earticle

영어

In Korean nuclear power plants (NPPs), two thermoluminescent dosimeters (TLD) were provided to workers who work inan inhomogeneous radiation field; one on the chest and the other on the head. In this way, the effective dose for radiation workers atNPPs was determined by the high deep dose between two radiation dose from these TLDs. This represented a conservative method ofevaluating the degree of exposure to radiation. In this study, to prevent the overestimation of the effective dose, field applicationexperiments were implemented using two-dosimeter algorithms developed by several international institutes for the selection of anoptimal algorithm. The algorithms used by the Canadian Ontario Power Generation (OPG) and American ANSI HPS N13.41, NCRP(55/50), NCRP (70/30), EPRI (NRC), Lakshmanan, and Kim (Texas A&M University) were extensively analyzed as two-dosimeteralgorithms. In particular, three additional TLDs were provided to radiation workers who wore them on the head, chest, and back duringmaintenance periods, and the measured value were analyzed. The results found no significant differences among the calculatedeffective doses, apart from Lakshmanan's algorithm. Thus, this paper recommends the NCRP(55/50) algorithm as an optimal two-dosimeter algorithm in consideration of the solid technical background of NCRP and the convenience of radiation works. In addition, itwas determined that a two-dosimeter is provided to a single task which is expected to produce a dose rate of more than 1 mSv/hr, adifference of dose rates depending on specific parts of the body of more than 30%, and an exposure dose of more than 2 mSv.