Radiopharmaceuticals are used in nuclear medicine for diagnostic or therapeutic acts. The short decay half-lives of medical radioisotopes, especially those used for diagnostics, imply that they should be produced cont...Radiopharmaceuticals are used in nuclear medicine for diagnostic or therapeutic acts. The short decay half-lives of medical radioisotopes, especially those used for diagnostics, imply that they should be produced continuously and transported as quickly as possible to the medical units where they are used. Neutron-rich medical radioisotopes are generally produced in research reactors, like technetium-99m, lutetium-177, holmium-166 and iodine-131. On the other hand, proton-rich radioisotopes are produced via reactions with charged particles from accelerators like fluorine-18, gallium-67, iodine-123 and thallium-201. Beside this, innovative nuclear reactors are advocated as solutions to the issues of nuclear waste production and proliferation threats. Fast neutron, thorium-cycle and accelerator-driven subcritical (ADS) reactors are some of the most promising of them, proposed as safer fuel breeders and “waste burners”. This article examines the use of a fast thorium-cycle ADS with liquid lead-bismuth eutectic coolant for the production of molybdenum-99/technetium-99m and lutetium-177. Burnup simulation has been made with the Monte-Carlo (MC) code SERPENT. It is demonstrated that MC codes can advantageously be used to determine the optimal irradiation time for a given radioisotope in a realistic reactor core. It is also shown that fast thorium-cycle ADS is an economical option for the production of medical radioisotopes.展开更多
The extractant di(1-methyl-heptyl)methylphosphonate(P350)shows excellent performance in the separation of thorium and uranium;however,it poses a significant challenge for the efficient stripping of uranium(VI)from the...The extractant di(1-methyl-heptyl)methylphosphonate(P350)shows excellent performance in the separation of thorium and uranium;however,it poses a significant challenge for the efficient stripping of uranium(VI)from the organic phase.To address this,a hydroxyl-functionalized ligand,hydroxyl-glutarimidedioxime(H2B),was designed and synthesized by introducing a hydroxyl group onto the piperidine ring of the parent ligand glutarimidedioxime(H2A).This structural modification markedly enhanced the aqueous solubility of H2B without altering its tridentate coordination mode with uranyl.Stripping experiments confirmed that H2B enables near-quantitative recovery of uranium(∼100%),significantly outperforming both H2A and conventional alkaline stripping agents.Computational and thermodynamic studies revealed that while H2B exhibits a slightly lower binding strength to uranyl than H2A,it maintains a strong affinity and an identical coordination geometry.These findings underscore that enhancing ligand solubility through subtle molecular design is a critical strategy for optimizing uranyl separation efficiency,providing a valuable new direction for ligand development in thorium fuel cycle reprocessing.展开更多
文摘Radiopharmaceuticals are used in nuclear medicine for diagnostic or therapeutic acts. The short decay half-lives of medical radioisotopes, especially those used for diagnostics, imply that they should be produced continuously and transported as quickly as possible to the medical units where they are used. Neutron-rich medical radioisotopes are generally produced in research reactors, like technetium-99m, lutetium-177, holmium-166 and iodine-131. On the other hand, proton-rich radioisotopes are produced via reactions with charged particles from accelerators like fluorine-18, gallium-67, iodine-123 and thallium-201. Beside this, innovative nuclear reactors are advocated as solutions to the issues of nuclear waste production and proliferation threats. Fast neutron, thorium-cycle and accelerator-driven subcritical (ADS) reactors are some of the most promising of them, proposed as safer fuel breeders and “waste burners”. This article examines the use of a fast thorium-cycle ADS with liquid lead-bismuth eutectic coolant for the production of molybdenum-99/technetium-99m and lutetium-177. Burnup simulation has been made with the Monte-Carlo (MC) code SERPENT. It is demonstrated that MC codes can advantageously be used to determine the optimal irradiation time for a given radioisotope in a realistic reactor core. It is also shown that fast thorium-cycle ADS is an economical option for the production of medical radioisotopes.
基金supported by the Central Government Guiding Fund for Local Science and Technology Development,Sichuan Province(Grant Nos.2023ZYYDF070,2025ZYDF001).
文摘The extractant di(1-methyl-heptyl)methylphosphonate(P350)shows excellent performance in the separation of thorium and uranium;however,it poses a significant challenge for the efficient stripping of uranium(VI)from the organic phase.To address this,a hydroxyl-functionalized ligand,hydroxyl-glutarimidedioxime(H2B),was designed and synthesized by introducing a hydroxyl group onto the piperidine ring of the parent ligand glutarimidedioxime(H2A).This structural modification markedly enhanced the aqueous solubility of H2B without altering its tridentate coordination mode with uranyl.Stripping experiments confirmed that H2B enables near-quantitative recovery of uranium(∼100%),significantly outperforming both H2A and conventional alkaline stripping agents.Computational and thermodynamic studies revealed that while H2B exhibits a slightly lower binding strength to uranyl than H2A,it maintains a strong affinity and an identical coordination geometry.These findings underscore that enhancing ligand solubility through subtle molecular design is a critical strategy for optimizing uranyl separation efficiency,providing a valuable new direction for ligand development in thorium fuel cycle reprocessing.
