Russian scientists from the School of Nuclear Science & Engineering at Tomsk Polytechnic University (TPU) are developing a technology for the construction of high-temperature, low-power reactors which use thorium fuel.
The scientists propose to use a mixture of thorium and weapons-grade plutonium in these units to produce both electricity and heat, TPU said on its website. Thermal energy generated at thorium reactors may be used hydrogen production and for desalinating water. The results of the study were published in Annals of Nuclear Energy in November 2017.
Associate Professor Sergey Bedenko from the School of Nuclear Science & Engineering said, "As a rule, a nuclear power plant is constructed on the riverside. Water is taken from the river and used in the active zone of the reactor for cooling. In thorium reactors, helium is used, as well as carbon dioxide (CO2) or hydrogen, instead of water. Thus, water is not required."
Bedenko noted that large amounts of weapons-grade plutonium was accumulated in the Soviet era. “The cost for storing this fuel is enormous, and it needs to be disposed of,” he said. Current reprocessing and recycling technologies still results in radioactive waste that contains plutonium. “Our technology tackles this problem as it allows 97% of weapons-grade plutonium to be burned."
The plant is capable of operating at low capacity (from 60MW).
"The main advantage of such plants is their multifunctionality,” Bedenko said. It efficiently disposes of one of the most dangerous radioactive materials; it generates power and heat, and it will contribute to industrial hydrogen production. Also, water can be desalinated at thorium reactors.
The authors of the study say that the advantage of thorium reactors is their higher level of safety in comparison with traditional designs, enhanced efficiency (40-59%), absence of coolant phase transitions, increased corrosion resistance. Thorium reactors also offer the possibility of using different fuels and their overload in operation, and simplified management of used nuclear fuel.