摘要
为了准确测定乏燃料后处理废TBP/煤油中Pu和总α活度,在蒸馏出废TBP/煤油中的煤油后,采用碳化氧化法消解TBP,阴离子交换法分离238U和237Np等核素,最后在洗脱Pu后,用大面积屏栅电离室 α谱仪测量总Pu。在对样品作初步处理后,测量总α的活度,并对此值作校正(以分离后总Pu中的239,240Pu的α活度为标准)。样品分析结果表明,α核素在废TBP/煤油样品中分布不均匀。
A reliable procedure for determination of plutonium and total alpha activity in spent TBP/kerosene is developed. Since the creeping property of kerosene on heating TBP/kerosene specimen for alpha counting cannot be directly prepared by simple heating-evaporation. In this work kerosene is safely removed by distillation without loss of alpha activity. TBP is then carbonized by treatment with concentrated H_2SO_4 and thoroughly digested with HNO_3-HClO_4 mixture. Plutonium is separated from other alpha emitters by anion-exchange chromatography after oxidation state adjustment and quantified by a large area grid ionization chamber alpha spectrometer. The recovery of (chromatographic) separation is standardized to be (102±3.5)% by triplicate reference runs. The total alpha activity is measured in a similar way, but without carbonization and chromatographic separation. In this case a correction for self-absorption has to be made. The self-absorption coefficient is obtained by (comparison) of^(239,240)Pu activities measured with and without carbonization and chromatographic separation for the same sample. In addition a continuously decreasing alpha activity profile along the depth in a TBP/kerosene container is observed.
出处
《核化学与放射化学》
CAS
CSCD
北大核心
2004年第4期234-238,共5页
Journal of Nuclear and Radiochemistry
