Inert matrix fuel with low melting point zirconium brazing alloys

Several versions of inert matrix fuel (IMF) using low melting point zirconium brazing alloys are suggested to improve their utilisation. The alloys are incorporated into a fuel component. Upon heating they melt down and due to capillary properties they penetrate fuel particle joints and ensure metallurgical contact between cladding and fuel elements as well as between fuel components themselves. The brazing alloys developed at A.A. Bochvar Institute have melting temperatures of 963–1133 K and are produced in the form of both granules and amorphous (metglass) strips. Zirconium brazing alloys used in IMF increase the thermal conductivity and allow an improved bonding to the fuel cladding, which will result in higher serviceability of fuels under transient conditions. Several versions of low melting point zirconium brazing alloy IMF are reviewed with respect to the feasibility of their utilisation.