A number of health and safety issues have arisen because of the occurrence of NORM, naturally occurring radioactive materials of the 226 radium and 228 radium decay chains, in production operations. Issues such as risk to workers or the general public, disposal of contaminated production fluids, disposal of NORM removed in cleaning equipment and tubing, and procedures to follow in well rework, equipment decontamination and other types of maintenance must be addressed.
This paper describes the application of a procedural aid to decision making known as PATHWAY EXPOSURE ANALYSIS to these issues. The procedure examines the radiation exposure of individuals and population groups by calculating the dose from each exposure route and pathway. The sum of these is used to calculate the overall risk to the individual or the group. This method can be used to examine managementand procedural options to identify the option offering the smallest risk. Risk information coupled with cost estimates then permits management maximum utilization of its available resources.
Three uses of Pathway Exposure Analysis will be discussed. The first will be a description of the identification of environmentally Sound disposal or remediationoptions for production sites. The secondwill be a description of how Pathway Exposure Analysis can be usedto determine acceptable water limits for a specific classor use of surface waters. The third will demonstrate how this method can be used to reconstruct employee dose.
International Commission on Radiation Protection and U.S. Environmental Protection Agency dose conversion and dose weighing factors are used to calculate individual exposure. Results are presented in the form of dose to the maximum exposed individual and, where appropriate, as the average exposure to the exposed population.