Measurements prove: No enhanced radioactivity level in foods produced near the Konrad mine

Farmers in the catchment area of the Konrad mine are concerned about the possible radiological contamination of their agricultural products. Therefore, the Federal Office for Radiation Protection has installed additional environmental monitoring equipment for the Konrad mine already before the mine is into operation as a repository. The data for 2012 is now available. Result: The concentrations of relevant radionuclides in the food samples are far below the limit values.

In a BfS information event that took place in mid April the results of the sampling around the Konrad mine were presented to members of the Lower Saxony Regional Farmers' Association.

It will still take some years until the Konrad repository will be taken into operation. Based on legal requirements, the vicinity of the Konrad mine needs to be monitored two years before the first radioactive waste will reach the repository. However, on request of the Lower Saxony Regional Farmers’ Association, the BfS has already now taken up environmental monitoring.

Control of exhaust air, waste water and plants

This way, all discharges are measured and controlled already before the Konrad mine will be taken into operation as a repository. This is mandated by the “Directive on the emission and immission monitoring of nuclear faclities” (REI). Not only is waste water sampled and measured but also the exhaust air from the shaft and plants growing near the mine. This is done by the operator and additionally by an independent measuring institution. Thus, the actual radiation level can be determined over corresponding reference values.

Samples taken within a radius of 10 kilometres

The Federal Office for Radiation Protection (BfS) has commissioned the IAF – Radioökologie GmbH with the external analytics of the samples, the IAF being a laboratory for radionuclide analytics and consulting. - The complementary measurement programme includes the examination of samples taken from an area within a radius of 10 km around the future repository. The examination of soil, grass, crop, milk, vegetables, fruit, water and air is required by law. Furthermore, the IAF also analyses corn, oil seeds, sugar beets, leaves/needles and woodruff. Thus, 195 samples are evaluated by the independent IAF measuring laboratory, in addition to the 52 samples per year required according to REI. The samples are taken by the Nuclear Control & Consulting GmbH (NCC). In order to be able to compare the results of the samples, reference measuring points were set up at the same time at a distance of ca. 60 kilometres, at the Drömling situated to the east of Wolfsburg.

Examination of 247 samples taken in different seasons

The Laboratory for Radioanalytics examined altogether 247 samples in the months of January, May, July and September/October. Some samples were taken at several times over the year, such as soil or meadow vegetation. Others such as oil seeds or vegetables were taken during the time of harvesting in July. Products such as sugar beets, corn, fruit or crop were harvested in September/October.

A selection of vegetation samples such as mushrooms, oak leaves and grass from the area near Konrad.

Searching for artificial radionuclides

The objective is to detect possibly occurring artificial radionuclides (such as tritium, cobalt-60, strontium-90, caesium-134, caesium-137 and iodine-131) that are e. g. generated in a nuclear reactor. Apart from the artificial radionuclides there is a number of naturally occurring radionuclides taken up daily, e.g. with the food.

Natural and artificial radionuclides in the soil

Garden soil or cropland contain all naturally occurring radionuclides. For example, one kilogram of soil contains about 5 milligrams of uranium-238 and its decay products on average. As a result of the nuclear tests and the Chernobyl reactor accident, the cropland in Lower Saxony contained on average 10 becquerels per kilogram of caesium-137 in 2007. For this radionuclide, the IAF determined in 2012 an activity of around 8 becquerels per kilogram of cropland in the examined samples. For the radionuclides cobalt-60 and strontium-90 the values were below the detection limit.

Caesium-137 in crop, feed, oil seeds, corn and sugar beets

In all aforementioned products from the vicinity of the Konrad mine the values of caesium-137 remained below 0.3 becquerels per kilogram in the past year. For comparison: In Germany, the legal limit value for importing foods is 600 becquerels per kilogram.

Caesium-137 in fruit and vegetables

Furthermore, examination results showed the following: In several vegetables such as salad, courgettes, beans, squash, potatoes, cabbage turnip, onions and beetroot the caesium-137 concentrations were below 0.3 becquerels per kilogram, in fruit (apples, pears, strawberries) the values were below 0.1 becquerels per kilogram.

An employee prepares sampling of crop

Values in animal products

In milk the maximum value of caesium-137 was around 4 becquerels per litre on the national average in 2007. The IAF analyses for the Konrad mine area resulted in a mean value below 0.2 becquerels per litre in 2012. In meat (wild boar, poultry) the value was below 0.3 becquerels per kilogram.

Tritium content in drinking water

In Germany the legal limit value for the radionuclide tritium in drinking water is 100 becquerels per litre. For drinking water and groundwater in the vicinity of the Konrad mine the IAF determined a concentration below 3 becquerels per litre.

All limit values according to Radiation Protection Ordinance well fallen below

Previous examinations show the current radiological loads in the biosphere near the future repository. As the operator, the Federal Office for Radiation Protection must prove that the limits for the population and the staff set out in the provisions of the Radiation Protection Ordinance are complied with. For discharges (waste water and exhaust air) and direct radiation resulting from repository operation the limit value is 1 millisievert per year. That is about half of the natural radiation level citizens of the Federal Republic of Germany are exposed to per year on average.