SUMMARY

The COMET metho has been used to solve whole core reactor eigenvalue and flux distribution problems with accuracy that is on par with Monte Carlo calculations with computational efficiency that is several orders of magnitude faster. A key to maintaining this efficiency is a flux expansion that is low in order while maintaining desired levels of accuracy. To this end, an adaptive expansion technique is developed and employed. Whereas before, all flux expansions were the same in a problem, the flux expansion is now allowed to vary depending on problem-dependent needs. This improvement to the method increases its computational efficiency. The adaptive technique is developed and demonstrated on several benchmark problems.