Materials for fusion & fission power

It has been predicted that by 2012 the UK's electricity generating capacity will no longer be enough to meet demand. Reliable new sources of multi-gigawatt electrical power will be vital for social stability and economic strength. Nuclear fusion and advanced fission power plants have been proposed, with possible years for operation in the range 2025 (advanced fission) to 2050 (fusion). These have the potential for large-scale, clean, CO2-free power generation for generations. However, they will not be viable unless some very difficult materials science problems are solved. The structural materials from which the power plants' core components will be built must have high strength and toughness at high temperatures, and retain good properties for decades despite being subjected to radiation damage from high-energy neutrons. The neutrons knock atoms from their positions, scrambling the materials' carefully-designed microstructures, and produce many small crystal defects which make the materials more brittle. The neutrons, unlike those in current nuclear power plants, have enough energy to cause transmutation reactions: this causes two problems. First, many elements ordinarily used in strong alloys cannot be used, because their transmutation products are highly radioactive for thousands of years, so we must design new strong alloys using a very restricted range of elements. Second, helium is produced in most reactions, and adds to the embrittling effects of the radiation damage.There are no fast-neutron facilities, and even slow-neutron test reactors are very expensive to use and take years for a single run . To develop the critical new materials quickly, we need to act now. We can use computer modelling of how the radiation-induced defects are formed, how they behave and how they interact to change material properties. Experimentally, ion irradiation can be used to produce the same damage types as from fast neutrons, in a few hours and without producing hard-to-handle radioactive specimens; but the amount of material affected is tiny - a layer 1/1000 mm thick. We have developed new techniques to test specimens made in these thin layers, and can use advanced microscopy to look at the radiation damage. This project will develop modelling and experiment further, and use them together so that experiments provide information to models and test their predictions. Researchers at Oxford, Liverpool and Salford Universities, UKAEA Fusion and the CEA will work together in a large project to form specialist small research teams developing innovative modelling and experimental methods, working on a problems critical to the applications of new alloys of steel and tungsten: how radiation damage can concentrate some elements at grain boundaries, making them brittle; how radiation effects on nanometre-sized oxide particles included in the alloys for high-temperature strength and to soak up helium and hydrogen.The project will make major advances in innovative experimental and modelling techniques operating at the microstructural scale where materials properties are determined, and it will verify the models' predictions against experimental data. Its success will significantly speed development of the new materials that are essential for the commercial realisation of fusion and new-generation fission power. It will help the UK to lead scientific developments in new materials and to train future experts for future fission and fusion programmes. The developments are also relevant to other important structural integrity issues (e.g. embrittlement, ductile-brittle transitions, stress corrosion cracking, and alloy strength). The project's leaders currently head world-leading research efforts in the areas which will form this integrated project. They are well-linked into the international fusion and UK fission communities, representatives of which will advise on the programme's direction and will speedily implement its results.

Looking ahead 20-30 years, this project addresses issues that will be show-stoppers for the exploitation of power sources that are two of the very limited options available to the post-oil world; everyone and their descendants are thus potential beneficiaries. This project alone cannot, of course, solve these national and global problems, but it will make a substantial contribution. It will also train new experts, maintain the UK's position in worldwide fusion materials research and will link the present rather separate fusion and fission materials research communities. The lead researchers and the steering committee members are all embedded in a wide range of other research projects, collaborations and committees. At the policy-influencing and forming level, Smith (Royal Society, DBERR, IOM3), Dudarev (EFDA), English (NNL) are highly active, and our collaborations with UKAEA, CEA and RR closely involve policy-level staff. In Oxford, the project will engage with the James Martin 21st Century Institute and the Smith School of Enterprise & the Environment, which have growing external visibility and influence. UK industry will gain from the project. To the companies and institutions collaborating in the project, the longer-term benefits are simple: unless the materials issues are solved, future reactors in which these bodies have a large stake either simply will not work, or will not work for long enough to be commercially viable. For current and next-generation fission plant, the project will tackle lifetime-determining radiation-induced materials degradation. If near-term exploitable results are identified of commercial value to one or more partners or external bodies, exploitation arrangements will be made, most probably, via Oxford's technology transfer subsidiary ISIS innovation. The further development in this project of the Micro-materials nanoindenter system will help raise this UK company's profile world-wide, and open up new markets for the company. Our collaborators, UKAEA, Culham, the CEA, Rolls Royce and Corus are representative of a wider range of companies and research institutes in the fission, fusion and materials production areas, all of whom will benefit from improved knowledge of radiation effects on advanced nuclear materials and in the development of the novel materials to be studied in this programme. The lead researchers' and our collaborators' wide connections, and the workshop series we will organise, will allow us to identify possible future partners and users and to identify new potential exploitation and application routes. The project website will keep the general public and potential users of our work up to date with developments and will give clear routes for communicating with us, whether for speakers for school or science club meetings or for discussions with interested researchers or companies. The training aspects of the programme and its role in developing research careers are important. One of its significant outputs for the UK will be scientists trained in nuclear materials. Our collaborators will also benefit by participating in the training of potential future employees. This flagship project will attract new blood into nuclear materials science, and transfer knowledge, skills and experience from a rapidly-aging researcher-base into the next generation.