Enery Secretary James B. Edwards said yesterday he would like the government to "acquire" the huge, never-used nuclear reprocessing plant sitting idle in his home state of South Carolina.

Edwards told the Senate appropriations subcommittee on energy and water development that the lack of any U.S. capacity to reprocess spent nuclear fuel means that other countries get business that would otherwise come here. But since startup costs are so high, "commercialization of reprocessing is something that's going to have to wait awhile," he said. "I would like for the federal government to acquire the Barnwell plant."

Former President Carter rejected the idea of a commercial reprocessing industry on grounds that reprocessing yields plutonium, in addition to retrieving unused unranium, and plutonium could be diverted to eventual bomb production, increasing dangers of nuclear proliferation.

The plant in Barnwell, S.C., was constructed privately in the early 1970s before Carter's decision and has never been opened. But Congress continues to fund $11.5 million in maintenance and staff salaries for it every year. The owners, Allied General Services Inc., have said they would be willing to sell the facility to the government and said it was worth $362 million when it was completed in 1978.

Edwards did not specify the manner or cost of possible acquisition and was not asked about that. The issue, however, is tied to the future of the Clinch River Breeder Reactor, which would be able to use the reprocessed waste to produce more fuel.While not specifically endorsing the controversial Clinch River, Tenn., site, Edwards told the senators that DOE "will continue development of the breeder reactor" and added that the fiscal 1982 budget "will clearly indicate our commitment."

His main concern, Edwards added, was establishing a permanent nuclear waste repository. "We have the technical ability," he said. "We just have to develop the political courage to start burying it somewhere and stop talking about it so much."

The overall DOE budget includes a $150 million cut in regulatory practices, a $40 million reduction in research programs and a major shift in synthetic fuel funding to place most of the work with the Synthetic Fuels Corporation, Edwards told the senators. Energy conservation programs have been made unnecessary by oil decontrol, he said, while solar energy research programs "have not been very cost-effective so far" and would be cut by $363 million in 1982.

Although dollar figures for nuclear development programs have not yet been released, Ralph Nader's Critical Mass Energy Project said the total energy program "assures that Americans will continue to waste energy and will please Mobil, Exxon and Texaco." Nader said the program looked "as though the devil, Exxon and Moscow got together to concoct an energy program that makes sure that America's energy consumption is more expensive and dangerous."

Edwards told the Senators that adjustments in the synthetic fuels program did not mean DOE was backing away from the concept but that more economical ways had been found to manage it.