A Model for the Mechanical Interaction Between Solid Breeder and Cladding Materials

Mechanical interaction between the solid breeder material and its cladding during power cycles is an important consideration in the design of solid breeder blankets. The analysis presented in the paper gives a design tool for material choices and lifetime prediction for breeder pins. The UCLA solid breeder blanket design is evaluated, and operating conditions are suggested. The material model for the pellet includes linear thermoelastic behavior and swelling. The cladding is assumed to be thin and to exhibit swelling and creep. Two alternate breeder/cladding material pairs have been analyzed, a Li₂O/2.25Cr-1Mo and a LiAlO₂/9-C design. While high swelling excludes the Li₂O/2.25Cr-1Mo design, it is found that in the LiAlO₂/9-C case compatibility of thermal expansion between the breeder and the cladding as well as low swelling of the breeder result in less than 0.5% total plastic strain after one year of operation.