Headquarters Daily report MAY 31, 1994 *************************************************************************** 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 - HEADQUARTERS MAY 31, 1994 MR Number: H-94-0055 NRR DAILY REPORT ITEM GENERIC COMMUNICATIONS BRANCH/EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT OFFICE OF NUCLEAR REACTOR REGULATION Subject: N/A NRC Information Notice 94-39, "Identified Problems in Gamma Stereotactic Radiosurgery," will be issued May 31, 1994. The NRC has identified the following areas of concern in gamma stereotactic radiosurgery: a published study of the frequency of generating and detecting human error in setting stereotactic coordinates for radiosurgery; symmetrical primary beams of radiation exiting the stereotactic unit when the shielding door was opened in the treatment mode; an incident inadvertent inverting of film of the treatment site for input into the treatment planning system and the subsequent overriding of the detection of the error by the treatment planning system; and an incident involving the failure of the treatment timer to activate after collimator alignment. Technical contact: James Smith, NMSS (301) 415-7904 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION I MAY 31, 1994 Licensee/Facility: Notification: Vermont Yankee Nuclear Power Corp. MR Number: 1-94-0061 Vermont Yankee 1 Date: 05/31/94 Vernon,Vermont SRI PC Dockets: 50-271 BWR/GE-4 Subject: REACTOR CLEANUP ISOLATION/REACTOR COOLANT RELEASE Reportable Event Number: 27319 Discussion: On May 31, 1994 at 5:26 p.m., the reactor water cleanup (RWCU) system isolated on high inlet temperature. Coincidentally, alarms in the control room indicated elevated radiation levels (20 mr/hr) in the reactor building (RB), a 3-fold increase in radioactive gas concentration (maximum 690 cpm) in the RB, a 2-fold increase in particulate concentrations (maximum 4000 cpm) in the RB, and a high water level in the RB floor and equipment sumps. Based on control room indications, the Shift Supervisor conservatively secured access to the RB pending the conduct of radiation and contamination surveys. At 5:35 p.m. both RB sump alarms cleared and at 5:56 p.m. the RB was entered for surveys. The licensee has preliminarily determined that an electrical fire in the RWCU control panel caused air-operated valve AO-40A to fail open pressurizing RWCU low pressure piping. This increase in pressure was mitigated by the actuation of relief valve, SR-36 (set at 150 psig). SR-36 is hard piped through the RB floor drain system to the RB sumps. Based on totalizer readings, 220 gallons of reactor coolant were discharge into the RB floor drain system. The actuated relief valve caused increased flow in the RWCU system and an approximate 2- inch reactor water level decrease from the steady state water level of 160". The decrease in reactor water level was automatically mitigated by an increase in feedwater flow causing a subsequent short-duration reactor power transient to 1614 MWt from an initial power level of 1594 MWt (100% rated power). When the RWCU system isolated on high inlet water temperature, the relief pathway was isolated and the reactor water level transient was terminated. The leakage of reactor coolant into the RB floor drain system through SR-36 caused an increase in radioactive gas and particulate levels as detected by the RB radiation monitoring system; however, subsequent air monitoring showed no increase. Contamination surveys near the supplemental fuel pool cooling system (located directly below the RWCU system) identified approximately 30kcpm/100sqcm general area and 800 mRad-beta near one floor drain indicating that the floor drain "backed up" when the relief valve lifted. Lower levels of radioactive concentrations have also been identified on most areas in the RB. The licensee identified a few gallons of reactor coolant and RWCU demineralizer resin in the vicinity of the floor drain. The licensee continues its investigation. Corrective actions include root cause determination, continuing assessment of reactor water level chemistry, and fire protection concerns. Major repair efforts are focused on restoring the "B" RWCU subsystem to service and assuring that low pressure piping has not been damaged by the overpressurization event. Regional Action: The resident inspectors will continue to monitor licensee actions. Contact: Harold Eichenholz (802)257-4319 John Shedlosky (215)337-5171 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III MAY 31, 1994 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-94-0101 Braidwood 2 Date: 05/31/94 Braceville,Illinois SRI VIA PC Dockets: 50-457 PWR/W-4-LP Subject: UNIT 2 STARTUP FOLLOWING FORCED OUTAGE Reportable Event Number: N/A Discussion: On May 29, 1994, Unit 2 synchronized to the grid, ending a 53-day forced outage. The outage was precipitated by an internal fault in the 2E main power transformer, and a control rod which became stuck during the subsequent reactor trip. During the forced outage, the licensee replaced the 2E main power transformer, removed an in-core thermocouple column reactor vessel head nozzle funnel pin which had become dislodged and was preventing downward motion of the control rod, performed a full core offload for reactor vessel inspection and selected fuel reconstitution (the unit had been operating with minor fuel cladding leakage), and conducted turbine maintenance. The outage was extended by the necessity to return the plant from Hot Shutdown to Cold Shutdown on May 27, due to an approximate 60 gpm primary coolant system leak from failed packing on a loop bypass valve. The subsequent heatup and restart were uneventful. Regional Action: Routine resident inspector followup. Contact: B.L. JORGENSEN (708)829-9635 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III MAY 31, 1994 Licensee/Facility: Notification: Consumers Power Co. MR Number: 3-94-0102 Palisades 1 Date: 05/31/94 Covert,Michigan INFORMATION ONLY Dockets: 50-255 PWR/CE Subject: PUBLIC MEETING Reportable Event Number: N/A Discussion: A public meeting has been scheduled for May 31, 1994, at 1:00 pm, at the Lake Michigan College, 2755 East Napier Avenue, Benton Harbor, Michigan. The purpose of the meeting is to present the findings of the NRC Diagnostic Evaluation Team. The team report will be issued following the meeting with the utility. Regional Action: Information Only. Contact: WAYNE KROPP (708)829-9633 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III MAY 31, 1994 Licensee/Facility: Notification: Toledo Edison Co. MR Number: 3-94-0103 Davis Besse 1 Date: 05/31/94 Oak Harbor,Ohio Dockets: 50-346 PWR/B&W-R-LP Subject: UNIT 1 RESTART FROM CYCLE 13-14 REFUELING OUTAGE ] Reportable Event Number: N/A Discussion: At about 12 p.m. on May 27, 1994, Unit 1 was critical following a refueling outage. At 12 a.m. on May 29, 1994, the licensee paralleled Unit 1 to the grid. The outage commenced on February 12, 1994, and the restart was delayed for about a week to make weld repairs to the instrument conoseal assembly. Major activities included major control room habitability enhancements, reactor protection system analog to digital change-out, large bore pipe support modifications, conoseal assembly modifications, 100 percent eddy-current inspection of all steam generators, erosion/corrosion inspection and replacement of secondary piping, and inspection and refurbishment of the main generator. Regional Action: The resident inspectors will monitor the startup progress. Contact: WAYNE KROPP (708)829-9633 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION III MAY 31, 1994 Licensee/Facility: Notification: Indiana MR Number: 3-94-0104 Cook 1 Date: 05/31/94 Bridgman,Michigan Dockets: 50-315 PWR/W-4-LP Subject: UNIT 1 RESTART FROM CYCLE 13-14 REFUELING OUTAGE Reportable Event Number: N/A Discussion: At about 12 p.m. on May 27, 1994, Unit 1 was critical following a refueling outage. At 12 a.m. on May 29, 1994, the licensee paralleled Unit 1 to the grid. The outage commenced on February 12, 1994, and the restart was delayed for about a week to make weld repairs to the instrument conoseal assembly. Major activities included major control room habitability enhancements, reactor protection system analog to digital change-out, large bore pipe support modifications, conoseal assembly modifications, 100 percent eddy-current inspection of all steam generators, erosion/corrosion inspection and replacement of secondary piping, and inspection and refurbishment of the main generator. Regional Action: The resident inspectors will monitor the startup progress. Contact: WAYNE KROPP (708)829-9633