ML20084T780
| ML20084T780 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 09/12/1972 |
| From: | Worden W COMMONWEALTH EDISON CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20084T764 | List: |
| References | |
| NUDOCS 8306240103 | |
| Download: ML20084T780 (1) | |
Text
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BOYCE GRIER,DIR OF COMPLIANCE REGION.3 US ATOMIC ENERGY.0055ff[S_SION 799 ROOSEVELT RD CLEN ELLYN ILL 60ib7 "c#
d SUPJECT8 DPR-25 DRESDEN NUCLEAR POWER ST g,Uf
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fj THIS WILL CONFIRM A C0!NERSATION WITH MR H :BANdE--C. GM pELIGL AT 114 5 HOURS THIS DATE CONCERNING TWO SEPA r
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ATE INCIDENTS ON UNIT 3.
_ gyer ON 9-9-72 VHILE MAKING A CALLAbATION ON EHC LOU OIL PRESSURE SCRAM SU ITCHES, THE SET POINT ON TWO SWITCHES WAS FOUND BELOW THE 900 PSIG TEC g
HNICJL SPECIFICATION LIMITS. PS-LS-1 HAD DRIFTED DOWN TO A SET POINT 0 F 895 PSIG. PS-LS-4 HAD DD f"TED DOWN TO A SET POINT OF 818PSIG.
PS-LS-1 MAS A HISTORY OF h
- TING SET POINT WHILE PS-LS-4 IS A NEW MO DEL SWITCH WITH A SUPOSIDL)
J. EATER ACCURACY. THE SET POINT ON ALL SUI TCHES HAS BEEN INCREASED TO 935PSIG. IN ADDITION A CALLABRATION CHECK WILL BE MADE ON PS-LS-4 ON A WEEKLY BASIS UNTIL THIS PROBLEM OF EXCESS t
8,.isos cuan i
IVE SET POINT DRIFT CAN BE CORR'ECTED.
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THE SECOND INCIDENT OCCURED ON 9-10-72 AT 0300 HOURS. LTILE CONDUCTING TURBINE WEEKLY CHECKS NUMBER 4 CONTROL VALVE FAILED TO INNICIATE A HA 15 SCRAM WHEN IT WAS FAST CLOSED. FUSE #590-725H WAS PULLED TO ACCUATE A HALF SCRAM UNTIL REPAIRS COULD BE COMPLETEDM MAINTENANCE CHECKED THE FAST ACTING SOLINOID ON #4 CONTROL VALVE AND F OUND IT LIMIT SWITCH WAS LOOSE. THE LIMIT SWITCH WAS ADJUSTED TIGHTENE D AND #4 CONTROL VALVE WAS TESTED SATISFACTORILY. ALL LIMIT SWITCHES WERE INSPECTED AND TIGHTENED. IN THE FUTURE DOUBLE NUTS WILL BE USED 0 N THE MOUNTING SCREWS WHICH SHOULD PREVENT THIS TYPE OF INCIDENT FROM
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REACCURING W P WORDEN SUPT DRESDEN NUCLEAR POWER STATION.
l DPR-25 3 1145 3 9-9-72 EHC 900 PSIG PS-LS-1 895PSIG PS-LS-4 81SPSIG P
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S-LS-1 PS-LS-4 935PSIC PS-LS-4 9-10-72 0300 #590-725H #4 #4 (1005A).
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