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Lessons learned from leaching of dry milled high burnup UO2 fuel under H2 atmosphere

Published online by Cambridge University Press:  20 February 2017

Anders Puranen ,
Michael Granfors ,
Ella Ekeroth  and
Kastriot Spahiu
Anders Puranen*
Affiliation:
Hot Cell Laboratory, Studsvik Nuclear AB, Nyköping, Sweden.
Michael Granfors
Affiliation:
Hot Cell Laboratory, Studsvik Nuclear AB, Nyköping, Sweden.
Ella Ekeroth
Affiliation:
Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden.
Kastriot Spahiu
Affiliation:
Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden.
*
*(Email: anders.puranen@studsvik.se)
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Abstract

A trend in the operation of nuclear power reactors is the increase in discharge burnup of the fuel. Intrusion of groundwater in a failed canister of a future deep repository is expected to occur in the presence of hydrogen, produced by the anoxic corrosion of iron and by radiolysis of water. Compelling evidence now exists that hydrogen inhibits oxidative dissolution of irradiated nuclear fuel or alpha doped UO2, however the number of studies involving high burnup fuel are limited. In the experiment PWR UO2 fuel with a burnup of ∼75 MWd/kgU was leached in simulated groundwater (10 mM NaCl, 2 mM NaHCO3) at room temperature under 5 MPa of hydrogen. Since the main objective was to investigate the fuel matrix dissolution, a fuel fraction that had previously been leached for over one year was reused. The U-238 and Tc-99 concentration was found to vary in the samples taken over 1100 days of leaching, depending on the degree of centrifugation. The erratic behavior of this autoclave experiment is tentatively attributed to a high surface area, with sub-micrometer sized fuel particles adhering to larger fuel fragments (evidenced by electron microscopy), caused by the fuel milling at the start of the experiment. This likely promoted an increased amount of pre-oxidation of the fuel as well as the potential for reductive precipitation and subsequent release of colloids from the autoclave. As a comparison, initial results from an ongoing autoclave experiment with coarser fuel fragments are also given.

Keywords

Corrosionwaste managementnuclear materials
Type
Articles
Information
MRS Advances , Volume 1 , Issue 62: Scientific Basis for Nuclear Waste Management XXXIX , 2016 , pp. 4169 - 4175
Copyright
Copyright © Materials Research Society 2017 

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References

Forsyth, R. S. and Werme, L. O., J. Nucl. Mater. 190 2–19 (1992).Google Scholar
Shoesmith, D. W., J. Nucl. Materials, 282, 1–31 (2000).Google Scholar
Ekeroth, E., Low, J., Zwicky, H-U, Spahiu, K., MRS Symp. Proc. 1124, 123–128 (2009)Google Scholar
Rollin, S., Spahiu, K. and Eklund, U-B. J. Nucl. Materials 297, 231–243 (2001)Google Scholar
Spahiu, K., Werme, L. and Eklund, U-B., Radiochim. Acta 88 507–511 (2000)CrossRefGoogle Scholar
Spahiu, K., Cui, D., and Lundström, M., Radiochim. Acta 92, 625–629 (2004).Google Scholar
Loida, A., Metz, V., Kienzler, B., and Geckeis, H., J. Nucl. Mat. 346 24–31 (2005)Google Scholar
Fors, P., Carbol, P., Van Winkel, S. and Spahiu, K., J. Nucl. Mater. 394, 1–8 (2009).Google Scholar
Guillamont, R. et al., Update on the chemical thermodynamics of U, Np, Pu, Am and Tc, OECD NEA, Elsevier 2003.Google Scholar
Johnson, L. et al. J. Nucl. Materials 420 54–62 (2012)Google Scholar
Zwicky, H-U, Low, J., Ekeroth, E., SKB Technical Report TR-11-03 (2011)Google Scholar
Roth, O. et al. Final Workshop Proceedings 7th EC FP FIRST-Nuclides 173–180 (2014)Google Scholar