Inspection and repair techniques in the reactor vessel of the experimental fast reactor Joyo; Observation technical development in a reactor vessel of the fast reactor, 3

Okuda, Eiji; Sasaki, Jun; Suzuki, Nobuhiro; Takamatsu, Misao ; Nagai, Akinori

In-Vessel Observation (IVO) techniques for Sodium Cooled Fast Reactors (SFRs) in service are important for confirming their safety and integrity. Since IVO equipment for an SFR has to be designed to tolerate the severe conditions (high temperature, high radiation dose and limited access route), fiberscopes used to be used in previous IVO for SFRs. However, in order to attain an IVO with higher quality and resolution, IVO using a radiation resistant camera was conducted in the fast experimental reactor Joyo and obtained some results. The demonstration results provided valuable insights for use in further improving and verifying IVO techniques in SFRs.