Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-23T05:18:13.241Z Has data issue: false hasContentIssue false

The Effect of Bromide on Oxygen Yields in Homogeneous α-radiolysis

Published online by Cambridge University Press:  16 January 2017

Lovisa Bauhn*
Affiliation:
Nuclear Chemistry, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
Christian Ekberg
Affiliation:
Nuclear Chemistry, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
Patrik Fors
Affiliation:
Vattenfall AB, SE-401 27 Gothenburg, Sweden
Kastriot Spahiu
Affiliation:
Swedish Nuclear Fuel and Waste Management Co., SE-101 24 Stockholm, Sweden
*
Get access

Abstract

In a scenario where ground water enters a canister for spent nuclear fuel in a deep geological repository, the presence of dissolved ions in the water could possibly influence the fuel dissolution due to effects on radiolysis yields. One species of particular interest in this context is bromide, which has a proven ability to scavenge hydroxyl radicals much faster than molecular hydrogen does. As a result, bromide could inhibit the beneficial effect of dissolved hydrogen, which has been shown in γ-radiolysis experiments. However, already a few hundred years after repository closure, α-decay starts to dominate in the radiation field from the spent fuel. Hence, the effects of α-radiolysis are expected to govern the fuel dissolution over the geological timeframes of the repository. In the present work, α-radiolysis experiments have been performed to determine the effect of bromide ions on the yield of hydrogen peroxide by mass spectrometric measurement of its decomposition product oxygen. The use of high activity 238Pu solutions has made it possible to study this effect during pure α-radiolysis from a homogeneously distributed radiation field. To simulate deep bedrock repository conditions, and to minimize the influence of in-leaking O2 from air, the studies were performed using graphite sealed stainless steel autoclaves with an initial atmosphere of 10 bar H2. The results show that addition of 1 mM Br- to the solution gives no significant effect on the O2 yield for radiation doses up to 2 MGy. This lack of effect is most likely explained by the limited radical escape yields from radiation tracks in pure α-radiolysis.

Type
Articles
Copyright
Copyright © Materials Research Society 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Shoesmith, D. W., J. Nucl. Mater. 282, 1 (2000).Google Scholar
Ekeroth, E., Roth, O. and Jonsson, M., J. Nucl. Mater. 355, 38 (2006).Google Scholar
Lousada, C. M., Trummer, M. and Jonsson, M., J. Nucl. Mater. 434, 434 (2013).CrossRefGoogle Scholar
Carbol, P. et al., J. Nucl. Mater. 392(1), 45 (2009).CrossRefGoogle Scholar
Fors, P. et al., J. Nucl. Mater. 394 (1), 1 (2009).Google Scholar
Pastina, B. and LaVerne, J. A., J. Phys. Chem. A 105, 9316 (2001).Google Scholar
Trummer, M. and Jonsson, M., J. Nucl. Mater. 396, 163 (2010).Google Scholar
LaVerne, J. A., Ryan, M. R. and Mu, T., (2009) Radiat. Phys. Chem. 78, 1148 (2009).Google Scholar
Metz, V. et al., Mater. Res. Soc. Symp. Proc. 985, 33 (2007).Google Scholar
Metz, V. et al., Radiochim. Acta 96, 637 (2008).CrossRefGoogle Scholar
Hata, K. et al., Nucl. Technol. 193, 434 (2016).CrossRefGoogle Scholar
Ödegaard-Jensen, A. et al., EU-project NF-PRO FI6W-CT-2003–02389 D-N°:1.5.17, 2008.Google Scholar
Roth, O. and LaVerne, J. A., (2011) J. Phys. Chem. A 115, 700 (2011).Google Scholar
Guimerà, J., Duro, L. and Delos, A., SKB Report R-06–105, 2006.Google Scholar
Allen, A. O. et al., J. Phys. Chem. 56 (5), 575 (1952).CrossRefGoogle Scholar
Hochanadel, C. J., J.Phys. Chem. 56 (5), 587 (1952).Google Scholar
Ghormley, J. A. and Stewart, A. C., J. Am. Chem. Soc. 78 (13), 2934 (1956).Google Scholar
Ollila, K. et al., J. Nucl. Mater. 442, 320 (2013).Google Scholar
Loida, A., Metz, V. and Kienzler, B., Mater. Res. Soc. Symp. Proc. 985, 15 (2007).Google Scholar
Carbol, P., Fors, P. and Spahiu, K., Geochim. Cosmochim. Acta 73 (15), 4366 (2009).CrossRefGoogle Scholar
Carbol, P. et al., SKB Report TR-05–09, 2005.Google Scholar
Spahiu, K., Cui, D. and Lundström, M., Radiochim. Acta 92, 625 (2004).Google Scholar