Actinides are heavy elements at the end of the periodic table. They are the backbone of nuclear fission technologies for electricity supply, with important applications in other strategic fields, from water management to space exploration and human health. Actinides exhibit very peculiar, diverse and complex chemical and physical properties, they can in particular display multiple allotropes (different structural forms), remarkable orders (magnetic, multipolar, hidden, topological…), unconventional super-conductivity and many other phenomena at the forefront of current scientific knowledge. Besides fundamental science interests, achieving a deep understanding of actinides is vital to ensuring a safe deployment of civil nuclear technologies.
FISSION, AS DISCUSSED in relation to nuclear power, is a nuclear process that involves the elements thorium, uranium, and some of the transuranium isotopes (for example plutonium), and occurs only in the actinides – those elements beyond actinium (atomic number Z=89) in the periodic table.
In handling nuclear fuels and waste we are confronted with solids and liquids (condensed matter) containing actinides, which possess 5f electrons (electrons located on the so called 5f electron shell). As valence electrons, these play a crucial role in determining physical and chemical behaviour of an element. Although in nuclear power generation we are primarily interested in nuclear properties, the overwhelming problems stem from the need to deal with actinides found in different physical and chemical forms.
Achieving the deepest possible understanding of the many complex properties of actinides is therefore vital to ensuring the safety and security of nuclear facilities old and new, as well as non-nuclear energy-related applications (such as medical therapy, long-lasting miniaturised power supply, etc.).
The extent of our understanding of actinides is limited, especially in relation to the rest of the periodic table, for example, in comparison with our knowledge of the properties of silicon, upon which the whole IT industry is based. The additional problem of nuclear instability in those elements beyond uranium – which are toxic and radioactive – requires improving our limited knowledge on properties of liquids and solids containing actinide elements.
Facilities for handling such materials are few in number and are very expensive to maintain. Yet understanding in detail the behaviour of actinides is essential for a safe and secure operation of nuclear applications. Additionally, there is an apparent need to learn how to separate and treat the waste as well as the recycled actinides. Finally, our models must be able to accurately predict the behaviour of nuclear waste containing actinides during long-term storage.
The Actinide UserLab (Actuslab) is an initiative that aims at providing the scientific community the opportunity to address at least some of these problems. On the condition that all research is published, it enables staff from universities, research institutes and industry to gain access to the facilities of the Joint Research Centre (JRC), operated by the European Commission. Students and young researchers are especially welcome at the JRC, which runs a summer school every two years, to bolster the aims of the UserLab in training future generations of scientists in the field.
An Academic Lynchpin
Fostering international collaboration with universities and research centres, and offering access to its specialised facilities through EU programmes, JRC is pivotal to the realisation and expansion of the European Research Area in the fields of actinide chemistry and physics. The Actuslab project has already demonstrated its ability to attract high-quality research students: more than 20 external PhD theses have included JRC-obtained results in their theses. Additionally, based on peer-review, feasibility and availability, 121 out of 201 proposals have been awarded operating days, meaning a total of 140 visitors from 15 different countries and 40 organisations have participated in the UserLab since its inception in 2001. Over 1,100 operating days have been delivered, resulting in the publication of about 150 articles.
Although most EU Member States exploit nuclear power plants or uranium mines, they do not all possess research facilities licensed for handling transuranium elements – the necessary facilities are singularly expensive to build and operate. Sharing such facilities at a European scale is one way to conduct both cost effective and high-quality research, stimulating collaboration and interdisciplinary synergy, and is very much in line with the concept of the European Research Area. In opening up the facilities of the JRC-ITU, itself the leading centre for basic actinide research and education in Europe, the UserLab has established itself as an academic lynchpin, contributing to the training of the next generation of actinide scientists and technologists.
Actuslab itself is unique in the world; it is the only user laboratory equipped for performing experiments on radioactive actinide materials under extreme conditions, and boasts an incredible array of world-class facilities, including those for samples preparation and a range of characterisation and investigation tools. Spectroscopic and structural characterisation can be performed under various conditions of high temperature and pressure. Transport, magnetic and thermodynamical properties can be measured in temperatures down to 0.3 K and in external magnetic fields up to 14 Tesla. The laboratory is the only in Europe capable of measuring the low temperature specific heat of transuranium materials, and offers state-of-the-art encapsulation techniques and facilities for thin and multi-layer materials production. All these facilities are offered free of charge to the user, along with the support and expertise of JRC staff and a service facilitating such aspects as the secure transport of samples and a radioprotection survey of users, according to the latest European and German safety standards. In short, the Actuslab programme is key to the training of new European specialists in a strategic field with high regulatory impact.
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These elements are the backbone of nuclear fission technologies for electricity supply, with important applications in other strategic fields, from water management to space exploration and human health.
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Objective assessment and modelling of the safety-related behaviour of nuclear materials.
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The hot cell laboratory consists of 24 shielded hot cells where highly radioactive materials (including full length light water reactor pins) can be...
For any further information about the Actinide User Laboratory, please email to:
Mrs. Krisztina Varga, Assistant
Dr. Eric Colineau, Coordinator
Dr Rachel Eloirdi, Head of Unit