Investigations on Ruthenium Transport in Highly Oxidising Conditions

International Conference "Nuclear Energy for New Europe 2005", Bled, Slovénie, 5-8 septembre 2005

A. Auvinen, U. Backman, J. Jokiniemi, M. Kissane, M. Kunstár, M. Lipponen, I. Nagy, N. Vér, R. Zilliacus.

During operation of a nuclear reactor, ruthenium will accumulate in the fuel in relatively high concentrations. In steam atmospheres ruthenium is far from being as volatile as caesium or iodine and is unlikely to be released from the fuel in significant amounts. However, if air comes into contact with overheated fuel during a severe accident or during plant maintenance, ruthenium may form volatile species, which may be released to the containment. Since the consequences from the release of ruthenium can potentially be as severe as from iodine and caesium combined, the understanding of the release and the subsequent transport of ruthenium oxides is of primary importance. Therefore the behaviour of ruthenium in oxidising conditions is studied in several experimental programmes in Europe.