未来先进核裂变能——TMSR核能系统

钍基熔盐堆(TMSR)核能系统项目是中科院未来10年先导研究专项之一,其研究目标是研发第四代裂变反应堆核能系统,计划至2020年之前建成2MW钍基熔盐实验堆,形成支撑未来TMSR核能系统发展的若干技术研发能力,并解决钍铀燃料循环和钍基熔盐堆相关重大技术挑战,研制出工业示范级钍基熔盐堆,实现钍资源的有效使用和核能的综合利用。钍基核燃料具有232Th/233U转换效率高、在热中子堆中也能增殖、产生较少的高毒性放射性核素、有利于防核扩散等优点,但也面临燃料制备困难、232U衰变子核的强γ辐射给乏燃料处理和燃料再加工带来的困难、钍铀转换反应链中间核233Pa会吸收堆内中子从而影响233U产量。核燃料利用的工作模式有开环模式、改进的开环模式和闭环模式。熔盐堆是第四代反应堆的6个候选堆型之一,非常适合用作钍铀燃料循环,熔盐堆加上干法在线分离技术有可能实现完全的钍铀燃料闭式循环。本世纪初提出的氟盐冷却高温堆(Fluoride salt-cooled High temperature Reactors,FHRs),用氟化熔盐作为冷却剂,采用TRISO燃料颗粒作为核燃料,其中球床型氟盐冷却高温堆可以在改进的开环模式实现钍铀燃料循环。熔盐堆良好的高温特性使其成为核能非电应用主要候选者之一,反应堆产生的高温热可直接用于页岩油开采和高温制氢等工业领域。

Advanced Fission Energy Program-TMSR Nuclear Energy System

"Thorium-based Molten-Salt Reactor(TMSR) nuclear energy system" is one of the "Strategic Priority Research Program" of CAS.With the mission to research and develop fission energy system of the fourth generation,the TMSR project intends to construct 2MW Thorium-based molten-salt reactors,form up R&D capability concerning techniques that support the evolution of TMSR nuclear energy system by 2020,then solve major technological challenges in Th-U fuel cycle as well as Thorium-based molten-salt reactor,build pilot TMSR of industrial scale,and achieve effective utilization of Thorium resource as well as composite utilization of nuclear energy.Th-based fuel has several advantages: a high transfer ratio of 232Th/233U,able to breed in thermal reactor,a less production of highly toxic radioactive nuclides,and a good non-proliferation.However,challenges still remain in fuel fabrication,strong gamma radiation from daughter nuclide of 232U which brings trouble in re-processing and re-fabrication,intermediate nuclide 233Pa in Th-U transfer chain absorb neutron in the core.Nuclear fuel can be used in open cycle,modified opencycle,and closed cycle.Being one of the six candidate Gen-IV reactors,MSR is very suitable for Th-U fuel.MSR combined with online dry reprocessing method is quite promising to achieve fully closed cycle of Th-U fuel.Proposed in the beginning of this century,FHRs use fluoride salt as coolant and TRISO fuel.Pebble-bed FHR can achieve modified open cycle of Th-U fuel.The feature of high temperature output makes MSR one of the major candidates for non-electricity application of nuclear energy.The high temperature output can be used directly in exploitation of shale oil,hydrogen production etc.