ML20102B121
| ML20102B121 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 07/10/1992 |
| From: | Haile D SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Scarfo G NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| References | |
| REF-PT21-92 NUDOCS 9207280188 | |
| Download: ML20102B121 (2) | |
Text
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r-7 POWER REACTOR lEVENTNUMEER:
23834 FACILITY: SUMMER REGION:
2 NOTIFICATION DATE: 07/10/92 UNIT:
[1] [ ] [ ]
STATE: SC NOTIFICATION TIME: 17:32 [ET)
RX TYPE: [1] W-3-LP EVENT DATE:
07/10/92 EVENT TIME:
16:00[EDT)
NRC NOTIFIED BY: DAVID HAILE LAST UPDATE DATE:
07/10/92 HQ OPS OFFICER:
THOMAS ANDREWS NOTIFICATIONS EMERGENCY CLASS: NOT APPLICABLE 10 CFR SECTION:
CDEG 21. 21(c) (3) (i)
DEFECTS / NONCOMPLIANCE UNIT SCRAM CODE RX CRIT INIT PWR INIT RX MODE CURR PWR CURR RX MODE 1
N Y
100 POWER OPERATION 100 POWER OPERATION EVENT TEXT
{THEEVALUATIONOFANIDENTIFIEDDEFECtPOTENTIALLYASSOCI ED WITH A SUBSTANTIAL SAFETY HAZARD AS DESCRIBED IN AN INTERIM REPORT SUBMITTED ON JANUARY 6, 1992 HAS BEEN BEEN COMPLETED.
THIS EVALUATION RESULTED IN A DETERMINATION THAT THE SUBSTANTIAL SAFETY HA3ARD DID EXIST.
ON NOVEMBER 7, 1991, THE
'C' FEEDWATER ISOLATION VALVE ACTUATOR (XVG-1611C-0-FW) FAILED DURING POST MODIFICATION TESTING.
THE FAILURE HAS BEEN TRACKED TO A ' POPPET' SEAL IN THE CONTROL VALVE ASSEMBLY WHICH CONTROLS THE OPENING AND CLOSING OF THE FEEDWATER ISOLATION VALVE.
SUBSEQUENTLY, SEVERAL ADDITIONAL FAILURES OCCURRED DURING EXTENDED TESTING.
AS A RESULT, A NEW DESIGN ' POPPET' SEAL WAS EXTENSIVELY TESTED AND PLACED INTO SERVICE, RESOLVING THE PROBLEM.
AT THIS TIME, THE LICENSEE IS EVALUATING THE FAILURES AS FOLLOWS:
1.
TESTING BY AN INDEriNDENT LAB TO DETERMINE THE PHYSICAL PROPERTIES OF THE ORIGINAL ' POPPET' SEALS.
2.
COMPARING 'AS FOUND' PHYSICAL PROPERTIES OF THE ' POPPET' SEALS TO
'AS SPECIFIED' PROPERTIES.
3.
PERFORMING ' FINITE ELEMENT' ANALYSIS ON THE ORIGINAL AND NEW
' POPPET' SEAL DESIGNS.
4.
DEVELOPING CONCLUSIONS AS TO 10 CFR 20.21 REPORTABILITY.
THE LICENSEE EXPECTS TO COMPLETE THIS EVALUATION BY JULY 15, 1992.
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l TACILITY: SUMMER PAGE # 2 OF EVENT NUMBER: 23834 Til S NOTIFICATION IS BEING MADE PER THE REQUIREMENTS OF 0 CFR
- 21. 21(C) ( 3) (I). A WRITTEN REPORT WILL BE SUBMITTED WITHIN 30 DAYS.
THE NRC RESIDENT INSPECTOR HAS BEEN NOTIFIED.
NO OTHER NOTIFICATIONS ARE REQUIRED OR ANTICIPATED.
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