GENERAL REACTOR ANALYSIS COMPUTER PROGRAM FOR THE IBM 704, PROGRAM GEORGE

Program George is an IBM 704 ccde that combines standard ANPD reactor analysis methcds for computing multiplication constant and spatial distribution of flux and power, as well as other nuclear parameters, in aircraft (heterogeneous) reactors. The elapsed time and the chance for human error between initial input and final output are greatly reduced in Program George. A matched set of reflector savings for a reflected, cylindrical core, which was formerly obtained by hand, is now computed by the program. In the C/sub 2/ pcrtion of Program George, the ccde computes the neutron slowingdown density and flux at 19 lethargy levels plus a thermal group in bare, homogeneous compositions with normal mode, ene ngy-dependent bucklings. The diffusion coefficient contains a transport correction as well as a Behrens correction for heterogeneous structure. Flux-depression factors at thermal and two epithermal levels are computed in annular, cylindrical geometry by one-energy, P/sub 3/ transport theory approximation in the I/sub 2/ pontion of the program, or they may be given as input. Flux weighting of various cross sections, transmission factors, and other parameters are computed in a multigroup representation. Two-energy-group constants from the regional compositions are supplied in the F/sub 2/ portion of the program, in which a two-energy group, one-space-dimensional, multiregion diffusion calculation yields multiplication constant, normalized fission density, fast flux, and slow flux in each onedimensional reactor pontrayed. If a reactivity match is requested, the reflector savings of the specified compositions are adjusted until the multiplication constant i n the radial F/sub 2/, longitudinal F/sub 2/, and the reference bare equivalent core of a cylindrical reflected reactor converge to the same value. (auth