SIMPLIFIED, COARSE-MESH, 3-DIMENSIONAL DIFFUSION SCHEME FOR CALCULATING GROSS POWER DISTRIBUTION IN A BOILING WATER REACTOR

Results obtained in a series of one- and two- dimensiona test cases indicate that this method may be o sufficient accuracy and simplicity for implementationin BWR- simulator computer programs. Computer requirements are very modest; thus, only 3N memory locations are required for incore treatment of the inner iteration in the solutionof a problem with N mesh points. The mesh width may be chosen equal to that fuel assembly pitch. Input data are in the for of conventional 2- group diffusion parameters. It is conclded hat the method presented has definite advantages in cmparison with the nodal coupling mehod.