[en] Relatively moderate scale emergency response actions by the public can provide substantial reductions in the number and chance of early and continuing health efects in the event of a major release of radionuclides from a nuclear power plant. In the event of a core melt accident scenario, early, precautionary evacuation of areas within 2 to 3 miles and sheltering elsewhere in the early time frame can substantially reduce the risk of early fatalities--to close to zero in some cases. In the further event of an actual major release of radioactivity to the atmosphere, expeditious relocation from highly contaminated areas would be necessary. This paper will discuss the calculations and emergency response assumptions that lead to these insights. Since emergency response is unlikely, the applications of these insights are more likely to be found in other areas such as emergency planning, siting and probabilistic risk analyses. (orig.)