白令海和北冰洋海水中铱的阴离子交换预富集-中子活化分析

研究了用阴离子交换预富集 中子活化法测定海水中铱的分析方法。192Ir示踪实验结果表明,在0 05～1 2mol/LHCl介质中,酸度越低越有利于树脂对Ir的吸附;阴离子交换法对pH=1 5的酸化海水中痕量Ir的回收率为89%;聚乙烯瓶和pH=1 5的酸化条件可以长期保存海水中的Ir。在超净实验条件下,用阴离子交换预富集 中子活化法测定了白令海和北冰洋垂直剖面样品中Ir的浓度,结果分别为(0 85～3 58)×10-12g/L(白令海,采集深度为0～3504m)和(1 26～1 97)×10-12g/L(北冰洋,采集深度为25～1900m),试剂空白值为(0 18～0 20)×10-12g/L。     

利用AG1-X8树脂放射化学中子活化法测定若干地质标准参考物中的Ir

利用192Ir放射性示踪研究了铱在AG1－X8阴离子树脂上的吸附解吸行为。首先用氯气对样品溶液中铱的化学种态进行调整，然后对吸附在树脂上的铱用抗坏血酸还原，最后用HClO4与HCl混合液洗脱，实验结果表明，全流程对铱的回收率高于92％，利用建立的流程测定了丹麦地质标准参考物FC－1，结果与推荐值吻合，测定了3个日本地质标准参考物JSd-1,JLk-1和JMn-1，铱的含量分别为0．10，0．03，1．70ng.g^-1。     

环境土壤样品微波消解及钚的ICP-MS测量

钚是环境放射性污染调查和核事故应急监测重点关注的污染核素,土壤样品中钚的定量分析包括样品消解、化学分离和仪器测量等3个步骤。为缩短样品消解时间、提高化学分离效率,对土壤样品微波消解和钚的阴离子交换分离进行了研究,建立了微波消解-阴离子交换分离-电感耦合等离子体质谱（ICP-MS）测量 同位素稀释法定量分析污染土壤样品中²³⁹Pu的流程。以6 mol/L盐酸为浸取试剂,在浸取液体积与土壤质量之比为4∶1~5∶1 mL/g时,5 g土壤样品中²³⁹Pu的加标回收率大于99%。以氢氟酸、硝酸和盐酸的混酸为消解试剂,在氢氟酸浓度为13.2 mol/L时,1 g土壤样品中²³⁹Pu的加标回收率大于94%。用所建流程测得的IAEA-375土壤标准样品中²³⁹Pu的含量与参考值无显著差异,该流程对1 g土壤样品中²³⁹Pu的检出限为84 mBq/kg。     

用放射性示踪技术研究海洋沉积物中铱的吸附和解吸行为及其富集机制

利用放射性示踪技术,结合静态吸附、解吸实验及可见分光光度分析,研究了海洋沉积物－海水体系中铱的吸附及解吸行为。结果表明,在极低的铱浓度范围内,铱的吸附－解吸等温线呈线性,咀吸附－解吸不可逆。IrCl6%2-形态的铱极易被沉积物所吸附,一旦吸附后又难解吸焉。沉积物沉积过程中不断地吸附海水中的IrCl6^2-,可能致使铱累积于沉积物中,从而引起铱富集,丹麦鱼粘土对铱的吸附能力弱于近海洋沉积物,说明丹麦鱼粘土高含量铱来源于其它成因控制,如火山或地外成因。     

地下水样品中硼同位素组成的测定

对地下水样品进行硼分离及其同位素组成及TIMS测试。针对地下水硼含量低、有机质含量高的特点,将样品采用C18固相萃取柱去除有机质,建立阴离子交换树脂法分离硼,并与混合离子交换树脂法分离结果进行对比。结果表明:两种分离流程回收率均在95%以上。样品经前处理后能满足同位素热电离质谱的测试要求,几乎不产生明显的同位素分馏,阴离子交换树脂法测量精度小于0.06%,且能够在分离的同时实现富集,更适用于地下水样品。     

草酸体系中镎、钚的阴离子交换分离

用阴离子交换法研究了TRPO流程中镎和钚的浓缩和分离。在适宜条件下,Np、Pu以草酸络阴离子被阴离子交换树脂吸附。用稀硝酸将镎、钚同时洗脱后,调节洗脱液为8mol/LHNO3,使镎和钚转成硝酸络阴离子,再用一阴离子交换柱吸附镎和钚后,用氨基磺酸亚铁-硝酸溶液还原解吸钚,最后用稀硝酸洗脱镎。在实验基础上,建立了镎、钚的离子交换分离流程。本流程的镎、钚浓缩倍数为840,它们的浓度达到约20g/L,镎和钚的分离系数βPu/Np＞100;βNp/Pu＞300;Np和Pu的回收率分别为97.6％和97.4％。     

多种锕系元素共存体系中微量~(235)Np的测定

本文为从复杂的多种锕系元素共存体系中准确测定超微量~(235)Np(10~(-15)-10~(-14)g/g)的含量,建立了一个特殊的中子活化分析流程。样品经阴离子交换柱浓集和PMBP萃淋树脂柱分离纯化,共存的~(237)Np作内标,高注量堆中子活化后,测定~(235)Np活化产物子体~(236)Pu而获得~(235)Np的含量。     

阴离子交换法分离锝的研究

测定了在不同硝酸根浓度和酸度下，锝在树脂相和水相间的分配比，求出了硝酸根和高锝酸根在阴离子交换树脂上的交换平衡常数以及高锝酸的离解平衡常数，得到了一个可根据样品中硝酸根浓度，酸度计算锝在两相间配比的公式，还测定了树脂床的性能，如湿树脂密度，空隙体积，总交换容量等，给出在了在含水量硝酸根溶液中用阴离子交换树脂分离锝时，保留体积与样品溶液中硝酸根浓度，酸度以及树脂床体积之间的关系，由此可确定分离样品溶     

海水中痕量铀的快速分光光度测定

1.绪言为了促进海水中痕量铀的回收研究工作,我们研究了一种快速而准确的分析方法。痕量铀用阴离子交换树脂和螯合树脂吸附分离,或用氢氧化铁和氢氧化铝共沉淀分离,或用溶剂萃取法分离浓缩后,可用分光光度法和荧光法进行分析,这些方法也适用于海水。我们采用了其     

居里级~(242)Cm的制备新工艺

本文研究了一个提取居里级~(242)Cm的化学流程,采用TBP萃取色层,除裂片元素,CH_3OH-HNO_3-阴离子交换树脂体系分离Am和Cm,产品中~(241)Am的α放射性与~(242)Cm的α放射性之比达到3×10~(-4)。此流程具有步骤少,操作方便和产品介质简单等优点。     

Generalized analysis method for neutron resonance transmission analysis

Neutron resonance densitometry (NRD) is a non-destructive analysis method, which can be applied to quantify special nuclear materials (SNM) in small particle-like debris of melted fuel that are formed in severe accidents of nuclear reactors such as the Fukushima Daiichi nuclear power plants. NRD uses neutron resonance transmission analysis (NRTA) to quantify SNM and neutron resonance capture analysis (NRCA) to identify matrix materials and impurities. To apply NRD for the characterization of arbitrary-shaped thick materials, a generalized method for the analysis of NRTA data has been developed. The method has been applied on data resulting from transmission through thick samples with an irregular shape and an areal density of SNM up to 0.253 at/b (≈100 g/cm²). The investigation shows that NRD can be used to quantify SNM with a high accuracy not only in inhomogeneous samples made of particle-like debris but also in samples made of large rocks with an irregular shape by applying the generalized analysis method for NRTA.     

Threat analysis for transport of radioactive material using morphological analysis

Abstract

The Swedish Defence Research Agency (FOI) was commissioned by the Swedish Nuclear Power Inspectorate to carry out a pilot study which would serve as the basis for a revised set of regulations regarding physical protection and administrative routines for the transport of radioactive material. The pilot study was to develop a prototype model by which a comprehensive threat analysis could be carried out. The study employed computer aided morphological analysis, which is a flexible, non-quantified modelling method developed at FOI during the 1990s. The paper will present the methodological foundations of morphological analysis and present the prototype models involving general threat scenarios, transport situations, antagonists and strategic measures.     

分子活化分析

评述了可用于元素化学种态研究的分子活化分析技术的基本概念、实验方法、优缺点、以及在生物、环境和地学中的应用，并展望了分子活化分析的发展前景。     

The role of data analysis and surveillance in reliability analysis

As an introduction the data problem is illustrated by discussing failure modes and the question of random versus systematic failures. Structural failures are addressed briefly, while system failures are treated with reference to control and instrumentation. The relevant German standards are investigated regarding probabilistic requirements. It is concluded, that reliability and risk assessments are still directed towards comparison, which on the other hand provide a powerful tool for a well balanced system design. Finally some examples are given on updating of literature data by experience.     

Multistate reliability analysis

The binary AND and OR operators are generalized to multistate systems with multistate components, by developing multistate operators which obey the Commutative and the Associative laws. In systems with such operators, components can be rearranged internally in any arbitrary way without affecting the mapping of the component states onto the state of the system. In addittion, all components, all subsystems and the system itself have the same set of states. Such systems are called homogeneous. Operators of homogeneous systems can be described by either their truth table or by the ranking of their states in order of relative dominance. If a homogeneous system is also coherent, then the mapping of the component states onto the system state, and the calculation of the probabilities of system states from those of the component states, become very simple. The sets of operators for 3-state and 4-state homogeneous coherent systems are given. In an example, the Auxiliary Feedwater System of a nuclear power plant is modeled as a homogeneous coherent multistate system composed of homogeneous coherent multistate subsystems, and its reliability is calculated.