Investigation of HTGR fuel
Investigation of irradiated HTGR fuel properties
Tech Area / Field
- FIR-FUE/Reactor Fuels and Fuel Engineering/Fission Reactors
8 Project completed
Senior Project Manager
Ministry of Energy of the Republic of Kazakhstan / Institute of Nuclear of Physics, Kazakhstan, Almaty
- Japan Atomic Energy Agency, Japan, Ibaraki
Project summaryThe high-temperature-gas-cooled nuclear reactor (HTGR) utilizes the so-called tri-structural isotropic fuel, or TRISO-coated fuel, which is made of ceramic-coated grains of uranium dioxide. The very-high-temperature reactor (VHTR) is a type of the HTGR and is one of the most promising candidates for the fourth generation nuclear energy system (GEN-IV). The VHTR fuel needs to be designed to exhibit excellent safety performance up to burn-up of about 15 to 20 per cent fissions per initial metal atom (%FIMA), in view of economy of the resource.
Post-irradiation examinations (PIEs) of the HTGR fuel is important for characterizing material properties of TRISO-coated fuel in detail under high level irradiation condition. Especially, PIEs data such as appearance and dimensional changes, burnup, additional fuel failure fraction of HTGR fuel compact under the irradiation shall be feedback for qualifying TRISO-coated fuel integrity and upgrading HTGR fuel design for further burnup extension.
Therefore, as HTGR fuel performance investigations, PIEs technologies will be developed with irradiated TRISO-coated fuel particles and fuel compact specimens. The result can enhance evaluation of fission gas release from TRISO-coated fuel and can contribute to upgrading TRISO-coated fuel design for further burnup extension. The PIEs will be carried out at INP RK, where both needed persons (the researchers and technicians familiar with material irradiation tests) and needed facilities are available.
The aims of this project are the following:
1. Constructions of devices for treating the irradiated HTGR fuel specimens.
2. .Developing special PIE devices and proceeding PIEs with the dismantled HTGR fuel specimens
Task 1 will be carried out in the 1st and the 2nd year of this project. Task 2 will be carried out in the 2nd and the 3rd year. The task implementation covers the following:
- · Dismantling technologies of HTGR fuel specimens from the irradiation capsule will be developed.
· Radiation shielding for hot cells will be designed and constructed in a basis of neutronic analyses (fission product inventories, neutron fluences, etc.).
· Irradiated HTGR fuel specimens will be transported to hot laboratory.
· Special devices for HTGR fuel PIEs (appearance observation, dimension of fuel compact specimens, electrical dissociation and acid leaching of fuel compact specimens to measure burnup and fuel failure fraction) will be developed and fabricated.
· PIEs with the irradiated HTGR fuel specimens will be carried out.
For Kazakhstan, PIE devices for the highly-irradiated HTGR fuel specimens are essential components of the technology of fuel characterization, as well as for entrance to the world market of the VHTR fuel. Besides, technology of development of a device for characterization of the irradiated HTGR fuel and technology for treating the highly-irradiated materials will allow:
- · Provide weapon scientists and specialists from Kazakhstan with possibility for reorientation of their abilities to peace activities;
· Encourage reintegration of Kazakhstan’s scientists to international scientific society;
· Support applied researches and development of civil technologies, especially, in the area of environment protection, energy production and nuclear safety.