A small leak in the bottom of a Palo Verde reactor pressure vessel will cost its owners between $10 million and $15 million in repairs while adding extra weeks to the unit's refueling outage.
Last week, plant engineers reported finding a white residue around a bottom-mounted instrumentation nozzle during a remote inspection at unit 3. Plant officials quoted in the Arizona Republic confirmed the material was evidence of a coolant leak. It is believed to amount to less than 1/100th of a gallon per minute and was not significant enough to be detected by nearby humidity sensors.
Nonetheless, restoring the reactor's coolant system pressure boundary won't be cheap. In addition to the repair expense, the utilities that own the plant expect the work will add 15 to 30 days to an ongoing maintenance outage. The reactor is one of three at the site outside Phoenix. Owned by seven southwestern utilities, all of the units are 1,340 megawatt Combustion Engineering System 80 pressurized water reactors operated by Arizona Public Service.