U.S. Nuclear Regulatory Commission
Operations Center
Event Reports For
01/24/2002 - 01/25/2002
** EVENT NUMBERS **
38648
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|Power Reactor |Event Number: 38648 |
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| FACILITY: SUSQUEHANNA REGION: 1 |NOTIFICATION DATE: 01/24/2002|
| UNIT: [1] [2] [] STATE: PA |NOTIFICATION TIME: 18:20[EST]|
| RXTYPE: [1] GE-4,[2] GE-4 |EVENT DATE: 01/24/2002|
+------------------------------------------------+EVENT TIME: 11:00[EST]|
| NRC NOTIFIED BY: GORDON ROBINSON |LAST UPDATE DATE: 01/24/2002|
| HQ OPS OFFICER: BOB STRANSKY +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: NON EMERGENCY |PETE ESELGROTH R1 |
|10 CFR SECTION: | |
|AINA 50.72(b)(3)(v)(A) POT UNABLE TO SAFE SD | |
|AINB 50.72(b)(3)(v)(B) POT RHR INOP | |
|AIND 50.72(b)(3)(v)(D) ACCIDENT MITIGATION | |
| | |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE
|
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1 N Y 93 Power Operation |93 Power Operation |
|2 N Y 100 Power Operation |100 Power Operation |
| | |
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EVENT TEXT
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| FAILURE OF REACTOR VESSEL WATER LEVEL SWITCH |
| |
| "At 11:00 EST, during performance of the 24 Month Calibration of Reactor |
| Vessel Water Level Channels on Unit 2, Level Indicating Switch |
| LIS-B21-2N031C would not properly relock following calibration. As a result |
| of this, the switch was declared inoperable. A review of the design drawings |
| revealed that this switch provides inputs (through relays) that affect the |
| reset logic for the 'A' and 'C' ESW pumps and the trips for the 'A' Reactor |
| and Turbine Building Chillers on a Low Reactor Water Level signal. Without |
| this switch functioning properly, the listed ESW pump start timers would not |
| reset as required and the listed chillers would not trip as required on the |
| Low Reactor Water signal. The Tech Spec Basis for this instrumentation |
| indicates that without these features, both offsite circuits and the |
| associated Diesel Generators would be inoperable. Given this, both offsite |
| sources and two (2) Diesel Generators were declared inoperable. SSES safety |
| analysis requires three Operable Diesel Generators to safely shutdown the |
| plant. Given this, this condition requires an 8 hour ENS notification in |
| accordance with 10CFR50.72(b)(3)(v). |
| |
| "As a result of this condition, LCO 3.0.3 was entered on both Unit 1 and |
| Unit 2 (in addition to other applicable LCO's). As of 13:00 on 01/24/02, the |
| switch was repaired and declared operable (and the associated LCO's were |
| cleared). |
| |
| "There were no Diesel Generators, ECCS, or Tech Spec Electrical Distribution |
| systems out of service at the time of the event." |
| |
| The NRC resident inspector has been informed of this notification by the |
| licensee. |
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