05000344/LER-1981-029, Forwards LER 81-029/03L-0.Detailed Event Analysis Encl

Forwards LER 81-029/03L-0.Detailed Event Analysis Encl

ML20039F519
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	12/31/1981
From:	Yundt C PORTLAND GENERAL ELECTRIC CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20039F520	List: 05000344/LER-1981-029, Forwards LER 81-029/03L-0.Detailed Event Analysis Encl 05000344/LER-1981-029-03, /03L-0:on 811202,containment Hydrogen Vent Sys Supply Valves Found Not Limited in Travel Per 800101 Commitment to Nrc.Caused by Valves Not Being Used During Modes 1-4.Valves Tagged Shut Until Adjustment Is Made
References
CPY-1038-81, NUDOCS 8201130067
Download: ML20039F519 (2)

LER-1981-029, Forwards LER 81-029/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3441981029R00 - NRC Website

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smut Portland General Electric Company Trojan Nuclear Plant P.O. Box 439 December 31, 1981 Rainier, Oregon 97048 CPY-1038-81 (503)556-3713 N

O Mr. R. H. Engelken, Director p

US Nuclear Regulatory Commission RECEIVED Region V - Suite 210 1450 Maria Lane g y pgg 8

Walnut Creek, CA 94596-5368 L

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Dear Sir:

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In accordance with the Trojan Plant Operating License, Appendix A, US NRC Technical Specification 6.9.1.9.c, attached is Licensee Event Report No. 81-29, concerning a failure to implement changes to the Hydrogen Vent System. At least one Containment Hydrogen Vent System must be operable in Modes 1 and 2 per STS 3.6.4.3.

It was discovered that the hydrogen vent supply valves were set to go full open versus a commitment to limit the degree to which they should open. The valve travel limit is necessary to assure the operability of the system.

These valves were shut at the-time of the discovery and are not normally operated in Modes 1-4.

There was no effect on the public' health or safety. This is a 30-day reportable occurrence.

Sincerely, Sw C. P. Yundt General Manager NA lt]ll-CPY/MLD/GJK:bb Attachments c: LER Distribution

_s llI M*uwaan:

PDR

REPORTABLE OCCURRENCE 1.

Report No.:

S1-29 2.

a.

Report Date:

December 31, 1981 b.

Occurrence Date: December 2, 1981 3.

Facility: Trojan Nuclear Plant, PO Box 439, Rainier, Oregon 97048 4.

Identification of Occurrence:

During a routine inspection by an NRC resident inspector, the Contain-ment Hydrogen Vent System supply valves were found not to be limited in travel as was required by a previous commitment to the NRC.

This raised a question of operability of the system per STS 3.6.3.1.

5.

Conditions Prior to Occurrence:

The plant was in Mode 1 at 100% power and steady state operation.

6.

Description of Occurrence:

Containment Hydrogen Vent System valves were to have been limited to 50 degrees open per a commitment dated January 1, 1980 and repeated

'in October 1981. NRC resident inspector found that their was no objective evidence that the supply valves were limited to 50 degrees open.

Inspection performed by plant personnel verified that the supply valves were in fact not limited to 50 degrees open.

7.

Designation of Apparent Cause of Occurrence:

These valves were not limited to 50 degrees because they are not opened during operation in Modes 1-4 to provide a path into the Containment.

Therefore, when the discharge valves travel was limited to 50 degrees, the plant wrongly believed that there was no need to limit the suction valves.

8.

Significance of Occurrence:

There was no effect on plant or public safety since these valves are normally shut in Modes 1-4.

9.

Corrective Action

Immediate corrective action included ensuring that these valves were tagged shut and adjusting the limit of travel of the two vent supply valves outside containment to 50 degrees open.

The two valves inside Containment will be set during the next refueling shutdown.