Optimal Design And Research Of Burnable Poisons For The Plate-type Advanced High-temperature Reactor

Energy security and air pollution has always been the focus of the publicattention. Nuclear energy as a safe, economic and clean energy, is very popular.From the beginning of nuclear energy using by human beings, it promotes thecontinuous development of nuclear reactor technology with the improving level ofresearch and practice experience. The Advanced High Temperature Reactor isdeveloped on the basis of the six candidates for the fourth generation of reactortechnology, which integrates the advantages of Molten Salt Reactor, the Very HighTemperature, the second generation of light water reactors, advanced thermal powerplants and Liquid Metal Cooled Fast Reactor, with a high security, economy,sustainability and nonproliferation. The United States has carried out four differentfuel types of Advanced High Temperature Reactor conceptual design, including:Pebble Bed Advanced High Temperature Reactor, Prismatic-type Advanced HighTemperature Reactor, Rod-type Advanced High Temperature Reactor and Plate-typeAdvanced High Temperature Reactor. Plate-type fuel is a redesign fuel elementbased on molten salt heat transfer capability for solid fuel molten salt reactor. TheOak Ridge National Laboratory has performed a lot of research work about theplate-type Advanced High Temperature Reactor(AHTR). The Oak Ridge NationalLaboratory developed a125MWt small modular advanced high temperature reactordesign in2010, one year later, They gave a preconceptual design of3400MWt largecommercial reactor, and some of the design parameters have been adjusted in2012.Because of its high initial excess reactivity, in addition to the use of control blades,the use of burnable poison is essential to compensate for the excess reactivity.In this paper, the research subjects is3400MWt plate-type advanced hightemperature reactor, with MCNP-ORIGEN2coupled program system as the mainresearch tool. Burnable poison design and loading optimization in plate-type AHTRis the main contents of the study. Four burnable poisons B4C, Gd2O3, CdO and Er2O3are selected as the candidates by comparing the six burnable poisons’ burnup chainand neutron cross section properties. Different refueling scheme of two-batch fuelcycle has been compared, and burnable poison layout to reduce peak power factorhas been considered. The specific research programs are as follows: first, sixcandidate burnable poisons were been studied. One optimal burnable poisons was identified by optimization calculation, second, four fuel management program oftwo-batch fuel cycle were calculated,and ultimately choose a scheme; Third,burnable poison arrangement has been considered to reduce peak power factor forthe selected scheme.The result shows that Er2O3particles are more suitable burnable poison for theplate-type advanced high-temperature reactor, which can share the control blades’task of reduce the reactivity, and has little negative impact on the life of the core;For a single-batch fuel cycle reactor the results of using Er2O3particles is better thanusing Eu2O3particles; For four scheme of two-batch fuel cycle of twelfth reactorcore, the fourth scheme is proposed after comparing the average discharge burnup,the maximum discharge burnup and cycle length etc. The recommended program hasthe deepest average discharge burnup and the lowest peak power factor. The peakpower factor reduced to less than2after using Er2O3particles. This research canprovide some reference for burnable poisons design of fuel management inplate-type advanced high temperature reactor.