Rosatom said the tests – one of the key steps in manufacturing a reactor – had confirmed the strength of the vessel and the quality of all welds.
Rosatom gave no details of the construction schedule for the MBIR plant but reports in Russia earlier this year said it would begin operation in 2024.
According to Rosatom, the MBIR will be the most powerful research reactor in the world with 150 MW of thermal capacity.
It is under construction at the Research Institute of Atomic Reactors (NIIAR) site at Dimitrovgrad in the Ulyanovsk region of western Russia.
The MBIR will primarily use sodium as a coolant and vibro-packed mixed-oxide (VMOX) fuel. VMOX is a Russian variant of MOX fuel in which blended uranium-plutonium oxide powders and fresh uranium-oxide powder are loaded directly into the cladding tube of the fuel assembly instead of first being manufactured into pellets.
The MBIR will be used for the development of materials for Generation IV fast neutron reactors. Scientists will use it to carry out experiments on the operating parameters of core components under normal and emergency conditions when using sodium, lead, lead-bismuth, gaseous and molten salt coolants.