This study proposes a method for^(99)Mo production via electron accelerator irradiation of a natural-uranium-bearing liquid molten salt target,with advantages including low nuclear proliferation risk,online extraction...This study proposes a method for^(99)Mo production via electron accelerator irradiation of a natural-uranium-bearing liquid molten salt target,with advantages including low nuclear proliferation risk,online extraction capability,and low construction costs.The approach primarily produces^(99)Mo through photofission of uranium(~95%),specifically^(238)U(γ,f).Secondary neutrons,originating from photonuclear interactions or fission processes,contribute minimally(~5%)to^(99)Mo production owing to their high energies and low fission cross sections.Key parameter analyses revealed that fluoride salt systems exhibit higher^(99)Mo yield.Their performance stems from high bremsstrahlung energy loss rate and superior photon yield,making them optimal molten salt target materials.To maximize photofission and photoneutron cross sections while minimizing highenergy gamma ray shielding requirements,an electron beam energy range of 40-80 MeV is recommended.To suppress local hot spots and prevent molten salt boiling,flow conditions were introduced to enhance convective heat transfer,effectively reducing the peak temperature.At a flow velocity of 0.5 m/s and under 80 MeV energy conditions,the maximum system temperature is only 808.9 K,which is significantly lower than the boiling point of 1773 K.Under optimized parameters,the maximum annual production capacity of~(99)Mo reaches 4486.49 Ci,sufficient for millions of diagnostic procedures and equivalent to 16.37% of China's projected demand for 2030.This method provides a viable pathway for stable,large-scale^(99)Mo production.展开更多
^(99)Mo是重要的医用放射性核素,溶剂萃取法是反应堆辐照^(235)U靶生产裂变^(99)Mo的分离方法之一。为探讨离子液体Cyphos IL 101用于裂变^(99)Mo分离的可能性,本研究评价了离子液体Cyphos IL 101在硝酸体系中对Mo(Ⅵ)的萃取行为,重点...^(99)Mo是重要的医用放射性核素,溶剂萃取法是反应堆辐照^(235)U靶生产裂变^(99)Mo的分离方法之一。为探讨离子液体Cyphos IL 101用于裂变^(99)Mo分离的可能性,本研究评价了离子液体Cyphos IL 101在硝酸体系中对Mo(Ⅵ)的萃取行为,重点考察了稀释剂、水相初始pH、萃取时间、温度、离子液体浓度等对萃取Mo(Ⅵ)的影响。结果表明,选用甲苯作为稀释剂时,Cyphos IL 101对Mo(Ⅵ)的萃取效果最好,在pH=3条件下,萃取率高达98.87%;萃取为自发进行的过程,且可在5 min达到平衡;选用1 mol/L Na_(2)CO_(3)作为反萃剂,一次反萃可将负载有机相中96.56%的Mo反萃到水相中。构建的离子液体Cyphos IL 101萃取体系对Mo与主要杂质Sr、Cs、Te等有很好的分离效果,体现了其对Mo(Ⅵ)的高选择性萃取能力。以上结果可为将离子液体Cyphos IL 101引入裂变^(99)Mo的分离工艺流程提供参考。展开更多
医用同位素锝-99m(99mTc)被广泛应用于核医学领域,其主要来源于母体核素钼-99(99Mo)的衰变。但是目前国内99Mo基本依赖进口,通常出现99Mo不能稳定供应的现象。为解决这个重大问题,实现国内99Mo自主化生产具有重要意义。本文基于中国科...医用同位素锝-99m(99mTc)被广泛应用于核医学领域,其主要来源于母体核素钼-99(99Mo)的衰变。但是目前国内99Mo基本依赖进口,通常出现99Mo不能稳定供应的现象。为解决这个重大问题,实现国内99Mo自主化生产具有重要意义。本文基于中国科学院近代物理研究所强流超导直线加速器(China ADS Front End,CAFE)提供的质子束流辐照天然铀靶件,主要开展铀裂变产物中医用同位素99Mo的高效化学分离、纯化及99Mo/99mTc发生器的制备。研究表明:通过α-安息香肟(α-BO)沉淀分离99Mo后,杂质核素去除率大于90%,99Mo的回收率大于90%。通过对99Mo沉淀进行纯化后,大部分杂质核素被去除。提取的99Mo被装配为99Mo/99mTc发生器,发生器淋洗曲线表明:99mTc产品收集在8 mL生理盐水内最为适宜,同时,99mTc回收率大于80%。电感耦合等离子体发射光谱仪(ICP-OES)测量结果表明,99mTc产品中Al、Mo以及U含量极低;同时,99mTc产品的γ谱图中未出现99Mo和其他杂质核素的γ能量峰。以上研究结果可为国内基于加速器辐照天然铀生产99Mo提供技术参考。展开更多
The current industrial-scale production of molybdenum-99(^(99)Mo)and iodine-131(^(131)I)is heavily predicated on thermal neutron irradiation of LEU targets.In this route,^(99)Mo and ^(131)I are separated using a solid...The current industrial-scale production of molybdenum-99(^(99)Mo)and iodine-131(^(131)I)is heavily predicated on thermal neutron irradiation of LEU targets.In this route,^(99)Mo and ^(131)I are separated using a solid-phase extraction approach.The goal of this study was to develop and evaluate copolymeric beads that could be used to separate ^(99)Mo and ^(131)I from their aqueous solutions.Different aminated styrenedivinyl benzene co-polymeric beads were successfully manufactured for this approach.The structural features of the synthesized copolymers were characterized.The resin frameworks were found to have homogeneous spherical shapes decorated with a very thin layer of amine moieties.The FT-IR peaks caused by N—H stretching and C—N bending vibrations show the successful functionalization of the resins'surfaces with amine moieties selective for the sorption of I-over Mo O_(4)^(2-)ions.Under various circumstances,the produced resins were assessed for sorption of ^(99)Mo and ^(131)I from their aqueous solutions.They showed an enhanced sorption capability for I-ions compared to MoO_(4)^(2-)ions and attained equilibrium in less than 20 min.Data declare that the sorption of MoO_(4)^(2-)and I-ions onto synthesized resins was attained through an ion exchange process with Cl-ions.In such interactions,one iodide ion(I-)consumes only one active site from the resin surface,while two active sites must be exhausted to retain one MoO_(4)^(2-)ion onto the surface of the resins.The exchange interaction of both MoO_(4)^(2-)and I-ions was an endothermic process.Further,the elution of ^(99)Mo and ^(131)I radioisotopes loaded on synthesized resins was investigated using various eluents.Additional sets of individual and binary dynamic experiments were performed using columns packed with trimethylamine styrene divinyl benzene(TMA-PSDVB)and triethylamine styrene divinyl benzene(TEA-PSDVB)resins.The individual breakthrough sorption capacity of TMA-PSDVB and TEA-PSDVB resins had values of 381.6 and352.6 mg·g^(-1)for ^(131)I and values of 134.7 and 117.2 mg·g^(-1)for ^(99)Mo isotopes,respectively.Furthermore,TMA-PSDVB resin exhibited breakthrough sorption capacity for ^(99)Mo and ^(131)I,in the binary system,amounting to 123.7 and 331.6 mg·g^(-1)with elution percentages reaching 75.4%and 12.1%,respectively.These findings demonstrate that Mo(Ⅵ)ions were efficiently separated from I(Ⅰ)ions.Finally,the reported aminated polymeric resins may be regarded as promising solid phases for the separation and recovery of Mo(Ⅵ)and I(Ⅰ).展开更多
基金supported by the National Natural Science Foundation of China(Nos.12435012,12175300,and 12475185)Shanghai Natural Science Foundation(No.24ZR1478500)Nuclear energy development project(HNKF202210(24))。
文摘This study proposes a method for^(99)Mo production via electron accelerator irradiation of a natural-uranium-bearing liquid molten salt target,with advantages including low nuclear proliferation risk,online extraction capability,and low construction costs.The approach primarily produces^(99)Mo through photofission of uranium(~95%),specifically^(238)U(γ,f).Secondary neutrons,originating from photonuclear interactions or fission processes,contribute minimally(~5%)to^(99)Mo production owing to their high energies and low fission cross sections.Key parameter analyses revealed that fluoride salt systems exhibit higher^(99)Mo yield.Their performance stems from high bremsstrahlung energy loss rate and superior photon yield,making them optimal molten salt target materials.To maximize photofission and photoneutron cross sections while minimizing highenergy gamma ray shielding requirements,an electron beam energy range of 40-80 MeV is recommended.To suppress local hot spots and prevent molten salt boiling,flow conditions were introduced to enhance convective heat transfer,effectively reducing the peak temperature.At a flow velocity of 0.5 m/s and under 80 MeV energy conditions,the maximum system temperature is only 808.9 K,which is significantly lower than the boiling point of 1773 K.Under optimized parameters,the maximum annual production capacity of~(99)Mo reaches 4486.49 Ci,sufficient for millions of diagnostic procedures and equivalent to 16.37% of China's projected demand for 2030.This method provides a viable pathway for stable,large-scale^(99)Mo production.
文摘^(99)Mo是重要的医用放射性核素,溶剂萃取法是反应堆辐照^(235)U靶生产裂变^(99)Mo的分离方法之一。为探讨离子液体Cyphos IL 101用于裂变^(99)Mo分离的可能性,本研究评价了离子液体Cyphos IL 101在硝酸体系中对Mo(Ⅵ)的萃取行为,重点考察了稀释剂、水相初始pH、萃取时间、温度、离子液体浓度等对萃取Mo(Ⅵ)的影响。结果表明,选用甲苯作为稀释剂时,Cyphos IL 101对Mo(Ⅵ)的萃取效果最好,在pH=3条件下,萃取率高达98.87%;萃取为自发进行的过程,且可在5 min达到平衡;选用1 mol/L Na_(2)CO_(3)作为反萃剂,一次反萃可将负载有机相中96.56%的Mo反萃到水相中。构建的离子液体Cyphos IL 101萃取体系对Mo与主要杂质Sr、Cs、Te等有很好的分离效果,体现了其对Mo(Ⅵ)的高选择性萃取能力。以上结果可为将离子液体Cyphos IL 101引入裂变^(99)Mo的分离工艺流程提供参考。
文摘医用同位素锝-99m(99mTc)被广泛应用于核医学领域,其主要来源于母体核素钼-99(99Mo)的衰变。但是目前国内99Mo基本依赖进口,通常出现99Mo不能稳定供应的现象。为解决这个重大问题,实现国内99Mo自主化生产具有重要意义。本文基于中国科学院近代物理研究所强流超导直线加速器(China ADS Front End,CAFE)提供的质子束流辐照天然铀靶件,主要开展铀裂变产物中医用同位素99Mo的高效化学分离、纯化及99Mo/99mTc发生器的制备。研究表明:通过α-安息香肟(α-BO)沉淀分离99Mo后,杂质核素去除率大于90%,99Mo的回收率大于90%。通过对99Mo沉淀进行纯化后,大部分杂质核素被去除。提取的99Mo被装配为99Mo/99mTc发生器,发生器淋洗曲线表明:99mTc产品收集在8 mL生理盐水内最为适宜,同时,99mTc回收率大于80%。电感耦合等离子体发射光谱仪(ICP-OES)测量结果表明,99mTc产品中Al、Mo以及U含量极低;同时,99mTc产品的γ谱图中未出现99Mo和其他杂质核素的γ能量峰。以上研究结果可为国内基于加速器辐照天然铀生产99Mo提供技术参考。
文摘The current industrial-scale production of molybdenum-99(^(99)Mo)and iodine-131(^(131)I)is heavily predicated on thermal neutron irradiation of LEU targets.In this route,^(99)Mo and ^(131)I are separated using a solid-phase extraction approach.The goal of this study was to develop and evaluate copolymeric beads that could be used to separate ^(99)Mo and ^(131)I from their aqueous solutions.Different aminated styrenedivinyl benzene co-polymeric beads were successfully manufactured for this approach.The structural features of the synthesized copolymers were characterized.The resin frameworks were found to have homogeneous spherical shapes decorated with a very thin layer of amine moieties.The FT-IR peaks caused by N—H stretching and C—N bending vibrations show the successful functionalization of the resins'surfaces with amine moieties selective for the sorption of I-over Mo O_(4)^(2-)ions.Under various circumstances,the produced resins were assessed for sorption of ^(99)Mo and ^(131)I from their aqueous solutions.They showed an enhanced sorption capability for I-ions compared to MoO_(4)^(2-)ions and attained equilibrium in less than 20 min.Data declare that the sorption of MoO_(4)^(2-)and I-ions onto synthesized resins was attained through an ion exchange process with Cl-ions.In such interactions,one iodide ion(I-)consumes only one active site from the resin surface,while two active sites must be exhausted to retain one MoO_(4)^(2-)ion onto the surface of the resins.The exchange interaction of both MoO_(4)^(2-)and I-ions was an endothermic process.Further,the elution of ^(99)Mo and ^(131)I radioisotopes loaded on synthesized resins was investigated using various eluents.Additional sets of individual and binary dynamic experiments were performed using columns packed with trimethylamine styrene divinyl benzene(TMA-PSDVB)and triethylamine styrene divinyl benzene(TEA-PSDVB)resins.The individual breakthrough sorption capacity of TMA-PSDVB and TEA-PSDVB resins had values of 381.6 and352.6 mg·g^(-1)for ^(131)I and values of 134.7 and 117.2 mg·g^(-1)for ^(99)Mo isotopes,respectively.Furthermore,TMA-PSDVB resin exhibited breakthrough sorption capacity for ^(99)Mo and ^(131)I,in the binary system,amounting to 123.7 and 331.6 mg·g^(-1)with elution percentages reaching 75.4%and 12.1%,respectively.These findings demonstrate that Mo(Ⅵ)ions were efficiently separated from I(Ⅰ)ions.Finally,the reported aminated polymeric resins may be regarded as promising solid phases for the separation and recovery of Mo(Ⅵ)and I(Ⅰ).
