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During the 5th Framework Program (FP5) the European Commission (EC) funded the PDS-XADS project (Preliminary Design Studies on an eXperimental Accelerator Driven System) mainly devoted to the demonstration of the feasibility of the coupling among an accelerator, a spallation target and a sub-critical core, and to preliminarily investigate the possibility of enhancing the transmutation rates for achieving values suitable for an Industrial Scale Transmuter.The on-going activities of the FP6 EUROTRANS integrated project (EUROpean research programme for TRANSmutation of high level nuclear waste in an accelerator driven system) are in continuity with the PDS-XADS project objectives, but with a significant change for what concerns the final goal in terms of demonstration level. In fact they are oriented to both the design of an industrial-scale transmuter (EFIT) and a small experiment facility (XT-ADS), serving as a test bench for as much component technologies as possible in a realistic irradiation environmentThe paper describes the main results of the design activities for the large and small LBE-cooled cores performed within PDS-XADS and discusses the constraints (e.g. those deriving from the spallation target and the accelerator), the requirements (such as the degree of subcriticality when operating at power as well as during refuelling), the design criteria and choices with the purpose to verify their applicability to new designs (EFIT, XT-ADS).

This document is a General Synthesis Report of the Different ADS Design Status being designed within the EUROTRANS Integrated Project; an FP6 European commission partially funded programme. This project had the goal to demonstrate the possibility of nuclear waste transmutation/burning in Accelerator Driven Systems (ADS) at industrial scale.The focus is on a Pb-cooled ADS for the European Facility on Industrial scale Transmuter (ETD/EFIT) with a back-up solution based on an He cooled ADS.As an intermediate step towards this industrial-scale prototype, an eXperimental Transmuter based on ADS concept (ETD/XT-ADS) able to demonstrate both the feasibility of the ADS concept and to accumulate experience when using dedicated fuel sub-assemblies or dedicated pins within a MOX fuel core has been also studied.The two machines (XT-ADS and Pb cooled EFIT) have been designed in a consistent way bringing more credibility to the potential licensing of these plants and with sufficient details to allow definition of the critical issues as regards design, safety and associated technological and basic R&D needs. The different designs fit rather well with the technical objectives fixed at the beginning of the project in consistency with the European Roadmap on ADS development.For what concerns the accelerator, the superconducting LINAC has been clearly assessed as the most suitable concept for the three reactors in particular with respect to the stringent requirements on reliability. Associated R&D needs have been identified and will be focused on critical components (injector, cryomodule) long term testing.The design of the different ADS has been performed in view of what is reasonably achievable pending the completion of R&D programmes. The way the EUROTRANS Integrated Project has been organised with other domains than the DM1 Design being specifically devoted to R&D tasks in support to the overall ETD/EFIT and ETD/XT-ADS design tasks has been helpful. The other domains were centred on the assessment of reactivity measurement techniques (DM2 ECATS), on the development of U-free dedicated fuels (DM3 AFTRA), on materials behaviour and heavy liquid metal technology (DM4 DEMETRA) and on nuclear data assessment (DM5 NUDATRA). Pending questions associated to technology gaps have been identified through the different appropriate R&D work programmes and a Catalogue of the R&D needs has been established.Finally, the work within the EUROTRANS integrated project has provided an overall assessment of the feasibility at a reasonable cost for an ADS based transmutation so that a decision can be taken to launch a detailed design and construction of the intermediate step Experimental ADS now already launched within the 7th FP programme under the name of Common Design Team (CDT).

International audience

The DEMETRA domain of the EUROTRANS project provides a wealth of experimental and theoretical results within key technological areas related to the Heavy Liquid Metal (HLM) Technology. HLMs as Pb and Lead-Bismuth Eutectic (LBE) are the reference coolant and spallation materials choices for the ADS facilities studied within the EUROTRANS project. For these coolants the key items that have been addressed within DEMETRA are: Coolant quality control in terms of oxygen and impurities control; Materials compatibility in terms of corrosion, mechanical and irradiation resistance; Thermal-hydraulics studies related to heat transfer in turbulent conditions through dedicated experiments on a single pin, a fuel bundle and integrated component tests; Safety related studies through experimental and simulation studies on HLM/water interaction; Support to component design and testing, where in particular substantial support has been given to the development of the windowless-neutron spallation target and the assessment of the window spallation target behaviour through the post test analysis of MEGAPIE; Measurement and operational techniques development; The technical work programme of DEMETRA is herein summarised and some major experimental results are discussed.

International audience; The experimental accelerator-driven system XT-ADS is being developed within the framework of the European FP6 project EUROTRANS. The device will serve a twofold purpose. Firstly it will act as an ADS concept demonstrator and secondly it will serve as a flexible fast neutron spectrum experimental irradiation tool for materials, fuel materials and radioactive isotopes studies. Because of a functional similarity between the XT-ADS and the MYRRHA concept that was developed earlier at SCK-CEN in Mol, Belgium, the design file of the latter was chosen as a starting point for the development of the XT-ADS.

International audience; The domain DM1_DESIGN of the FP6 integrated project EUROTRANS has the mission to launch the conceptual design of a lead-alloy-cooled European Facility for Industrial Transmutation (EFIT) loaded with transmutation-dedicated minor actinide fuel to “prove” transmutation at the industrial level. EFIT would represent a modular unit of a large power system able to handle European high-level waste. In parallel to the EFIT design, DM1_DESIGN partners are developing a detailed design of the short-term XT-ADS (eXperimental demonstration of Transmutation in an Accelerator Driven System) that would serve the full-scale demonstration of the ADS concept and be able to accept up to a full MA fuel assembly. XT-ADS is also intended to serve as a test banc for some components of EFIT. The Work Plan of the domain DM1_DESIGN addresses the following main issues of EFIT and XT-ADS: Definition of the design parameters for the optimisation of the transmutation objectives in an economical way for EFIT and the short-term realisation for XT-ADS including the most essential features of EFIT. Development and assessment of the reference Pb design of EFIT and the back-up option based on gas. In parallel and in a synergetic way XT-ADS with only Pb-Bi reference design is developed in a more detailed manner. Further development of the high-power proton accelerator (HPPA) needed for both EFIT and XT-ADS and, in particular, qualification of the beam reliability, the development of the beam transport line and the demonstration of the prototypical components of the chosen HPPA. Proof of feasibility windowless spallation targets making maximum use of the existing work for defining the needed complementary experimental work for XT-ADS spallation targets. Evaluation of the safety performance and licensability of the three designs developed in the DOMAIN DM1. Cost estimates and planning issues for the deployment of the transmutation facilities. In this paper we give the progress accomplished in these different work packages and present the first results obtained after 18 months of activity.

International audience; The XT-ADS is an experimental accelerator-driven system (ADS) that is being developed within the framework of the European FP6 EUROTRANS project that runs from 2005 to 2009. In this paper the current level of the design of the XT-ADS spallation target and the status of corresponding R&D topics with respect to LBE handling, thermal-hydraulics and spallation product confinement are discussed.