29th Symposium on Fusion Technology (SOFT 2016)

P3.117 Thermo-mechanical analyses and ways of optimization of the helium-cooled DEMO First-Wall under RCC-MRx rules

7 Sep 2016, 11:00

1h 20m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 117

Poster F. Plasma Facing Components P3 Poster session

Speaker

Julien Aubert (DEN)

Description

The EUROfusion Consortium develops a design of a fusion power demonstrator plant (DEMO) in the framework of the European “Horizon 2020” innovation and research program. One of the key components in the fusion reactor is the breeding blanket surrounding the plasma, ensuring tritium self-sufficiency, heat removal for conversion into electricity, and neutron shielding. Among the 4 candidates for the DEMO Breeding Blanket, 2 of them use helium as coolant, and another one uses helium to cool down the FW only. Due to uncertainties regarding the plasma Heat Flux load the DEMO Breeding Blanket integrated First Wall will have to cope with, a set of sensitive thermal and thermo-mechanical analyses have been performed in order to define the possible margin against HF the integrated Helium Cooled Eurofer FW could have. Based on the Helium Cooled Lithium Lead (HCLL) equatorial outboard module dimensions, thermal and stress FEM analyses have been performed with Cast3M with various FW front wall thicknesses and Heat Flux, under normal steady state condition. Stress have been analysed with RCC-MRx code including high temperature (creep), cyclic (fatigue) and irradiated rules. This paper shows that the thickness of the plasma-facing wall of the FW should be minimized, within the limits necessary to withstand primary stresses, in order to reduce the temperature on the structure and thus prevent fatigue and creep damage as well as a reduction of the stress limit Sm which is function of temperature to prevent ratcheting. Moreover, the paper will discuss the importance of having constant HF during the reactor operation. A small variation of HF could increase a lot the risk of damage such as fatigue and creep. At the end, the effect of irradiation shows up to be the limiting criterion and penalizes the capacity of the FW to withstand high HF.