Inhibition of radiation induced dissolution of UO 2 by sulfide ― A comparison with the hydrogen effect [1] Miao Yang, Alexandre Barreiro Fidalgo, Sara Sundin, Mats Jonsson Division of Applied Physical Chemistry, KTH September 6, 2013 Roskilde, Denmark [1] M. Yang, A. B. Fidalgo, S. Sundin, M. Jonsson, J. Nucl. Mater., 434 (2013) 38-42
18
Embed
Inhibition of radiation induced dissolution of UO2 by … of radiation induced dissolution of UO 2 by sulfide ― A comparison with the hydrogen effect [1] Miao Yang, Alexandre Barreiro
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Inhibition of radiation induced dissolution of UO2 by sulfide ― A comparison with the hydrogen effect [1]
Miao Yang, Alexandre Barreiro Fidalgo, Sara Sundin, Mats Jonsson
Division of Applied Physical Chemistry, KTH
September 6, 2013 Roskilde, Denmark
[1] M. Yang, A. B. Fidalgo, S. Sundin, M. Jonsson, J. Nucl. Mater., 434 (2013) 38-42
Outline
Introduction Experimentals Results and discussion Conclusions Acknowledgement
2
Long term safety for Spent Nuclear Fuel Introduction
3
Spent Nuclear Fuel Final Disposal - Deep Geological Repository
Introduction
4
Radiolytical oxidation and its inhibition of UO2
Kinetic of Radiolytical oxdiation of UO2 Inhibition of radiolytical oxidation of UO2
U(IV)
H2O2
2OH-
x HCO3-
UO2(CO3)X(2-2X)(aq)+x H+
H2
2H+
ε
Scheme Processes causing oxidative dissolution of UO2 & Noble metal particle catalyzed H2-inhibition [2]
U(VI)
Introduction
[2] M. Trummer, O. Roth, M. Jonsson, J. Nucl. Mater., 383 (2009) 226-230 5
Motivation
H2S
Reduce H2O2?
Reduce U(VI)?
Poison Pd catalyst?
6
Introduction
Sulfide sources
Bacterial sulfate reduction, BSR, Major source
Thermochemical sulfate reduction, TSR, required 100-140 °C
Dissolution of sulfide minerals, e.g. Pyrite, low solubility in deep repository
Introduction
[3] T. E-L Tullborg, C. J Smellie, G. A-Ch Nilsson, SR-Site sulphide content in the groundwater at Forsmark, TR-10-39 (2010) 45
[3]
7
Infuluence factors
pH and [CO32-] [S2-]
[U(VI)]0=168.3μm, [S2-] T=2.0 mM [U(VI)]0=168.3μm, [CO32-] T=4.0 mM
UO22++HS-↔UO2+S0+H+ [4]
[4] B. Hua, H.F. Xu, J. Terry, B.L. Deng, Environ. Sci. Technol., 40 (2006) 4666-4671
Introduction
8
Pd catalyst poisoning effect
Catalyst
poisoning by
sulfide [5-8]
Competitive adsorption of H2S/HS- with the reactants e.g. UO2
2+ + H2→ UO2 + 2H+
H2S/HS- VS. H2
Modification of the electronic properties of the palladium