Occurrence and behaviour of radionuclides in the Moselle river — Part IV: Deposition of radioactive particulate matter in high-sedimentation areas

• Published in: Journal of environmental radioactivity 1996, Vol.32 (3), p.193-212
• Main Author: Mundschenk, H.
• Format: Article
• Language: English
• Subjects: Applied sciences; Continental surface waters; Exact sciences and technology; Natural water pollution; Pollution; Water treatment and pollution
• ISSN: 0265-931X; 1879-1700
• DOI: 10.1016/0265-931X(95)00060-N

The nuclides 58Co, 60Co and 110mAg were used to trace the transport of particulate radionuclides from their discharge from the French NPP Cattenom over a distance of more than 200 km in the German part of the Moselle river. To describe the sedimentation of radioactive particulate matter in high-sedimentation areas, a sedimentation model has been applied which was developed in a previous study of the Rhine. Sedimentation rates were determined by means of drill-core measurements and with 137Cs and 60Co as tracers. The influence of grain-size effect on the transfer of particulate radionuclides to the bottom sediment was demonstrated, and a correction factor for fractionation was derived from field measurements. The relatively wide variations of radionuclide concentrations in sediment are mainly due to an inhomogenous distribution of radionuclides in the bottom layers as shown in samples from the Weser river. Validation of the sedimentation model was performed by comparing measured values with calculated data. The evaluation of the radiation exposure of the population in the Moselle valley due to radioactive effluents from the NPP Cattenom showed that the internal dose rate through the ‘drinking water path’ as well as the external dose rate from the ‘spoil field path’ were both far below the dose limit defined in the German legal regulations.