A nuclear industry specialist has been selected to lead the AECOM-EnergySolutions joint venture that will decommission the San Onofre Nuclear Generating Station (SONGS) in California.

The companies announced Wednesday that Tom Dieter would succeed AECOM Senior Vice President Matt Marston as executive sponsor at SONGS Decommissioning Solutions.

Dieter’s over 32 years of work in management of commercial and federal nuclear projects covers decommissioning of government test reactors, three plutonium and uranium production plants, spent fuel pools, and a number of support sites, according to a press release. He has also worked at commercial atomic energy sites.

In December 2016, SONGS majority owner Southern California Edison selected the joint venture as the general contractor for what is expected to be a $4.4 billion cleanup job at the San Diego County plant. That will make it the largest commercial nuclear power plant decommissioning in U.S. history, encompassing radiological decommissioning, used fuel management, and site restoration.

Reactor Unit 1 has already been largely decommissioned after shutting down in 1992, while the remaining Units 2 and 3 were permanently retired in 2013.

SONGS Decommissioning Solutions has been doing early phase work, primarily taking control of various operations at the plant. The majority of the decommissioning cannot begin until the California Coastal Commission issues a coastal development permit, which the contractor hopes to secure by the first quarter of 2019.