Scmr Core Multiplication Problem Research

With the development of social economy, nuclear energy is more and moreimportant,but the development of nuclear energy is limited by nuclear resource. Howto improve the utilization rate of resources is a target of Fourth Generation of NuclearPower Reacto（rreferred to as GEN-IV）. Supercritcial Water-Cooled Reactor (referredto as SCWR) is the six of GEN-IV with light water as coolant. It is available in awater-cooled reactor technology and supercritical thermal power technologydeveloped on the basis of design innovation. The coolant density of SCWR is low, soit can be designed into a thermal reactor or fast reactor. Many performance parametersof the thermal reactor and the fast reactor of SCWR are complementary incharacteristics, in order to integrate the advantages of thermal spectrum and fastspectrum SCWR and overcome their shortcomings,the mixed spectrum SCWRconcept design was put forward.In this paper, after the full investigation of mixed spectrum based on SCWR, ithas built a Supercritcial Water-cooled Mixed-spectrum Reactor (referred to asSCMR)with four square mixed spectrum SCWR as reference. It has taken thefollowing work around the proliferation problem:1. From SCWR several candidate cladding material,it has selected core physicalparameters better T-91steel as the SCMR core cladding material with the corephysical parameters as consideration.2. Afterselecting core cladding, the SCMR core parameters are studied.3. Proliferation is the focus of this paper. Firstly,it improves the proliferation offuel assembly:through adjustment of the thermal zone assembly,from3×3to5×5tunnel layout, the hot zone assembly’s conversion ratio has improved; by reducing theSCMR of fast zone assembly breeder layer fuel enrichment (reduced from0.7%to0.2%)、adding thorium in the fission layer、increasing the layers of fuel rods in thefast zone and augmenting the thickness of the proliferation layers in the fast zone’sfuel rods to60cm, finally to the purpose of proliferation. And he SCMR has beendesigned into a hot zone capacity, fast zone proliferation.4.It found the existence of power distortion in the hot junction of hot zone and fast zone, so considering the design of three channel model, and SCMR fast zone hasachieved negative void reactivity.