Headquarters Daily Report OCTOBER 22, 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 OCTOBER 22, 1996 MR Number: H-96-0077 NRR DAILY REPORT ITEM GENERIC COMMUNICATIONS NRC Information Notice 96-56, "Problems Associated with Testing, Tuning, or Resetting of Digital Control Systems While at Power," dated October 22, 1996. The NRC is issuing this information notice to alert addressees to recent reactor transient events, reactor trips, and engineered safety feature actuations caused by testing, tuning, or resetting of digital control systems while at power. Technical Contacts: Charles Petrone, NRR (301) 415-1027 John K. Ganiere, NRR (301) 415-2921 Jerry L. Mauck, NRR (301) 415-3248 _ REGION II MORNING REPORT PAGE 2 OCTOBER 22, 1996 Licensee/Facility: Notification: Virginia Power Co. MR Number: 2-96-0098 North Anna 2 Date: 10/22/96 Richmond,Virginia Dockets: 50-339 PWR/W-3-LP Subject: NORTH ANNA UNIT 2 SHUTDOWN TO REPAIR STEAM LINE Discussion: On October 21 at 6:06 p.m., North Anna Unit 2 was taken off line to repair a pin hole leak in the high pressure turbine exhaust balance line. This 14-inch line, which equalizes the exhaust pressure between the right and left sides of the high pressure turbine, normally operates at approximately 200 p.s.i. The unit is presently in MODE 3 with the main steam trip valves closed. The licensee plans to remain in this configuration while repairs are performed. The licensee estimates that the unit will be shutdown for approximately 60 hours to perform non-destructive testing and effect repairs. After the unit was offline, the reactor was tripped. In accordance with procedures, the reactor was borated until the required shutdown margin was verified due to four control rods indicating greater than 10 steps (between 11 and 12 steps) withdrawn. Preliminary investigations revealed that the individual rod position indicators needed adjustment. Rod drop time testing will be performed to verify that all control rods insert properly. Regional Action: The resident inspectors observed portions of the shutdown and will continue followup. Contact: LARRY GARNER (404)331-5536 _