Storage of defective fuel pins in SFR core

Artikel i vetenskaplig tidskrift, 2016

An open fuel pin failure is a breach in the fuel pin cladding that allows direct contact between the primary coolant and the nuclear fuel. In this paper we focus on the sodium-fuel interactions in a Sodium cooled Fast neutrons Reactor (SFR), reviewing the main aspects of the fuel pin failure evolution with an emphasis on the Reaction between the Oxide fuel and the Sodium (ROS). This reaction leads to the formation of an uranoplutonate phase with approximately half the density of the initial oxide. In turn this can cause significant fuel swelling and the potential further degradation of the fuel pin. The maximal fuel swelling due to the formation of the uranoplutonate can be estimated for non-irradiated fuel based on the physico-chemical properties of the pellets, as further described in this paper.