this unexpected loss of an auxilliary transformer is attributed to "INVALID SIGNAL FROM THE TRANSFORMER FAULT | PRESSURE RELAY." Power Reactor |Event Number: 36576 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: THREE MILE ISLAND REGION: 1 |NOTIFICATION DATE: 01/10/2000| | UNIT: [1] [] [] STATE: PA |NOTIFICATION TIME: 14:02[EST]| | RXTYPE: [1] B&W-L-LP,[2] B&W-L-LP |EVENT DATE: 01/10/2000| +------------------------------------------------+EVENT TIME: 11:45[EST]| | NRC NOTIFIED BY: JOHN SCHORK |LAST UPDATE DATE: 01/10/2000| | HQ OPS OFFICER: STEVE SANDIN +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: N/A |LAWRENCE DOERFLEIN R1 | |10 CFR SECTION: | | |AESF 50.72(b)(2)(ii) ESF ACTUATION | | | | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |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 +------------------------------------------------------------------------------+ | AUTOSTART OF THE "1B" EMERGENCY DIESEL GENERATOR DUE TO THE UNEXPECTED LOSS | | OF THE "A" AUXILIARY TRANSFORMER | | | | THE "1B" EMERGENCY DIESEL GENERATOR AUTOSTARTED AND LOADED FOLLOWING THE | | LOSS OF THE "A" AUXILIARY TRANSFORMER. A PRELIMINARY INVESTIGATION | | ATTRIBUTES THE CAUSE TO AN INVALID SIGNAL FROM THE TRANSFORMER FAULT | | PRESSURE RELAY. TROUBLESHOOTING IS CURRENTLY IN PROGRESS INCLUDING ANALYSIS | | OF THE TRANSFORMER OIL. BASED ON THE RESULTS OF THE ONGOING INVESTIGATION, | | THE LICENSEE TENTATIVELY PLANS TO RETURN THE TRANSFORMER TO SERVICE AND | | SECURE THE EDG LATER TODAY. | | | | THE LICENSEE INFORMED THE NRC RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+ http://www.nrc.gov/NRR/DAILY/der.htm =========================================

-- LSRY2K (admin@lsry2k.net), January 11, 2000