HTGRs have coated fuel particle for its fuel. This paticle has UO2 kernel with fourfold ceramic coating and its diameter is smaller than 1mm. Its coating protects the UO2 kernel and confines fission products generated by nuclear fission. The ceramic coating offers resistance to high temperatures so that it will not failure even at temperature of 1600 deg C.
For the core structure of HTGRs, graphite is applied. Graphite has high radiaiton hardness, heat resistance and thermal conduction, and low neutron absorption characteristic so that it has an ablitity to keep its fuel and nuclear chain reaction by moderating fast neutron.
For the coolant of HTGRs, helium gas is applied. Since helium gas is an inert gas, it can carry heat at high temeprature ranges without any chemical reactions between the fuel, structure material and coolant.
- What is HTGR ?
- Structure of HTGRs
- Temperature Ranges Applicable to Various Industrial Fields
- Development Status of HTGRs in the World
- Outline of High Temperature Engineering Test Reactor
- Establishment of technical bases of high temperature gas-cooled reactor with the HTTR
- Various Hydrogen Production Methods
- R&D on Thermochemical IS Process
- Hydrogen Society in the Future