Headquarters Daily report SEPTEMBER 09, 1994 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS X REGION I X X REGION II X REGION III X REGION IV X *************************************************************************** PRIORITY ATTENTION REQUIRED MORNING REPORT - HEADQUARTERS SEP. 09, 1994 MR Number: H-94-0082 NRR DAILY REPORT ITEM GENERIC COMMUNICATIONS BRANCH/EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT OFFICE OF NUCLEAR REACTOR REGULATION Subject: N/A NRC Administrative Letter 94-11, "Request for Voluntary Comment on the Pilot Program for NRC Recognition of Good Performance by Nuclear Power Plants," was issued September 7, 1994. The NRC issued this administrative letter to request industry comment, on a voluntary basis, on the Pilot Program for NRC Recognition of Good Performance by Nuclear Power Plants. Contacts: Michael T. Markley, NRR (301) 504-1011 Loren R. Plisco, NRR (301) 504-1231 NRC Administrative Letter 94-12, "Operator Licensing National Examination Schedule," to be issued September 12, 1994. The NRC is issuing this administrative letter to request addressees, on a voluntary basis, to submit information pertaining to their previous estimates of the number of candidates to be tested for fiscal years (FYs) 1995 through 1998. Contact: Stuart A. Richards, NRR (301) 504-1031 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV SEPTEMBER 9, 1994 Licensee/Facility: Notification: Pacific Gas & Electric Co. MR Number: 4-94-0094 Diablo Canyon 1 Date: 09/07/94 Avila Beach,California RESIDENT INSPECTOR Dockets: 50-275 PWR/W-4-LP Subject: FAILURE OF A CHANNEL IN THE EAGLE 21 REACTOR PROTECTION SYSTEM Reportable Event Number: N/A Discussion: On September 7, 1994 at 2:19 p.m. PDT, Unit 1 experienced a failure of one channel of their new Eagle 21 reactor protection system. This resulted in all associated bistables going to the tripped condition and analog outputs failing low. The bistables and analog outputs cycled several times and then returned to normal. This resulted in a loss of one of three pressurizer level channels, one of four pressurizer pressure channels, and one of three RCS flow channels in each loop. The pressurizer level and pressure channels which failed had been selected as the controlling channels. Operators responded per procedures taking manual control of pressurizer pressure and level to stabilize plant conditions. A CVCS letdown isolation occurred. The licensee declared the protection set channel inoperable and tripped the associated bistables. Troubleshooting revealed a problem which is believed to be associated with an intermittent failure of a relay in the power supply distribution panel. The power supply distribution panel has been replaced and the protection set channel returned to service following an operational test at 3:07 a.m., PDT September 8, 1994. The licensee is sending the failed power supply distribution panel to Westinghouse for analysis. Both the licensee and Westinghouse are pursuing the potential generic implications of this failure. Regional Action: The residents are following the licensee's actions. Contact: D. Kirsch (510)975-0290 M. Tschiltz (805)595-2354 D. Corporandy (510)975-0319 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV SEPTEMBER 9, 1994 Licensee/Facility: Notification: Arizona Public Service Co. MR Number: 4-94-0095 Palo Verde 2 Date: 09/09/94 Wintersburg,Arizona PHONE CALL FROM RESIDENTS Dockets: 50-529 PWR/CE80 Subject: UNEXPECTED DILUTION AT POWER Reportable Event Number: N/A Discussion: At 4:58 a.m., on September 7, 1994, a routine reactor coolant system dilution was commenced with Unit 2 operating at 100 percent power. The intended automatic addition of 100 gallons of water to the volume control tank (VCT) did not stop as expected. The addition of water continued until a high level alarm in the VCT was noted by a reactor operator. A total of approximately 350 gallons of water was added to the VCT over a period of about five minutes. The operator, who had been distracted by other control room activities, responded by adding a volume of boric acid calculated to compensate for the over-dilution. The operators did not notice any appreciable change in reactor power or reactor coolant system temperature. The licensee's preliminary investigation identified that a makeup water control valve did not close as designed. The licensee identified the following concerns: 1) the operator did not notify the shift supervisor of the over-dilution, 2) operators were aware of prior problems with the dulution makeup control valve, and 3) the operator was distracted from a sensitive evolution which should have taken less than two minutes to complete. The licensee has responded by forming an incident investigation team. Regional Action: The resident inspectors will follow the licensee's evaluation. Contact: Howard Wong (510)975-0296 Ken Johnston (602)386-3638