Monitoring artificial radioactivity in the Nordic countries

This report describes the national systems for monitoring artificial radioactivity in the five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden), including national similarities and differences regarding strategy and equipment. The backbone of the national system for early warning is a network of automatic gamma monitoring stations. It is complemented by manual stations and/or survey teams measuring in predetermined points. Air filter stations are used for nuclide specific analyses of aerosols and gaseous iodine. Fallout maps (especially for cesium-137) and isocurves (dose equivalent rates) are produced based on data from airborne measurements, monitoring stations, survey teams and environmental samples. All five countries have extensive programs for checking food contamination. Whole body counting and organ measurements are used to determine internal contamination. External contamination of people, vehicles, goods etc. is checked with survey meters and other equipment at checkpoints or as needed. Field measurements of various kinds complete the national systems. Current routines and systems for exchange of radiation data between the Nordic countries are summarized. A joint Nordic program for airborne measurements is suggested. Possible future development and planned improvements are discussed. (au)