Depth dose, dose equivalent and quality factor for reactor neutron spectra.

Abstract

The distributions of absorbed dose, dose equivalent, and quality factor in the depth of a cylindrical phantom are calculated for reactor neutron spectra under a variety of shield conditions. The calculations are reported for 12 neutron spectra, which include three experimental critical assemblies-HPRR, VIPER and VINCA-and light water reactor neutrons leaking through various shields such as Al, Pb, Fe, Be, graphite, concrete, etc. The spectral dependence of H(n, gamma) dose, total absorbed dose, dose equivalent, and quantity factor are discussed. For spectra degraded by low-Z materials without capture, the dose at a depth of 1 cm persisted even up to 5 cm; the effective quality factor for the spectra studied ranged from 5 to 9.7 at a depth of 1 cm. The latter remained practically constant (7.2) at all depth for light water shields (60 cm). In comparison, a rapid decrease was observed for spectra leaking through high-Z materials.