A commemorative postage stamp on the Attainment of Criticality of the ‘Joyo’ (nuclear reactor), Oarai, Ibaraki prefecture, Honshu island, Japan :
Issued by Japan
Issued on Jun 6, 1977
Issued for : A postage stamp was brought out to commemorate the attainment of criticality of the first Japanese experimental fast breeder reactor named “Joyo” at Ōarai, Ibaragi prefecture. The construction of “Joyo” was started in 1970.
It is the first time that Japan has succeeded in this big development project entirely with its own technologies.
Design : Illustration of fast breeder reactor Joyo’s core.
Designer : Mr. Hitoshi Otsuka
Colour : Multicolour
Type : Stamp, Postal Used
Denomination : 50 Yen
- The fast breeder reactor is an ideal power generation reactor making use of nuclear fission. It is often referred to as an power reactor of dream. This reactor is characterized by the fact that it produces much new fuel than it consumes for power generation. If it is put into operation, the reactor is believed to make possible the use of uranium and contribute to the solution of energy problems. Some fast breeder reactors have already been completed in the United States, Britain, France and the Soviet Union.
- In Japan, the Prime Minister decided in 1968 to develop this reactor as a national project, and development efforts have been being made by the Power Reactor and Nuclear Fuel Development Corporation and other organizations. The policy has been made to develop a reactor using natrium as cooling material and oxide compound of plutonium and uranium as fuel. The reactor for practical use will be built after developing experimental and prototype reactors.
- The experimental reactor “Joyo” has been being built since March, 1970 at the Oarai Engineering Center in Ibaraki Prefecture, located northeast of Tokyo. Fuel has been put since March this year, and it attained criticality on April 24 for the first time.