ML20086J058

AO 75-19:on 750304,setpoint of Condenser Low Vacuum Scram Pressure Switch Found Outside Tech Spec Limits.Caused by Setpoint Drift.Switch Recalibr to within Tech Spec Limits

ML20086J058
Person / Time
Site:	Peach Bottom
Issue date:	03/14/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A Office of Nuclear Reactor Regulation
References
AO-75-19, NUDOCS 8401230077
Download: ML20086J058 (2)

Text

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C U PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET PHILADELPHIA. PA.19101 (215) 841-4o00 March 14, 1975

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s f' '/.9 Mr. A. Giambusso '

Ni Director Division of Reactor Licensing 4 X.%3 v; , ', g*: .

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Of fice of Nuclear Reactor Regulations . Um ,

United States Nuclear Regulatory Commission

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Washington, DC 20555

Subject:

Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, Region 1, Of fice of Inspection and Enforcement, U.S. NRC on March 5, 1975 Written notification was made to Mr. James P. O'Reilly, Region 1, Of fice of Inspection and Enforcement, U.S. NRC on March 5, 1975 In accordance with Section 6.7 2.A of the Technical Specifications, Appendix A of 11PR 4h for liri r ? Paach Rat + = a+ ir D~ne S t :t i c ., t h e f ! ! c.. i r,-

report is being submitted to the Directorate of Reactor Licensing as an Abnormal Occurrence. v

Reference:

License Number DPR-44 Technical Specification

Reference:

Table 3 1.1 Report No.: 50-277-75-19 Report Date: March 14, 1975 ,

Occurrence Date

March 4, 1975 Facility: Peach Bottom Atomic Power Station l R.D. 1, Delta, Pennys1vania 17314

, Identification of Occurrence:

l Setpoint of condenser low vacuum scram pressure switch found to be outside the limits allowco by the Technical Specifications.

Conditions Prior to Occurrence:

Reactor was operating at 100% power.

Description of Occurrence:

During a routine instrument surveillance test, the setpoint

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- of the low vacuum scram swi tch, PS-2-5-11C was found to be outside the f limit of greater than or equal to 23 in. Hg. The device was found to trip at 22.85 in. Hg. The trip function of the device performed satis-I factorily. 298.l 8401230077 750314

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March 14, 1975 Page 2 <

Designation of Apparent Cause of Occurrence:

Setpoint drif t of the pressure switch.

Analysis of Occurrence:

The contacts of this device are arranged in a one-out-of-two twice trip logic. The setpoint of this device, not the trip function, was unsatisfactory. All other devices monitoring the parameters of condenser vacuum were immediately tested and found to be operational and correctly calibrated. Because of the above, this occurrence has

- minimal safety implications. "

Corrective Action:

The out-of-tolerance pressure switch was immediately recali-brated to within the allowable limits of the Technical Specifications.

Failure Data:

Six occurrences of this type have been previously reported as:

A0-50-277-74-1, A0-50-277-74-19, A0-50-278-74-24, A0-50-277-74-35, A0-50-277-43 and A0-50-277-75-1.

Very truly yours, jf . /#

M. . Cooney Ass' t Gen' t Superintendent Generation Division i

g cc: Mr. J. P. O'Reilly, Director Region 1 Office of Inspection and Enforcement United States Nuclear Regulatory Cannission 631 Park Avenue King of Prussia, PA 19406

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