Headquarters Daily report AUGUST 10, 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 - REGION II AUGUST 10, 1994 Licensee/Facility: Notification: Tennessee Valley Authority MR Number: 2-94-0074 Browns Ferry 2 Date: 08/10/94 Decatur,Alabama Dockets: 50-260 BWR/GE-4 Subject: CONTROL ROD FAILS TO INSERT DURING TESTING Reportable Event Number: N/A Discussion: On August 8, 1994, the unit was at 70% power. While performing a surveillance to verify the scram insertion times of 10% of the control rods, rod 30-15, located in the center of the core, failed to insert when given a test signal. The problem was determined to be due to a failed scram pilot solenoid valve. Initial indications are that the ASCO solenoid valve failed to reposition as designed when a test signal was generated. The resident inspectors determined that system design would have allowed the control rod to properly insert on an actual scram signal due to the backup scram valves. The licensee was able to use the control rod drive system to fully insert the control rod and then electrically disabled it. The valve was then replaced and the control rod was successfully tested and returned to service. The licensee intends to perform a failure analysis of the solenoid valve. The licensee is aware of recent industry experience regarding ASCO solenoid failures due to valve internal contamination from thread compound. Preliminary indications are that the licensee uses Teflon tape as a sealant. Regional Action: The resident inspectors will follow these activities. Contact: Mark S,. Lesser (404)331-0342