The transmutation of the Minor Actinides (Am, Np and Cm) separated from the spent nuclear fuel as unloaded from nuclear power plants is studied in the European Union with an aim to ease the disposal strategy of the nuclear waste. A way to transmute such radioactive elements is to use Accelerator Driven Sub-critical systems (ADS). These systems require a neutron spallation target (heavy liquid-metals such as lead or lead-bismuth eutectic) located in a sub-critical core. The neutrons in the spallation target are produced via spallation reactions by impinging a high energy proton beam on such a heavy liquid-metal target. Generally, a 1 - 2 MW neutron spallation target would be required for a sub-critical system having a sub-criticality factor (k(eff)) between 0.95 and 0.98 and a core power between 50 - 100 MW(th). In order to get a high energy intense neutron source, use of heavy liquid metals mentioned above as spallation material has been envisaged. But, this type of heavy liquid metal systems to be irradiated in a proton field have never been built, even though in the past several conceptual studies have been carried out. Therefore, an initiative was launched in 1999 to build and safely operate the MEGAPIE (MEGAwatt Pilot Experiment) Pb-Bi eutectic (LBE) spallation target with a continuous proton beam supplied by SINQ at PSI, Villigen (CH). The SINQ facility is a cascade of three accelerators (a Cockroft-Walton column as pre-accelerator and two cyclotrons) that deliver a proton beam of about 590 MeV and a current up to 1.8 mA with a total proton beam power ranging between 0.7-1 MW.
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Record Number: 9009 / Last updated on: 2008-04-03