A handy method for estimating radiation streaming through holes in shield assemblies

A ‘handy method’ has been developed for performing quick estimates of radiation streaming through cylindrical and rectangular holes in shield assemblies. Quick estimates are often needed during conceptual studies or detailed design of nuclear plants. For example, ITER (International Thermonuclear Engineering Reactor) has a large number of penetrations in the blanket and vacuum vessel and biological shield. This method estimates the levels of radiation that leaks through these holes as well as the magnitude of the fluxes along the hole wall. Results obtained using the ‘handy method’ are in good agreement with 3-D Monte Carlo calculations suggesting that the method provides a practical tool for streaming analysis.