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Near Term and Promising Long Term Options for Deployment of Thorium Based Nuclear Energy
Closed for proposals
Project Type
Project Code
T12026CRP
1553Approved Date
Status
Start Date
Expected End Date
Completed Date
23 May 2016Description
There is an increased interest among the Member States for the use of thorium fuel cycle in addressing the sustainable growth of nuclear energy. The major incentives for use of thorium include natural abundance of thorium resources, inert nature of thoria, improved thermo- physical properties compared to urania, high burnup capability, suitability of high conversion ratio fuel cycles, and inherent proliferation resistance characteristics of thorium based fuels. Thorium based fuels have been studied for their potential applications in almost all types of reactors including PWRs, BWRs, PHWRs, HTRs, FBRs and MSR, though on a smaller scale as compared to U/ U-Pu fuels. Thorium has several inherent physical and neutronic characteristics that may be exploited in current as well as next generation nuclear energy systems to achieve, for example, enhanced capabilities for high conversion, further augmented inherent safety characteristics, reduced MA production, etc. Some Member States are of the view that near term deployment of thorium fuels in proven reactor types is not only feasible, but also attractive for contributing to meeting expanding energy needs. Several options are also currently under consideration and even under active development for deployment in a longer term. The CRP will provide a platform for sharing of research results and previous experience among the participating national laboratories and research institutes of the Member States. This CRP also aims to produce a comprehensive reference document that will provide objective technical assessments of thorium based fuels for use in various types of reactors.
Objectives
To develop strategies for the timely deployment of thorium based nuclear energy systems that can serve as a component of the global energy supply.
Specific objectives
The CRP will provide a platform for sharing of research results and previous experience among participating Member States. A key focus will be on the development of strategies for deployment of thorium based nuclear energy in near, medium and long term timeframes and the identification of gaps in achieving the same. The following topics, pertaining to thorium fuel cycle will be covered.
i) Reactor Systems: Concepts and designs that can effectively use thorium as a fuel;
ii) Thorium based fuel fabrication / processing technologies;
iii) Thorium fuel performance;
iv) Thoriumspent fuel reprocessing technologies;
v) Economics of thorium fuel cycles;
vi) Identification of gaps that may affect commercial deployment;
vii) Strategies for deploying thorium fuel cycles in different time frames.
The CRP findings will be consolidated in the form of Technical Document.
Impact
Based on the studies carried out by the participating institutes, following conclusions could be drawn:
? Thorium can be used in conjunction with a range of actinides in a variety of nuclear reactor systems to achieve various fuel cycle objectives.
? Technical and system specific challenges were identified. However, no fundamental insurmountable barriers were found that would prevent the deployment of the studied systems.
? The implementation path to adopting thorium fuel cycle would depend on the availability of suitable fissile materials.
? Substantial benefits can be derived from a closed thorium fuel cycle. Whereas the application of thorium to a once through fuel cycle offers only marginal benefits, except for the niche application as a fuel matrix for once through Pu disposition.
? Closed thorium fuel cycles can, in principle, achieve net breeding of fissile 233U in different reactor systems. Breeding or high conversion rate of thorium into fissile 233U enables substantial natural resource savings.
? A number of development paths are available to establish a closed thorium fuel cycle. Some could leverage existing technologies and operating experience, other, more advanced, systems which offer enhanced performance require further development.
? There are potential long term waste management benefits by implementing a thorium closed fuel cycle versus a closed Uranium fuel cycle. However, the transition time to a future in which all nuclear generation uses the closed thorium cycle is long (on the order of decades). During this transition, the waste management benefits are marginal as compared to the closed uranium fuel cycle.
? Thorium fuel can be effectively used for continuous recycling of transuranic actinides in a variety of reactor systems: reduced moderation LWRs, MSRs and fast reactors. The use of thorium fuel in this context is key to achieving a defendable safety case due to more favourable reactivity feedback coefficients.
? Since thorium irradiation generates a chain of nuclides with relatively small amounts of plutonium and minor actinides, it is particularly suitable fuel matrix for burning actinides produced in other nuclear systems. This results in a need for fewer burner reactors to balance actinide generation in once-through LWRs as compared with uranium fuel matrix-based actinide burning systems.
The outputs of this CRP will be useful for the scientists and engineers involved in R&D activities related to the use of thorium in nuclear reactors
Relevance
Some Member States are of the view that near term deployment of thorium fuels in proven reactor types is not only feasible, but also attractive for contributing to meeting expanding energy needs.