V. S. O. P. - Computer Code System for Reactor Physics and Fuel Cycle Simulation

V .S .O .P . (Very Superior Old Programs) is a system of codes linked together for the simulation of reactor life histories. It comprisesneutron cross section libraries and processing routines, repeated neutron spectrum evaluation, 2-D diffusion calculation based onneutron flux synthesis with depletion and shut-down features, incore and out-of-pile fuel management, fuel cycle cost analysis, and thermal hydraulics (at present restricted to Pebble Bed HTRs). Various techniques have been employed to accelerate the iterativeprocesses and to optimize the internal data transfer. A limitation of the storage requirement to 360 K-bites is achieved by an overlaystructure. The code system has been used extensively for comparison studies of reactors, their fuel cycles, and related detailed features. Beside its use in research and development work for the High Temperature Reactor the system has been applied successfully to Light Water and Heavy Water Reactors