PNO-V-85-077, on 851113,blown Fuse in Water Level Control Sys Resulted in Reactor Feedpumps Overfeeding & Reactor Trip.Caused by Faulty Inverter.Facility Shut Down to Allow Installation of Instrumentation to Monitor Vibrations

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PNO-V-85-077:on 851113,blown Fuse in Water Level Control Sys Resulted in Reactor Feedpumps Overfeeding & Reactor Trip.Caused by Faulty Inverter.Facility Shut Down to Allow Installation of Instrumentation to Monitor Vibrations
ML20136B074
Person / Time
Site: Columbia Energy Northwest icon.png
Issue date: 11/13/1985
From: Qualls P, Toth A
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
References
PNO-V-85-077, PNO-V-85-77, NUDOCS 8511200124
Download: ML20136B074 (1)


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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-V-85-77 Date: 11/13/85 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public intsrest significance. The information presented is as initially received without verification

'or Gvaluation and is basically all that is known by Region V staff on this date.

FACILITY: Washington Public Power Supply System Licensee Emergency Classification WHP-2 Notification of Unusual Event Docket No. 50-397 Alert Site Area Emergency General Emergency XX Not Applicable.

SUBJECT:

TRIP OF WNP-2

' On November 13, 1985 at 6:02 am (PST), while operating at 50% power, a blown fuse in the wztsr level control system resulted in Reactor Feedpumps overfeeding the reactor vessel.

Thia condition resulted in high reactor vessel water level which properly tripped the

' turbine, thus leading, as expected, to a reactor trip. The licensee has experienced over "th2 past months- vibration problems with fast speed operation of the "B" recirculation pump This has necessitated plant operation below 73% power. The licensee has opted as a result of this. trip to stay shutdown for several days to allow the installation of additional instrumentation to monitor. vibration of the "B" recirculation pump. This vibration problem appears to have had no input into the plant trip. The licensee expects to resume plcut operation in 3 or 4 days. After the trip, the licensee's investigation revealed that a fculty inverter may have caused the blown fuse. -

- CONTACT: P. Qualls A. Toth FTS 463-3759 (509)-377-2627 DISTRIBUTION:

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ACRS Licensee: 2.'o9 CA (Reactor Licensees) REGION V: FORM 211 PDR Resident Inspector _ (Revised 3/14/83)

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PNO-V-85-077 - -

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