The Effect of Gamma Irradiation on the Physiochemical Properties of Caesium-Selective Ammonium Phosphomolybdate-Polyacrylonitrile (AMP-PAN) Composites
The Effect of Gamma Irradiation on the Physiochemical Properties of Caesium-Selective Ammonium Phosphomolybdate-Polyacrylonitrile (AMP-PAN) Composites
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DOI：
10.3390/cleantechnol1010020
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发表时间：
2019-12-01
影响因子：
3.8
通讯作者：
Edge, Ruth
中科院分区：
文献类型：
--
作者：
Holdsworth, Alistair F.;Eccles, Harry;Edge, Ruth
管理核燃料循环的某些副产品，如铯的放射性同位素：Cs-134、Cs-135和Cs-137，由于其环境流动性和放射性而具有挑战性。虽然许多材料可以通过离子交换从中性或碱性水溶液中分离Cs+离子，但除了磷钼酸铵（AMP）之外，很少有材料在酸性介质中有效地起作用。AMP及其在聚丙烯腈（PAN）中的多孔复合材料用于管理各种核废料中的Cs放射性同位素的用途已经知道了几十年，并且被充分研究，但是辐射对这种复合材料的理化性质的影响迄今为止仅受到有限的关注。在以前的出版物中，我们证明了100 kGy的伽马辐照剂量对AMP和AMP-PAN的离子交换性能的影响可以忽略不计，在乏核燃料（SNF）再循环中发现的Cs+浓度和酸度下的容量或动力学。作为先前研究的延续，在本出版物中，我们使用一系列表征方法探索了伽马辐照对AMP和AMP-PAN理化性质的影响。本文报道了相同γ剂量对AMP和AMP-PAN中Mo氧化态的影响，AMP和AMP-PAN的热降解，以及AMP高温降解的初步研究。辐射的影响，其可能的机制，在SNF回收的条件，并为这些材料的寿命结束处置或回收进行了讨论。
Managing certain by-products of the nuclear fuel cycle, such as the radioactive isotopes of caesium: Cs-134, Cs-135 and Cs-137 is challenging due to their environmental mobility and radioactivity. While a great many materials can isolate Cs+ ions from neutral or basic aqueous solutions via ion exchange, few of these, with the exception of ammonium phosphomolybdate (AMP), function effectively in acidic media. The use of AMP, and its porous composite in polyacrylonitrile (PAN) for management of Cs radioisotopes in various nuclear wastes have been known for decades and are well studied, yet the effects of radiation on the physiochemical properties of such composites have only received limited attention to date. In a previous publication, we demonstrated that a 100 kGy gamma irradiation dose has negligible effect on the ion exchange performance of AMP and AMP-PAN with respect to capacity or kinetics under the Cs+ concentrations and acidity found in spent nuclear fuel (SNF) recycling. As a continuation of this prior study, in this publication we explore the effects of gamma irradiation on the physiochemical properties of AMP and AMP-PAN using a range of characterisation methods. The effects of the same gamma dose on the oxidation state of Mo in AMP and AMP-PAN, the thermal degradation of both AMP and AMP-PAN, combined with a first study into the high-temperature degradation AMP, are reported. The implications of irradiation, its possible mechanism, the conditions present in SNF recycling, and for the end-of-life disposal or recycling of these materials are also discussed.