05000277/LER-1982-027, Forwards LER 82-027/01T-0.Detailed Event Analysis Encl

Forwards LER 82-027/01T-0.Detailed Event Analysis Encl

ML20065J553
Person / Time
Site:	Peach Bottom
Issue date:	09/24/1982
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20065J560	List: 05000277/LER-1982-027, Forwards LER 82-027/01T-0.Detailed Event Analysis Encl
References
NUDOCS 8210060074
Download: ML20065J553 (3)

LER-2082-027, Forwards LER 82-027/01T-0.Detailed Event Analysis Encl

Event date:
Report date:
2772082027R00 - NRC Website

text

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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 1215)841-4000 September 24, 1982 Mr. R. C. Haynes, Administrator Region I US Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

SUBJECT:

Licensee Event Report Narrative Description

Dear Mr. Haynes:

The following occurrence was reported to Mr. Blough, Region I, United States Nuclear Regulatory Commission on September 10, 1982.

Reference:

Docket No. 50-277 Report No.: 2-82-27/lT Report Date.: September 24, 1982 Occurrence Date: September 10, 1982 Facility: Peach Bottom Atomic Power Station RD#1, Delta, PA 17314 Technical Specification

Reference:

Technical Specification 3.7.A.2.

&V IS210060074 820924

! PDR ADOCK 05000277 (U .. PDR

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Mr. R. C. Haynes Page 2 Description of Event:

During the Unit 2 operational period from August 12 through September 10, 1982, oxygen content in the primary containment was within technical specifications, but hicher than normal. Purging requirements to maintain drywell pressure were also significantly less than normal. An investigation identified an open service air manual outer isolation valve. The service air system normally operates at 100 psig, and therefore provided a source of in leakage of air to the containment through leaking individual -

service air connection valves in the drywell.

Probable Consecuences of Occurrence:

The line in auestion is provided with an outer isolation valve and a check valve prior to entering containment. Inside containment the line has a second manual isolation valve as well as several valves where users of service air are normally connected. Since drywell pressure was maintained at 0.5 psig without frequent venting to control pressure, in leakage is believed to have been minimal. The service air system normally operates above even the maximum drywell pressure that would occur during a LOCA. That pressure difference would prevent leakage from the drywell, provided there is electrical power to the air

, compressors, and the service air piping is intact. The check j valve in this line inboard of the outer isolation valve, although .

not routinely tested, is an isolatiOu boundary which also '

provides resistance to out-flow from the containment if the service air pressure was less than containment pressure. The inner closed service air valves also would prevent out-leakage from containment, unless the service air piping within the drywell failed. Based on the remote probability of simultaneous high pressure transients in containment, release of fission products to containment, and a failure of the air piping both inside and outside containment, safety sionificance is considered minimal. Even in this event, the check valve in the line outside containment would restrict out leakage.

Cause of the Event:

During a Unit 2 planned maintenance outage, the service air to the containment was placed in service. This involved opening both the inner and outer locked closed isolation valves on this line. At the end of the planned maintenance outage, the unit was started up without returning these valves to the closed and

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Mr. R. C. Haynes Page 3 locked position. Based on the primary containment integrity definition in paragraph 1.0 of the technical specificiations, primary containment integrity was therefore not established during reactor operation. Investigation indicated that the cause of this event was due to the failure of operations personnel to make an entry in the locked valve log book upon unlocking the valves. As a result, review of the locked valve log book by operations oersonnel prior to start un did not indicate that these valves were not in the proper position.

Corrective Action:

The outer isolation valve was closed and locked shortly after it was identified as being opened. In order to determine tha status of the inner isolation valve, a plant shutdown was initiated on 9/10/82. Containment entry was made, and the inner isolation valve which was found open, was closed and locked.

With primary containment re-established, reactor startup was initiated. Additional corrective action undertaken to this event is a repeat of the locked valve check-cff list for Unit 2.

The importance of adhering to Administrative Procedures concerning locked val 7es was re-emphasized with operations personnel. In addition, steps are being taken to highlight the locked valves so that the importance is more easily recognized by plant personnel. This effort will be completed for accessible valves by 11/1/82 and for inaccessible valves during the next outage with a planned duration of more than 5 days.

Valving oroblems at Peach Bottom have been reviewed and additional actions in the areas of training and controls are being considered.

Very truly yours, hk M,[J. Cooney Superintendent Generation Division - Nuclear cc: Director, NRC - Office of Inspection & Enforcement Mr. Norman M. Haller, NRC - Off.of Mgmt & Prog. Anal.

R. Blough, Site Inspector