On-site radiation exposure in severe reactor accidents: Scoping study

The results of a scoping study of onsite radiation exposures which could take place in each of three types of postulated reactor accidents are presented. The accident types are (1) a fuel handling accident at a Mark III BWR; an interfacing system LOCA or V sequence at a PWR; and and Anticipated Transient Without Scram (ATWS) at a Mark I BWR. Both external and internal dose pathways are considered. The results of the study indicate the prohibitively high radiation doses could be received in some plant areas if personnel were to remain there. However, times of the order of a few minutes to a few hours, depending on the type of accident, would be available before life-threatening doses would be accumulated assuming that the provided full face respiratory protection equipment were used promptly. Special attention was given radiation doses possibly received by control room personnel for several control room air in-leakage assumptions. For occupancy during severe accidents it would be advisable for control room personnel to use self-contained apparatus (SCBA) to limit exposure via inhalation. The results of this study will be useful to individuals responsible for accident management procedures. It is indicated that it will be important for each plant to develop estimates of the time of onset of prohibitively high radiation levels in various important plant areas. It is concluded that respiratory protection is a major factor owing to the large inhalation doses which might otherwise be encountered. 20 refs., 8 figs., 6 tabs