Water Reactor Mox Fuel Performance Analysis And Program Development

MOX stands for "Mixed-Oxide Fuel", which is a nuclear fuel made by plutonium mixed with uranium. The utilization of MOX fuel in light water reactor is the important direction in the development of light water reactor fuel. It can save the resource of Uranium, burn the plutonium from nuclear cycle. The research work on MOX fuel has been performed about 40 years in the world, so that the technique of utilization of MOX fuel in light water reactor is mature. Because nuclear power is fast developing and the spent fuel reprocess plant is under building, MOX fuel will also be used in light water reactor in China in the future.In the MOX fuel research and design activity, it is necessary to develop a computer code to analyze the behavior of MOX fuel under irradiation. Now, the countries that use MOX fuel have developed their own computer codes, such as French code-METEOR, US code-FRAPCON-3. But China has not yet such a code for MOX fuel. In order to meet the requirements of MOX R&D work in China, it have to develop a relatively computer code as the tool for the MOX fuel research, design and safety analysis.The METEOR 1.5 code was introduced form CEA of France, but the version can only be used for UO₂ fuel behavior analysis. In this work, the MOX fuel behavior analysis code was developed on the basis of METEOR 1.5 by augmentation of MOX modular into the original source code of METOER1. 5. These MOX models mainly come from CEA, some of the models come from MATPRO data base.In the first part of this paper, the background of MOX fuel researching and situation of the computer code developing are introduced. In the second part, the METEOR1.5 code is introduced. In the third part of this paper, the different models of MOX fuel are presented. After the work of source file compiling, we use the updated code to analyze the MOX fuel behavior under irradiation condition for Qinshan Nuclear Power Plant (QNPP). The conclusions are list as following: 1) The updated code could be used for the calculations of thermal-hydraulic, mechanical and fission gas release for the MOX fuel behavior of LWR. And the calculation results have a good agreement with the international research results.2) Under the same irradiation conditions, MOX fuel has higher pellet temperatures, cladding stress, rod inner gas pressure and fission gas release fraction than the UO2 fuel in LWR. However, there have no great differences between MOX fuel and UO2 fuel.3) Although there are some differences between MOX and UO2 fuel behaviors, the differences are not so great. From the view point of single rod, the MOX fuel rod can be used in reactor of Qinshan NPP.