Event Notification Report for November 11, 2005

MANUAL REACTOR TRIP DURING STARTUP FOLLOWING FAILURE OF ROD CONTROL POWER CABINET

"During a reactor startup, while withdrawing the second shutdown bank, a failure of the 2BD rod control power cabinet occurred. Shutdown Bank B group 2 rods failed to withdraw. After gathering data and indications for troubleshooting, a manual reactor trip was initiated. All rods fully inserted. The Unit was and remains in mode 3. There were no other required or actual ESF actuations."

The licensee will notify the NRC Resident Inspector.

MANUAL REACTOR TRIP AFTER LOSS OF ALL CONDENSER CIRCULATING WATER PUMPS

"Waterford 3 manually tripped the reactor at 20:34 [CST] on 11/11/05 due to lowering main condenser vacuum caused by a loss of all circ water pumps. Subsequently an Emergency Feedwater Actuation Signal (EFAS) was received due to low steam generator levels. The plant is currently being maintained in mode 3 with both Steam Generators being fed from the Auxiliary Feedwater system with Steam Generator levels in the normal operational band for mode 3. The EFAS has been reset. The plant will be maintained in Mode 3 while a Post Trip Review is performed. This report is submitted as required by 10CFR50.72."

All control rods fully inserted on the manual trip. The main steam isolation valves are shut and the heat sink is through the atmospheric dump valves. The electrical grid is stable and plant power is from the startup transformer. No primary or secondary relief valves or safety valves lifted. The site was able to restart the B & D circ water pumps. There is no significant steam generator tube leakage.

The licensee notified the NRC Resident Inspector.

* * * UPDATE FROM PICKENS TO HUFFMAN AT 13:55 EST ON 11/14/05 * * *

"This notification is an update to an immediate notification that was called into the NRC Operations Center at 04:48 (eastern time) on November 12, 2005 (Event # 42138). The event was reported as an 8-hour event. This update to the original notification is to communicate that, based on further review, the event notification should have been made within 4 hours since it was reportable within 4 hours as well as the 8-hour reporting criteria and therefore the call should have been made within the 4 hour period. The condition is reportable under four hour reporting criteria 50.72(b)(2)(iv)(B) for a manual trip of the plant in anticipation of receiving a RPS Trip with the Reactor critical. The condition is reportable within eight hour reporting criteria 50.72(b)(3)(iv)(A) for the automatic actuation of EFAS upon low steam generator levels. This update does not report a change to the event description reported. As mentioned in the original report, Waterford 3 manually tripped the reactor at 20:34 on November 11, 2005 due to lowering main condenser vacuum caused by a loss of all circulating water pumps. Subsequently an Emergency Feedwater Actuation Signal (EFAS) was received due to low steam generator levels. The plant was then maintained in Mode 3 with both steam generators being fed from the Auxiliary Feedwater System with steam generator levels in the normal operational band for Mode 3. The EFAS had been reset at the time of the original notification. The plant was maintained in Mode 3 while a Post Trip Review was performed. Further details of the event will be reported under the 60 day LER reporting criteria."

The licensee notified the NRC Resident Inspector. R4DO (Clark) notified.

REPORT OF DEGRADED CONDITION DUE TO DEFECTIVE STEAM GENERATOR TUBES

"This is a 4-hour report as required by Technical Specification (TS) 5.5.9, Table 5.5.9-2, reported via the ENS in accordance with 10 CFR 50.72(b)(3)(ii)(A), 'Any event or condition that results in the nuclear power plant, including its principal barriers, being seriously degraded'.

"Greater than one percent of steam generator (SG) 1-1 and SG 1-2 tubes were determined to be defective and require plugging. Diablo Canyon performs 100% bobbin inspection of SG tubes, thus, no expanded bobbin inspection scope was required.

"On November 11, 2005, during the Unit 1 thirteenth refueling outage (1R13), final analysis of eddy current data of SG 1-1 and SG 1-2 indicated that greater than one percent of the total tubes inspected in two SGs were defective placing them in Category C-3. Thirty seven (37) defective tubes in SG 1-1 and forty one (41) defective tubes in SG 1-2 were detected and are being plugged. Most of the pluggable indications are due to circumferential outside diameter stress corrosion cracking at the hot leg tube support plates and at the hot leg top of tubesheet. Results of SG tube inspections that fall into Category C-3, requires a 4-hour non-emergency report to accordance with Diablo Canyon TS 5.5.9, Table 5.5.9-2 and 'Notification to the NRC pursuant to 10 CFR 50.72(b)(2)' (a 4-hour requirement, replaced by 10 CFR 50.72(b)(3)(ii), now an 8-hour requirement).

"An NRC teleconference in accordance with TS 5.6.10.d to report the preliminary SG tube inspection results was conducted on November 9, 2005, at 1100 PST.

"A Special Report in accordance with TS 5.6.10.a to report the number of tubes plugged in each SG, and TS 5.6.10.c describing the cause of the tube degradation and corrective measures taken to prevent recurrence will be submitted prior to returning Diablo Canyon Unit 1 to power operation."

The licensee notified the NRC Resident Inspector.