PNO-I-87-096, on 871016,plant Scrammed on High Neutron Flux from 89% Power During Testing Causing Main Steam Pressure Oscillations Triggering APRM High Flux Scram.Crd Stub Tube Leakage Identified.Hydrostatic Tests Performed

PNO-I-87-096:on 871016,plant Scrammed on High Neutron Flux from 89% Power During Testing Causing Main Steam Pressure Oscillations Triggering APRM High Flux Scram.Crd Stub Tube Leakage Identified.Hydrostatic Tests Performed

ML20235Z560
Person / Time
Site:	Nine Mile Point
Issue date:	10/19/1987
From:	Cook B, Jerrica Johnson NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-87-096, PNO-I-87-96, NUDOCS 8710210195
Download: ML20235Z560 (1)

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DCS No: 50220871016

, Date: October 19, 1987 F

i PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-I-87-96 I

This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without h verification or evaluation, and is basically all that is known by the Region I staff on this date.

{

l Facility: Licensee Emergency Classification: l

[. Niagara Mohawk Power Corporation Notification of Unusual Event j l Nine Mile Point Unit 1 Alert i DN 50-220 Site Area Emergency '

General Emergency X Not Applicable

Subject:

FORCED OUTAGE GREATER THAN 48.,HOUTS At 12:26 a.m. on 10/16, the plant scrammed on high neutron flux from 89*4 power during 1 a weekly Turbine Stop Valve surveillance test. A failure in the Electrical Pressure Regulator (EPR) caused main steam premre oscillations which triggered the APRM high flux scram before operators could shift to the Mechanical Pressure Regulator (MPR).

The licensee entered the drywell to identify sources of leakage and discovered a potential Control Rod Drive stub tube leek which may require stub tube rolling. As of 10:00 a.m. on 10/19 the licensee was making preparations to perform a hydrostatic test at 500 psig to pinpoint the laakage. Startup could occur as early as Wednesday, 10/21 if stub tube rolling is not required.

The resident inspectors are onsite monitoring the licensee's actions. '

The State of New York has been notified.

CONTACT: Jon Johnson Bill Cook 488-1234 8-315-342-4041 DISTRIBUTION:

H. St. MNBB Phillips E/W Willste Mail: ADM:DMB Chairman Zech EDO NRR NMSS DOT:Trans only Comm. Roberts PA OIA RES Comm. Bernthal OGC AEOD NRC Ops Crt Comm. Carr Comm. Rogers ACRS Air Rights INP0----

SECY SP NSAC----

CA PDR Regional Offices _ TMI Resident Section RI Resident Of fice Licensee:

Region I Form 83 (Reactor Licensees)

(Rev. August 1987) c0 fo V R 130L8bi SG-08NSO 8710210195 071019 1. b o i PDR I&E $ 5 PNO-I-87-096 PDR

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