反应堆辐照元件中锝的测定  

MEASUREMENT OF TECHNETIUM IN THE SPENT FUEL

作　　者：朱国辉[1] 

机构地区：[1]中国原子能科学研究院

出　　处：《原子能科学技术》1989年第4期45-51,共7页Atomic Energy Science and Technology

摘　　要：一、前言核燃料燃耗的测定是极为重要的,历年来作为燃耗监测体的有^(99)Mo,^(137)Cs,^(144)Ce,^(148)Nd和^(99)Tc等,其中^(99)Tc是60年代以来就受到重视的一个。在铀的裂变产物中质量链为99的仅见^(99)Tc的寿命较长。而且^(99)Tc具有高裂变产额,因此在堆温小于1400℃时它是一个较好的燃耗监测体。有关锝的分析方法文献中作了较为详细的介绍。为了准确测定核燃料元件溶解液中的^(99)Tc,首先应将Tc与大量放射性元素分离,其中Foster Jr R.E.The extraction-spectrophotometrical determination (with the precision of±1%)of technetium, which recovery is about more than 96%, is described. First Tc inthe NaOH-Na_2CO_3 solution of fission products is extracted into the 2,6-dimethyl-pyridine and reextracted into H_2SO_4 solution from the organic phase by theaddition of CCl_4, then Tc is extracted into tetra-alkyl-ammonium(7402)-n-butylchloride phase by in order to be purified and spectrophotometric determinated.The n-butyl chloride phase contacts with H_2SO_4 solution containing KSCN andbecome purplish red. The colored complex with peak of absorption at 512 nm. hasa molar absorptivity of 5×10~4, and is stable for several hours. Of over 20common metals are studied, none interferes for the spectrophotometricdetermination of Tc. The results of Tc determination of 8 samples from spent fuel elements are incoincidence with the monitor of ^(148)Nd for burnup determination.

关 键 词：锝 反应堆 辐照元件 萃取 测定 

分 类 号：TL352.28[核科学技术—核技术及应用]