Effect of Transient Thermal Loads on Tungsten Monoblock Module in DEMO

Thermo-hydraulic analyses of the tungsten mono-block divertor module with a water cooling tube made from a diamond/copper composite (DCC) as a laminate and a martensitic steel EUROFER against the power loadings expecting in DEMO operation is presented. Thermal analysis is carried out by using the code MEMOS, which simulates W armor damage under the repetitive edge localized modes (ELM) heat impact. Heat transfer to the water coolant is studied for various coolant conditions which allow one to keep the material temperatures within the allowable design limits under neutron irradiation. The thermal performance is analyzed for the DEMO I and DEMO II reactor conditions for un-mitigated and mitigated ELMs. The importance of W vapor shielding effect is discussed.