INVESTIGADORES
SOBA Alejandro
artículos
Título:
An interdiffusional model for prediction of the interaction layer growth in the system uranium molybdenum/aluminum
Autor/es:
SOBA; DENIS
Revista:
JOURNAL OF NUCLEAR MATERIALS
Referencias:
Año: 2007 vol. 360 p. 231 - 241
ISSN:
0022-3115
Resumen:
The codes PLACA and DPLACA, elaborated in this working group, simulate the
behavior of a plate-type fuel containing in its core a foil of monolithic or dispersed
fissile material, respectively, under normal operation conditions of a research reactor.
Dispersion fuels usually consist of ceramic particles of a uranium compound in a high
thermal conductivity matrix. The use of particles of a U Mo alloy in a matrix of Al
requires especially devoted subroutines able to simulate the growth of the interaction
layer that develops between the particles and the matrix. A model is presented in this
work that gives account of these particular phenomena. It is based on the assumption
that diffusion of U and Al through the layer is the rate-determining step. Two moving
interfaces separate the growing reaction layer from the original phases. The kinetics of
these boundaries are solved as Stefan problems. In order to test the model and the
associated code, some previous, simpler problems corresponding to similar systems for
which analytical solutions or experimental data are known were simulated. Experiments
performed with planar U Mo/Al diffusion couples are reported in the literature, which
purpose is to obtain information on the system parameters. These experiments were
simulated with PLACA. Results of experiments performed with U Mo particles disperse
in Al either without or with irradiation, published in the open literature were simulated
with DPLACA. A satisfactory prediction of the whole reaction layer thickness and of
the individual fractions corresponding to alloy and matrix consumption was obtained.