ML20236M671

PNS-I-87-012:on 870803,unlicensed Operator Found Indicating Lamp Lenses Changed on Uninterruptible Power Supplies in Vital Area of Plant.Lenses on Auxiliary Switchgear Panel Also Found Changed & Lens Missing.Licensee Investigating

ML20236M671
Person / Time
Site:	Limerick
Issue date:	08/05/1987
From:	Bailey R, Joyner J, Keimig R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNS-I-87-012, PNS-I-87-12, NUDOCS 8708110178
Download: ML20236M671 (1)

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DCS: 50-352/870805 Date: August 5,1987 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNS-87-12 This preliminary notification contains information of nuclear power plant physical security and/or public interest significance and has been confirmed by the licensee.

- Facility: Licensee Emergency Classification:

Philadelphia Electric Company Notification of Unusual Event Limerick Generating Station, Unit 1 Alert J.imerick, Pennsylvania Site Area Emergency Docket No. 50-352 General Emergency X Not Applicable

Subject:

POSSIBLE MALICIOUS EQUIPMENT TAMPERING At 11:30 a.m. on August 3, 1987, the NRC was notified that, at 11:45 p.m. on August 2, with the plant in cold shutdown and in the 82nd day of a refueling outage, an unlicensed operator on a routine tour had found the indicating lamp lenses changed on four pieces of equipment (uninterruptible power supplies) in a vital area in the plant. That operator reportedly had cbserved the colored lenses to be in the correct configuration approximately 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> earlier. The lenses have no effect on equipment operation. The inverters supply power to the reactor protection system and the process and security computers. At 10:30 a.m., on August 3,1987, two indicating lamp lenses on the 13KV Auxiliary Switchgear panel were also found changed and another lens was missing. Licensee security investigators are onsite

' reviewing access records and interviewing personnel . Similar occurrences were reported to the NRC and investigated by the licensee in February 1987. No perpetrator was then identified. The resident inspectors and Region I safeguards personnel are following the licensee's investigation.

The licensee did not notify the FBI.

The IAT and the Commonwealth of Pennsylvania have been notified. This PN is current as of Noon August 5,1987 and is issued for information only.

CONTACT: R. Bailey R. Keimig J. Joyner 488-1237 488-1255 488-1251 8708110178 PDR 18<E e70005 PNS-I-sy-012 PDR l

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