OMAHA, Neb. (AP) — The Omaha Public Power District is set to vote on whether to close the nation’s smallest nuclear power plant in Fort Calhoun.

The district board will vote on the fate of Fort Calhoun Nuclear Station on Thursday.

Once closed, a nuclear plant must undergo a decommissioning process to remove or decontaminate materials and equipment that have been exposed to radioactivity. The Nuclear Regulatory Commission requires decommissioning to be completed within 60 years of a plant’s closing.

Cleaning up the site after its closure is estimated to cost about $1 billion.

Power district President and Chief Executive Director Tim Burke has recommended using a decommissioning method that would give the utility the full 60 years to let radioactivity at the plant decay naturally and to fully dismantle the plant.