Strength evaluation of JRR-3 high-performance moderator vessel for cold neutron beam, 2

Arai, Masaji ; Tamura, Itaru  ; Komeda, Masao   ; Mineshima, Hiromi

Existing moderator vessel for JRR-3 cold neutron source (CNS) facility is ovoid shape with stainless steel. In order to increase the intensity of cold neutron beam, we are developing high-performance moderator vessel which is new boat-bottom shape with aluminum alloy. The strength analysis of new moderator vessel has been evaluated by nonlinear finite element analysis code ABAQUS bellow maximum allowable working pressure, and the results met the technical criterion required by the national law. The validity of a result was confirmed by the hydraulic pressure test used by the test moderator vessel. Additionally, strength analysis in 1.5 times pressure (internal pressure about 0.675 MPa) of maximum allowable working pressure was carried out for the pressure proof test of the technical criterion and the soundness of new moderator vessel was newly studied.