ML20086J475

AO 74-6:on 740915,instrument Piping to Main Steam Line High Flow Differential Pressure Indicator Switches on Main Steam Line B Found Reversed.Caused by Piping Reversed in Instrument Piping Tray During Installation

ML20086J475
Person / Time
Site:	Peach Bottom
Issue date:	09/25/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086J477	List: ML20086J475 ML20086J479
References
AO-74-6, NUDOCS 8401240029
Download: ML20086J475 (2)

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PHILADELPHIA ELECTRIC COMPANY i~> 'f; bkjac dfo  ;

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. d September 25, 1974 Mr. A. Giambusso Deputy Director of Reactor Projects United States Atomic Energy Commission Directorate of Licensing Washington, D.C. 20545 -

Dear Mr. Giambusso:

Subiect: Abnormal Occurrence The following occurrence was reported to Mr. Walt (

Baunack, A.E,C. Region 1 Regulatory Operations Office on September 16, 1974.

Written notification was made to Mr. James P. O'Reilly Region 1 Regulatory Operations Office on September 16, 1974. In accordance with Section 4.7.2.A of the Technical Specifications, Appendix A of DPR-56 for Unit 3 Peach Bot tom Atomic Power Station, the following report is being submitted to the Directorate of ,

Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-56 Technical Specification Reference 3.2. A Report No.: 50-278-74-6 Report Date: September 25, 1974 Occurrence Date: Septenber 15, 1974 Facility: Peach Cottom Atomic Power Station R. D. 1, Delta, Pennsylvania 17314 Identification of Occurrence:

Instrument piping to the Unit 3 Main Steam Line High Flow Differential Pressure Indicator switches (DPIS) on the "B" Main Steam Line was reversed.

Condi tions Prior to Occurrence:

Reactor operating at approximately 2 7 pawar. Startup testing in progress.

8401240029 740925  :

PDR ADOCK 05000278 S PDR o b , #_a '/(0

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E GOPY SENT REGk'ON [ .

, -Mr. A. Giambusso September 25, 1974 'T f Page 2

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's Description of Occurrence:- .

During a routine inspection of the plant the operator no'ted D all four DPIS on the "B" Main Steam line were reading downscale while i the DPIS on the other main steam lines were reading slightly upscale. -

Designation of Apparent Cause of Occurrence: q

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The piping was reversed in the instrument piping tray during installation.

Analysis of Occurrence:

The reversed differential rendered the four high flow switches unable to respond to a high flow condition in the "B" -

main steam line. Thus, a Group I's isolation due to a "B" main -

steam line rupture would have been prevented. This is the first ,

time the reactor has been at this power level and therefore the ,

first time that significant steam flow element differential pressure i has been available to verify correct' operation of these switches.

N ed Corrective Action:

Both Main Steam Isolation Valves (MSIV) in the "B" steam line were shut. Instrument piping at the instrument rack was temporarily re-piped to. produce the proper differential to the DPIS.

Surveillance tests were performed on all four DPIS to verify operability and setpoints. The "B" steam line MSIV's were re-opened i with the resultant proper indication on all f'our DPIS. 'The 12 i DPIS on the three other main steam lines were all checked ~and N found to be operating properly. Permanent piping corrections are being made during the current outage.

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lVeryjtruly.yours,

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Z f.e'gi M.'

. Cooney) ,

. As s t . L Ge n ' 1 '. Superintenden t; Generation Division cc: Mr. J. P. O'Reilly- ~

Director, Region'l' .

United States-Atonic _ Energy Comnission-

- 631'ParkEAvenue King of' Prussia, PA 19406 Il L

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