ML20084N861

Telecopy Ro:On 750826,pressure Switches PS3-263-53A,53B & 53C Drifted Above Tech Spec Limit.Probably Caused by Inactivity Due to Refueling Outage

ML20084N861
Person / Time
Site:	Dresden
Issue date:	08/28/1975
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	Rusche B Office of Nuclear Reactor Regulation
Shared Package
ML20084N845	List: ML20084N841 ML20084N853 ML20084N859 ML20084N861
References
NUDOCS 8306090097
Download: ML20084N861 (1)

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WU INF0 MASTER l-011234C240 08/28/75 ,

TLX"WU TFC WSH 030 '

TWX 7108240415 NRC BHDA SPLO30 WAD 037 (0949)(2-00 8125D240-001 )PD 08/2 8/7 5 0901 '

ICS IPMWAWF WSH - '

SUSPECTED DUPLICATE: 2-007725E240 WAD 026 ICS IPMBNGZ CSP 8159424449 TDBN MORRIS IL 206 08-28 0830A CDT -

PMS DERNARD C RUSCHE, DIRECTOR DIRECTORATE OF LICENSING WUX US NUCLEAR REGULATORY COMMISSION -

WASHINGTON DC 20555 C

SUBJECT:

DPR-25, DRESDEN NUCLEAR POWER STATION, UNIT 3 THIS WILL

' CONFIRM A CONVERSATION WITH MR R KNOP OF YOUR OFFICE AT 1710 HOURS 8-26-75 CONCERNING INSTRUMENT DRIFT OF -

1. ISOLATION CONDENSOR SUSTAINED HIGH REACTOR PRESSURE SWITCHES PS3-263-53A,8&C TO A90VE THE TECH. SPEC. LIMIT OF LESS THAN OR E006L TO 1070 PS IG. PS3-263-53A WAS FOUND AT 1090PSIJ 538 AT 10 87PS I J 53C AT ll22 PSI. SWITCHES ARE :lELETRON TYPE AND DRIFT IS BELIEVED CAUSED

.8Y INACTIVITY CAUSED BY CURRENT REFUEL OUTAGE. '

2. ADDITIONALLY, REACTOR PRESSURE ECCS INITIATION SWITCHES PS3-263-52A-1 AND SPA-2 WERE ALSO FOUND ABOVE TECH. SPEC LIMITS OF 300PSIG LESS THAN OR EQUAL TO P LESS THAN OR EQUAL TO 3 50PS IG . THE MELETRON SWITCHES WERE FOUND AT 365PS I (A-1) AND 366 PSI (A-2). THESE DRIFTS ALSO ARE BELIEVED TO BE CAUSED BY INACTIVITY.

3. MAIN STEAM LINE DRAIN ISOLATION VALVE M03-220-1, DURING MAINTENANCE, WAS FOUND WITH A FAILED OVERLOAD RELAY WHICH CAUSED MALOPERATION OF THE VALVE DURING TESTING. PRIMARY CONT AINMENT INTEGRITY MAY HAVE BEEN AFFECTED IN THE SINGLE FAILURE MODE WOULD '

HAVE AN ISOLATION DURING OPERATION OC, CURRED. ADDITIONAL INFORMATION ,.

, WILL FOLLOW IN A TEN DAY REPORT.

B B STEPHENSON SUPERINTENDENT DRESDEN NUCLEAR POWER STATION COMMONWEALTH EDISON CO RR.! MORRIS ILLINOIS 60450 s I

1046 EST ,

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