Development of Irradiation Capsules in Liquid Metal Environment in Joyo and Their Application to Irradiation Creep Measurement of Vanadium Alloys

Abstract

In order to perform irradiation experiments in a liquid metal environment in a nuclear reactor, an irradiation technique with sodium bonding irradiation capsules was developed and a series of neutron irradiation experiments with sodium bonding irradiation capsules were performed in Joyo. The design and fabrication of sodium bonding capsules, sodium filling into capsules, capsule loading to Joyo, irradiation experiments, dismantling for irradiated capsules, removing the irradiated specimens from sodium-filled capsules, and sodium cleaning of the irradiated specimens were established through this study. Using the Joyo irradiation with the sodium bonding capsules where irradiation temperature was distributed uniformly, the irradiation creep experiment for highly purified V-4Cr-4Ti alloys, NIFS-Heat, was carried out and the knowledge about the irradiation creep behavior of the alloys was obtained.