PNO-I-85-051A, on 850717,diesel Generator 1 Failed Monthly Surveillance Test.Initially Attributed to Possible Tampering W/Load Limit Setting Knob.Investigation Concluded That Knob May Have Been Inadvertently Moved During Cleaning

PNO-I-85-051A:on 850717,diesel Generator 1 Failed Monthly Surveillance Test.Initially Attributed to Possible Tampering W/Load Limit Setting Knob.Investigation Concluded That Knob May Have Been Inadvertently Moved During Cleaning

ML20126L812
Person / Time
Site:	Beaver Valley
Issue date:	07/25/1985
From:	Lester Tripp, Wenzinger E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-85-051A, PNO-I-85-51A, NUDOCS 8508010043
Download: ML20126L812 (1)

r DCS No: 50334850717 Date: July 25, 1985 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-I-85-51A 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 the Region I staff on this date.

Facility: Licensee Emergency Classification:

Duquesne Light Company Notification of Unusual Event Beaver Valley Unit 1 Alert Shippingport, PA Site Area Emergency DN 50-334 General Emergency X Not Applicable

Subject:

POTENTIAL TAMPERING WITH DIESEL GENERATOR (UPDA'E) T At about 1:00 a.m. on July 17,1985, the No.1 Diesel Generator (DG) failed its routine monthly surveillance test (would only accept 390 kw load; normal full load is 2850 kw).

Subsequent licensee investigation disclosed that the Woodard governor load limit setting (knob) was set at 3 as compared to the normal setting of 10. As reported in PNO-I-85-51, licensee review was continuing including investigation of the changed load limit setting as a possible tampering act.

Subsequent licensee checks of other critical safety equipment disclosed no other abnormal conditions. Personnel interviews of persons entering the DG area subsequent to the last successful surveillance test did not identify any person (s) who had reason to or would admit changing the load limit setting. After contacts with the DG manufacturer and further evaluation of the DG Woodard governor controls, the licensee has concluded that, contrary to the earlier evaluation, the load limiter setting (knob) can be inadvertently changed with one motion with the DG in the normal standby condition if the fuel rack lever is in the full out position (a possible final position after the end of a surveillance test). 'It was noted that the No. 1 DG had received extensive cleaning during the time period between successive surveillance tests (3 men ,

for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> each). Although the possibility of a tampering act cannot be ruled out, the licensee believes the most probable explanation of the changed setting is that it was caused by an inadvertent act such as an accidental bumping during cleaning.

The Commonwealth of Pennsylvania has been notified.

CONTACT: L. E. Tripp E. C. Wenzinger 488-1227 488-1224 DISTRIBUTION:

H. St. MNBB Phillips E/W Willste Mail: ADM:DMB Chairman Palladino EDO NRR IE NMSS DOT:Trans only Comm. Zech PA OIA RES Comm. Bernthal ELD AE00 Comm. Roberts Comm. Asselstine 3: 9 ACRS Air Rights INP0-SECY SP NSAC g g CA PDR Regional Offices TMI Resident Section }_ O RI Resident Office 3'rs Licensee:

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