Japan, heavily reliant on the United States for its nuclear fuel, is planning eventually to go it alone. The Atomic Energy Commission (AEC) recently revealed a plan calling for development of a commercial uranium enrichment plant to begin operation by 1987.
And, subject to final American approval, this country's ability to reprocess spent nuclear fuel is to be drastically increased.
Totally dependent on imported uranium ore, the Japanese are also stepping up efforts to develop secure long-term sources of supply through joint exploration and mining ventures in several countries, including the US, Australia, and some African states.
All this is necessary if the government is to achieve its target of almost doubling nuclear-power output over the next decade. At present, there are 22 reactors with total output capacity of 15 million kw. in operation. These produce 12 percent of Japan's electricity needs.
Current plans have another 14 either under construction or in the planning stage. When completed, another 13 million kw. of nuclear power output would be added.
At present, all Japan's uranium ore is processed (enriched) for nuclear-reactor use in the United States. There are strict safeguards on its use, and the US also has the final word on disposal of the spent fuel.
The spend fuel can be reprocessed for further use.
So far, much of the reprocessing has been farmed out to Britain and France. But since 1977, a small part has been carried out here at the state-run power reactor and Nuclear Fuel Development Corporation's Tokaimura plant.
The plant, however, has a maximum capacity of 210 tons per year, and in recent weeks the Tokyo government has been negotiating with the US for permission to build a second reprocessing plant to go into operation by 1990. It would be capable of reprocessing all the spent fuel to be produced annually by the nuclear plants expected to be in operation then.
Officials of the science and technology agency say final agreement with the US has yet to be reached, especially on the tight safeguards the US requires.
The other main thrust of Japan's self-reliance will be development of uranium-enrichment capability.
The Atomic Energy Commission's scenario goes like this:
* Construction and operation of a uranium-enrichment prototype plant with annual capacity of 200 tons SWU (seperation work units), by the Power Reactor and Nuclear Fuel Development Corporation (PNC) in cooperation with the private sector.
Construction work is expected to start in mid-1982 at Okayama. The PNC already has a pilot enrichment plant in operation there with a yearly capacity of 50 tons.
* A commercial plant to be constructed by the private sector, with some government assistance, to be in partial operation by 1988. It should be capable of producing 1,000 tons a year by 1995 and 3,000 tons annually by the end of the century.
If this target is reached, experts say Japan will be able to achieve at least 30 percent self-sufficiency in its estimated enriched uranium requirements at that time.
There has been prolonged and fierce debate over the feasibility of government uranium enrichment plans. The debate has centered on who should be responsible -- the public or private sector -- and also on whether the high cost justifies the effort.
Government experts admit that for some time it will be far more expensive for Japan to enrich its own uranium than to rely on the US. But the effort is considered worthwhile in helping to develop a domestic "atomic energy industry" that could eventually go into the export business.
All, of course, depends on reliable supply of uranium ore or semiprocessed ore known as yellow cake.
The government's general energy advisory council recently urged there should be less reliance on straight commercial purchases of foreign uranium and more Japanese involvement in mine and development.
Only 18 percent of Japan's imports now come from sources where there is Japanese capital and managerial participation. The council wants this boosted to at least 50 percent.
Both the PNC and consortiums of Japanese power companies and trading firms are extremely active in exploration and mine development in the Australian Northern Territory and West Australia, with at least one project coming to fruition next year.
The Japanese are also highly active in the West African state of Niger, and the PNC has just signed an agreement for joint exploration in southern Zambia.
A consortium of 10 Japanese companies reportedly is looking for ore in Noserock, N. M., while the PNC has a joint venture agreement -- in which it will eventually have a 50 percent stake -- with Continental Oil for prospecting at Powder River, Wyo.