Experience in irradiation testing of low-activation structural materials in fast reactor BOR-60

A Russia/US collaborative irradiation experiment on low-activation structural materials, mainly vanadium alloys, was recently completed in the BOR-60 reactor at the Research Institute of Atomic Reactors (RIAR) in Russia. The experiment, designated Fusion-1, was designed to investigate the effects of neutron-induced displacement damage on the microstructure and mechanical properties of these materials at low temperatures, 300–360°C. For purpose of heat transfer and impurity control, the specimens were lithium-bonded to the capsule. After reaching the goal damage dose of 20 displacements per atom (dpa) in approximately 1 year of irradiation, the capsule was discharged and disassembled in a hot cell at RIAR. All specimens were retrieved from the capsule. This paper summarizes the experiment, covering capsule construction, lithium purification and filling, irradiation, disassembly and specimen retrieval, and calculated results of specimen temperatures and damage dose.