Numerical simulation on bake-out of the ITER diagnostic upper port plug

Abstract

The diagnostic upper port plug in ITER is fixed to the upper port of the vacuum vessel as a cantilevered beam with bolts and forms a primary vacuum boundary. It needs to be baked out for outgassing before normal operation. This study calculated the required bake-out time and the transient thermal stress during baking for the diagnostic upper port plug. The calculation was done through numerical simulation. The analysis took into consideration the gradual temperature increase of working fluid. In order to look into the effect of radiation heat transfer from the upper port plug to the vacuum vessel port, the upper vacuum vessel port was included in this analysis.