Development And Application Study Of A Molten Salt Reactor Fuel Management Code System Based On MCNP5 And ORIGEN2.1

The molten salt reactor uses the molten salt as fuel and coolant, which is the only liquid fuel reactor in Generation IV advanced nuclear energy systems. The liquid molten salt reactor is characterized by remarkable advantages in economy, inherent safety and nonproliferation. Over the world, the research on molten salt reacor is active in many countries, in which the burnup analysis and fuel management is an important aspect. In a liquid fuel molten salt reactor, the fuel and the fission products circulating flow in the primary loop, and the fuel can be processed and refueled on-line, which all make the fuel management of liquid fuel molten salt reactor significantly different from conventional solid fuel nuclear reactors. Therefore, it is important to develop a code system suitable for the molten salt reactor burnup analysis and fuel management and to carry out study on the schedule of fuel management and burnup characteristic, which can provide valuable theoretical basis for MSR development.In this paper, ARIES, a new fuel management and burnup analysis code, is developed based on the Monte Carlo neutron transport code MCNP5 and point burnup code ORIGEN2. Fisrt, MCNP5 and ORIGEN2 are introduced, the calculation method of important physical parameters is described in detail; the treatment on a number of important physical issues is analyzed; the flow diagram and data structure of the ARIES code system are given; and the specific methods of main modules in ARIES are implemented. The methods and novel arrangements used in the ARIES code system are also introduced, which makes it suitable for the flowing fuel in molten salt reactor involving on-line processing and refueling functions. After development of the ARIES code system, some benchmarks are carried out to verify the code system. A PWR pin cell burnup benchmark was validated firstly. Then, a fast reactor benchmark is employed for verification. Considering the fuel of molten slat reactor depleted in the first loop for long time during the reactor operation, a high burnup PWR UO2 lattice benchmark is studied. All the verification results shows that the new developed ARIES code system is applicable to reactor fuel burnup analysis management. After benchmark verification, the ARIES fuel management code sytem is used for the study on the fuel management and operation schemes of a small modular molten salt fast reactor and a large-scale molten salt fast reactor. The results show that the calculation results of ARIES code system can fully describe the fuel circulation and on-line processing and refueling.The ARIES fuel management code system is expected to play a very important role on the conceptual design of innovational liquid fuel molten salt reactors and on the design of liquid fuel molten salt experimental reactor in the future.