

Philtdelphia, Pennsylvania Site Area Emergency l Dockets: 50-352 General Emergency j X Not Applicable  !

Subject:

LIMERICK UNIT 1 AUTOMATIC REACTOR TRIP - MEDIA INTEREST At 6:32 pm on April 20, 1999, Limerick Unit 1 automatically shutdown  !

(trip) from 100 percent power on low reactor water level due the loss of ,

main feedwater. All control rods inserted completely. No safety or l relief valves lifted. Main feedwater was lost due to malfunction of the I condensate deep bed demineralizer system. The High Pressure Coolant Injection (HPCI) and the Reactor Core Isolation Cooling (RCIC) systems actuated on low reactor vessel water level as designed and successfully rectored level. The unit is in hot shutdown with HPCI and RCIC initially controlling reactor pressure and level and is proceeding to a cold shutdown condition. Cold shutdown is defined by reactor vessel water tempsrature less than 200 degrees Fahrenheit and reactor pressure equal to atmospheric pressure. The normal feedwater system has been restored,  ;

which allowed for the securing of RCIC and HPCI systems.

Subsequent to the trip several equipment malfunctions occurred which are b2ing investigated. One of two 'A' Recirculation Pump trip circuit breakers failed to open as required. The other breaker worked as danigned and shutdown the 'A' Recirculation Pump. Operators shut the Main Steam Isolation Valves (MSIV) when condenser vacuum decreased due to an unavailability of auxiliary steam and the mechanical vacuum pump not starting. PECO plans to make repairs prior to restarting the unit.

The Region I Public Affairs is prepared to respond to media inquiries.

The Senior Resident Inspector responded to the site as a result of the trip. 1 The resident. inspectors continue to follow the licensee's actions since the event.

The licensee has issued a press release concerning the trip.

The Commonwealth of Pennsylvania has been notified.

This information is current as of 11:00 am on April 21, 1999. ,

Contact:

Curtis J. Cowgill (610)337-5233 9904260069 PDR 16E 990421 PNG-I-99_o19 PDR .

l9)