Some Improvements in Finite-Element Method Applied to Neutron-Diffusion Calculations

摘要

This report describes some aspects of the finite element theory related to the solution of the multigroup neutron diffusion equation in X-Y geometry. The topics investigated are: the advantages of large, high order general quadrilaterals as elements; cross sections which vary smoothly (in space) over an element; the Jacobian of a general quadrilaternal is not a constant; and the use of distinct orders of approximations along the X and Y directions. The theory was incorporated into the experimental code QUFEM. (ERA citation 07:053853)