效率示踪-液闪法测定后处理厂中 ^(99)Tc  

DETERMINATION OF 99 Tc ACTIVITY WITH EFFICIENCY TRACING LIQUID SCINTILLATION COUNTING METHOD(ET LSC)

作　　者：梁俊福[1] 杨大助[1] 刘秀琴[1] 

机构地区：[1]清华大学核能技术设计研究院

出　　处：《原子能科学技术》1997年第5期446-451,共6页Atomic Energy Science and Technology

摘　　要：研究了萃取－液闪技术快速测定９９Ｔｃ的方法。用环己酮作萃取剂，在Ｈ２ＳＯ４介质下从水相中选择性萃取Ｔｃ，使Ｔｃ与样品中的Ｕ、Ｐｕ、Ａｍ、Ｅｕ、Ｓｒ、Ｃｓ、Ｒｕ、Ｉ等干扰元素分离，９９Ｔｃ的萃取率大于９８％，对干扰元素的分离系数大于１０４。对３０％ＴＢＰ－煤油有机相样品，可用Ｈ２Ｏ反萃后转成Ｈ２ＳＯ４介质。萃取后的有机相直接加入闪烁液中测量，以效率示踪法确定测量效率，得到９９Ｔｃ活度。本方法可用于后处理工艺或废液样品中９９Ｔｃ的测定。A simple radiochemical method using selective separation by solvant extraction and measurement by efficiency tracing liquid scintillation counting method (ET LSC) is developed for determination of 99 Tc activity.Cyclohexanone is demonstrated to be a suitable extractant with a high selectivity for Tc.The recovery of Tc from 1 mol/L H 2SO 4 with 100% cyclohexanone extraction is over 98%,the separation factors of 99 Tc from other radioactive nuclides and elements,e.g. 90 Sr , 137 Cs ,U,Np,Pu,Am,Ru,I and rare earth elements are over 10 4.After separation,the organic phase is mixed with scintillation cocktail and measured activity of 99 Tc using the ET function of Packard 2550 CA liquid scintillation analyzer.The influence of quenching on ET correction is examined.Analytical result of 99 Tc is satisfactory at quenching levels of tSIE>35.This method can be applied for the monitoring of 99 Tc in nuclear fuel cycle and some environmental samples.

关 键 词：环己酮 萃取-液闪法 效率示踪法 后处理厂 锝99 

分 类 号：TL276.99[核科学技术—核燃料循环与材料]