ASTRA code for thermal mode calculation of a fuel cluster with coaxial turbular elements

The description and text of the ASTRA code for thermal calculation of a coaxial tubular fuel element cluster inserted into the Field type channel or direct - flow channel are given. The code is written in FORTRAN and permits to calculate the distribution of heat fluxes from fuel element surfaces, temperatures of a coolant in gaps between them, temperatures of external surfaces of fuel elements, temperatures of contact of fuel pellets with cladding and maximum rod temperatures along the core length