Appendix D. Examples of Monitoring Programs

Abstract

This Section provides information on selected elements of national monitoring programs in Germany, the Russian Federation, Slovenia, and USA. While many countries have national monitoring, the selected examples show a range of monitoring media and density, each designed for the needs of that country. There is no “one size fits all” national monitoring system. Because of the high spatial density of nuclear facilities in Europe, the European programs focus more on early warning with a much denser monitoring network than the USA, which has a lower density of nuclear power plants (NPPs) and very few in bordering countries. Considerations of the spatial density of nuclear facilities also affect the components of a national monitoring system. With the higher density of nearby reactors in Europe, dose rate measurement is much more effective for early warning than it would be in the USA. Because of the vast distance from Europe and Asia to USA, there is little need in USA for dose rate monitoring for early warning of emergencies on those continents since dispersion and decay of radionuclides over that distance and travel time will reduce dose effective rate to trivial levels. The US national monitoring system focuses on the much more sensitive collection of airborne particulates rather than dose rate, although the US is beginning to implement dose rate measurement to be more aligned with the international community and to provide rapid and unambiguous messaging to the public, scientists, and decision makers. Countries developing or updating their national programs are recommended to review these and other programs’ parameters as they design a program that fits their needs and operates within their resource parameters. A common consideration with national monitoring is how many stations are needed and where should they be placed. While this applies to dose effective rate monitoring, the issue is more significant for air sampling, which is much more expensive and resource intensive. In general, more air particulate samplers are better, but the number ultimately is based on resources. Most air particulate monitors require personnel to change filters, analyze filters, and perform periodic maintenance. All of these issues need to be considered when determining the number of air particulate samplers to place as a part of a national or regional system. Many strategies can be used to determine the best locations for air particulate samplers. For local monitoring, it may be best to set up samplers that encircle the plant, so monitors are present in all directions. On a regional level, economic interests such as agriculture are likely to guide the locations for air samplers. Nationally, population and geographical coverage are generally the primary considerations for sampler locations. Grid patterns may also be used to determine locations. Regionaland national-level monitoring locations may be determined using atmospheric dispersion computer models to determine probabilities of radioactive material transport from various source locations. This approach typically works best for a limited number of potential sources within a region. Some aspects and details of NPP monitoring for USA and Slovenia are provided below for reference. Comprehensive radiological effluent monitoring and environmental monitoring programs are typically required at NPP sites for facility operation. Each country should evaluate various aspects of these programs to determine the best fit for their nation, using applicable parts of these programs. Plant monitoring systems should be designed to ensure early warning and alarm monitoring is a part of the monitoring strategy.