Controlling occupational radiation exposure at operating nuclear power stations

The historical development of the philosophy of keeping the radiation exposure of workers at light-water reactors as low as reasonably achievable (ALARA) is presented. A review is made of some of the ALARA activities of the Nuclear Regulatory Commission, the Energy Research and Development Administration, and various nuclear installations. Data compiled by the NRC show that routine and special maintenance at light-water reactors accounts for 72 percent of all occupational exposure at these sites. The role that Oak Ridge National Laboratory has taken in ALARA research is presented, with emphasis placed on a study of valve malfunctions at light-water reactors. The valve study indicates a trend toward decreasing valve reliability over the past few years. Finally a cost--benefit analysis of radiation dose reduction is discussed. The rationale for assigning a cost per man-rem based on the radiation exposure level that is encountered is presented