Study on In-vessel ISI for JOYO; Ultrasound propagation characteristic in the core support plate

Ariyoshi, Masahiko; Ara, Kuniaki ; Hirabayashi, Masaru

This report describes the feasibility study on the in-vessel inspection technique to be applied for the experimental fast reactor JOTO. The object of this examination is to comfirm the integration of reactor structure under sodium environment by an immediate means. The core support plate which is an important structure supprts the weight of the core assembly is selected to an object of the inspection.In the examination until last year, the core support plate inspection equipment concept which combined ulutrasound sensor with manipulator was constructed.In this conceprt, the ulutrasound sensor is accessed to a low-pressere plenum sidewall and integrity of the core suppot plate weld is inspected.