Environmental radioactivity in Germany. Report of the federal installations and the Federal office of radiation protection. Data and evaluation

This report is a compilation and evaluation of data on radioactivity in the environment and in the vicinity of nuclear facilities in Germany from 2011 to 2013. The mean radiation exposure of the public in Germany was about 4.0 mSv in 2013, of which natural radiation exposure accounted for about 2.1 mSv and man-made radiation exposure for 1.9 mSv. An international work group is in charge of the preparation of quality standards for radon measurements. These latter also serve as a basis to implement the regulations of the new EURATOM Basic Safety Standards Directive. Rice grown within the contaminated zone around Fukushima has been certified as reference material for food monitoring. The trace analysis laboratory for airborne radioactive substances obtained several striking results of measurements performed during the reporting period. Man-made radionuclides from the Fukushima nuclear accident were detectable, too. Assessment of anthropogenic radioactivity also requires thorough measurement of ''natural'' radiation components. Three different measurement areas are used as a reference for calibration. Discharges of radioactive substances into the exit air and wastewaters from nuclear power plants remained far below the authorised limit from 2011 to 2013. There has been a trend of decreasing discharges since 1975. The nine nuclear power plant units in operation at the end of the reporting period had a total capacity of 12.7 GW and accounted for 15 per cent of power generation. The annual mean values provided by the measuring network of the Deutscher Wetterdienst (DWD; German Meteorological Service) amounted to 0.6 mBq/m³, 0.7 mBq/m³ and 0.7 mBq/m³ for the total -activity in the air and 58 Bq/m², 38 Bq/m², and 27 Bq/m² for the total -activity deposited by precipitation in 2011, 2012 and 2013, respectively. The higher annual value for 2011 is due to the Fukushima releases. The activity concentrations of ⁸⁵Kr measured by the BfS in Freiburg remained at about 1.5 Bq/m³. The measured activity concentrations of ¹³³Xe ranged from one to 100 mBq/m³, except for the time after the Fukushima disaster. Almost all measured values of ¹³⁷Cs concentrations in drinking water and groundwater are below the detection limit The BfS, in cooperation with the PTB, carried out interlaboratory comparisons to determine natural radionuclides in drinking water in 2012 and 2014. In the North Sea sampling was performed every August. The ¹³⁷Cs activity concentration ranged from 1.3 Bq/m³ in the Elbe estuary up to 3.0 Bq/m³ in the outer German Bight. Compared to this, the ¹³⁷Cs activity concentration in the Baltic Sea is higher, ranging from 20 Bq/m³ in the western part, to 34 Bq/m³ in the eastern part of the region under study, as a result of the Chernobyl reactor accident. Consequently, the measured ¹³⁷Cs activity concentrations in fish are also higher in the Baltic Sea than in the North Sea, reaching up to 11 Bq/kg during the reporting period. Increased activity concentrations are still being measured in fish from inland waters, especially from lakes. In Southern Germany, these have declined from more than 200 Bq/kg moist mass in 1986 down to 2.3 Bq/kg up to now. As a result of the Fukushima nuclear disaster, more than 10 PBq of ¹³⁴Cs and ¹³⁷Cs (1 PBq = 1015Bq) entered the Pacific Ocean every. While soil contamination with ¹³⁷Cs is due to the Chernobyl accident, most of the ⁹⁰Sr deposits go back to the time of the atmospheric nuclear weapons tests. In feedstuffs, mean values ranging from < 0.1 Bq/kg up to 0.8 Bq/kg were measured for ¹³⁷Cs and from 0.1 Bq/kg up to 2.3 Bq/kg for ⁹⁰Sr. Contamination of milk constantly remains at a low level. Dietary intake of ¹³⁷Cs and 90Sr was 73 Bq and 29 Bq, respectively, on average in 2013. An interlaboratory comparison involving 72 institutions from Germany and neighbouring countries was carried out to determine the levels of ⁴⁰K, ⁸⁹Sr, ⁹⁰Sr, ¹³¹I, Ba-133, ¹³⁴Cs, and ¹³⁷Cs in raw milk. More than 94 per cent of the measurement results obtained for all nuclides were within the allowed range of dispersion. Apart from ¹³¹I, which was detected in many samples of fly ash/filter dust and is assumed to originate from nuclear medicine applications, ¹³⁷Cs from the Chernobyl accident was still detectable. Mean values of 14 Bq/kg of dry matter were measured in clearing sludge in Southern Bavaria. ¹³⁴Cs from the Fukushima accident was also detectable temporarily in 2011. As a consequence of the Chernobyl accident, the ¹³⁷Cs activity concentration was found to be enhanced in samples of plants used to make pharmaceuticals or tea still in 2013. Buckbean leaves from Poland had 35 Bq/kg of dry matter, and Iceland moss from Russia 15 Bq/kg of dry matter.