R. Meyder

Self-cooled blanket concepts using Pb7Li as liquid breeder and coolant

Abstract A blanket design concept using Pb17Li eutectic alloy as both breeder material and coolant is described. Such a self-cooled blanket for the boundary conditions of a DEMO-reactor is under development at the Kernforschungszentrum Karlsruhe (KfK) in the frame of the European blanket development program. Results of investigations in the areas of design, neutroncs, magneto-hydrodynamics, thermo-mechanics, ancillary loop systems, and safety are reported. Based on recent progress, it can be concluded that the boundary conditions of a DEMO-reactor can be met, tritium self-sufficiency can be obtained without using beryllium as an additional neutron multiplier, and tritium inventory and permeation are acceptably low. However, to completely judge the feasibility of the proposed concept, further studies are necessary to obtain a better understanding of the magneto-hydrodynamic phenomena and their effects on the thermal-hydraulic performance of a fusion reactor blanket.

Test program preparations of the ITER toroidal field model coil (TFMC)

The preparative experimental and analysis work as well as the code development for testing the ITER (International Thermonuclear Experimental Reactor) TFMC, one of the large projects of the ITER research and development programme, is described. The expected critical currents of the Nb3Sn superconducting cable are derived from the numerous short sample strand and subcable measurements. A data set of the thermo-hydraulic properties of the bundle conductor with a central channel was elaborated in experiments as an input for the thermo-hydraulic calculation codes GANDALF and MITHRANDIR combined with the hydraulic network code FLOWER. On this basis, the quench behaviour and the injection of gaseous heated helium slugs for determining the operation limits are treated. The mechanical behaviour of the test configuration was investigated by a finite element calculation. The winding type in which the conductor is embedded in radial plates has to be considered for transient voltage peaks as an electrical network. Arising over-voltages by resonance frequencies in the winding pack have to be considered for the integration of the electrical insulation system of the TFMC. Numerous sensors are installed to compare the predicted values and behaviour with the measurements

Analysis of an unmitigated quench in a poloidal field coil of ITER

Abstract In the paper the consequences of an unmitigated quench in the equatorial poloidal field coil (PF3) of ITER are investigated. This coil is crucial because its thermal failure would pose a hazard to all equatorial ports of ITER. The analysis shows that about 0.08 m 3 of conductor copper will get molten temporarily but the steel jacket will contain the melt.