STUDY FOR CONCENTRATION OF TECHNETIUM IN THE LOW LEVEL RADIOACTIVE LIQUID WASTE

低放射性液体废物中锝浓度的研究

基本信息

批准号：
06680460
负责人：
ITO Katsuo
金额：
$ 1.41万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

Reprocessing facilities for used nuclear fuels would produce the low level radioactive liquid waste containing actinides and technetium, which could not permit to discard into the environment since their activities are too high to waste. Investigator designs to recycle the concentrated liquid waste in the nuclear fuel cycling system and to dispose of them in the air-ground building. Evaporation technique is efficient for the low level radioactive liquid which does not involve the vaporizable radioactive meterials. Vaporization technique is difficult for the chemical matters of technetium compound, since technetium in the solution is easy to vaporize in the air. Firstly basic information regarding thin film evaporator was looked for, and the adequate conditions are follows : temperature : 50ﾟC,rotational speed : 600 rpm, feeding rate of sample solution : 13 ml/min, vacuum pressure : 15 mm Hg. Under these conditions the instrument could operated continuously. The solutions of tracer leve … More l of technetium were concentrated using above fixed conditions, the recovery of Tc in the concentrate was 98%, and the concentration of Tc in the distilllate was too low to determine. To get the location of 2% of Tc in the concentrating procedure, the diluted rhenium (Re) solution (100x10^<-6>g/ml) was investigated for the purpose of checking the mass balance, since chemical properties for rhenium is similar to that of technetium. The concentration of Re in the distilllate was 2x10^<-9>g/ml determined by using Inductively Coupled Plasma Mass Spectrometry, and that of concentrate was 2000x10^<-6>g/ml determined by using Inductively Coupled Plasma Atomic Emission Spectrometry. The recovery of Re was 98% which correspond to that of Tc. A decontamination factor for Re calculated from the concentration of Re both in the distilllate and feed solution was 2x10^4. The location of Re in the distilllation procedure should be studied more. Next study should be carried out for the solutions containing a salt like sodium nitrate and organic matter like dodecane. Less

二手核燃料的重新处理设施将产生含有actinides和Technology网的低水平放射性液体废物，因为它们的活动太高而无法浪费，因此不允许将其丢弃到环境中。研究人员设计以回收核燃料自行车系统中的集中液体废物，并将其处置在空中建筑物中。蒸发技术对于低水平放射性液体是有效的，该液体不涉及可蒸发的放射仪。对于技术化合物的化学物质而言，蒸发技术很难，因为溶液中的Technetium很容易在空气中蒸发。首先，寻找有关薄膜蒸发器的基本信息，并遵循了足够的条件：温度：50°C，转子速度：600 rpm，样品溶液的进料速率：13 mL/min，真空压：15 mm Hg。在这种情况下，仪器可以连续运行。示踪剂水平的溶液…使用上述条件浓缩了更多L的techtium，浓度中TC的恢复为98％，蒸馏酸盐中TC的浓度太低而无法确定。为了在浓度过程中获得2％的TC位置，研究了稀释的rhenium（RE）溶液（100x10^<-6> g/ml），以检查质量平衡，因为rhen的化学特性与Technetium相似。 RE在酿酒酸酯中的浓度为2x10^<-9> g/mL，使用电感耦合的等离子体质谱法确定，浓度的浓度为2000x10^<-6> g/ml，通过使用电感偶联的血浆原子发射光谱法确定。 RE的回收率为98％，与TC相对应。从酿酒厂和进料溶液中的RE浓度计算出的重复污染因子是2x10^4。 RE在蒸馏过程中的位置应进行更多研究。下一项研究应针对含有硝酸钠和有机物等盐等盐等溶液进行。较少的