05000270/LER-1980-015, Forwards LER 80-015/03L-0

Forwards LER 80-015/03L-0

ML19344B583
Person / Time
Site:	Oconee
Issue date:	10/16/1980
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML16148A364	List: 05000270/LER-1980-015, Forwards LER 80-015/03L-0 05000270/LER-1980-015-03, /03L-0:on 800916,valve 2LP21 Failed to Open During Performance of Engineered Safeguard Channel Test.Caused by Loose Setscrew on Motor Driven Pinion.Screw Repaired
References
NUDOCS 8010210534
Download: ML19344B583 (2)

LER-1980-015, Forwards LER 80-015/03L-0

Event date:
Report date:
2701980015R00 - NRC Website

text

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DtJKE POWER COMPANY Powen Dint.nixo 422 Socin Cut:wcu Srster. CitAntorre; N. C. 2na42

'* w a o. 4anca.a.

October 16, 1980 i

Yect Persi= tut-7t6t h cot' N t* M 4 Set.* Pacouccow 2'34 93 Mr. James P.' 0'Reilly, Director 4

- U. S. Nuclear Regulatory Commission

~'

Region II 101 Marietta Street, Suite 3100

- Atlanta, Georgia 30303 4

Re: Oconee Nuclear Station, Unit 2 Docket No. 50-270 i

1

Dear Mr. O'Reilly:

I-Please find attached Reportable Occurrence Report R0-270/80-15. This report is submitted pursuant.to Oconee Nuclear Station Technical Specification 6.6.2.1.b(2),'which concerns operation in a degraded mode permitted'by a limiting condition for operation, and describes an incident which is con-sidered to be of no significance with respect to plant safety nor to its effect on the health and safety of the public.

t' Very.truly yours, L-r Af

(,

q7 William 0.~ Parker, Jr.

~

/F/Tf[

J1Jiscs Attachment J

i cc: Director Mr. Bill Lavallee Office of' Management'& Program Analysis Nuclear Safety Analysis Center

- U. S. Nuclear Regulatory Commission' P. O. Box 10412

Washington,TD. C.

20555 Palo Alto, California 94303 i

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1 8 010510gg e

o DUKE POWER COMPANY OCONEE UNIT 2 Report Number:

R0-270/80-15 Report Date: October 16, 1980 Occurrence Date:

September 16, 1980 Facility: Oconee Unit 2, Seneca, South Carolina Identification of Occurrence: Valve 2LP21 Inoperable Concitions Prior to Occurrence: Oconee 2 - 100% FP Description of Occurrence:

At 0848 on September 16, 1980, valve 2LP-21 failed to open during performance of the Engineered Safeguard Channel Test. Upon investigation of the failed valve, it was determined that the inoperability was due to a loose setscrew in a motor-driven pinion. The problem was corrected and the valve was returned to service at 1656 on September 16, 1980.

Apparent Cause of Occurrence:

The failure was caused by a loose setscrew on the motor-driven pinion of the "Limitorque" operator. The setscrew was tightened on June 25, 1980, so loosening from age can be ruled out.

Vibration is considered to be the most probable reason for the setscrew coming loose.

Analysis of Occurrence:

Operation with one train of the low pressure-injection (LPI) system out of service is permitted for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided the redundant train is operable.

In this particular incident the redundant train was available and the valve was returned to service well within the required 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period permitted by Oconee Nuclear Station Technical Specification 3.3.2.b(2).

Since this incident consti-tuted operation in a degraded mode permitted by a limiting condition for operatien, it must be reported in accordance with Technical Specification 6.6.2.1.b(2).

How-ever, this incident was of no significance with regard to safe operation, and the health and safety of the public were not affected.

Corrective Action

The immediate corrective action was to *:se the manual handwheel to open the valve and declare the valve inoperable. The loose screw was repaired and the valve returned to service.

Based on the valve's previous history, 2LP-21 can be expected to perform in a reliable manner.