PyNE R2S is a mesh-based R2S implementation with the capability of performing shutdown dose rate(SDR)analysis directly on CAD geometry with Cartesian or tetrahedral meshes.It supports advanced variance reduction for f...PyNE R2S is a mesh-based R2S implementation with the capability of performing shutdown dose rate(SDR)analysis directly on CAD geometry with Cartesian or tetrahedral meshes.It supports advanced variance reduction for fusion energy systems.However,the assumption of homogenized materials of PyNE R2S with a Cartesian mesh throughout a mesh voxel introduces an approximation in the case where a voxel covers multiple non-void cells.This work implements a sub-voxel method to add fldelity to PyNE R2S with a Cartesian mesh during the process of activation and photon source sampling by performing independent inventory calculations for each cell within a mesh voxel and using the results of those independent calculations to sample the photon source more precisely.PyNE sub-voxel R2S has been verifled with the Frascati Neutron Generator(FNG)-ITER and ITER computational shutdown dose rate benchmark problems.The results for sub-voxel R2S show satisfactory agreement with the experimental values or reference results.PyNE sub-voxel R2S has been applied to the shutdown dose rate calculation of the Chinese Fusion Engineering Testing Reactor(CFETR).In conclusion,sub-voxel R2S is a reliable tool for SDR calculation and obtains more accurate results with the same voxel size than voxel R2S.展开更多
An analysis of the neutron activation and shutdown dose rates was performed for the EAST high-power deuterium neutral beam injector test facility(EAST NBITF) by using the multiparticle transport code FLUKA2011.2. Also...An analysis of the neutron activation and shutdown dose rates was performed for the EAST high-power deuterium neutral beam injector test facility(EAST NBITF) by using the multiparticle transport code FLUKA2011.2. Also, the neutron and neutron-induced gamma spectra of the facility's vacuum vessel were evaluated. The results identified the major radionuclides^(99) Mo,^(65)Ni,^(58) Co,^(56)Mn, and^(51) Cr for the vacuum vessel and the primary nuclide^(64) Cu for both the ion dump and the calorimeter.The simulated results indicated that, when the EAST NBITF operates within the design parameters of deuterium energy 80 ke V, current 50 A, and pulse 100 s, the neutron intensity will achieve 10^(11)n/s with no radiation safety problems after the EAST NBITF shuts down.展开更多
为了准确分析核设施停机后周围空间的三维辐射剂量场分布情况,基于严格两步法(rigorous two step method,R2S)停堆剂量计算的方法,开发了基于蒙特卡罗输运计算程序MCNP5和燃耗计算程序ORGEN2.1耦合的三维停堆剂量计算程序MOCA,实现了中...为了准确分析核设施停机后周围空间的三维辐射剂量场分布情况,基于严格两步法(rigorous two step method,R2S)停堆剂量计算的方法,开发了基于蒙特卡罗输运计算程序MCNP5和燃耗计算程序ORGEN2.1耦合的三维停堆剂量计算程序MOCA,实现了中子输运计算、材料活化计算和光子剂量计算的自动耦合,并通过中子辐照例题与SuperMC程序进行对比验证,结果表明MOCA的计算结果与SuperMC计算的结果吻合较好,可以为核设施的运维检修以及退役的剂量率空间分布提供参考数据。展开更多
基金carried out within the flnancial support of the National Key R&D Program of China(Nos.2017YFE0300503 and 2017YFE0300604)National Natural Science Foundation of China(No.11775256)funded by the China Postdoctoral Science Foundation(No.BX20200335)。
文摘PyNE R2S is a mesh-based R2S implementation with the capability of performing shutdown dose rate(SDR)analysis directly on CAD geometry with Cartesian or tetrahedral meshes.It supports advanced variance reduction for fusion energy systems.However,the assumption of homogenized materials of PyNE R2S with a Cartesian mesh throughout a mesh voxel introduces an approximation in the case where a voxel covers multiple non-void cells.This work implements a sub-voxel method to add fldelity to PyNE R2S with a Cartesian mesh during the process of activation and photon source sampling by performing independent inventory calculations for each cell within a mesh voxel and using the results of those independent calculations to sample the photon source more precisely.PyNE sub-voxel R2S has been verifled with the Frascati Neutron Generator(FNG)-ITER and ITER computational shutdown dose rate benchmark problems.The results for sub-voxel R2S show satisfactory agreement with the experimental values or reference results.PyNE sub-voxel R2S has been applied to the shutdown dose rate calculation of the Chinese Fusion Engineering Testing Reactor(CFETR).In conclusion,sub-voxel R2S is a reliable tool for SDR calculation and obtains more accurate results with the same voxel size than voxel R2S.
基金supported by the International S&T Cooperation Program of China(No.2014DFG61950)National Magnetic Confinement Fusion Science Program(No.2013GB101001)the National Natural Science Foundation of China(No.11405207)
文摘An analysis of the neutron activation and shutdown dose rates was performed for the EAST high-power deuterium neutral beam injector test facility(EAST NBITF) by using the multiparticle transport code FLUKA2011.2. Also, the neutron and neutron-induced gamma spectra of the facility's vacuum vessel were evaluated. The results identified the major radionuclides^(99) Mo,^(65)Ni,^(58) Co,^(56)Mn, and^(51) Cr for the vacuum vessel and the primary nuclide^(64) Cu for both the ion dump and the calorimeter.The simulated results indicated that, when the EAST NBITF operates within the design parameters of deuterium energy 80 ke V, current 50 A, and pulse 100 s, the neutron intensity will achieve 10^(11)n/s with no radiation safety problems after the EAST NBITF shuts down.
文摘为了准确分析核设施停机后周围空间的三维辐射剂量场分布情况,基于严格两步法(rigorous two step method,R2S)停堆剂量计算的方法,开发了基于蒙特卡罗输运计算程序MCNP5和燃耗计算程序ORGEN2.1耦合的三维停堆剂量计算程序MOCA,实现了中子输运计算、材料活化计算和光子剂量计算的自动耦合,并通过中子辐照例题与SuperMC程序进行对比验证,结果表明MOCA的计算结果与SuperMC计算的结果吻合较好,可以为核设施的运维检修以及退役的剂量率空间分布提供参考数据。
