Experimental reactor Joyo

The experimental fast reactor Joyo is the first liquid sodium-cooled fast reactor in Japan. The purpose of constructing Joyo was to obtain technical information about sodium-cooled fast reactors (SFRs) through experience with its design, construction, and operation, and to use the reactor as a fast neutron irradiation facility for the development of fuels, materials, and other components required for the SFR program. Through design, construction, testing, operation, and maintenance experience, Joyo has contributed much to the SFR development program. In addition to providing operating experience, many kinds of irradiation tests have been conducted for the development of fuels and materials under the conditions of higher fast neutron flux and temperature than those in light water reactors. Through its successful operation over a quarter-century, Joyo has demonstrated the safety and reliability of the sodium-cooled fast reactor.