ML18353B276

Palisade - 04/28/1975 Letter Submitting Abnormal Occurrence Report AO-75-09 Re Containment High-Pressure Switch Out of Calibration

ML18353B276
Person / Time
Site:	Palisades
Issue date:	04/28/1975
From:	Sewell R Consumers Power Co
To:	Office of Nuclear Reactor Regulation
References
Download: ML18353B276 (3)

Text

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• consumers

• Power company General Offices: 212 West Michigan Avenue, .Jackson, Michigan 49201

• Area Code 517 788-0550 April 28, Division of Reactor Licensing Re: Docket 50-255 US Nuclear Regulatory Commission License DPR-20 Washington, DC 20555 Palisades Plant A0-75-9 Gentlemen:

Attached is Abnormal Occurrence Report A0-75-9. This occurrence was not recognized or designated to be an abnormal oc-currence until April 17, 1975. The analysis of the occurrence concluded that there was no significant effect on safety.

Yours very truly, DAB/mel Ralph B. Sewell Nuclear Licensing Administrator CC: JGKeppler, USNRC

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• ABNORMAL OCCURRENCE REPORT Palisades Plant

l. Report Number: A0-75-09, Docket 50-255.

2. a. Report Date: April 25, 1975.

b. Occurrence Date: April 17, 1975.(designated an abnormal occurrence).

3. Facility: Palisades Plant, Covert, MI.

4. Identification of Occurrence: *Containment high-pressure switch out of calibration.

5. Conditions Prior to Occurrence: On December 23, 1974, when three out of four high-pressure switches were observed to be above the Technical Specifications limit, the plant was in a shutdown condition.*

6. Description of Occurrence: While performing refueling 9urveillance Procedure M-VAS-2 containment high pressure on December 23, 1974, it was found that three of the four reactor trip pressure switches (PS-1801,

es-1802 and PS-1803) were above the Technical Specifications limit (Table

• 2.3.l) of less than or equal to 5 psig by 0.2 to 0.3 psig

• The switch settings were immediately corrected. However, this was not recognized as a reportable incident until April 17, 1975 due to the press of other activities.

7. Designation of Apparent Cause of Occurrence: When these switches were re-placed (see AO letter dated 3-26-74) during July 1974, their subsequent calibration was performed using "Normal Maintenance Procedure M-MSI-5 Basic Pressure Switch Calibration and the Instrument Index" instead of the "Refueling Surveillance Procedure M-VAS-2." The instrument index set point called for a 5 psig set point instead of 4.8 psig as per the sur-veillance procedure.

8. Analysis of Occurrence: The use of the incorrect maintenance procedure was the result of a human error. The out-of-calibration condition existed for only one month of power operation, October 1974. Due to the small error relative to the containment design.pressure, we conclude that this occurrence had no significant effec~ on safety.

9. Corrective Action:

a. Revise instrument index to reference proper section of Technical Specifications rather than an absolute number.

b. Revise remarks statement in surveillance procedures to read "if as-found tolerances are.outside expected band, report to I and C Engineer for prompt initiation of an abnormal occurrence report, if r:equ.ired. 11

• 9. Corrective Action:

c.

(Contd)

Revise the surveillance procedure set point to allow for an 0.3 psig set point drift instead of the present 0.2 psig allowance.

10. Failure Data: Not applicable

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