Modular High-Temperature Helium-Cooled Nuclear Reactor with Spherical Fuel Elements for Electricity and Hydrogen Production

The results of optimizational neutron-physical and thermohydrulic calculations of the core of a modular high-temperature helium-cooled reactor with mobile spherical fuel elements are presented. A special structural feature of such fuel elements is that they contain fuel microelements with multilayered ceramic coatings capable of confining radioactive fission products at high temperatures with deep burnup of nuclear fuel. The thermal power of the reactor is 850 MW(t) with average power density 30 MW/m3 and helium temperature 1000°C at the core exit. This makes it possible to use such reactors to produce hydrogen by a cost-effective high-temperature process using steam conversion of methane and to generate electricity in a one-loop helium turbosystem with efficiency >45%.