Research On The Concept Design Of New Two-Loop Alternate Helium Cooled Solid Blanket For Fusion Reactor

All partnership countries of the International Thermonuclear Experiment Reactor particular engineer design on (ITER) program, including EU, Japan, China, USA, Korea and India have proposed their own design concepts of solid test blanket module to be tested in ITER. The relevant engineering manufacture and material experiment are in process during ITER construction. Some countries have performed the concept design on the solid blanket for fusion demonstration reactor, the next step for fusion power generation after ITER. The research work of this dissertation developed a new type of helium cooled solid blanket concept with two alternate cooling tube batches under the frame of ceramic blanket. Neutronics, thermal hydraulic and mechanical analyses have been carried out on the scale of demo-type fusion reactor. This new type of helium cooled solid blanket with two alternate cooling tube batches are characterized by its stability on tritium breeding performance and uniform power density during long time operation, and also by its enhanced safety in case of one loop LOCA/LOFA accident.Appropriate selection has been performed on the physical parameters such as thickness dimensions, material fraction and the first wall armor, etc. In order to analyze the consumption of breeding material and the tritium production, a depletion analysis method with variable reaction rate has been applied. Particular study has focused on the solid blanket tritium breeding performance and power density varying with operation time. Accordingly, 5 cases of 6Li enrichment arrangement have been compared. The optimal design of the blanket module has been obtained, in which the breeder layers close to the first wall employ high 6Li enrichment and layers close to the back plane employ low 6Li enrichment. This optimal design can keep steady tritium breeding performance and power density for long term operation, and can ultilize 6Li effectively as well. A three-dimensional neutronics model of fusion reactor with detailed coolant tube configuration inserted in the solid blanket has been set up for MCNP simulation. With this MCNP simulation model, neutronics performance such as global tritium breeding ratio (about 1.16) and power density distribution have been analyzed.Coupled neutronics and thermal hydraulic calculations have been performed to find an optimal solution for the configuration of the two-batch alternate helium cooling solid blanket with the breeder pebble bed parallel to the first wall. During normally operation, cooling loops system can keep the material temperature below the safety limit, and also can achieve a high thermal efficiency; however, if one inlet pipes of the two coolant tube batches breaks or is jammed, the temperature rising of the blanket will be effectively slowed without extra emergency system. The safety action by increasing the flow rate of remaining coolant loop can ensure the heat to be carried out from the blanket safely. The two-batch alternate cooling design concept makes a progress on issues of the availability and safety of the blanket. It can decrease the melting probability of blanket effectively, leading to the improvement of fusion reactor availability. A preliminary mechanics analysis is also performed on the coolant channel.This research work is a promotion concept study on the fusion reactor solid blanket design, some ideas and methodological exploration embedded in this dissertation are expected to be useful for future China fusion power reactor solid blanket design.