ML20086G859

AO 75-37:on 750701,main Steam Line Radiation Monitor RIS 3-17-251C Failed Downscale.Caused by Failure of Test Relay to Pick Up Following Test.Failed Test Relay Replaced & Drawer Receipt of Detector Signal Verified

ML20086G859
Person / Time
Site:	Peach Bottom
Issue date:	07/11/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Anthony Giambusso Office of Nuclear Reactor Regulation
Shared Package
ML20086G862	List: ML20086G859
References
AO-75-37, NUDOCS 8401120545
Download: ML20086G859 (2)

Text

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PHILADELPHIA ELECTRIC COMPANY, f

2301 MARKET STREET PHILADELPHI A. PA.19101 azist 84t-4ooo July 11, 1975 r

Mr. A. Gi ambusso

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/1 Director f

Division of Reactor Licensing Office of Nuclear Reactor Regulations United States Nuclear Regulatory Commission Washington, DC 20555

Subject:

Abnormal Occurrence f

The f ollowing occurrence was reported to Mr. Tom Shedlowsky, Region 1, Of fice of Inspection and Enforcement, United States Nuclear Regulatory Cornnission on July 2,1975 Written notification was made to Mr. James P. O'Reilly, Region 1, Of fice of Inspection and Enf orcement, United States Nuclear Regulatory Commission on July 2, 1975 In accord-ance with Section 6 7 2.A of the Technical Specifications, Appendix A of DPR-56 for Unit 3 Peach Bottom Atomic Power Station, the following occurrence is being submitted to the Directorate of Reactor. Licensing as an Abnormal Occurrence.

Reference:

License Number DPR-56 Technical Specification

Reference:

3 1 Table 3 1.1 Report No.:

50-278-75-37 Report Date:

July 11,1973 Occurrenec Date:

July 1,1975 F aci li ty:

Peach Bottom Atomic Power Station R.D. 1, Delta, Pennsylvania 173i4 q <

Identification of Occurrence:

Main Steam Line Radiation Monitor RIS 3-17-131C failed down-i scale.

Conditions Prior to Occurrence:

Plant operating at approximately 50% power.

Description of Occurrence:

Main Steam Line Radiation Monitor RIS 3-17-251c' failed downscale while the plant was operating at approximately 50% power'.

lhe downscale resulted from a loss of signal due to failure of the test relay to pick up after testing.

8401120545 750711 PDR ADOCK 05000278

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1 Mr.A.Giambus*o O

J 50-278-75-37 July 11, 1975 Page 2 i

Designation of Apparent Cause of Occurrence:

Failure of the test relay to pick up following test.

' Analysis of Occurrence:

The Monitor downscale f ailure made the particular channel'

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inoperative. Because of the redundant channels of instrumentation, the remaining Main Steam Line High Radiation Isolation and Scram signals l

still had the capability of performing their intended functions.

Mini-mal safety significance is attached to this occurrence.

~

Corrective Action:

The f ailed test relay was innediately replaced end it was i

verified that the drawer was again receiving the detector signal.

1 Failure Data:

One previously reported as Abnormal Occurrence 50-278-75-16.

Very truly yours, M

J. Cooney Ass't Gen'l S perintendent Generation Division cc:

Mr. J. P. O'Reilly Director, Region 1 Office of Inspection and Enforcement United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 t

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