Year: 2024
Type: article
Abstract: Solid surfaces play a crucial role in many processes, yet their impact on nuclear safety is not well understood. This study investigates how solid surfaces affect the behavior of radioactive gaseous species, focusing on the interaction of fission product complexes formed under nuclear accident conditions. Specifically, we examine the condensation and decomposition of Cs–Mo complexes, CsHMoO 4 and H 2 MoO 4, when interacting with MoO 3 deposits in a reactor cooling system, considering two surface terminations: O and Mo. Using density functional theory (DFT), we calculate the Gibbs free energy for these reactions on MoO 3 surfaces at temperatures ranging from 300 to 1800 K. CsHMoO 4 condenses below 850 K and dissociates between 300 and 650 K on O-MoO 3 and 650–1250 K on Mo-MoO 3, forming Cs 2 MoO 4 and MoO 3, along with steam release. H 2 MoO 4 condenses below 500 K and decomposes between 600 and 800 K, but only on Mo-terminated surfaces. These findings improve the accuracy of nuclear simulations, helping to predict species composition and transport within the reactor cooling system during accidents.
Authors: Mariam Saab, Sidi M. O. Souvi, Jean Denis, François Virot, Monica Calatayud
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4405287507