Functional Plasma-Sprayed Ceramic Coatings for use in Fusion Energy Systems

Statement of the Problem or Situation that is Being Addressed Nuclear fusion, the phenomenon by which massive quantities of energy are released when atomic nuclei collide together, is one of the most promising options for generating stable carbon-free energy, in face of climate change and declining supplies of fossil fuels. In order to achieve an extremely hot plasma condition for fusion reactions to occur, typical fusion reactor designs involve a tokamak that magnetically confines the plasma, and a breeding blanket that provides reliable structural support despite of the massive heat and neutron flux. The dual-coolant lead-lithium (DCLL) blanket is an attractive breeding blanket concept that facilitates high temperature (~700oC) and high thermal efficiency (>40%), but the temperature limit and the molten Pb-Li coolant corrosion are still pressing issues on the RAFM steel, the current structural material of breeding blankets, before the DCLL blanket concept is applicable to commercial fusion reactors. Statement of how this Problem or Situation is Being Addressed Solution Spray Technologies will develop a novel functional coating system on the RAFM steel using a new plasma spray process so as to enhance the corrosion resistance of the steel against molten Pb-Li coolant while maintaining a good thermal stability in the flowing liquid breeder. Process parameters of the plasma spray will be developed for optimized coating properties, and the sample pieces will be evaluated under realistic tests. Commercial Applications and Other Benefits The project will result in development of a novel functional coating system for the RAFM steel, which is a crucial factor for the application of the DCLL blanket concept in commercial fusion reactors. Development and utilization of nuclear fusion reactors provide several benefits to society including minimizing environmental burden by eliminating carbon emission, reducing energy cost by improving energy efficiency, providing a stable and sustainable energy supply therefore strengthening energy security, facilitating local economy development, and creating long term, high income jobs. Keywords Fusion, plasma-spray, functional coating, corrosion, RAFM Summary for Members of Congress Solution Spray Technologies will develop a novel functional coating system on the RAFM steel with the potential to cost effectively enable a promising technology to be utilized in the highly-efficient generation of nuclear fusion energy, helping to minimize environmental burden, secure national energy supply, and create new jobs.