TBP-TEVA萃取色层分离-α能谱法测定辐照镎靶溶解液中痕量~(236)Pu的可行性
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摘要
~(236)Pu的含量控制是钚热源的一项重要参数,通过α能谱准确测量镎靶溶解液中痕量~(236)Pu,建立镎靶辐照靶件溶解液中钚的分离方法。根据杂质组成特点采用TBP-TEVA萃取色层双柱分离,用氨基磺酸亚铁以及亚硝酸钠对钚进行调价,对靶件溶解液中的Al、Fe、U、Th和Np等进行分离,去污系数均大于104,钚的回收率为90.7%。研究大量~(238)Pu对α能谱测定~(236)Pu的干扰,结果表明,大量~(238)Pu会造成仪器本底升高,~(238)Pu能谱峰分辨率降低;在7 500Bq ~(238)Pu干扰下,测量4.3h时,~(236)Pu的最小可检测活度为1.20×10-2 Bq(当量质量为6.11×10-16 g)。计算结果表明,镎靶溶解液样品中钚的同位素比值n(~(236)Pu)/n(~(238)Pu)≥4.63×10-8时,取合适的样品量使得电沉积源中~(238)Pu活度在450～7 500Bq范围内,均可测量其中的痕量~(236)Pu,同时可准确测定同位素比值n(~(236)Pu)/n(~(238)Pu)。
The content of ~(236)Pu in the ~(238)Pu product is limited in the range of 2 ppm to protect the workers during the manufacture of the heat source.Therefore,the content must be reduced as much as possible in the production process,and the ~(236)Pu content index must be strictly controlled.The control of plutonium content is an important parameter of plutonium heat source,studied the conditions for accurate measurement of trace ~(236)Pu in irradiated Np target.A separation method for Pu in the solution of irradiated Np target was established.According to the composition of solution,TBP-TEVA double extraction chromatographic column separation was adopted.The plutonium valence was adjusted by FS sulfonic acid and sodium nitrite,and the impurities of Al,Fe,U,Th and Np in the plutonium were decontaminated,the decontamination coefficient was greater than 104,and the recovery of plutonium was 90.7%.In this paper,the interference of a large amount of ~(238)Pu on ~(236)Pu was studied,and the results showed that a large amount of ~(238)Pu would cause increasing of the background,and coarsening of the resolution of ~(238)Pu peak and increase the MDA.The MDA of ~(236)Pu is 1.20×10-2 Bq and the isotope ratios of n(~(236)Pu/~(238)Pu)is 4.63×10-8,when the ~(238)Pu is7 500 Bq background interference and measure it for 4.3 h.When the isotope ratios of n(~(236)Pu/~(238)Pu)is more than or equal 4.63×10-8 in the sample of irradiation Np target,meanwhile sampling the suitable amount can make the ~(238)Pu activity in the electroplating source range from 450-7 500 Bq,then the trace ~(236)Pu can be detected,and the ratios of n(~(236)Pu/~(238)Pu)can be accurately measured.The determination of trace ~(236)Pu in ~(238)Pu heat resource is an important technical indicator in neptunium target irradiation process and product of heat source.In this study,the combined TBP-TEVA resin was used to separate and purify the plutonium from the irradiated neptunium target solution,and the alpha energy spectrum method was used to analyze it.
The content of ~(236)Pu in the ~(238)Pu product is limited in the range of 2 ppm to protect the workers during the manufacture of the heat source.Therefore,the content must be reduced as much as possible in the production process,and the ~(236)Pu content index must be strictly controlled.The control of plutonium content is an important parameter of plutonium heat source,studied the conditions for accurate measurement of trace ~(236)Pu in irradiated Np target.A separation method for Pu in the solution of irradiated Np target was established.According to the composition of solution,TBP-TEVA double extraction chromatographic column separation was adopted.The plutonium valence was adjusted by FS sulfonic acid and sodium nitrite,and the impurities of Al,Fe,U,Th and Np in the plutonium were decontaminated,the decontamination coefficient was greater than 104,and the recovery of plutonium was 90.7%.In this paper,the interference of a large amount of ~(238)Pu on ~(236)Pu was studied,and the results showed that a large amount of ~(238)Pu would cause increasing of the background,and coarsening of the resolution of ~(238)Pu peak and increase the MDA.The MDA of ~(236)Pu is 1.20×10-2 Bq and the isotope ratios of n(~(236)Pu/~(238)Pu)is 4.63×10-8,when the ~(238)Pu is7 500 Bq background interference and measure it for 4.3 h.When the isotope ratios of n(~(236)Pu/~(238)Pu)is more than or equal 4.63×10-8 in the sample of irradiation Np target,meanwhile sampling the suitable amount can make the ~(238)Pu activity in the electroplating source range from 450-7 500 Bq,then the trace ~(236)Pu can be detected,and the ratios of n(~(236)Pu/~(238)Pu)can be accurately measured.The determination of trace ~(236)Pu in ~(238)Pu heat resource is an important technical indicator in neptunium target irradiation process and product of heat source.In this study,the combined TBP-TEVA resin was used to separate and purify the plutonium from the irradiated neptunium target solution,and the alpha energy spectrum method was used to analyze it.
引文
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[7]Sekine K,Kasai A.Liquid-liquid extraction separation and sequential determination of plutoniuma Americium in environmental samples by alpha spectrometry[J].Talanta,1987,34(6):567-570.
[8]颜启民,刘寿荪.GB 11219-89.土壤中钚的测定-萃取色层法[S].北京:中国标准出版社,1989.
[9]Musramatsu Y,Uchida S,Tagami K,et al.Determination of plutonium concentration and its isotopic ratio in environmental materials by ICP-MS after separation using and extration chromatography[J].Joural of Analytical Atomic Spectrometry,1999,14(5):859-865.
[10]Ketterer M E,Shaffer K M,Jones V J,et al.Rapid dating of recent sediments in loch less inductively coupled plasma mass spectrometric measurements of global fallout plutonium[J].Science of the Total Environment,2004,322:221-229.
[11]Aggarwal S K,Alamelu D,Hotheaded P S.Determination of 238Pu in plutonium bearing fuels by thermal ionization mass spectrometry[J].Journal of Radio analytical and Nuclear Chemistry,2007,273(3):775-778.
[12]黄乃明.低水平放射性测量中的探测限及其计算[J].辐射防护通讯,2004,24(2):25-32.Huang naiming.Concept and calculation of detection limit in low level radioactive sample measurement[J].Journal of Radiation Protection Bulletin,2004,24(2):25-32(in Chinese).
[2]陆治美.放射性同位素提取及制源工艺[M].北京:中国原子能出版社,2012:203.
[3]Tomlinson F K,Smith W H.Two methods of determining ppm quantities of plutonium-236in plutonium-238[J].Nuclear Technology,1971,12(3):314-319.
[4]Curtis M L.Determination of parts-per-million quantities of plutonium-236in plutonium-238by alpha pulse height analysis[J].Anal Chem,1968,40:1 352-1 354.
[5]严叔衡,苏树新,张淑兰.分子电镀法定量沉积铀和钚[J].原子能科学技术,1977(3):260-266.Yan Shuheng,Su Shuxin,Zhang Shulan.The deposition of uranium and plutonium by molecular electrodeposition[J].Atomic Energy Science and Technolog,1977(3):260-266(in Chinese).
[6]贾瑞和,刘秉仁,梁俊福,等.电沉积法制备镅、钚和镎的α源[J].同位素,2000,13(3):135-141.Ja Ruihe,Liu Bingren,Liang Junfu,et al.The preparation of alpha sources for plutonium,neptunium and americium by electrodeposition[J].Journal of Isotopes,2000,13(3):135-141(in Chinese).
[7]Sekine K,Kasai A.Liquid-liquid extraction separation and sequential determination of plutoniuma Americium in environmental samples by alpha spectrometry[J].Talanta,1987,34(6):567-570.
[8]颜启民,刘寿荪.GB 11219-89.土壤中钚的测定-萃取色层法[S].北京:中国标准出版社,1989.
[9]Musramatsu Y,Uchida S,Tagami K,et al.Determination of plutonium concentration and its isotopic ratio in environmental materials by ICP-MS after separation using and extration chromatography[J].Joural of Analytical Atomic Spectrometry,1999,14(5):859-865.
[10]Ketterer M E,Shaffer K M,Jones V J,et al.Rapid dating of recent sediments in loch less inductively coupled plasma mass spectrometric measurements of global fallout plutonium[J].Science of the Total Environment,2004,322:221-229.
[11]Aggarwal S K,Alamelu D,Hotheaded P S.Determination of 238Pu in plutonium bearing fuels by thermal ionization mass spectrometry[J].Journal of Radio analytical and Nuclear Chemistry,2007,273(3):775-778.
[12]黄乃明.低水平放射性测量中的探测限及其计算[J].辐射防护通讯,2004,24(2):25-32.Huang naiming.Concept and calculation of detection limit in low level radioactive sample measurement[J].Journal of Radiation Protection Bulletin,2004,24(2):25-32(in Chinese).