Cross-section adjustment with Monte Carlo sensitivities: Application to the Winfrith iron benchmark

The Monte Carlo analysis of the Winfrith Iron Benchmark required about 2h computing time on an IBM 3033; the discrete ordinates analysis required an order of magnitude more than this. The Winfrith Iron Benchmark had relatively simple geometry; for more complicated geometries the difference in computing times is expected to become even more significant. For integral measurements taken in complex situations such as a power reactor, the Monte Carlo adjustment procedure presented in this work may be the only one that is feasible. Other advantages pertinent to this method are that the removal of bias factors gives less opportunity for subjective judgment to influence the adjustment procedure and that the use of point nuclear data makes it clear that the adjustments are not simply compensating for group averaging errors. This work enables adjustment procedures to be applied more efficiently, more generally, and more reliably