Morning Report for August 24, 1999
Headquarters Daily Report AUGUST 24, 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 III AUGUST 24, 1999 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-99-0074 La Salle 2 Date: 08/22/99 Marseilles,Illinois Licensee report/Resident call 8/23 Dockets: 50-374 BWR/GE-5 Subject: Automatic Shutdown on Low Reactor Water Level Discussion: At 22:00 on 8/21/99 Unit 2 operators commenced a load drop to repair a degraded condition on the main generator phase A potential transformer. At 22:55 with the reactor at 78 percent power, the reactor scrammed automatically due to low reactor level induced by a feedwater level transient. All control rods fully inserted. Reactor level and pressure followed expected trends. All systems responded as expected. Subsequent to the scram, minor problems were encountered putting the main turbine and the "A" turbine driven feed pump on their respective turning gear. The licensee's preliminary investigation of the event has determined two causes for the scram. First, was inadequate testing and tuning of the feedwater control system at this power level. The licensee plans to conduct further feedwater system testing and tuning during the return to full power. Second, the operator did not perform the expected procedural actions in response to the event. The licensee is continuing to determine the potential extent of condition and corrective actions. Regional Action: The senior resident inspector responded to the site and is monitoring the licensee's post scram investigation and corrective actions. Contact: Melvyn Leach (630)829-9705 _ REGION III MORNING REPORT PAGE 2 AUGUST 24, 1999 Licensee/Facility: Notification: Commonwealth Edison Co. MR Number: 3-99-0075 La Salle 2 Date: 08/22/99 Marseilles,Illinois Licensee report, 8/23/99 R.I. call Dockets: 50-374 BWR/GE-5 Subject: Automatic Shutdown on Low Reactor Water Level Reportable Event Number: 36056 Discussion: At 22:00 on 8/21/99 Unit 2 operators commenced a load drop to repair a degraded condition on the main generator phase A potential transformer. At 22:55 with the reactor at 78 percent power, the reactor scrammed automatically due to low reactor level induced by a feedwater level transient. All control rods fully inserted. Reactor level and pressure followed expected trends. All systems responded as expected. Subsequent to the scram, minor problems were encountered putting the main turbine and the "A" turbine driven feed pump on their respective turning gear. The licensee's preliminary investigation of the event has determined two causes for the scram. First, was inadequate testing and tuning of the feedwater control system at this power level. The licensee plans to conduct further feedwater system testing and tuning during the return to full power. Second, the operator did not perform the expected procedural actions in response to the event. The licensee is continuing to determine the potential extent of condition and corrective actions. Regional Action: The senior resident inspector responded to the site and is monitoring the licensee's post scram investigation and corrective actions. Contact: Melvyn Leach (630)829-9705 _
Page Last Reviewed/Updated Wednesday, March 24, 2021
Page Last Reviewed/Updated Wednesday, March 24, 2021