Power Line
The Federation of Electric Power Companies of Japan Vol.2
November 1998

Japan's Nuclear Fuel Cycle is Poised for Completion

TRUE OR FALSE: There is a safe, cost-competitive and reliable energy source that is recyclable and can be used by a network of existing power plants. If this sounds like fantasy, think again. Uranium ore is processed into fuel to be burned in nuclear reactors; once the fuel is spent and reprocessed, the residual unburnt uranium and another fissile by-product, plutonium is extracted for use once again.

This process is known as the nuclear fuel cycle and has been adopted by a number of countries, the United Kingdom and France among them. The attraction for Japan to institute a nuclear fuel cycle is obvious: The country must rely on imports for about 80 percent of its primary energy needs, including almost 100 percent of its oil. And as the world's second-largest economy, Japan's consumption of energy, especially electricity, keeps rising.

The upshot: A nuclear fuel cycle established in Japan would provide the resource-destitute country with a quasidomestic energy source. The Japanese have had to rely on countries like the U.K. and France to reprocess most of the spent fuel it produced. The rest has been handled by the Tokai Reprocessing Plant, located in Ibaraki Prefecture, 120 kilometers from Tokyo. Since commencing pilot operations in September 1977, the Tokai plant owned and operated by the Japan Nuclear Cycle Development Institute (JNC) has reprocessed, as of March 1998, some 940 tons of uranium spent fuel.

To place Japan's nuclear fuel cycle on firmer footing, however, additional reprocessing capacity is a must. A new facility is currently under construction at Rokkasho Village in Aomori Prefecture, 700 kilometers north of Tokyo. Slated to come on-line some time after 2003, it will be able to reprocess 800 tons of uranium spent fuel per year.

The Nuclear Fuel Cycle

Mining : Extraction of uranium ore (crude ore) from mines.
Refining : Removal of impurities from the ore to produce yellow cake (uranium concentrate).
Conversion : Conversion of yellow cake into uranium hexafluoride. (UF6)
Enrichment : Treatment of UF6 to increase the concentration of uranium 235, which burns readily but which is contained only in small quantities (0.7%) in UF6, to be- tween 3 and 5 percent.
Reconversion : Conversion of enriched UF6 to uranium dioxide (UO2).
Fabrication : Sintering of UO2 to form it into hardened pellets which are sealed inside zirconium alloy tubes for arrangement into fuel assemblies.
Generation : Loading of fuel assemblies into a reactor for use in the generation of electric power.
Reprocessing : Recovery of the residual unburned uranium and newly produced plutonium in fuel that has been in use for three or four years or so (spent fuel) and separation of the radioactive waste.
Re-use : Recovered uranium and plutonium is processed to be burned as fuel again.