Morning Report for August 13, 1999
Headquarters Daily Report AUGUST 13, 1999 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS X REGION I X REGION II X REGION III X REGION IV X PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION I AUGUST 13, 1999 Licensee/Facility: Notification: New York Power Authority MR Number: 1-99-0029 Indian Point 3 Date: 08/13/99 Buchanan,New York Dockets: 50-286 PWR/W-4-LP Subject: SUPPLEMENTAL REACTOR TRIP INFORMATION Reportable Event Number: 36023 Discussion: At approximately 4:05 a.m. on August 12, 1999, the Indian Point-3 reactor tripped on low steam generator level following a loss of main feedwater and a turbine runback that resulted from the loss of one instrument bus. A blown fuse in the static inverter to the 34 instrument bus caused the bus to de-energize, which removed control power to all feedwater regulating valves causing them to fail closed. The bus does not have an automatic transfer to an alternate power supply. Following the reactor trip, one pressurizer power-operated relief valve and one steam generator safety relief valve lifted. In addition, the instrument bus loss resulted in the loss of the high pressure main steam dumps and two of four steam generator atmospheric relief valves. Secondary heat removal was provided by the remaining steam generator atmospheric relief valves. At approximately 5:05 a.m. and again at 5:45 a.m. the 32 steam generator safety valve lifted again and reseated at the appropriate setpoints. The instrument bus was placed on the alternate power supply after approximately 1-1/2 hours and the main steam dumps were restored as the means for secondary heat removal. The licensee is evaluating the causes of the instrument bus failure, the subsequent plant transient, and operator performance following the reactor trip. Regional Action: Continue to monitor licensee's review. Contact: John Rogge (610)337-5146 _
Page Last Reviewed/Updated Wednesday, March 24, 2021
Page Last Reviewed/Updated Wednesday, March 24, 2021