MEGAPIE target: a relevant demonstration for ADS

International audiencePartitioning and Transmutation (P&T) techniques could contribute to reduce the radioactive inventory and itsassociated radio-toxicity. Sub-critical Accelerator Driven Systems (ADS) are potential candidates as dedicatedtransmutation systems, and thus their development and more particularly the spallation target, is a relevant R&Dtopic. Thus, the MEGAwatt PIlot Experiment (MEGAPIE) (1 MW) was initiated in 1999 in order to design andbuild a liquid lead-bismuth spallation target, then to operate it into the Swiss spallation neutron facility SINQ atPaul Scherrer Institute (PSI). Many studies, carried out by the project partners addressed specific critical issuesin the fields of neutronics, materials, thermal hydraulics, mass and heat transfer, structure mechanics and liquidmetal technology, using analytical, numerical and experimental approaches. Moreover, it was necessary toperform safety and reliability assessments in order to demonstrate the integrity and operability of the target; andthus to develop the licensing process. The target has been built in France then shipped to Switzerland : in orderto demonstrate the target characteristics and safe operability prior to irradiation foreseen in 2006, the target hasbeen installed in PSI Test facility, fitted with all the ancillary systems, then tested off-beam. The alreadyperformed steps, conceptual and engineering design, manufacturing and assembly, safety and reliabilityassessment, integral tests have brought to ADS Community a unique relevant design and out-off beamoperational feedback. The target is now installed in the SINQ facility, ready to be irradiated. The following steps: Irradiation, decommissioning, post irradiation experiments and waste management will complete the feedbackfrom this unique experiment