Southern California Edison said that its plan to decommission the San Onofre Nuclear Generating Plant would cost $4.4 billion.

The draft plan, called a Post-Shutdown Decommissioning Activities Report, spells out the timetable for major decommissioning work expected to begin in early 2016 and indicates that adequate funds exist to pay for the work, according to SCE. The plan is expected to take 20 years to implement.

SCE has asked its Community Engagement Panel to review the plan. The plan is expected to go before the Nuclear Regulatory Commission in September.

“We look forward to receiving feedback from the Community Engagement Panel on this blueprint for decommissioning,” said Chris Thompson, SCE vice president of Decommissioning. “These key decommissioning documents given today to our community advisers embody our commitments to safety, to transparency with the public and to serving as a good steward of the environment and our customers’ money.”

According to SCE, the decommissioning trust funds established contain about $4.1 billion. Based on the updated cost estimate, anticipated cost escalation and future trust fund earnings, Thompson said, San Onofre decommissioning is now fully funded and no further customer contributions are required.

In June of 2013, SCE announced it was closing down units 2 and 3 of San Onofre. Leaks had been discovered early in 2012.

San Diego Gas & Electric Co. owns 20 percent of the San Onofre Nuclear Generating Plant.