Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Ito, Chikara; Iwata, Yoshihiro; Harano, Hideki*; Iguchi, Tetsuo*; Aoyama, Takafumi
Transactions of the American Nuclear Society, 102(1), p.416 - 417, 2010/06
no abstracts in English
Maeda, Yukimoto; Ito, Chikara; Soga, Tomonori
Transactions of the American Nuclear Society, 102(1), p.742 - 743, 2010/06
The experimental fast reactor Joyo is the first sodium cooled fast reactor in Japan. Irradiation tests in Joyo were commenced from 1983 after the completion of core conversion work from the MK-I breeder core to the MK-II irradiation test bed core. Many valuable irradiation tests were carried out to develop fuels and materials for the prototype fast reactor Monju and a demonstration fast reactor. After the 35 duty cycles operation by the MK-II core, Joyo was upgraded to the high performance MK-III core to increase irradiation capability in 2003. Unique irradiation tests for the FaCT project such as MA bearing MOX fuel and ODS ferritic steel were carried out in the MK-III core. In light of the shutdown of several fast reactors around the world, the ability to make such major contributions to reactor development takes on even greater significance. Irradiation tests in Joyo contribute to the FaCT project, and also to promote the international cooperation such as Generation-IV.
Maeda, Yukimoto
no journal, ,
In the experimental fast reactor Joyo, failure of disconnecting MARICO-2 occurred and the top of the irradiation test subassembly was bent onto the in-vessel storage rack, and the sodium flow regulating grids and guide tubes on the bottom of Upper Core Structure were deformed by contact with the bent subassembly. This incident necessitates the replacement of damaged UCS and the retrieval of the bent subassembly for Joyo re-start. In-reactor vessel observation, 
dose rate measurement in reactor vessel for evaluation of the radioactivity of UCS and a lift up test of bent subassembly in order to confirm the condition of the bent subassembly were conducted to reflect to the design of retrieval device of bent subassembly and UCS replacement device. The experience obtained through the restoration work in Joyo will provided valuable prospect for further improvements of in-reactor vessel inspection and repair techniques in SFRs.