HEADQUARTERS DAILY REPORT APRIL 21, 1994 ********************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT REC'D RECEIVED REGION I X REGION II X REGION III X REGION IV X HEADQUARTERS X ****************************************************************** PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV APRIL 21, 1994 Licensee/Facility: Notification: Arizona Public Service Co. MR Number: 4-94-0034 Palo Verde 1 2 3 Date: 04/21/94 Wintersburg,Arizona RI Telecon Dockets: 50-528,50-529,50-530 PWR/CE80,PWR/CE80,PWR/CE80 Subject: RESTRUCTURING OF MAINTENANCE, ENGINEERING, AND NUCLEAR ASSURANCE Reportable Event Number: N/A Discussion: On April 19, 1994, the licensee announced a restructuring of the Palo Verde Maintenance, Engineering, and Nuclear Assurance organizations which includes a planned reduction of 497 personnel by mid-July 1994. The restructuring resulted from an effort initiated in October 1993 to "reengineer" Palo Verde work processes to increase work efficiency. The three organizations, which currently include 1349 APS employees and 415 contractors, were part of the "first wave" of reengineering. The licensee plans to eliminate 256 APS positions and 241 contractor positions. The greatest number of positions cut from the APS staff will be in midlevel management. The new organizations feature a centralized maintenance organization, the addition of maintenance engineers, the relocation of design engineers from the Phoenix office to the Palo Verde site, and an oversight organization aligned to the major SALP categories. The licensee has initiated the personnel selection process and anticipates the selection of supervisors and managers in early June and the selection of frontline employees in July. Subsequent "waves" of reengineering will be applied to Operations, Training, Licensing, Radiation Protection, Security, and other organizations. Regional Action: During management meetings, Region IV has discussed the overall plans for reengineering with the licensee. Regional inspectors and the NRC resident inspectors will monitor the licensee's performance during implementation of the restructuring. Contact: H. Wong (510)975-0296 K. Johnston (602)386-3638 NRR HEADQUARTERS DAILY REPORT April 21, 1994 NRC Administrative Letter 94-05, "Notification Concerning Changes to 10 CFR Part 55," will be issued April 25, 1994. NRC is issuing this administrative letter to inform addressees of the implementation of the amendments to the regulations in Title 10, Code of Federal Regulations, Part 55 (10 CFR Part 55) concerning renewal of operator licenses. Technical contacts: D. J. Lange, NRR M. A. Ring, RIII (301) 504-1031(708) 829-9703 R. J. Conte, RIJ. L. Pellet, RIV (610) 337-5210(817) 860-8159 T. A. Peebles, RII (404) 331-5541 April 21, 1994 SIGNIFICANT EVENT Catastrophic Turbine Generator Failure at Fermi 2 Classified as a Significant Event The NRR/AEOD Events Assessment Panel on April 19, 1994, classified the sudden catastrophic failure of the turbine generator at Fermi 2 as a Significant Event for the purpose of the NRC Performance Indicator Program. The basis for the classification is that the event was a scram with complications that included a hydrogen burn/explosion in the turbine generator system, and flooding of the turbine building. On December 25, 1993, while at 93% power, a sudden catastrophic failure of the Fermi 2 turbine generator occurred. The turbine was manufactured by GEC Turbine Generators, Limited of England. The plant received multiple turbine vibration alarms, a seismic alarm, and a fire alarm annunciated in the control room. Vibrations were felt in the control room and throughout the plant for approximately one to two minutes. There were loud sounds associated with the vibrations. The turbine tripped and the reactor scrammed. Main steam isolation valves closed on condenser high pressure. With the loss condenser vacuum, reactor pressure was controlled via RCIC and SRVs. The reactor decay heat was removed via the torus and RHR system. When attempting to place Division II shutdown cooling in service, the "B" recirculation pump discharge valve would not fully close. Shutdown cooling was initiated using the "A" loop. Approximately 15 minutes after the initiation of the event, plant personnel put on self-contained breathing apparatus and entered the turbine building. Heavy smoke and large amounts of flowing water were observed in several areas of the turbine building. Fire brigade members extinguished a small exciter fire and burning debris on the floor. Approximately 500,000 gallons on water was released to the turbine building floors due to: 1) Actuation of the fire protection system, 2) Damage to a General Service Water (GSW) pipe to the generator's hydrogen coolers, and 3) Damage to a Turbine Building Closed Cooling Water (TBCCW) system pipe. In addition, the rupture of a supply line from the generator lube oil tank resulted in the release of approximately 17,000 gallons of oil to the turbine building floors. Although the water and oil that originally spilled to the turbine building floors was not radioactively contaminated, the water became contaminated after mixing with the contents of the tanks and sumps in the radwaste building. - 2 - Ejected parts of the Number 3 LP Turbine also damaged condenser tubes that allowed Circulating Water (CW) to enter the hot well. This caused an increase in hotwell inventory that was rejected to the Condensate Storage Tank (CST). This resulted in water in the CST with higher than normal conductivity and chlorides. The source of water for the Standby Feedwater (SBFW) system that was being used to maintained water level in the in the reactor vessel was the CST. Consequently, the water in the CST was pumped to the reactor vessel via the SBFW system. This resulted in higher than normal conductivity and chlorides in the reactor vessel. The maximum conductivity value was 180 micromhos (T.S. limit is 10 micromhos). In response to the Fermi 2 event, the NRC dispatched an Augmented Inspection Team (AIT) to the site with Ron Gardner as Team Leader. An inspection by the AIT was conducted from December 28, 1993 through January 19, 1994. The areas examined during the inspection and the AIT findings are discussed AIT Report 50-341/93029 (DRS). There have been turbine generator failures at other US plants. The two most recent ones are at Susquehanna 1 on July 12, 1993 and at Salem 2 on November 9, 1991. The Susquehanna turbine generator failure was attributed to high cycle fatigue of blades in a LP turbine manufactured by GE. Two blades separated from the rotor causing damage to other blades and the stationary rotor. In addition, 50 to 100 condenser tubes were damaged by blade fragments. At Salem a turbine overspeed caused blade loss in a LP turbine manufacture by Westinghouse. The excessive vibration from overspeed and mass loss breached the hydrogen and oil system. Missiles penetrated the turbine casing. There was a hydrogen explosion and oil fires. The main condenser was damaged by turbine missiles.