Reactor fuel rod - with tabletted fuel stacked in argon filled pressurised zircalloy container

摘要

A reactor fuel element in which the tablet form fuel is stacked within a zircalloy containment. The containment is argon filled and pressurised the resulting internal/external pressure differential enabling thin walled zircalloy to be utilised with consequent cost and neutron economy. Within the containment and arranged above the fuel stack between spring restrainst is an inner chamber with a diffusion membrane. The membrane is pref. of silicon dioxide, borosilicate glass or caesium chloride. Gaseous fission products i.e. Xe or Kr which if allowed to accumulate might prejudice the container pressure differential diffusie into the chamber. The rate of diffsuin is dependant upon the choice of membrane bra for silcone dioxide a membrane life of 20 to 30,000 MWD/tonne is projected.