Sökning: "transmutation"

Visar resultat 1 - 5 av 47 avhandlingar innehållade ordet transmutation.

1. 1. Studies of Accelerator-Driven Systems for Transmutation of Nuclear Waste

   Författare :Marcus Dahlfors; Ane Håkansson; Alfred Hogenbirk; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nuclear physics; transmutation; accelerator-driven systems; Energy Amplifier; subcritical reactors; nuclear waste; Monte Carlo simulation; burnup; actinides; fission products; benchmark; nuclear data; neutron cross sections; sensitivity analysis; neutron source; spallation target; n_TOF experiment; neutron time-of-flight; cross section measurement; FLUKA; EA-MC; MCNP; MCNP-X; EADF; TRADE; Kärnfysik; Nuclear physics; Kärnfysik;

   Sammanfattning : Accelerator-driven systems for transmutation of nuclear waste have been suggested as a means for dealing with spent fuel components that pose potential radiological hazard for long periods of time. While not entirely removing the need for underground waste repositories, this nuclear waste incineration technology provides a viable method for reducing both waste volumes and storage times. LÄS MER

3. 2. Transmutation of Americium in Fast Neutron Facilities

   Författare :Youpeng Zhang; Janne Wallenius; Sandra Dulla; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; americium; transmutation; fast reactor; Nuclear physics; Kärnfysik; TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : In this thesis, the feasibility to use a medium sized sodium cooled fast reactor fully loaded with MOX fuel for efficient transmutation of americium is investigated by simulating the safety performance of a BN600-type fast reactor loaded with different fractions of americium in the fuel, using the safety parameters obtained with the SERPENT Monte Carlo code. The focus is on americium mainly due to its long-term contribution to the radiotoxicity of spent nuclear fuel and its deterioration on core's safety parameters. LÄS MER

4. 3. Transmutation of Am in sodium fast reactors and accelerator driven systems

   Författare :Youpeng Zhang; Janne Wallenius; Gérald Rimpault; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sodium cooled fast reactor; accelerator driven system; americium; transmutation; transient analysis;

   Sammanfattning : In this thesis, the feasibility to use sodium cooled fast reactors loaded with MOX, metallic and nitride fuels for efficient transmutation of americium is investigated by performing transient analysis for cases with different americium contents in fuels, using safety parameters obtained with the SERPENT Monte Carlo code. It was then demonstrated that there is no solid limit for the Am introduction into oxide, metallic and nitride fuels that were loaded into sodium fast reactors. LÄS MER

5. 4. The Use of Aliquat-336 in a Partitioning and Transmutation Process and a Kinetic Study of the Oxidation of U(IV) to U(VI)

   Författare :Anders Landgren; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; partitioning; quaternary ammonium salts; transmutation; hydrolysis; Aliquat-336; liquid-liquid extraction; kinetics; oxidation; uranium IV ;

   Sammanfattning : Spent nuclear fuel contains several long-lived radionuclides that must be stored in a safe manner for a long time. Transmutation of these radionuclides into short-lived or stable nuclides reduces the necessary storage time by several orders of magnitude. The nuclides most suitable for transmutation are those of the actinides. LÄS MER

7. 5. Radiolytic Degradation of BTBP type Molecules for Treatment of Used Nuclear Fuel by Solvent Extraction

   Författare :Anna Fermvik; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; transmutation; lanthanides; degradation; solvent extraction; actinides; radiolysis; BTBP; partitioning;

   Sammanfattning : Nuclear fuel that has been discharged from nuclear reactors is highly radiotoxic and must be kept isolated from the biosphere for very long time periods. This requires an advanced final repository. One way to decrease the long-term radiotoxicity and thermal load of the used fuel is Partitioning and Transmutation (P&T). LÄS MER