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Transmutation of spent nuclear fuel. Jaroslav Šoltés 1 Jiří Skalička 2 1 – Czech Technical University, Prague 2 – Brno University of Technology 3 – Joint Institute of Nuclear Research, Dubna. Supervisor: Lukáš Závorka 3. Main goals of transmutation.
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Transmutation of spent nuclear fuel Jaroslav Šoltés1 Jiří Skalička2 1 – Czech Technical University, Prague 2 – Brno University of Technology 3 – Joint Institute of Nuclear Research, Dubna Supervisor: Lukáš Závorka3
Main goals of transmutation • Burnup of minor actinides in spent nuclear fuel to reduce its radioactivity (Am, Cm) • Converting fertile isotopes to fissile isotopes (232Th, 238U)
Accelarator driven systems • High energy and intensive neutron source is needed • They cannot be obtained via standard thermal or fast fission in a reactor • Spallation reactions are required which can be achieved only by using an accelerator driven system (ADS)
Neutron reactions in the ADS core • Fission of heavy nuclei (Am, Cm, U, Th, Pu) • Neutron capture on Th, U and fissile isotopes creation • (n,xn) on Th creating additional neutrons
Measurements carried out • Time of irradiation: 16 h • Number of measurements: 8 • Measured 2 h, 3 h, 11 h, 28 h, 36 h, 50 h, 45 d and 105 d after irradiation
Samples evaluation • Identification of dominant gamma peaks in spectra • Energy calibration • Non-linearity correction • Background correction • Single escape and double escape peak correction • Effectivity calibration correction • Isotopes identification
Identified isotopes • Fission products: 85mKr, 85mSr, 85mY, 87Kr, 88Kr, 88Rb, 90mY, 91Sr, 92Sr, 92Y, 93Y, 95Nb, 95mTc, 96Nb, 97Zr, 99Mo, 103Ru, 105Ru, 105Rh, 123I, 127Cs, 127Sb, 128Sb, 131Ba, 131I, 132Cs, 132I, 132Te, 133I, 134I, 135I, 135Xe, 138Cs, 139Ba, 139Ce, 140Ba, 140La, 141Ce, 142La, 143Ce • Decay products of (n,xn) reactions isotopes: 210Po, 210mBi, 213Bi, 214Pb, 219Rn, 223Ra, 224Ac, 226Ac, 226Ra, 227Ac, 230Th • Activation product of 232Th: 233Pa
Detected nuclei count Nuclei count: 232Th-11: 3,52*1020 232Th-12: 3,64*1020 233Pa-11: 7,72*108 233Pa-12: 4,46*108
Conclusion • Detected fission products indicate fast neutron fission of the target 232Th • Detected isotopes of 233Pa which beta-decays into 233U show effective fissile fuel breeding possibilities ADS • (n,xn) reactions are important additional source to neutron balance • 232Th is therefore ideal candidate for the ADS breeding zone
Thank you for your attention soltes.jaro@gmail.com jiri.skalicka@gmail.com