Activation, Depletion, and Decay
ORIGEN Assembly Isotopics (ORIGAMI) computes detailed isotopic compositions for LWR assemblies containing UO2 fuel by using the ORIGEN code with pre-generated ORIGEN libraries for a specified assembly power distribution. The assembly may be represented by a single lumped model with only an axial power distribution or by a square array of fuel pins with variable pin powers, as well as an axial distribution. Multiple cycles with varying burn times and down times may be used. ORIGAMI produces files containing SCALE and MCNP composition input for material in the burnup distribution, files containing decay heat for use in thermal analysis, and energy-dependent radioactive source for use in shielding calculations.
A series of 1470 pre-generated burnup libraries for use in ORIGEN and ORIGAMI are provided with SCALE for 61 fuel assemblies for commercial and research reactors.