WHIRLAWAY--A THREE-DIMENSIONAL, TWO-GROUP NEUTRON DIFFUSION CODE FOR THE IBM 7090 COMPUTER

WHIRLAWAY is an IBM 7090 FORTRAN programmed code for the solution of two- group neutron diffusion equations in xyz geometry. The code was designed to run under control of the IBM 7090 FORTRAN Monitor System on a machine with at least six tape units. The maximum number of mesh points is limited to 12,750. Arbitrary distributions of materials and mesh spacing are permitted. The boundary conditions are either zero flux or zero current at each of the six faces of the reactor, and the code will, if desired, compute the adjoint-flux and associated flux-adjoint-flux region integrals that are necessary for perturbation calculations. Computation time is approximately 0.006 sec per point iteration. Normally, running times are about 2 to 3 hr for a 10,000-point problem. (auth)