ML20114B177
| ML20114B177 | |
| Person / Time | |
|---|---|
| Site: | University of Wisconsin |
| Issue date: | 12/31/1991 |
| From: | WISCONSIN, UNIV. OF, MADISON, WI |
| To: | |
| Shared Package | |
| ML20114B174 | List: |
| References | |
| NUDOCS 9208250179 | |
| Download: ML20114B177 (1) | |
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bWNR'ANNUALREPoRT 1991-92 PAGE 9 or 14 B.
OPERATING STATISTICS AND FUEL EXPOSURE Critical Ooeratina Period
.Sla.rigns
_ Hrs MW Hrs Pu!scs FY 1991-92 138 637.67 556.07 36 Total Present Core 2430 899i.74 7475.59 570 Total TRIGA Cores 4465 1G256.73 12463.77 1881 I
The excess reactivity of core 123 R12 increased slightly during the year to 4.51 percent.
C.
EMERGENCY SHUTDOWNS AND INADVERTENT SCRAMS There were 7 automatic scrams during the year distributed as follows:
7/25/91 High pool level alarm due to thermal expansion plus currents due to leak in polyethylene tube conveying water to whale tube C2.
The currents caused actuation of the float switch while the pool level was below the actual setpoint. The polyethylene tubing was replaced.
T. s following 6 scrams are retrospectively classified as range switch problems on the picoammeters. The picoammeters provide an electronic scram function, as well as the techrJeal specification required electronic scram. This electronic scram sometimes actuates even though the bistable (which produces both electronic and relay scrams) does not change state.
6/1/91
& 8/1/91 (2 scrams)
Electronic scrams in one case while reducing power, in the other case during steady-state operatk n with no control manipulations taking place. No upscale movements on any instruments, and no bistable operation. After investigation, solder joints in the logic element were resoldered, and the contacts of the logic element connector were burnishea.
9/24/91 Another electronic scram with no upscale indication on any instrument. Since this appeared to be a recurrence of the electronic scrams on 8/1/91, it was decided to replace one of the three instruments (logN-period amplifier and the two 4208250179 920819 gDR ADoCKOSoog6 1
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