The high burn-up structure(HBS)is characterized by the grain size of 100-300 nm and a porosity of up to 20%,which is formed at the rim of the nuclear fuel pellet due to 2-3 times higher local burn-up during the in-pil...The high burn-up structure(HBS)is characterized by the grain size of 100-300 nm and a porosity of up to 20%,which is formed at the rim of the nuclear fuel pellet due to 2-3 times higher local burn-up during the in-pile irradiation.HBS is considered a new potential structure for high-performance fuels.However,it is difficult to prepare HBS by conventional sintering methods.In this study,flash sintering was used to prepare HBS using CeO_(2)as a surrogate for a preliminary investigation.A new experimental configuration for rapid sintering of CeO_(2)pellets was provided,in which the green body can be rapidly preheated and pressure-assisted by the induction heating electrodes.An insulated quartz tube was used as the die for the flash sintered samples,allowing the current to flow through the sample and providing a stable condition for applying an external pressure of approximately 5.3-7.0 MPa during flash sintering process.Using an initial electric field of 141 V cm-1 and holding for 1-7 min at the maximum current density of~98 mA mm^(-2),CeO_(2)ceramics with a grain size of 114-282 nm and a relative density of 75.4-99.7%were prepared.The densification and microstructure evolution behaviors during flash sintering in this new experimental configuration have been discussed in detail.This new experimental configuration may provide a promising approach for preparing UO_(2)ceramics and their HBS.展开更多
The code system COUPLE2.0[1] was developed by the Institute of Nuclear and New Energy Technology (INET) of Tsinghua University, which can be used for coupled neutron transport and nuclide burn-up analyses of Accelerat...The code system COUPLE2.0[1] was developed by the Institute of Nuclear and New Energy Technology (INET) of Tsinghua University, which can be used for coupled neutron transport and nuclide burn-up analyses of Accelerator Driven sub- critical reactor System(ADS). The Institute of Modern Physics, Chinese Academy of Sciences imported the code system in 2014, and developed the version COUPLE3.0 according to the requirements of new function and preliminary verifications based on the fast reactor and ADS benchmarks were done.展开更多
基金The work was financially supported by the National Natural Science Foundation of China(Nos.51874023,U1860206)the Fundamental Research Funds for the Central Universities(No.FRF-TP-20-02B)the Recruitment Program of Global Experts.
文摘The high burn-up structure(HBS)is characterized by the grain size of 100-300 nm and a porosity of up to 20%,which is formed at the rim of the nuclear fuel pellet due to 2-3 times higher local burn-up during the in-pile irradiation.HBS is considered a new potential structure for high-performance fuels.However,it is difficult to prepare HBS by conventional sintering methods.In this study,flash sintering was used to prepare HBS using CeO_(2)as a surrogate for a preliminary investigation.A new experimental configuration for rapid sintering of CeO_(2)pellets was provided,in which the green body can be rapidly preheated and pressure-assisted by the induction heating electrodes.An insulated quartz tube was used as the die for the flash sintered samples,allowing the current to flow through the sample and providing a stable condition for applying an external pressure of approximately 5.3-7.0 MPa during flash sintering process.Using an initial electric field of 141 V cm-1 and holding for 1-7 min at the maximum current density of~98 mA mm^(-2),CeO_(2)ceramics with a grain size of 114-282 nm and a relative density of 75.4-99.7%were prepared.The densification and microstructure evolution behaviors during flash sintering in this new experimental configuration have been discussed in detail.This new experimental configuration may provide a promising approach for preparing UO_(2)ceramics and their HBS.
文摘The code system COUPLE2.0[1] was developed by the Institute of Nuclear and New Energy Technology (INET) of Tsinghua University, which can be used for coupled neutron transport and nuclide burn-up analyses of Accelerator Driven sub- critical reactor System(ADS). The Institute of Modern Physics, Chinese Academy of Sciences imported the code system in 2014, and developed the version COUPLE3.0 according to the requirements of new function and preliminary verifications based on the fast reactor and ADS benchmarks were done.
