Edison Requests Audit of Mitsubishi’s Generator Designs for San Onofre

Majority owner of the San Onofre Nuclear Generating Station wants to review the manufacturing designs of replacement generators blamed for the plants ultimate shuttering in June

By Jim Shilander

Southern California Edison announced Monday that it has asked Mitsubishi Heavy Industries to allow an audit of the manufacturer’s design of the replacement steam generators at San Onofre Nuclear Generating Station.

The utility and the manufacturer have been at loggerheads for the last several months, as the utility attempts to get additional funds to help defray the costs of replacement power since the plant went down in January 2012. In July, Edison filed a notice of breach of contract against Mitsubishi, arguing the manufacturer had provided the utility with generators that were flawed and ultimately led to the plant’s retirement.

Last week, the utility accused Mitsubishi of “stonewalling” efforts to recover the costs of investigating the outage, as well as taking corrective action, including plugging steam generator tubes in the nuclear reactors, units 2 and 3.

In January 2012, tubes in Unit 3 ruptured due to a previously unseen level of wear as the result of the high pressure steam going through them. Unit 2, which was down for refueling, was also found to have wear, though not to the same level as Unit 3. Edison attempted to restart Unit 2 at reduced power, but as the regulatory process moved forward, the utility decided instead to shutter the plant.

A press release from Edison said three attempts have already been made to have Mitsubishi submit to an audit, but all have been refused. Edison claims contractual language gives the utility the right to examine much of the documentation related to the design process of the replacement steam generators. Mitsubishi claims the contractual language is only for financial records.

If the two companies are unable to come to a settlement within 90 days of the date Edison filed the breach of contract notice, the two must enter into binding arbitration to settle the issue.