Long-lived Radionuclides in the Surface Environment (LO-RISE)- Mechanistic Studies of Speciation, Environmental Transport and Transfer

放射性对人类和更广泛环境的影响由地下水、土壤和沉积物中放射性核素的行为控制，这种行为由放射性核素的数量及其化学形态决定。我们将研究一些特别重要的放射性核素，因为它们可能以相对大量的形式存在，在环境中是可移动的，并且很容易被活的有机体吸收。我们将要研究的主要放射性核素是：碳-14，它存在于自然界中，但早在20世纪60年代和60年代通过核武器试验产生，也存在于核废料中；以及铀(及其衰变产物镭)，它存在于自然界和一些核废料中。我们将使用英国四个这些放射性核素水平较高的地区作为研究地点。它们是南特拉斯(康沃尔的一个老铀矿)、针眼(苏格兰西南部的一个铀矿脉)、英格兰西北部的埃斯克河口，以及爱尔兰东北海的近海沉积物。在这最后两个地点，沉积物中的放射性水平因批准的塞拉菲尔德排放而升高，主要是在20世纪70年代。除了研究放射性如何在土壤、水、植物和(在近海沉积物中)动物中发生和移动之外，我们还想了解控制这种移动的环境和生物过程。为此，我们将进行一系列实验室实验，观察土壤/沉积物条件对溶液中放射性核素浓度的影响，溶液中放射性核素的形式，放射性核素被植物和动物吸收的方式，以及它们在植物组织中的分布方式。我们将利用实地和实验室研究的结果来开发和测试放射性核素运输和转移过程的数学模型。这些都很重要，因为它们让我们能够预测行为，而不是不得不进行测量。这些预测模型可用于评估环境影响、清理受污染的土地和预测放射性废物处置的长期影响。

The impact of radioactivity on humans and the wider environment is controlled by the behaviour of the radionuclides in groundwaters, soils and sediments, and this behaviour is dictated by the quantities of radionuclides, and their chemical forms. We will study some of the radionuclides which are particularly important because they are potentially present in relatively large quantities, are environmentally mobile, and are readily taken up by living organisms. The main radionuclides we are going to study are:Carbon-14, which occurs in nature, but was produced back in the 1960s and 60s through nuclear weapons testing, and is also present in nuclear wastes; and Uranium (together with its decay product radium) which is present in nature, and also in some nuclear wastes.We will use four areas of the UK which contain elevated levels of these radionuclides as our study sites. These are South Terras (an old uranium mine in Cornwall), the Needle's Eye (a uranium mineral vein in SW Scotland), the Esk Estuary in NW England, and offshore sediments in the NE Irish Sea. At these last two sites, the sediments contain elevated levels of radioactivity from authorised Sellafield discharges, mainly in the 1970s. As well as studying how radioactivity occurs in, and moves through, the soils, waters, plants and (in the offshore sediments) animals, we want to understand the environmental and biological processes which control this movement. To do this, we will do a series of laboratory experiments, looking at the way soil/sediment conditions influence the radionuclide concentrations in solution, the form of the radionuclides in the solution, the way radionuclides are taken up into plants and animals, and the way they are distributed in plant tissues. We will use the results from our field and laboratory studies to develop and test mathematical models of radionuclide transport and transfer processes. These are important because they allow us to predict behaviour, rather than having to make measurements. These predictive models can be used in assessing environmental impacts, cleaning up contaminated land and predicting the long term impact of radioactive waste disposals.