Headquarters Daily Report JUNE 10, 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 - REGION II JUNE 10, 1996 Licensee/Facility: Notification: Tennessee Valley Authority MR Number: 2-96-0052 Sequoyah 1 2 Date: 06/10/96 Soddy-Daisy,Tennessee Dockets: 50-327,50-328 PWR/W-4-LP,PWR/W-4-LP Subject: SEQUOYAH ORGANIZATIONAL CHANGES EFFECTIVE JUNE 10, 1996 Discussion: Bob Adney, Sequoyah Site Vice President, announced the following organizational changes to be effective June 10, 1996: Mark Shepherd, Sequoyah Training Manager, will be filling the position of Methods and Procedures Manager in Business and Work Performance. Dick Driscoll, Nuclear Assurance and Licensing Manager at Sequoyah, will be filling the position of Sequoyah Training Manager. Mike Fecht, Quality Assurance Manager in Corporate Nuclear Assurance and Licensing, will be filling the position of Nuclear Assurance and Licensing Manager at Sequoyah. Regional Action: None. Contact: Scott E. Sparks (404)331-5619 _ REGION IV MORNING REPORT PAGE 2 JUNE 10, 1996 Licensee/Facility: Notification: Houston Lighting & Power Co. MR Number: 4-96-0055 South Texas 1 Date: 06/10/96 Wadsworth,Texas Resident Inspector Dockets: 50-498 PWR/W-4-LP Subject: PLANT RESTART FOLLOWING REFUELING OUTAGE 1RE06 Discussion: On June 9 at 3:15 p.m. the licensee closed the main generator output breakers, which ended Refueling Outage 1RE06. The outage was completed in 22 days. In addition to normal refueling activities, licensee personnel completed refurbishment of one of the low pressure turbines. They also performed nondestructive examination of 100 percent of the steam generator tubes. Regional Action: None. Contact: L. Smith (817)860-8183 R. Kopriva (817)860-8104 _ REGION IV MORNING REPORT PAGE 3 JUNE 10, 1996 Licensee/Facility: Notification: Entergy Operations, Inc. MR Number: 4-96-0056 Grand Gulf 1 Date: 06/07/96 Port Gibson,Mississippi Resident Inspector Dockets: 50-416 BWR/GE-6 Subject: MULTIPLE SAFETY RELIEF VALVES OPEN AND RESULT IN MANUAL REACTOR SCRAM Discussion: At 11:27 a.m. (CDT), on June 6, 1996, operators manually scrammed the reactor after six safety relief valves (SRVs) lifted. Control room operators noticed reactor vessel water level decreasing, suppression pool temperature increasing, and indication of six SRVs opening. Because suppression pool temperature was increasing rapidly, operators scrammed the plant to prevent exceeding the Technical Specification maximum temperature of 110 degrees Farenheit. Two SRVs had been open for approximately 2.5 minutes, and operators had initiated the scram in 2.2 minutes. Following the scram, operators maintained reactor vessel level using the feedwater control system and controlled reactor pressure using the turbine bypass control valves. Plant equipment operated properly during the event. The licensee identified the root cause for the SRVs lifting as a transient in the Division II SRV logic 24 Vdc power supply circuit. All 20 SRVs can be actuated by either Division I or Division II logic, and the 20 SRVs received a spurious 200 millisecond open signal. This open signal was sufficient to actuate the "seal-in" for the six SRVs that have the Lo Lo Set relief feature. Four of the six Lo Lo set SRVs quickly reseated but two remained open for 2.5 minutes. The other 14 SRVs did not open. The SRV logic card file is one of four card files supplied from the Division II 24 Vdc power supply. Each card file contains several trip unit cards that have logic circuits for safety-related components. Licensee personnel found a blown fuse to one of the other circuit card files, and determined that a trip unit card in the card file associated with the failed fuse had a failed capacitor that likely caused the fuse to fail. When the fuse failed, a current surge initiated the power supply voltage transient. The licensee replaced the faulted trip unit card and verified that all associated trip unit cards tested satisfactorily. The licensee is reviewing the power supply design, which allows six SRVs to open on a single failure, to determine if modifications are warranted in the future. The licensee remained in Hot Standby (Mode 3) until they completed repairs to the SRV power supply circuitry, replaced an intermediate range monitor detector, and repaired a residual heat removal test return valve. The licensee entered Mode 2 at 10:36 a.m. on June 8 and entered Mode 1 at 7:51 a.m. on June 9. REGION IV MORNING REPORT PAGE 4 JUNE 10, 1996 MR Number: 4-96-0056 (cont.) Regional Action: A conference call was conducted on June 7, 1996, among various headquarters divisions, Region IV, and the licensee to gain a better understanding of the circuit operation and the event. The resident inspectors reviewed licensee activities related to startup of the facility. Contact: J. Tedrow (601)437-4620 _