One of the biggest challenges for European research reactors is securing their nuclear fuel supply to ensure a sustainment of medical isotopes for Europe and the world. This is particularly true for the few operating High Performance Research Reactors (HPRRs) in Europe, which produce the vast majority of medical isotopes. The obligation to convert them from high to low enriched uranium (LEU) nuclear fuels while keeping similar radioisotopes production ratios makes it necessary to develop higher uranium density fuels. The R&D related to that topic was started in previous EURATOM projects (HERACLES-CP and LEU-FOREvER). The main goal of the EU-QUALIFY project is to qualify such fuels and qualify the capability to fabricate such fuels. This will be done by a multi-disciplinary consortium composed of fuel designers/manufactures, reactor operators, research organizations and a university, namely: SCK CEN, CEA, CERCA, ILL, TUM, and G-INP. The EU-QUALIFY project will build on previous LEU fuel development work with specific focus on the qualification of three particular types of fuels: the dispersed U-Mo, the monolithic U-Mo and the high-loaded dispersed U3Si2 fuels. This qualification will be accomplished through fabrication and concurrent qualification of pilot manufacturing equipment and processes, irradiation under representative irradiation conditions, post-irradiation examinations, as well as modelling of the in-pile behavior to support LEU conversion safety analyses. This project will contribute to ensuring the availability of HPPR’s, and thus enhance the security of the EU’s capacity in the production of medical radioisotopes. It will thus contribute to health care through provision of innovative medical radioisotopes necessary for diagnostic and therapy and will support European industry by maintaining access to research reactor irradiation capabilities.

In the framework of the joint international efforts to reduce the risk of proliferation by minimising the use of highly enriched uranium, a new research reactor fuel based on uranium-molybdenum (UMo) alloys is being developed by the HERACLES group. HERACLES is composed of AREVA-CERVA, CEA, ILL, SCK•CEN and TUM, all organisations with a long-standing history in fuel manufacturing and qualification. HERACLES works towards the qualification of UMo fuels, based on a series of “comprehension” experiments and manufacturing developments. There are two types of UMo fuel fine particles dispersed in an Al matrix, and monolithic foils. The qualification phase of these fuels is scheduled to begin in 2019; the project will prepare the way with an initial comprehension phase, to improve our understanding of the fuels’ irradiation behaviour and consequent the manufacturing/industrialisation process. One of the key components in the project is the SEMPER FIDELIS irradiation test, which aims at investigating the fuel swelling phenomenon and the effects of coating, with a view to arriving at procedures for fuel engineering. The challenges as regards manufacture lie in the basic elements of both fuel types’ production process and plate manufacturing. For the dispersed fuel, this includes the pin casting for the rotating electrode process and the atomization process itself. For the monolithic fuel, this concerns the development of coating for the foils. All these components are essential to prepare the fuel qualification phase. High-performance research reactors are at the start of the supply chain for medical isotopes like 99Mo. Successful conversion to lower enriched and where possible LEU fuel is therefore a key element in the mitigation of the risks surrounding the supply of isotopes as demanded by NFRP 8. However, the role of the HPRRs is far broader, as they are providing scientific and engineering solutions to questions of high societal importance.

VVER reactors constitute a significant and dynamic part of the European energy market. The safe LTO of VVER (maintenance, refuelling, safety-upgrade, revamping) is based on the industrial use of neutronics and thermal-hydraulics codes and methods that allow studying the behaviour of the plant in normal and accidental conditions. The objective of CAMIVVER project is to develop and improve codes and methods for VVER comprehensive safety assessment. Such development is strongly required for the following reasons: 1) Current codes and methods used for VVER safety assessment are subjected to international export controls from outside EU. Export controls from major countries have increase in the last years, threatening the EU sovereignty and security in terms of energy supply. 2) A new generation of innovative codes and methods are being developed within Europe. These new codes and methods are improving 3D-multiphysics modelling capabilities, and uncertainty quantification capabilities. These codes and methods are worth being transferred from lab to industry as they will substantially improve the physics comprehension of PWR and VVER behaviour. 3) European codes and methods development for VVER safety assessment will open the VVER market to the European nuclear industry and will support a free and fair competition on this market. To achieve this objective, CAMIVVER will perform developments required for the new generation codes to be fully applied on VVER scope (and to PWR scope too), CAMIVVER will generalise 3D-multiphysics coupling, CAMIVVER will perform experimental validation and benchmark against current industrial codes used for VVER safety assessment, and CAMIVVER will demonstrate CFD utility and compatibility with uncertainty propagation in the frame of a safety assessment. Finally, CAMIVVER will provide guidance to European Safety Authorities, to VVER operators, and to the international research community, concerning the use of these innovative approaches of codes and methods development.

Europe is the world’s largest supplier and among the world’s largest users of medical radioisotopes. A secure supply of these isotopes is key to support a safe, high quality and reliable use of radiological and nuclear technology in healthcare. As most medical radioisotopes are produced by the European HPRRs (high-power research reactors) and MPRRs (medium-power research reactors), these reactors play a major role for the time-critical supply chain of these radioisotopes, but also for fundamental and applied research using neutrons. The proposed project EU-CONVERSION will contribute to securing these supply chains via the supply of safe low-enriched uranium fuels for the HEU to LEU conversion and long-term operation of the European research reactors. To facilitate their deployment, the project will generate the necessary trust at the nuclear regulators and technical support organizations for the challenges of the upcoming conversions, including the use of digital technologies and advanced computational methods in nuclear safety. In a long term, the knowledge and innovations created within this project will also contribute to the European strategic goals to maintain a world-leading innovative nuclear industry, and to increase the competencies in nuclear technology. To achieve these objectives, the proposed actions within EU-CONVERSION include the consolidation of generic fuel qualification data together with two reactor-representative irradiation tests for HPRR conversions, the demonstration of sustainable and efficient European supply chains for advanced LEU research reactor fuels for HPRRs and MPRRs, as well as the establishment of modern computational methods for nuclear safety analysis and fuel performance modeling.

Securing the nuclear fuel supply for European research reactors is the overall objective of the LEU-FOREvER project. Our analysis points out two main risks of shortage: (i) the very challenging conversion of High Performance Research Reactors (HPRRs) from High to Low Enriched Uranium fuels (LEU), (ii) the ROSATOM monopoly to fuel medium power research reactors (MPRRs) with original Soviet design. On HPRRs, a multi-disciplinary consortium composed of fuel/core designers, operators and fuel manufacturer has been built to tackle both issues. Five European organisations (AREVA NP, CEA, ILL, SCK•CEN, TUM), which compose the HERACLES group, have been strongly involved for almost 20 years now in the development of LEU fuels. To enter the qualification phase in 2021, HERACLES is pushing towards the completion of an understanding phase. The baseline lies on the development of UMo fuels and their variants. Within LEU-FOREvER, optimisation of both manufacturing process (up to the design of pilot equipment) and modelling of the in-pile behaviour of these fuels are proposed. As a result of an independent review undergone in 2015, an alternative to UMo fuels has to be considered: this will be high-loaded U3Si2. Within LEU-FOREvER, it will be optimised to prepare an ambitious in-pile test (“High PROSIT”). For European MPRRs, the ultimate goal is to design a new core which could work with both the original ROSATOM and European elements that would be developed, licensed and qualified (“4EVERTEST”) within LEU-FOREvER. The Czech LVR-15 reactor (CV Rez) has been selected as a case study, and preliminary design by AREVA-TA is based on U3Si2/Al flat fuel plates. To improve economic competitiveness, AREVA NP will reinvestigate its manufacturing process and propose optimisations. Strong synergies are expected between both activities. The modernization of research reactors appears as a key element in the mitigation of the risks surrounding the supply of isotopes, as expressed in the NFRP-11 topic.