DESIGN OPTIMIZATION OF A FUSION REACTOR DIVERTOR COOLING FINGER DESIGN FOR DECREASED THERMO-MECHANICAL STRESSES

In this paper a design of a divertor cooling finger for a fusion reactor is looked at with the aim of reducing the thermo-mechanical stresses. The function of a divertor in a fusion reactor is to reduce the dilution of the plasma by removing alpha particles, helium and other impurities. In addition, this component has to remove approximately 15% of the total thermal power. The divertor is therefore exposed to a significant thermal load, and during the operation it has to be actively cooled, which can be done using helium. However, the high thermal gradients also result in undesired local stress concentrations. In this work a cooling finger assembly is analyzed. The assembly includes the brazing layer that provides bonding between the thimble and the tile, the two main parts of the cooling finger. In nearly all numerical thermal-mechanical analyses on cooling finger designs described in literature, the brazing layer is usually neglected in the modeling process. The design of the tile is further optimized with the aim to reduce stresses inside the cooling finger, in particular the thimble. The proposed design changes involve circumferential vertical notches in the tile, raising the flexibility of the tile itself and thus reducing bending of the thimble. Even a thimble notch design option is proposed. Three different notch designs are exposed and parametric studies are performed to assess the influence of their locations, depths and widths on the stress level of the thimble.

MATTEOLI Camilla;  MARTIN Oliver;  SIMONOVSKI Igor; 

2013-02-28

Nuclear Society of Slovenia

JRC77199

https://publications.jrc.ec.europa.eu/repository/handle/JRC77199,