Study Of The IMF Fuel’s Neutronics Characteristic Which Is Used For Pressurized Water Reactor To Transmute MA

Recently UO2 is the most common reactor fuel in China. As it provides a lot of electric power to our country, it produces a large number of spent fuel which contains Long-Lived Radioactive Waste. LLRW is mainly consists of Long-Lived Fission Product and Minor Actinide as Np,Am and Cm. LLFP and MA is mainly produced by neutron capture reaction of U and Pu. How to deal with their harm appropriately is a significant problem of nuclear energy development.Inert Matrix Fuel consists of Pu O2 and inert matrix(This article studys two kinds of IMF that proposed by MIT: Pu O2-Zr O2-Mg O and Pu O2-Th O2). As IMF do not include U in it, it can incinerate Pu and reduce the production of Pu in the nuclear reaction. Because of the good destruction ability of TRU, IMF fuel becomes one of the new type fuels which are in broad scale researching. Thermal neutron reactor is the most mature and widely used reactor in our country, And MA has relative large capture cross section and fission cross section for thermal neutrons.Literature shows that 60% MA transmutation rate can be realized in CANDU reactor which uses IMF fuel mixed with MA. Because MA has distinct different neutronic characteristics to U and Pu, adding of MA will impact on the fuel cell and assembly physical parameters. Searching for the limit of loaded MA’s amount is a significant question to realize the thermal reactor’s transmutation of MA. So it is of great significant to study the transmutation of MA in thermal reactor which loaded the IMF fuel.This article selects common PWR fuel cell and fuel assembly as the research object, compares and studies the neutronics features of IMF fuels and UO2 fuels, MOX fuels. And we also study the neutronics features and feasible range of IMF fuels that have different fuel components. In addition, we study the influence to neutronics parameters(keff, DC, MTC) of adding MA into IMF fuel cell and 17*17 fuel assembly.The research shows that IMF fuel has harder neutron energy spectrum, adding of MA will decrease the reactivity of fuel, so the enrichment of fuel should be increase in order to transmute MA in PWR.And the kinf of IMF fuel which has higher Pu O2 volume fraction decreases relatively little along with the adding amount of MA; IMF fuel which added MA meets the requirement that fuel temperature coefficient(or Doppler Coefficient DC) is negative. And the Pu-Th IMF fuel’s DC becomes more negative with the adding of MA due to the reason that it has relative small H/HM, high neutron flux in resonance energy region,and the adding of MA extends its resonance energy region so this process strengthens the effect of resonance absorption; Adding of MA makes the MTC of IMF fuel more negative. This article’s research result provides the reference to the application and transmutation of MA and IMF in thermal reactor.