ML20102B104
| ML20102B104 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 05/08/1992 |
| From: | Labruna Public Service Enterprise Group |
| To: | Scarfo G NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| References | |
| REF-PT21-92 NUDOCS 9207280177 | |
| Download: ML20102B104 (1) | |
Text
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e h0WERREACTOR ENT NUMBER:
23429 j
FACILITY: HOPE CREEK REGION:
'l NOTIFICATION DATE: 05/08/92 UNIT:
[1] [ ] [ ]
STATE: NJ NOTIFICATION TIME: 17:43 [ET)
RX. TYPE: [1] GE-4 EVENT DATE:
05/04/92 EVENT TIME:
12:00[EDT)
NRC NOTIFIED BY: LABRUNA LAST UPDATE DATE:
05/08/92 HQ OPS OFFICER:
GREG SCARFO NOTIFICATIONS EMERGENCY CLASS: NOT APPLICABLE 10 CFR SECTION:
CDEF 21. 21(b) (2)
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 l EVENT TEXT A DESIGN DEFECT WAS DISCOVERED IN THE DEGRADED GRID TRIP / BUS TRANSFER SCHEME FOR CLASS IE VITAL BUS EQUIPMENT.
THIS DESIGN WAS SUPPLIED BY j
BICHTEL POWER CORPORATION.
l THE-STATION SERVICE. TRANSFORMERS "1AX501" AND "1BX501" (13.8KV/4.16KV)
UTILIZE AUTOMATIC LOAD TAP CHANGERS WHICH EACH FEED TWO OF FOUR CLASS 1E BUSES.
AN EMGINEERING ANALYSIS INDICATES THAT IF AN AUTOMATIC LOAD CHANGER FAILED IN 'THE " LOW POSITION" CONCURRENT WITH A LOCA, A BUS SWAPOVER FROM ONE: STATION SERVICE TRANSFORMER TO THE.OTHER (THE ALTERNATE POWER SUPPLY)
COULD OCCUR.
AC POWER SUPPLIED TO THE CLASS IE LOADS COULD BE ELECTRICALLY OUT-OF-PHASE WITH THE ORIGINAL POWER SUPPLY AND MAY DAMAGE THE SAFETY EQUIPMENT.
BECHTEL POWER CORPORATION SUPPLIED THE DESIGN OF THIS BUS L
TRANSFER SCHEME.
A CORRECTIVE ACTION WAS IMPLEMENTED TO INCORPORATE A
.7 SECOND TIME DELAY IN THE LOADING SCHEME TO ALLOW LOADS TO DROP OFF OF THE AUTO-SWAPPED CLASS 1E BUSES AND PREVENT 'IHEM FROM BEING DAMAGED.
THE LICENSEE HAS DETERMINED THAT THE ADDITIONAL TIME DELAY WILL NOT AFFECT THE ACCIDENT LOADING. THE LICENSEE IS DRAFTING A PART 21 REPORT AND WILL SUBMIT IT WITHIN 30 DAYS, l
l I
9207280177 920508 ADOCKOSOOg4 DP V
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