Current status of neutron guides at the JRR-3

Tamura, Itaru  ; Nagahori, Kazuhisa; Sasajima, Fumio; Wakimoto, Shuichi  ; Wada, Shigeru

The JRR-3 research reactor is a swimming pool type research reactor with nominal thermal power of 20 MW. The JRR-3 has several utilization facilities for irradiation tests, production of RI and provides thermal and cold neutrons for neutron beam experiments. Five neutron guides have been installed in order to transport thermal and cold neutrons from the reactor reflector to the beam hall. Two thermal neutron guides are approximately 60 m long and three cold neutron guides are 31-51 m long. JRR-3 and its several utilization facilities have suffered the Great East Japan Earthquake on March 11 2011. The misalignment of neutron guides occurred. Since all neutron guides at JRR-3 have curved sections, the misalignment of neutron guides results in reduction of the strength and the shifting of the characteristic wavelength of transferred neutrons. In this presentation, the recovery of neutron guides from the earthquake and the current status of neutron guides at JRR-3 are reported.