[2O01-05] Reactor Pressure Vessel Steels 1

10:15 AM - 10:30 AM JST(1:15 AM - 1:30 AM UTC)

[2O03] Neutron irradiation tests of structural materials for nuclear reactors using JRR-3 and WASTEF(3)Temperature control technology of the JRR-3 vertical irradiation facility

*Hiroki Ushijima¹, Kento Mitsui¹, Takumi Fuyushima¹, Yuji Okada¹, Yasuichi Endo¹, Yoshinori Matsui¹, Yoosung Ha¹, Kuniki Hata¹, Takemi Nakamura¹ (1. JAEA)

Keywords:

JRR-3,material irradiation,temperature control

It is desirable to irradiate materials at a constant temperature in irradiation tests, because irradiation temperature is one of the factors influencing irradiation damage. However, it is difficult to maintain the thermostatic conditions during reactor power increases and for a few days after criticality when the control rods are frequently moved. In this irradiation test, it was confirmed that the sample was maintained at the target temperature at reactor start-up by automatic control of the vacuum of the insulation layer and heater output. In addition, the function to balance vacuum and heater prevented the heater output deviating from the controllable range due to post-criticality power fluctuations. We have successfully achieved stable temperature control throughout one cycle of JRR-3 operation.