In a flurry of letters late last year, Southern California Edison and the manufacturer that designed the steam generators at the now-dark San Onofre nuclear power plant appeared to be at odds over a long-term plan to repair the troubled facility.
In the exchange, Mitsubishi Heavy Industries proposed a repair plan that it said could have the plant back online at full power in about a year and also suggested a far more aggressive and expensive repair job that would take more than five years to complete.
By the end of 2012, however, the companies were unable to come to an agreement on a long-range plan.
At the same time, Edison warned Mitsubishi that the ongoing problems at the nuclear plant had “seriously harmed” the utility and its stakeholders and that it expected the manufacturer to “accept full responsibility” for the problem.
The plant had been offline at that point for nearly a year because of unusual wear on tubes that carry radioactive water in the plant’s newly replaced steam generators, which were designed and manufactured by Mitsubishi. The problem came to light in January 2012 after a small amount of radioactive steam leaked from one of the tubes.
Edison asked the U.S. Nuclear Regulatory Commission in October for permission to restart one of the plant’s two units and run it at 70% power for a few months to see whether the reduced power would alleviate the conditions that led to the wear.
But the company was pushing Mitsubishi to develop a plan that would allow both units at the plant to return to service at full power for the 40-year intended life span of the steam generators.
The letters between the companies were recently released as part of an examination by the California Public Utilities Commission of the costs of the plant’s outage.