Euratom Nuclear Research - Fission
Key areas of activity
Recent Euratom Framework Programmes, including the current FP7, have focused on projects that address major issues and challenges in nuclear fission and radiation protection research:
Management of radioactive waste
Research in the area of management of radioactive waste has been a priority of the Euratom Framework Programme for many years. It focuses on two complementary management strategies. The first is the geological disposal of the most hazardous radioactive waste (essentially the most radioactive and radiotoxic forms of waste, which is either spent nuclear fuel or the vitrified residues from the reprocessing of this fuel to enable recycling of fissile material), and the second concerns the reduction of quantities and toxicity of waste material by chemical and nuclear processes.
Many years of research, including much undertaken within the Euratom Framework Programmes, has demonstrated the scientific and technical feasibility of the disposal of nuclear waste in engineered facilities constructed in deep and stable rock formations. Typical host rock formations include granite, clay or salt, situated at depths of 400-500 m. This 'concentrate and confine' strategy in geological repositories is considered by the scientific community to be the only safe long-term solution for the management of such wastes.
Scientific research has focused for decades on both characterising the rock surrounding potential repositories and on the potential for migration of radionuclides from the waste containers to the Earth's surface or biosphere. Such investigations take a long time to carry out, simply because the movement of the particles through the many barrier materials is so slow. Results of these studies in the past few years have underscored the viability of geological disposal as a safe and practical waste-management solution. Much of the latest research is taking place in underground research laboratories specially constructed in potential host rock formations at typical repository depths.
The focus of current activities is now shifting away from more basic studies to 'implementation oriented' research, dealing more with repository design, demonstration of technology, and reducing uncertainties. Once again, the Euratom effort in FP7 is making an important contribution to these activities, in particular as part of the activities coordinated by the Implementing Geological Disposal Technology Platform (see collaborative platforms). For example, in a recent Euratom project on development of engineering prototypes, an international team of engineers developed robotic machinery to gently insert waste containers into their disposal tunnels, and remove them again just as carefully if the need arises.
The first operational geological repositories for nuclear waste are expected to be in operation in Europe around 2020. Research is continuing to ensure safety is maintained throughout the construction, operation and closure of these facilities.
Partitioning & transmutation
The methods used to reduce the quantities and toxicity of radioactive waste are known collectively as partitioning and transmutation (P&T). In terms of waste management, the objectives of P&T are to minimise the amount of 'ultimate waste' that needs to go to geological repositories and to drastically reduce the time that this waste needs to be isolated from the biosphere by the engineered and natural barriers.
Partitioning refers to the chemical separation of the most hazardous radionuclides from high-level waste or spent nuclear fuel. Transmutation is their nuclear conversion into stable or shorter-lived nuclides. Research in this area is fundamental to the practical realisation of advanced reactor systems, in particular the Generation-IV designs, in which the nuclear reactor and the associated fuel cycle have been geared to produce as little 'ultimate waste' as possible, through careful design of the reactor and the fuel, choice of fuel composition, and recycling followed by nuclear transmutation of the problematic radionuclides in the core of the reactor. Another option involves dedicated 'waste burners', which are sub-critical reactors (accelerator-driven systems) designed to transmute as much waste as possible, and with the potential to drastically reduce quantities of ultimate waste.
In P&T, after several years of research at the laboratory scale the challenge is now to scale up the processes to demonstrator systems, either in the form of dedicated 'waste burners' or as an integral part of Generation-IV reactors and fuel cycles. In either case, it should be stressed that geological repositories will still be required for the ultimate waste, but quantities will be smaller and potentially less radiotoxic, thereby enabling more efficient use of the geological repositories.
Reactor systems and safety
This broad area of research covers current as well as future reactor technology, and includes a wide range of disciplines and technical areas. Safety is a principal underlying theme in all activities. In the Euratom programme, most aspects of the nuclear fuel cycle are within the scope of the research that can be supported, though uranium mining is not included, nor practices that are an advanced level of industrial maturity (manufacture of fuel for current reactors, decommission / dismantling of shut-down facilities, etc.). Because of the close link with nuclear reactors and fuel cycles, partitioning and transmutation (see management of radioactive waste) are included in the activities covered, and is often carried out in common with research on advance reactor technology. All activities are within the scope of the work being coordinated by the Sustainable Nuclear Energy Technology Platform (see collaborative platforms). A lot of the Euratom effort concerns research in cross-cutting areas such as numerical simulation (using sophisticated computer modelling tools that increasingly rely on high-performance computing), structural and fuel materials, and generic safety studies.
Nuclear installation safety
Nuclear power plants are complex technological systems, and their continued safe operation is paramount. Maintaining a high level of safety requires a cutting edge technical research and training programme and the promoting of a strong safety culture in order to minimise the risk of human error. These activities have been a priority of the Euratom programmes since the beginning, and the current (7th) Euratom FP is actively involved in several key initiatives, including in collaboration with countries outside Europe. Currently supported projects cover several specialised areas of science and engineering, including instrumentation and control, investigations on material ageing in order to safely prolong the operating lives of current reactors, advanced safety-assessment methodologies and the prevention and mitigation of severe accidents. Europe is a world leader in nuclear technology and services, and its research sector works closely with industry, helping to secure Europe's position as a top supplier of technological expertise in an increasingly competitive global market.
Advanced nuclear systems
The vast majority of currently operating nuclear power plants are 'Generation-II' designs, while those now being constructed are usually 'Generation-III' reactors, which are evolutionary Generation-II designs offering enhanced safety characteristics in the event of very unlikely extreme events, improved fuel efficiency and extended design lifetimes.
However, the focus of the global research effort in nuclear technology is now on Generation-IV nuclear systems, though commercial deployment is not foreseen before 2040. These are truly innovative reactor concepts, offering a high level of safety combined with favourable economics and competitiveness. By including safety as an integral part of the basic research on the design of these future reactors, safety will be 'built in' rather than 'added on'. This maximises dependence on passive systems in the event or operating incidents, and ensures there are zero off-site impacts even in the event of the most severe accident scenarios. Importantly, Generation-IV reactors and fuel cycles will enable much more efficient use of natural uranium resources, can minimise production of high-level radioactive waste and reduce dramatically the risk of proliferation of nuclear weapons. The Euratom FP is contributing to the global efforts in all these aspects of Generation-IV systems through support for fundamental research on design options and cross-cutting research on fuels, materials and waste management.
Radiation protection research focuses on assessing and mitigating the risks from low and protracted exposure to radiation, including from medical uses as part of diagnostic or therapeutic techniques. The main objective is to ensure a robust and socially acceptable system of radiation protection that does not unduly limit the beneficial uses of nuclear technology. Research in this area combines a wide range of disciplines - such as epidemiology, radiobiology, cellular and molecular biology and radioecology, to name only a few - and extends beyond the limited scope of the Euratom Framework Programme. Therefore, there is also a need for effective cooperation with areas falling under the EC Framework Programme. Radiation protection activities under the Euratom Framework Programme extend also to the issue of emergency management in the highly unlikely event of a severe accident at a nuclear facility, and the rehabilitation of any resulting contaminated territories.
Quantifying the risks of low doses
Research underpins radiation protection legislation. Ensuring these standards continue to represent an adequate level of protection for workers and the general public requires, in particular, investigation into the specific risks posed by low and protracted exposure to radiation. In this regard, a key objective of Euratom FP7 is to help resolve the controversy over the risk posed by such exposure.
Current legislation is based on the assumption that there is a linear relationship between dose and risk (i.e. the risk increases proportionally with the radiation dose, and the risk only drops to zero at zero dose), though there are other schools of thought, e.g. a 'threshold dose' exists below which there's no risk, or that there's a heightened sensitivity at low doses, or even that a small dose of radiation can 'immunise' people against the effects of radiation. Settling this debate could have profound implications for use of radiation in both medicine and industry. In addition, a person's response to a particular radiation exposure may depend on his or her genetic make-up, and understanding and managing these effects in the population as a whole are complex research and regulatory questions.
Recognising the need for a more strategic approach to research on effects of low doses of radiation, the High-Level Expert Group on European Low-Dose Risk Research (HLEG), set up with Euratom FP7 support, brought together six national bodies responsible for radiation protection research funding in a group of the principal EU Member States involved in these activities. One of the main outputs from the HLEG was to recommend the establishment of the 'Multidisciplinary European Low-Dose Initiative', or MELODI (see collaborative platforms), which was launched in 2009 and brings together leaders and experts from across the radiation protection research community to resolve the important open questions. Euratom FP7 will continue to support research in this field in line with the strategy developed within MELODI.
Radiation in medicine: protecting patients and workers
We are all continually exposed to naturally occurring sources of radiation (e.g. radon gas, cosmic rays, radionuclides in building materials and foodstuffs, and even natural sources in our own bodies). Collectively, these natural sources constitute the so-called background level of exposure. Apart from extreme cases of exposure to high levels of radon gas in certain situations, there is no epidemiological evidence that exposure to these background levels is harmful.
Nonetheless, it is known that radiation is a carcinogen, albeit a weak one, and unnecessary additional exposure above the background level should therefore be avoided. Where this is unavoidable, the practice must be justified and strictly controlled. There are two fundamental principles: (1) the benefits from the additional exposure must outweigh the risks, and (2) additional exposures must be kept as low as reasonably achievable (the ALARA principle).
The fastest growing source of exposure to ionising radiation is from man-made sources used in medical diagnosis and therapy. By comparison, the exposure to a typical member of the public resulting from the use of nuclear power is negligible.
Diagnostic tools that use ionising radiation include standard X-rays and more advanced computed tomography (CT) that provides high-quality images of isolated sections of the patient's body using a thin, rotating beam of X-rays. Dynamic 3-D imaging techniques are also being used more and more (e.g. positron-emission tomography, PET, and single photon emission tomography, SPECT), which allow tissue or organ functions to be viewed using a gamma camera that follows the movement of a radioactive 'tracer' injected into the body.
Ionising radiation is also used to treat certain types of cancer. High-energy X-rays, gamma rays or beta particles are targeted on tumours, with the goal of killing cancer cells. In brachytherapy, radiation sources are positioned on or introduced into the body so as to deliver localised doses to the tumour.
Euratom FP7 supports research on optimising doses of radiation used in such medical applications so that the best results can be obtained with the lowest possible exposure to patients. This is particularly relevant in light of the rapidly increasing use of these techniques in the developed world. Carefully controlling the doses and practices used in medical applications is also essential to protect those working with radioactive materials such as doctors and nurses.
Emergency response: a European effort
The Chernobyl accident in 1986 was a major turning point for the nuclear industry worldwide. Since then, nuclear safety has become a cross-border concern, and optimising the design and operation of monitoring systems a European, if not global, effort. Following the disaster, several monitoring systems were put in place, though these may now need replacing or upgrading.
National emergency centres in Europe use 'decision-support' systems that were developed with European funding. However, efforts are continuing to improve the coherence and integration of emergency management systems in Europe through the development of common tools and strategies and to demonstrate their effectiveness in operational environments. The upkeep of these systems is increasingly the responsibility of the end users, though Euratom FP7 can play an effective role in optimising methodologies, improving designs and generally maintaining technology at the state of the art.
The Euratom FP works closely with the Security Research Programme, part of the EC FP, in the area of security research linked to nuclear and radiological security risks, sharing expertise, experience and best practices to best handle cases of malevolent (criminal) exposure to radioactive material.
It is crucial that European nuclear scientists and engineers have access to facilities that will enable them to carry out their research. An important Euratom activity is therefore to facilitate access to (and the availability of) nuclear research infrastructures in Europe so that research can be conducted using the best techniques and equipment. Research infrastructures also have a crucial link with training, and many Euratom actions seek to combine these two important cross-cutting aspects. The Euratom programme can support refurbishment and even construction of new infrastructures, though the limited budget means that such support can only be relatively modest. Indeed, the high cost of such infrastructures often mean that they cannot be supported by one country alone, and cooperation amongst EU Member States, and even 3rd countries outside Europe, is essential. The EU research programme can facilitate such cooperation. Other Euratom FP actions promote and support trans-national access by research groups to existing facilities, thereby optimising the use of these infrastructures.
Human resources, mobility, and training
Close to half a million people are employed in Europe's high-tech nuclear fission sector. Harnessing the scientific competence and experience of seasoned nuclear engineers and scientists is important in all domains of nuclear fission and radiation protection. Indeed, capturing and passing on this know-how to a new generation of scientists and engineers is crucial if we are to maintain high levels of safety in the future. In Euratom FP7, 5% of the total budget of every large research project has to be earmarked for training and knowledge management activities, enabling younger scientists and engineers to benefit from the experience of older experts. Other Euratom FP7 projects, with more of a coordinating remit, are dedicated to establishing sustainable education and training networks in specific thematic fields. This promotes integration and coordination among educational systems across the EU and adds real value to existing national programmes by making the most of the region's expertise, talent and facilities. Such policies are essential if we are to attract and retain qualified researchers, engineers and technicians.
(Refer also to Young scientists)