钍,铀和钚在盐环境中的迁移行为研究

采用柱迁移实验研究了钍、铀和钚在盐柱上的迁移行为。实验结果表明，体系中水溶液中的ｐＨ值对钍、铀的回收率影响很大，ｐＨ≥３时，约８５％Ｔｈ＾４＋被阻滞在盐柱上，铀通过ＮａＣｌ柱时，其化学回收率与ｐＨ值的关系曲线呈“马鞍型”；ｐＨ≤２或ｐＨ≥８时，化学回收率〉８４％，ｐＨ≈６时，化学回收率仅为９％，进料液或淋洗液中的配位剂影响铀，钚在盐柱上的迁移，阻滞在盐柱上的大部分铀分布在距离进料口下端２ｃｍ之内，     

钍-铀燃料后处理中新萃取剂的研究 Ⅰ.双取代酰胺类的研究及其结构与性能的关系

合成并研究了10种双取代酰胺萃取铀、钍、裂片元素的情况,结果表明,取代己内酰胺的萃取性能优于非环状双取代酰胺。和1mol/1的TBP相比,取代己内酰胺萃取铀的能力比TBP强,萃取钍的能力和TBP接近。除OCLA外,酰胺对于铀钍的分离性能均比TBP好,酰胺对Zr-Nb的去污性能优于TBP。还初步探讨了酰胺类萃取剂结构与性能的关系。     

上海纱罩厂部分职工体内钍含量调查

本文介绍了利用呼气中(气土)浓度测定法对上海纱罩厂部分工作人员体内钍含量进行调查的结果。调查人数为51人,其中行政人员6人,体内钍含量平均值为0.36Bq,与对照组0.33Bq 相比无显著差异;操作工人45人,平均值为1.65Bq,比对照组高4倍,最大值为8.35Bq,约高出24倍。还分析了呼气中(气土)浓度及体内钍含量与工种、工龄的关系,比较了呼气中(气土)浓度测定法与中子活化测定法的调查结果。     

某厂放射性废水排放口外江浅滩底质泥污染调查(二)

本文是对某钍水冶厂放射性废水造成江浅滩底质泥污染的第二篇报告。作者测定了底质泥表面上的γ照射量率,认为底质泥的污染可能是符合高斯分布的。根据深度为40厘米泥芯样的测量结果,表明最大污染层深度为20厘米左右。作者对1975—1979年期间的废水监测资料进行了统计分析,发现 pH 值呈正态分布((?)=8.0,(?)=2);钍、铀和镭的浓度呈对数正态分布。     

用织纤布吸附快速测定钍废水中的α放射性

本文介绍一种快速监测钍废水中放射性核素浓度的方法。该法简单,其具体步骤是将一定大小的织纤布浸泡于废水中,搅动一定时间后取出,冲洗并烘干,即可直接测量。在一小时或更短的时间内便可得到结果。实验发现4号布对钍系有选择性吸附的能力。当废水中所含放射性核素以钍系为主时,所得实验结果与放化分析结果相差大约为10%,对含有少量铀的钍废水监测下限为10~(-11)居里/升。     

改良型双滤膜法测定呼气的研究

本文叙述了一个用于测定呼气的改良型双滤膜装置。改良型双滤膜装置是在通用型双滤膜装置上加入了一个气溶胶输给系统,因而显著降低了原装置的壁吸附,大大提高了灵敏度。根据本文采用的程序能测出~(232)Th 在人体内最大容许体负荷量的0.03%。本方法不但能测定呼气(气土),还可以测定环境空气中的氡、(气土)浓度。本文详细介绍了该装置的原理、设备、计算方法以及测定结果。     

The effect of synthesis conditions on the phase composition and structure of thorium bearing murataite ceramics

Samples of thorium-bearing ceramic with a target composition (wt%) 5 Al₂O₃, 10 CaO, 55 TiO₂, 10 MnO, 5 Fe₂O₃, 5 ZrO₂, 10 ThO₂ were produced by melting in glassy carbon crucibles in a resistive furnace and by cold crucible inductive melting (CCIM) at a vibration power of 10 kW and operation frequency of 5.28 MHz. All the samples contained 85–95 vol% murataite polytypes with 5- (5C), 8- (8C), and 3-fold (3C) elementary fluorite unit cell composing core, intermediate zone and rim of the grains, respectively, and minor crichtonite, perovskite, pyrochlore, rutile, etc. A feature of the ceramics obtained by melting in glassy carbon crucibles is formation of Fe (II) titanate whereas the inductive-melted ceramics contained traces of vitreous phase due to melt contamination with a cold crucible putty material. Melting rate in the cold crucible of up to 350 kg/(m² × h) has been achieved. The ceramics obtained have excellent chemical durability.     

钍在HCl－H_3PO_4介质中阳离子交换分配系数的测定

叙述了应用分析手段测定钍在ＨＣｌ—Ｈ３ＰＯ４介质中阳离子交换分配系数，得出了从复杂组分中分离，纯化出单质钍的基本方法。     

Highly selective and sensitive Th<Superscript>4+</Superscript>-PVC-based membrane sensor based on 2-(diphenylphosphorothioyl)-<Emphasis Type="Italic">N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-diphenylacetamide

A Th⁴⁺ ion-selective membrane sensor was fabricated from poly (vinyl chloride) (PVC) matrix membrane containing 2-(diphenylphosphorothioyl)-N′,N′-diphenyl acetamide (DPTD) as a neutral carrier, potassium tetrakis (p-chlorophenyl) borate (KTpClPB) as anionic excluder and o-nitrophenyloctyl ether (NPOE) as a plasticizing solvent mediator. The effects of the membrane composition, pH and additive anionic influence on the response properties were investigated. The sensor, comprising 30% PVC, 63% solvent mediator, 4% ionophore and 3% anionic additive demonstrates the best potentiometric response characteristics. It displays Nernstian behavior (15.2 ± 0.5 mV per decade) over the concentration range 1.0 × 10⁻²–1.0 × 10⁻⁶ M. The detection limit of the electrode is 6.3 × 10⁻⁷ M (∼140 ng/ml). The response time of the electrode is 30 s .The sensor can be used in the pH range 3.0–9.0 for about 6 weeks. The membrane sensor was used as an indicator electrode in the potentiometric titration of Th⁴⁺ ions with EDTA. It was successfully applied to the determination of thorium ions in binary mixture.