Headquarters Daily Report JANUARY 26, 1996 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS û REGION I û REGION II û REGION III û REGION IV û PRIORITY ATTENTION REQUIRED MORNING REPORT - HEADQUARTERS JANUARY 26, 1996 MR Number: H-96-0008 NRR DAILY REPORT ITEM GENERIC COMMUNICATIONS NRC Information Notice 96-07, "Slow Five Percent Scram Insertion Times Caused by Viton Diaphragms in Scram Solenoid Pilot Valves," dated January 26, 1996. The NRC is issuing this information notice to alert addressees to slow five percent scram insertion times associated with fluoroelastomeric (Viton) diaphragms used in scram solenoid pilot valves. Contacts: Jerome Blake, RII (404) 331-5539 David Skeen, NRR (301) 415-1174 _ REGION II MORNING REPORT PAGE 2 JANUARY 26, 1996 Licensee/Facility: Notification: Florida Power & Light Co. MR Number: 2-96-0007 Saint Lucie 1 Date: 01/26/96 Florida Dockets: 50-335 PWR/CE Subject: EXCESSIVE BORON DILUTION Discussion: At approximately 0220 on January 22, 1996, the Unit 1 control board Reactor Controls Operator (RCO) observed that Reactor Coolant System loop cold temperature (Tc) had decreased from 549 degrees F (normal 100 percent power value) to 548.7 degrees F. At 0225, he began a manual dilution to the RCS by aligning the Primary Makeup Water (PMW) system directly to the suction of the 1B Charging Pump (approximately 44 gpm capacity). He intended to dilute by adding between 25 and 40 gallons of PMW. Moments after beginning the dilution, the board RCO saw the desk RCO return from the kitchen. He requested that the desk RCO relieve him so that he could prepare his lunch. During the relief, there was no discussion of the dilution in progress. The Nuclear Plant Supervisor (NPS), who was at the desk RCO station, was not aware that a dilution was in progress. The Board RCO returned between 5-10 minutes later and immediately recognized his error. He was securing the dilution when the control room annunciator M-16 "RCP CONT BLDOFF PRESS HIGH" alarmed due to a higher than normal VCT pressure caused by high VCT level (a result of the charging pump taking suction from PMW instead of the VCT). The NPS directed the Assistant NPS take charge and begin a manual boration. Unit 1 briefly entered TS LCO Action Statement 3.2.5 for Tc greater than 549 degrees F. The maximum Tc obtained was 549.9 degrees F at 100.2 percent reactor power. The licensee has the root cause under investigation. Regional Action: A three-member inspection team consisting of two residents and one region-based inspector is onsite investigating this event and evaluating the licensee's corrective actions. Contact: K. LANDIS (404)331-5509 M. MILLER (407)464-7822 R. SCHIN (404)331-5588 _