Occurrence and behaviour of radionuclides in the Moselle River—Part I: Entry of natural and artificial radionuclides

Various sources contribute to the radioactive contamination of the Moselle River, among which the French NPP Cattenom with four units of 1300 M We represents the most important. Appropriate operational precautions were taken in order to monitor the nuclide transfer on different pathways under normal and accidental conditions and the effectiveness of these measures has been tested using natural (²¹⁴Pb/²¹⁴Bi, ⁷Be, ⁴⁰K) and artificial radionuclides. (³H, ⁵⁸Co, ⁶⁰Co, ¹³¹I, ¹³⁷Cs) as tracers. Measurements of suspended matter have revealed that the inputs of natural nuclides exceed the discharges of the NPP Cattenom. In 1992 the annual loads of ⁷Be and ⁴⁰K in suspended matter at Palzem amounted to 21 and 130 GBq year⁻¹, whereas the emission rates of ⁶⁰Co and ¹³⁷Cs were about 2.6 and 1.0 GBq year⁻¹. The total nuclide load of ¹³⁷Cs at Palzem reached 6.2 GBq year⁻¹, which is about six times the quantity emitted by the NPP Cattenom in the same year. This excess is due to the accident at Chernobyl and to a lesser extent to prior atmospheric weapons tests.