COLUMBUS (AP) — The cleanup of a Cold War-era uranium plant in southern Ohio is expected to take another three decades or more, according to the U.S. Department of Energy.

U.S. Sen. Rob Portman had asked whether the administration was committed to decontaminating and decommissioning the Portsmouth Gaseous Diffusion Plant in Piketon at an accelerated rate and finishing by 2024, as announced by former Energy Secretary Steven Chu. In a response sent earlier this month and shared Tuesday by Portman, the department said the 2024 goal “is not achievable.”

Instead, without much elaboration, it said its target range for finishing the cleanup is between 2044 and 2052.

That indicates “the project was either severely mismanaged or the commitments made to the community were no more than empty promises,” Portman, an Ohio Republican, said in a statement calling the situation unacceptable. He said he will work with congressional colleagues “to get this project back on track.”

The timetable for the cleanup is a key concern for workers and others in the area because it could help clear the way for redevelopment at the site and, in the meantime, is a major source of jobs.

The cleanup employs more than 1,800 people and provides some of the best-paying jobs in a pocket of high unemployment, which is why the threat of hundreds of layoffs last year caused plenty of anxiety locally until Congress provided a last-minute infusion of funding through the end of the current fiscal year.

Funding remains a concern. Much of the project is funded through a barter program in which the government sells uranium on the open market, creating uncertainty as prices fluctuate. Some lawmakers have pushed for the government to appropriate more direct funding.

The regional office that oversees the project for the DOE didn’t immediately respond to a message seeking comment Wednesday.