The so-called pluthermal process -- burning plutonium extracted from spent nuclear fuel in light-water reactors for power generation -- will be a "pillar" in the nation's nuclear fuel cycle policy for several decades to come, a government advisory panel said in its interim report released Jan. 20.Given that prospect, it is extremely important to improve economic efficiency of the pluthermal process by reducing the cost of mixed oxide fuel, known as MOX, which is a mixture of plutonium and uranium, a subcommittee of the Advisory Committee for Energy said. The report says the government should proceed with its plan to recycle nuclear fuel, promoting use of spent nuclear fuel as an energy source.While pushing the pluthermal process, the report also says a fast-breeder reactor, which uses plutonium as fuel, remains a key technology that must be steadily developed to ensure the nation's energy security in the medium to long term. The report says the nation is at the initial stage of establishing a nuclear fuel cycle that uses plutonium extracted from spent nuclear fuel.It says it is "adequate" that nuclear plant operators will have in place three or four pluthermal-type power generating systems by 2000. Several more systems will be added during the first decade of the next century, it said.