Low-pressure distillation has been proposed as a suitable technique for the recovery of carrier salt from molten salt reactor spent fuel.A closed-chamber distillation system,in which the pump is stopped and pressurein...Low-pressure distillation has been proposed as a suitable technique for the recovery of carrier salt from molten salt reactor spent fuel.A closed-chamber distillation system,in which the pump is stopped and pressureinduced salt distillation is performed,was arranged for fluoride salt treatment.A stair-step optimization process was demonstrated to improve the recovery efficiency by up to 99%.The pressure change curve was feasible for estimating the distillation process,and a method for displaying the pressure value online in order to determine the endpoint was also developed.The decontamination factor of Nd in the condensate salt was deduced to be greater than 100 with 1 wt%NdF3–FLiNaK distillation.The optimal conditions developed in this study showed a high recovery ratio for the fluoride carrier salt and a high separation efficiency for rare earth products.展开更多
The fluoride volatility method (FVM) is a technique tailored to separate uranium from fuel salt of molten salt reactors. A key challenge in R&D of the FVM is corrosion due to the presence of molten salt and corros...The fluoride volatility method (FVM) is a technique tailored to separate uranium from fuel salt of molten salt reactors. A key challenge in R&D of the FVM is corrosion due to the presence of molten salt and corrosive gases at high temperature. In this work, a frozen-wall technique was proposed to produce a physical barrier between construction materials and corrosive reactants. The protective performance of the frozen wall against molten salt was assessed using FLiNaK molten salt with introduced fluorine gas, which was regarded as a simulation of the FVM process. SS304, SS316L, Inconel 600 and graphite were chosen as the test samples. The extent of corrosion was characterized by an analysis of weight loss and scanning electron microscope studies. All four test samples suffered severe corrosion in the molten salt phase with the corrosion resistance as: Inconel 600>SS316L>graphite>SS304. The presence of the frozen wall could protect materials against corrosion by molten salt and corrosive gases, and compared with materials exposed to molten salt, the corrosion rates of materials protected by the frozen wall were decreased by at least one order of magnitude.展开更多
Compared with other stream applications, scientific stream programs are usually bound by memory accesses. Reusing streams across different iterations, i.e. loop-carried stream reuse, can effectively improve the SRF lo...Compared with other stream applications, scientific stream programs are usually bound by memory accesses. Reusing streams across different iterations, i.e. loop-carried stream reuse, can effectively improve the SRF locality, thus reducing memory accesses greatly. In the paper, we first present the algorism identifying loop-carried stream reuse and that exploiting the reuse after analyzing scientific computing applications. We then perform several representative microbenchmarks and scientific stream programs with and without our optimization on Isim, a cycle-accurate stream processor simulator. Experimental results show that our algorithms can effectively exploit loop-carried stream reuse for scientific stream programs and thus greatly improve the performance of memory-bound scientific stream programs.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(No.21771188)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA02030000)A study on some key issues regarding the Th-U fuel cycle was also funded(No.QYZDY-SSW-JSC016).
文摘Low-pressure distillation has been proposed as a suitable technique for the recovery of carrier salt from molten salt reactor spent fuel.A closed-chamber distillation system,in which the pump is stopped and pressureinduced salt distillation is performed,was arranged for fluoride salt treatment.A stair-step optimization process was demonstrated to improve the recovery efficiency by up to 99%.The pressure change curve was feasible for estimating the distillation process,and a method for displaying the pressure value online in order to determine the endpoint was also developed.The decontamination factor of Nd in the condensate salt was deduced to be greater than 100 with 1 wt%NdF3–FLiNaK distillation.The optimal conditions developed in this study showed a high recovery ratio for the fluoride carrier salt and a high separation efficiency for rare earth products.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Science(No.XDA02030000)
文摘The fluoride volatility method (FVM) is a technique tailored to separate uranium from fuel salt of molten salt reactors. A key challenge in R&D of the FVM is corrosion due to the presence of molten salt and corrosive gases at high temperature. In this work, a frozen-wall technique was proposed to produce a physical barrier between construction materials and corrosive reactants. The protective performance of the frozen wall against molten salt was assessed using FLiNaK molten salt with introduced fluorine gas, which was regarded as a simulation of the FVM process. SS304, SS316L, Inconel 600 and graphite were chosen as the test samples. The extent of corrosion was characterized by an analysis of weight loss and scanning electron microscope studies. All four test samples suffered severe corrosion in the molten salt phase with the corrosion resistance as: Inconel 600>SS316L>graphite>SS304. The presence of the frozen wall could protect materials against corrosion by molten salt and corrosive gases, and compared with materials exposed to molten salt, the corrosion rates of materials protected by the frozen wall were decreased by at least one order of magnitude.
文摘Compared with other stream applications, scientific stream programs are usually bound by memory accesses. Reusing streams across different iterations, i.e. loop-carried stream reuse, can effectively improve the SRF locality, thus reducing memory accesses greatly. In the paper, we first present the algorism identifying loop-carried stream reuse and that exploiting the reuse after analyzing scientific computing applications. We then perform several representative microbenchmarks and scientific stream programs with and without our optimization on Isim, a cycle-accurate stream processor simulator. Experimental results show that our algorithms can effectively exploit loop-carried stream reuse for scientific stream programs and thus greatly improve the performance of memory-bound scientific stream programs.
