5-9 September 2016
Prague Congress Centre
Europe/Prague timezone

P3.164 Passive decay heat removal for solid breeder blanket

7 Sep 2016, 11:00
1h 20m
Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Foyer 2A (2nd floor), 3A (3rd floor)

Prague Congress Centre

5. května 65, Prague, Czech Republic
Board: 164
Poster H. Fuel Cycle and Breeding Blankets P3 Poster session

Speaker

Hyoseong Gwon (Department of Blanket System Research)

Description

Decay heat produced by neutron irradiation can lead to temperature rise in blanket even after plasma shutdown. The excessive temperature increase of blanket structure would be concerned with increase of decay heat when assuming loss of cooling capability for blanket even though vacuum vessel is assumed to be normally cooled with a safety function. The neutron wall loading is designed to be 0.78 MW/m22 in ITER and become larger in DEMO. Thus, mitigating temperature rise of DEMO blanket caused by decay heat should be examined for integrity of in-vessel components. We focused on passive cooling performance of blanket structure with ribs under the assumption that coolant in the blanket was totally lost. Arrangement of ribs, direction of cooling channels in the ribs, and width of the rib were considered as design parameters. For the different models decay heat with neutron wall loading up to 3MW/m22 was calculated by using a 2D nuclear-thermal-coupled analysis code. The obtained decay heat was applied to finite element model as boundary condition. Radiation condition was considered to a back wall of the blanket. Insulation condition was applied to the other faces of the blanket box. The thermal response of the blanket with different configuration was evaluated by using FEM codes. The maximum temperature of the blanket was different according to arrangement of the ribs. The temperature of blanket with ribs in parallel to the first wall was higher than that of the blanket placing the ribs vertically to the first wall. The temperature difference was over 400 K. In addition natural convection of helium gas injected in vacuum vessel was considered. The thermal hydraulic analysis was conducted to investigate thermal and hydrodynamic characteristics of helium gas in the vacuum vessel. Injection of helium gas contributed to mitigating temperature increase of the blanket.

Co-authors

Hisashi Tanigawa (Department of Blanket System Research, Japan Atomic Energy Agency, Ibaraki, Japan) Hyoseong Gwon (Department of Blanket System Research, Japan Atomic Energy Agency, Ibaraki, Japan) Yoshinori Kawamura (Department of Blanket System Research, Japan Atomic Energy Agency, Ibaraki, Japan)

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