Analysis of accidental sequence tests and interpretation of fission product release : interdependence of Cs, Mo, and Ba release
G. Nicaise, R. Dubourg, P. Taylor.
Proceedings of 11th Symposium on Thermodynamics of Nuclear Materials, Karlsruhe, 6-9 sept 2004. Journal of Nuclear Materials, numéro spécial à paraître.
The behaviour of fission products (F.P.) during fuel life in a nuclear reactor is of particular importance as it plays a significant role in the release kinetics during hypothetical reactor severe accident transients.
A description of 137Cs, 99Mo, and 140Ba chemical states after some UO2 fuel irradiation stages is drawn. Molybdenum is assumed to be located in a MoO2 precipitate (volatile over 1273 K) and chemical reactions with condensed Cs oxides and/or uranates are possible. According to this description, a coherent interpretation is presented for some accidental sequence tests providing new ideas for release mechanisms of Cs, Mo, and Ba.