1. 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

2. 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)

3. 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)

4. Accelerator driven systems

5. 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

6. QUINTA experiment

7. HPGe γ - spectrometer Ortec

8. 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

9. 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

10. 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

11. Detected nuclei count Nuclei count: 232Th-11: 3,52*1020
233Pa-11: 7,72*108
233Pa-12: 4,46*108

12. 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

13. Thank you for your attention