COLUMBUS, Ohio (AP) _ Workers at an Ohio uranium plant handled a type of plutonium-laced uranium that was more dangerous than the government has acknowledged, The Columbus Dispatch reported Wednesday.

At the Portsmouth Gaseous Diffusion Plant in Piketon, spent nuclear-reactor fuel was converted to enriched uranium for reuse. That operation, known as oxide conversion, was halted around 1977 because of concerns about radiation exposure, according to Energy Department documents the newspaper obtained.

The government in August said about 100,000 tons of plutonium-laced uranium was handled by Piketon's sister plant in Paducah, Ky. Some of that uranium, containing small amounts of plutonium, later was sent for enrichment to Piketon.

Energy officials had insisted that Paducah workers handled all the initial conversion, and most of the initial enrichment, of that material before it was sent to Piketon, the Dispatch said. That would have meant Piketon workers dealt with material with a much lower plutonium level, they said.

However, it now is clear that Piketon received some undiluted material directly from nuclear power plants, an Energy Department spokesman told the newspaper Tuesday after being shown his agency's documents.

He said officials do not know the exact quantities but believe they are small.

Three workers at the Paducah Gaseous Diffusion Plant have filed a lawsuit, claiming that workers were unknowingly exposed to plutonium for 23 years and that plant operators falsified documents about waste disposal and contamination.