Capacity curves, spray distributions, and droplet size distributions of light water reactor [pressurized water reactor (PWR) and boiling water reactor (BWR)] containment spray nozzles are obtained, and the heat removal effectiveness is evaluated by a computer pro gram CONDENSE. It is revealed by the calculations that spray droplets from a PWR spray nozzle always attain the containment atmosphere temperature and spray droplets from a BWR spray nozzle attain the containment atmosphere temperature above ≈70°C.