Headquarters Daily report APRIL 27, 1995 *************************************************************************** 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 APRIL 27, 1995 Licensee/Facility: Notification: Northeast Utilities MR Number: 1-95-0061 Millstone 1 Date: 04/26/95 Waterford,Connecticut RI Call Dockets: 50-245 BWR/GE-3 Subject: Millstone Unit 1 Director Change Reportable Event Number: N/A Discussion: On April 25, 1995, Northeast Utilities announced that William J. Riffer was appointed as the new Unit No.1 Director effective May 17, 1995. He recently retired after 26 years in the Navy. He held positions as commanding officer of the USS Simon Lake and Boston, and Director of START Verification for the Joint Chiefs of Staff. He recently completed an INPO orientation at Perry Nuclear Plant. Mr. Riffer is replacing Mr. P. Przekop, the Acting Director, who temporarily assumed the duties vacated by Mr. H. Haynes. Mr. Haynes was assigned to lead the NU Nuclear Group reengineering effort. (See MR 1-95-0022) Regional Action: This Is For Informational Purposes Only. Contact: Jacque P. Durr (610)337-5224 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III APRIL 27, 1995 Licensee/Facility: Notification: Detroit Edison Co. MR Number: 3-95-0075 Fermi 2 Date: 04/27/95 Newport,Michigan RESIDENT OFFICE TELECON Dockets: 50-341 BWR/GE-4 Subject: REACTOR TRIP DUE TO BYPASS VALVES SUDDENLY OPENING AND CLOSING Reportable Event Number: 28724 Discussion: AT 11:59 A.M. EDT ON APRIL 25, 1995, BOTH TURBINE BYPASS VALVES FULLY OPENED, AND THEN RECLOSED WITHIN APPROXIMATELY 5 SECONDS. THE RESULTING PRESSURE TRANSIENT CAUSED A COLLAPSE IN VOIDS AND A POWER SPIKE UP TO 121 PERCENT POWER, RESULTING IN A REACTOR TRIP ON HIGH POWER (118 PERCENT SETPOINT). ALL CONTROL RODS INSERTED AND THE PLANT RESPONDED AS EXPECTED WITH ONE EXCEPTION. THE MAIN GENERATOR FAILED TO TRIP ON REVERSE POWER, AND THE GENERATOR REMAINED CONNECTED TO THE GRID UNTIL THE OPERATORS TRIPPED THE GENERATOR APPROXIMATELY TEN MINUTES AFTER THE SCRAM. THE LICENSEE CONTINUES TO INVESTIGATE THE CAUSE OF THE BYPASS VALVES OPENING AND RECLOSING AND THE GENERATOR ANTI-MOTORING BREAKER FAILING TO ISOLATE THE GENERATOR FROM THE GRID. THE LICENSEE IS ALSO ASSESSING THE EFFECTS OF THE FAILURE OF THE GENERATOR TO DISCONNECT FROM THE GRID. DURING THE TURBINE COASTDOWN FROM THE SCRAM, MAXIMUM VIBRATION LEVELS AT THE CRITICAL SPEED OF APPROXIMATELY 860 RPM WERE 21 MILS (ON BEARING #5). Regional Action: THE RESIDENT INSPECTORS WILL CONTINUE TO PROVIDE INSPECTION COVERAGE OF THE LICENSEE'S INVESTIGATIVE AND ASSESSMENT EFFORTS. Contact: M. PHILLIPS (708)829-9637