Research On Key Issues Of The Design Of Typical Molten Salt Reactor

The Molten Salt Reactor (MSR) is one of the six Generation IV systems with a broad application prospect. Molten salt pressure equipment usually works in the corrosive environment with a high temperature. A proper design of the pressure equipment is of great importance for the safe operation of the molten salt reactor. Currently China has no pressure vessel codes that could be used for the design of such high temperature pressure equipment. The limit load analysis and elastic-plastic analysis are advanced pressure vessel design methods; they are accepted by a variety of design codes. China's research on these two methods has just started and only few engineering design cases could be used as references. Based on these backgrounds, structural design and optimization of a typical molten salt pressure vessel was conducted by using limit load analysis and elastic-plastic analysis. Multi-axial creep design of the molten salt reactor was done by using multi-axial creep deformation criterion.The main contents and conclusions are listed as following:(1) Tensile testing at elevated temperature was done and the true stress-true strain curve of N06625 was got which could be used in the elastic-plastic analysis. The exponent n and modulus B in Norton Equation, modulus of elasticity, Poisson's ratio of N06625 at working temperature were got by consulting relevant literature.(2) Structural design of the molten salt reactor was conducted by using design by rules, limit load analysis and elastic-plastic analysis. The results indicate that with the help of limit load analysis and elastic-plastic analysis, the shell thickness could be reduced sharply.(3) Based on limit load analysis and elastic-plastic analysis, the effect of the location of the nozzle, the nozzle thickness, the size of head opening on limit load was studied and the structure was optimized.(4) Based on multi-axial creep deformation criterion, the membrane strain, membrane strain+bending strain were got by using strain linearization. The results show that the membrane strain at 100,000 hours was less than 1% while the membrane strain+bending strain was less than 2%. Besides, the change rate of the membrane strain is faster than that of the membrane strain+bending strain.