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Subcritical reactor Wider choice for reactor fuel ( 238 U, 232 Th) Transmutation of nuclear waste Increased safety Accelerator Protons or light ions of energy around 1 GeV Very high powers (tens, hundreds of MeW) Stability of the beam Spallation reaction
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Mitja Majerle for the Energy Plus Transmutation collaboration Subcritical reactor Wider choice for reactor fuel ( 238 U, 232 Th) Transmutation of nuclear waste Increased safety Accelerator Protons or light ions of energy around 1 GeV Very high powers (tens, hundreds of MeW) Stability of the beam Spallation reaction C.Rubbia at CERN (protons on lead block) MUSE Cadarache (reactor k eff =0.95 with (d,t) source) TRADE Casaccia (reactor coupled with cyclotron) MEGAPIE at PSI (target research) Until today: cross-section measurements on 660 MeV protons Lead+parafine (GAMMA-2) Lead target (PHASOTRON) Energy Plus Transmutation Lead in graphite block (GAMMA-MD) Future: Subcritical Assembly Dubna (SAD) Lead target MeV protons Activation detectors (Au, Al, Bi) 129 I samples Focus spatial distribution of fast neutrons Lead target + nat U blanket Protons (0.7-2 GeV), deuterons ( GeV) Activation detectors (Al, Au, Bi, Cu, In, Ta, Y) Solid state nuclear track detectors ( 235 U, 238 U, nat Pb) Fast neutrons in uranium Lead target + graphite moderator Deuterons 1.6 GeV Activation detectors (Al, Au, Bi, Cu, In, Ta, Y) Solid state nuclear track detectors ( 235 U, 238 U, nat Pb) Fast neutrons in graphite Monoisotopic materials (Au, Al, Bi, In, Ta, Y, ) Activation during the irradiation (n,xn), (n, ), (n, ) reactions, but also (p,pxn),.. Activity measurement after the irradiation Activity number of produced isotopes n (n,xn), (n, ), HPGe detector Irradiator material (Pb, 235 U, 238 U) + plastic, mica (n,f) reactions - fission fragments leave tracks in plastic Chemical etching Track counting with microscope Tracks number of fissions n n,fission tracks chemical etching MCNPX, FLUKA -> spectral fluence Spallation Transport of particles Spectral fluence folded with cross-sections = number of produced isotopes or fissions -> experimental values Experiment / calculations inside 30%: Cross-sections or Monte-Carlo codes ? by A. Potapenko Phasotron experiment at 660 MeV : measurement/FLUKA calculation. Detectors are placed on top of the target along its length. Energy plus transmutation at 1.5 GeV: Measurement / MCNPX calculation. Detectors are placed in radial direction In the first gap. (n,xn) reaction in energy range MeV Materials in detectors: Al, Au, Bi, Cu, In, Ta, Y Other : 127 I, 129 I Higher x reactions n,3n-n,10n few measurements (n,f) reactions in energy range MeV Materials : Pb, 235 U, 238 U Other heavy materials : Au, W, Bi, Th For materials other than U few measurements Monte-Carlo predictions of XADS within 30% with the experiment better accuracy needed for real ADS Mostly (n,xn) and (n,f) cross-sections in energy range MeV are needed Cross-sections that we need can be used also for monitoring neutron fluxes at other experiments, in reactors... Currently we work on some measurements inside EFNUDAT (Ondrej Svoboda talk)