Component Testing and Materials Development for Fusion Applications Using Materials Test Reactors
Fusion power plant operation will strongly depend on the economy and reliability of crucial components, such as first wall modules, tritium breeding blankets and divertors. Their operating temperature shall be high to accomplish high plant efficiency. The materials properties and component fabrication routes shall also assure long reliable operation to minimize plant outage. The components must be fabricated in large quantities based on demonstrations with a limited amount of test beds. Mock-ups and test loops will, through iteration processes, demonstrate the reliable operation under reference thermal-hydraulic conditions. 14 MeV neutrons escaping the plasma dominate the nuclear conditions near the first wall. Neutron transport analyses have shown that large portions of the components near the plasma have to cope with a neutron spectrum resembling that of a fission core. MTR's, Materials Test Reactors, have been used successfully to test components for fusion power plants. Their space and availability will also ensure their role as future test bed for (sub) components such as blankets, first walls and divertors. The future generation of MTR's will allow faster testing, because of the higher neutron fluxes possible with advanced driver fuels. The strong limitation of MTR's for fusion testing will remain the limited production of helium and hydrogen, because of the lack of 14 MeV neutrons. Though large parts of the fusion components are subjected to nearly fission neutron spectra, in the domain near the burning plasma 14 MeV neutrons are dominant. IFMIF will produce the 14 MeV neutrons to fill that gap by the end of the next decade. In the meantime the MTR's will generate relevant data for fusion power plant component design. After IFMIF is operational the new generation MTR's will still have a function in testing components in a nuclear environment. The new generation test reactors will also be used for the development of component operating at high temperature in the generation-4 fission power plants. The R&D climate will be most stimulating for cross fertilization of fission and fusion component development, leading to more efficient use of the earth's resources.
Structural materials development and databases
Abstract Fusion plants will have a large scale and therefore need a high availability and reliability to generate electricity economically. The materials total life cycle controls the choices of crucial plant components such as blankets and divertors to a high degree. Materials applications so far rely on data obtained with fission reactors up to levels of 80 dpa. Such fission simulations miss the effects of the He and H generated in a fusion plasma environment. The International Fusion Material Irradiation Facility, IFMIF, a 14 MeV neutron source, will provide more realistic tests. Its design will rely on the databases obtained with fission reactors. IFMIF itself will produce materials databases that will be incorporated in design codes for fusion power plants. The first generation of blankets will be built with reduced activation steels. The race for higher thermal efficiencies leads further to the application of oxide dispersion strengthened steels and SiC ceramic composite. SiC structural utilisation requires breakthroughs. Tungsten alloys are attractive for divertors operating with high heat flux surfaces at high temperature. Their high temperature embrittlement is presently improved with promising thermo-mechanical treatments. Research results should be incorporated in “early bird” databases improving design and materials expert interaction.
Handbook of Concrete Engineering
Handbook of concrete engineering , Handbook of concrete engineering , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی