Irradiation tests of a small-sized motor with radiation resistance

A small-sized motor with a resistance to neutron and gamma-ray radiation was developed. This motor was rotating normally at a gamma-ray dose of 7 × 108 Gy, a fast neutron (E > 1 MeV) fluence of 2 × 1021 m−2 and a thermal neutron (E < 0.683 eV) fluence of 4 × 1022 m−2. The gamma-ray dose for this motor was about 700 times as high as the specification of a commercial motor. Much progress in radiation resistance was attained by using radiation-proof materials without organic lubricant. It became clear that this small-sized motor is able to be used for in-pile tests of a fusion blanket using the Japan Materials Testing Reactor (JMTR).