Search

Setup and operation of emergency care centres (sometimes also addressed as emergency reception centres) are part of emergency response in the environs of nuclear power plants. The preparation of an exercise scenario for such a centre is very demanding on the responsible agency. Therefore, a computer code has been developed which helps to translate the exercise objectives into instructions for figurants which simulate the affected population. These instructions are intended to steer a determined flow of people through the emergency care centre by providing fictitious radiological readings and by injecting the demand for additional actions of response personnel by statements and questions.

Four institutes, all of which are involved in nuclear-emergency management in the Dutch-German border region, have compared their short-range dispersion and radiological dose models using scenarios consisting of single-station meteorology and two dispersed radionuclides. After adjustment of some of the parameters, the consequence of the differences in parameters on the effective dose was quantified at several stages from source to exposure. Results for the neutral stability class agreed within a factor of four. Variations in wet deposition of radioactive material, giving rise to external radiation from the ground, can cause significant variations to the effective dose. Furthermore, the way the different emergency-management tools model the atmospheric dispersion for a stable stability class in the horizontal plane can generate large differences. Finally, the methodology of calculating cloudshine is not comparable among the models, which causes the effective dose near the source to show large deviations for high emission sources.

Publisher Summary This chapter provides an overview of the most important phenomena that determine the pathways of radioactive substances from an accidental release to the environment and the people living there. In most cases accidental releases resulting from loss of coolant and subsequent melting of the core will take place in the first hundred meters above the ground. Releases into higher parts of the atmosphere are possible if the release has a high thermal energy and/or an upwards directed mechanical momentum. There are a great number of atmospheric dispersion models. Most of them are dedicated to air pollution assessments with the end points of concentration or time integrated concentration of pollutants. Some models include the simulation of dry and wet deposition. Many programs are able to calculate radiation doses. The main options for preventing and limiting exposures are generally: evacuation, respiratory protection, relocation, Potassium iodide (KI) blockage, decontamination of people, decontamination of land and buildings, protection of the food chain, and medical treatment.

Infant mortality was documented for the Federal Republic of Germany as well as for the individual Federal Laender (before German unification) during 1973 and 1988. 31 Cause-of-Death groups, 5 Age-of-Death groups, and both sexes were considered. During the observation period the infant mortality rate decreased to 1/3 of the value of 1973 and is now well below 1%. The temporal decrease of infant mortality is different with regard to causes of death, age of death, sex, and Federal Land: Infant mortality due to congenital malformations decreased to about one half within the observation period, but its relative contribution to all natural causes of death increased from about 20% in 1973 to about 30% in 1988.

On account of the lack of a comprehensive cancer registry with national coverage for the Federal Republic of Germany, the long-term and interregional evaluation of cancer mortality data is of particular relevance. Therefore, the TUV Rheinland instructed by the Federal Ministry for the Environment, Nature Protection, and Reactor Safety maintains an "Information System on Cancer Mortality and District Characteristics (IKK)" using official cause of death and resident population statistics. Mortality data for a variety of different cancer sites are documented with local and temporal separation for the area of the Federal Republic of Germany (before the German unification) and for a period of 20 years. The IKK data can be employed as a meaningful tool for epidemiological investigations relating to the correlation of cancer mortality and environmental agents. In the present paper the principles of the IKK are described and some examples of results are presented.

The assessment of radiological consequences resulting from accidental releases of a nuclear installation is based on the calculation of atmospheric transport of radionuclides. An intercomparison of the calculation procedure in Germany and France shows differences characterized as follows: the relevant guideline in Germany recommends usage of the Gaussian-plume-model and dispersion parameters derived from the dispersion experiments at the research centers of Ju- lich and Karlsruhe /BMU, 1989/ official guidelines to calculate the radiological consequences do not exist in France. At the Institut de Protection et de Surete Nucleaire (IPSN) radiological consequence assessment can be done by using three different types of Gaussian based models (nomograms, plume- or puff-model), each of them with the dispersion parameters based on Doury (1976).

Basic concepts, technical applications and details of the updated meteorological pre-processor using SODAR data (MPS) as well as additional meteorological measurements are presented. The pre-processor allows the calculation of boundary-layer parameters, i.e. friction velocity, Monin-Obukhov length and mixing layer height, on the basis of SODAR measurements which serve as input parameters for subsequent dispersion calculations, e.g. within the frame of the DFK model for the calculation of the atmospheric dispersion and radiation exposure related to an accidental release of radioactive material in the near range of a nuclear installation (DFK French-German Commission for Information Interchange on Nuclear Safety). The MPS is an extension to the DFK model which presently only includes the meteorological pre-processor MPT, calculating the boundary layer parameters on the basis of wind-speed data and temperature gradient from tower measurements. The improved DFK model can be implemented within the remote monitoring system of German reactor sites as well as nuclear installations in other countries, provided that either tower data or SODAR data are available as meteorological input.

In case of accidental atmospheric releases of toxic substances it is an urgent need for decision makers to be provided with data as actual and precise as possible. In the past the assessment of pollutant impact based on measured meteorological parameters and hypothetical emission rates was associated with relatively great uncertainties. To improve this situation the new system SMART has been developed, which reduces the uncertainties substantially. This is in the first step achieved by feedback of actual measurements of the environmental impact into diagnostic calculations in order to adapt the calculations to the current measurements. The result is a more realistic set of model parameters, including the source term. Subsequently these parameters are used as input data for the second step of SMART which is real-time projection of the dispersion situation.