ML20086H106

AO 75-65:on 751002,drywell Radiation Monitor Inoperable. Caused by Rust Blockage of Pressure Control Valve.Valve Cleaned,Reassembled & Returned to Svc

ML20086H106
Person / Time
Site:	Peach Bottom
Issue date:	10/10/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Boyd R Office of Nuclear Reactor Regulation
Shared Package
ML20086H108	List: ML20086H106 ML20086H111
References
AO-75-65, NUDOCS 8401130428
Download: ML20086H106 (2)

Text

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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET PHILADELPHI A. PA.19101 1215)841-4000 October 10, 1975 Mr. Roger S. Boyd Acting Director O' Division of Reactor Licensing Office of Nuclear Reactor Regulations ,

United States Nuclear Regulatory Conmi ssion Washington, D. C. 20555 .A@

Dear Mr. Boyd:

Subj ect: Abnormal Occurrence The following occurrence was reported to Mr. Waf t Baunack, Region 1, Of fice of Inspection and F.nforcement, Uni ted States Nuclear Regulatory Commi ssion on October 3, 1975 Written notification was made to Mr. James P. O'Reilly, Office of Inspection and Enforcement, Region 1, United States Nuclear Regulatory Commission on October 3,1975 In accordance with Section 6.7 2.A of the Technical Specifications, Appendix A of DPR-56 for Uni t 3 Peach Bottom Atomic Power Station, the following report i s being submitted to the Directorate of Reactor Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-56 Technical Specification

Reference:

3 6.C.2 Report No.: 50-278-75-65 -

Repcrt Date: . Octcber 10, 1975 Occurrence Date: October 2, 1975 Facility: Peach Bottom Atomic Power Station R.D.1, Del ta, Penn sylvania 17314 Identification of Occurrence: ,

Drywell Radiation Monitor inoperabic.

Conditions Prior to Occurrence:

Uni t 3 at approximately 55% power.

Description of Occurrence:

An alarm was received indicating that sampling system exhaust pump suction pressure was low. During the subsequent investigation it was found that flow to the Drywell Radiation Moni tcring System was reduced due to a blockage at a pressure control valve.

I^1 8401130428 751010 ""' ~"

PDR ADOCK 05000278 B PDR RDPY SENT RBGI

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Mr. Roger S. Boyd October 10, 1975 (} 50-27I'I'65 Page i--

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4 Designation of Apparent Cause of Occurrence:

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Rust blockage of the pressure control valve.

Analysi s of Occurrence:

The Drywell Radiation Monitor was returned to service shortly after the problem was identified, and satisfactory operation has continued. Data

, displayed on the radiation monitor when returned to service indicated nornal' drywell radiation levels, making the safety implications of this occurrence minimal.

Corrective Action:

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The pressure control valve was disassembled and found to be partly clogged with rust particles from the carbon steel sample inlet piping. -The' pressure control valve was c1 caned, reassembled and returned to service.

Additionally, the carbon steel sample piping is scheduled to be replaced with' stainless steel, -

Failure Data:

None.

Very truly yours,

,f

• M. )'. Cooney% "!

Superintendent ,

Generation Divi sion - Nuclear

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i cc: Mr. J. P. O'Rei lly

Director, Region 1 -

Of fice of Inspection and Enforcement Uhited States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 1

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