Electromagnetic Analyses For Test Balanket Moduel Under Transient Plasma Excitations

International Thermonuclear Experimental Reactor(ITER) is currently being built and would be the world’s largest Tokamak experimental reactor, which carried human being’s greatest expectation in exploring the safe, clean, inexhaustible fusion energy. The original intention of the ITER Project was to develop nuclear energies in a peace way through a world wide range of human cooperation, whose main goal was to accumulate fusion experimental data and practice experiences like tritium breeding, high grade heat extraction technics for future commercial fusion plants via the Test Blanket Module(TBM) program. The Helium Cooled Ceramic tritium Breeder Test Blanket Module(HCCB TBM) had been defined to join in the ITER TBM program for experiment by China.The TBM would be installed in the equatorial port of the ITER Tokamak, whose structure has to withstand the challenge of strong magnetic fields, high heat flux density, and high flux neutron radiation. Due to the adoption of ferromagnetic structural materials in HCCB TBM, the TBM would undertake a very strong Lorentz force in the plasma disruption events, which was caused by severe eddy current induced in the TBM conductor that was results of the intense electromagnetic transients produced by the fast decay of the plasma current with a typical value of 15 MA, which would be ended in just a few dozen milliseconds. Moreover, a large Maxwell force would be added up to the TBM as the magnetization of several tons of its ferromagnetic structural materials under high magnetic field. Based on the investigation and summary of domestic and abroad methods implemented in the TBM electromagnetic security analyses, the electromagnetic forces that induced on China HCCB TBM during Major Disruption and Vertical Displacement Events has been evaluated by means of finite element method analysis in this paper.The key problem of the electromagnetic analysis of TBM was the simulation of shape variation of the plasma both in time and position. An approximation of the coordinates variant current filaments sets produced by the ITER plasma simulation has been conducted in this paper by the modeling of several uniform shaped and coordinates fixed current coils. Time steps of the transient analysis have been simplified through feature point extraction. Meanwhile, load step files have been exported as well.A finite element model of the ITER 1/18 sector has been created in ANSYS by way of entity modeling method, which covered most of the essential components of ITER Tokamak. Based on batch processing technic and MVP(Magnetic Vector Potential) method, three transient electromagnetic analyses of TBM during Major Disruption and Vertical Displacement Events have been accomplished in the use of this ITER sector model, which presented the Lorentz forces of the TBM in related scenarios. The Maxwell force of the HCCB TBM was obtained through static analysis by means of MSP(Magnetic Scalar Potential) method.Analyses Results have shown that, the radial component of the Lorentz force and the Maxwell force induced on the China HCCB TBM during those three disruption scenarios was far more severe than other two directions. The radial forces, which pulled the TBM toward the plasma, was up to 55.47 kN for Lorentz force and up to 117.88 kN for Maxwell force. By moment calculations and qualitative analysis, TBM would twist and vibrate due to the Lorentz force impact under certain plasma disruptions.