Headquarters Daily report AUGUST 09, 1994 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS X REGION I X REGION II X REGION III X REGION IV X *************************************************************************** PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION IV AUGUST 9, 1994 Licensee/Facility: Notification: Arizona Public Service Co. MR Number: 4-94-0077 Palo Verde 1 2 3 Date: 08/08/94 Wintersburg,Arizona NOTIFICATION FROM PUBLIC Dockets: 50-528,50-529,50-530 PWR/CE80,PWR/CE80,PWR/CE80 Subject: PIPE BREAK IN PHOENIX WATER SUPPLY TO PALO VERDE Reportable Event Number: N/A Discussion: At approximately 7:00 a.m. on August 8, 1994, a 66-inch diameter pipe that carries makeup water (from Phoenix) to the Palo Verde water reclamation facility ruptured approximately one mile east of the licensee's owner controlled area. At the time of the rupture, the pipe was carrying approximately 55,000 gallons per minute (gpm) of secondary treated effluent from the Hassayampa pumping station to the licensee's water reclamation facility for processing prior to storage in the cooling tower makeup reservoir. Water from the rupture created a small crater and flooded a nearby road before the pumping station secured the water flow. The reservoir contains enough water for an additional seven to ten days at the current makeup rate. The water reservoir is used for makeup to the cooling towers from losses due to evaporation, blowdown, and drift from the towers, and is not the ultimate heat sink for safety-related equipment. The licensee receives treated sewage water from the Phoenix metropolitan area from the Hassayampa pumping station. The water is processed and then stored in a 670 million gallon reservoir. At the time of the rupture, the water reclamation facility was supplying makeup water to the three units at the rate of approximately 55,000 gpm (equal to the supply rate). Between 8:00 a.m. and 4:00 p.m., the reservoir level dropped approximate 3 percent from the initial 100 percent level. At this makeup rate, the reservoir will be empty in approximately seven to ten days without restoring the supply piping. However, many factors, including reactor power level, local temperature, humidity, and wind velocity influence the makeup rate. The supply pipe is constructed of prestressed concrete. Repairs to the pipe require dewatering and excavating the pipe which is normally buried under eleven feet of soil, and then replacing the damaged piping. An NRC inspector viewed the ruptured area and noted areas of concrete where the steel reinforcing bars appeared to have corroded away. The licensee has replacement piping at the rupture location. The licensee initially estimates that the repairs will take approximately three to four days to complete. Regional Action: The resident staff will monitor the licensee's progress to determine if the failure will impact operation of the three units. Contact: H. Wong (510)975-0296 H. Freeman (602)386-3650