Thorium proliferation resistance

Three of these awards were for proliferation resistant reactors. By exploring advanced concepts such as modular reactors with long-life cores and thorium-based firel cycles, we may be able to find solutions to the greatest challenges facing the nuclear energy industry. 

Advanced Proliferation Resistant, Lower Cost, Uranium-Thorium Dioxide Fuels for Light Water Reactors, Nuclear Energy Research Initiative, Idaho National Engineering and Environmental Laboratory, Idaho Falls, ID, 2000. 

The investigation of safety and more particularly of severe accident conditions is important for accelerator driven systems (ADS). Subcritical ADS could be of particular interest for the actinide transmutation from the safety point of view, because fast reactors with Neptunium, Americium and Curium have a much smaller fraction of delayed neutron emitters (compared to the common fuels and U), a small Doppler effect and possibly a positive coolant void coefficient. This poses a particular problem of control since the fraction of delayed neutrons is essential for the operation of a nuclear reactor in the critical state. In addition, the IRC presented in the past a review of accelerator-driven sub-critical systems with emphasis on safety related power transients followed by a survey of thorium specific problems of chemistry, metallurgy, fuel fabrication and proliferation resistance. 

To overcome these problems various concepts of accelerator driven systems aiming at the transmutation of actinides and long lived fission products have been proposed in the recent past. The JRC presented a review of accelerator-drivai sub-oitical systems with emphasis on safety related power transients followed by a survey of thorium specific problems of chemistry, metallurgy, fuel fabrication and proliferation resistance. 

Because commercial thorium fuel recycling facilities have not been built, there is an opportunity to establish a new, proliferation-resistant technology for recycling. 

In general, thorium cycles are all quite proliferation resistant for a variety of reasons. Prominent among those are that separated is always accompanied by is a... 

The molten-salt reactor uses molten salt as either the primary coolant or fuel. In either case, both are in motion around the core. One such prototype reactor was built and operated at the Oak Ridge National Laboratory in the 1960 decade. The concept is primarily focused on the thorium/U-233 fuel cycle. The reactor primarily operates near atmospheric pressure, allows for continuous removal of fission products, and offers natural proliferation resistance characteristics. 

At the time of this report, no practicable means existed to extract plutonium from the coated fuel particles. Uranium-thorium and uranium carbide fuel could also be used in the AFPR to enhance its proliferation resistance. 

Enhanced proliferation resistance Use of thorium based TRISO type fuel. 

Pebble bed and prismatic reactor are the two major design variants. Both are in use today. In either case, the basic fuel construction is the TRISO-coated particle fuel. Uranium, thorium, and plutonium fuel cycle options have been investigated and some have been operated in the reactors. Spent fuel may be direct disposed or recycled. The unique constmction and high bumup potential of the TRISO fuel enhances proliferation resistance. 

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