Permit issued for San Onofre decommissioning

The Commission unanimously approved the permit at its meeting on 17 October in Chula Vista.

"We appreciate the commissioners for their diligence in understanding the issues involved and Coastal Commission staff for their efforts in making sure all voices were heard in the process," said Doug Bauder, SCE vice president and chief nuclear officer. "I also want to thank the members of the public who spoke in favour of the permit for their support in helping get this project under way."

SCE said the approval allows it "to move forward with removing above-grade structures on the site, such as the twin containment domes". The utility said it anticipates beginning major decommissioning work in 2020.

Units 2 and 3 at the San Onofre Nuclear Generating Station - also known as SONGS - were permanently retired in June 2013 due to regulatory delay and uncertainty after problems were found in replacement steam generators.

Located on the Pacific coast of California, in the northwestern corner of San Diego County, the plant is owned by Edison International, parent of SCE, with 78.2%, San Diego Gas & Electric Company, 20%, and the City of Riverside Utilities Department, 1.8%.

SONGS Decommissioning Solutions - a joint venture between Aecom and EnergySolutions - was selected in December 2016 as the decommissioning general contractor.

The decommissioning of San Onofre is expected to create about 600 jobs during the 8-to-10 year dismantlement phase. The USD4.4 billion decommissioning project is financed through existing trust funds, including SCE's share of the project as majority owner. The total cost includes the dismantlement work awarded to SONGS Decommissioning Solutions, continued on-site storage of San Onofre's used nuclear fuel until the federal government provides a required repository and restoration activities. SCE said its customers contributed about one-third of the trust funds while two-thirds is due to investment growth over time.

An international arbitration panel in March ordered Mitsubishi Heavy Industries to pay the owners of SONGS USD125 million for defective steam generators supplied to the plant in 2009 and 2010. The four replacement steam generators Mitsubishi supplied for units 2 and 3 of the plant were intended to enable the pressurised water reactors to continue operating until 2022, but were found to be suffering from excessive wear after less than one year in service. Both reactors were taken offline in early 2012 only to be closed permanently in June 2013 when SCE decided not to continue a protracted regulatory process to show that lower power operation would be safe.