Development of DHCV test techniques for the irradiated CANDU pressure tube materials in hot cell

The delayed hydride cracking (DHC) phenomenon was first observed in zirconium-niobium material in experiments in 1972. Since many pressure tubes are cracked by DHC during operation in Canada it has been intensively studied. Some tubes in domestic CANDU reactors had been found with cracks from DHC during operation. Little attention for the irradiated pressure tube has been given to the DHCV behaviors because of not preparing for the test techniques and equipment in domestic. To perform the DHCV test for the operated pressure tube materials it is necessary that the test techniques are to be developed in hot cell facility. In hot cell usages the equipment are specially designed to be operated by the remote control and endure radiation atmosphere. The electric discharge machine (EDM), dynamic, static universal testing machine, hydrogen charge system and direct current potential drop (DCPD) system are to be adopted to the test and test procedures and data analysis method to determine DHCV will be optimally developed through the study