Professor Jo Moon-sung at the Next Generation Nuclear Fuel Technology Development Division of the Korea Atomic Energy Research Institute (KAERI) announced on May 12 that his research team developed a prototype of coated particle nuclear fuel for use in very high temperature reactors (VHTRs) and successfully finished the seven-month-long combustion performance test in the Hanaro research reactor.
The VHTR is a type of fourth-generation nuclear reactor. It uses the nuclear fission energy of the uranium element to decompose water with a heat of over 950C and produce hydrogen and electricity at the same time. In the event of any accident, it cools the reactor through air circulation by its passive safety system and therefore can guarantee much improved safety.
The nuclear fuel used in the VHTR is a coated particle-type fuel with a diameter of 1mm, in which spherical uranium particles are triply surrounded by carbon and silicon carbide. The three layers prevent the nuclear fission products from leaking out of the nuclear fuel during combustion. After combustion, the nuclear diffusion is hindered because it is difficult to recover the plutonium.
The research team has tested the performance and soundness of the fuel in the Hanaro reactor and is planning to produce a block-type fuel element of 1,000 or so particles. KAERI is going to set up a demonstration-version VHTR in or after 2020.