Radiological environmental monitoring at the ESS facility : annual report 2019
Аннотация
Radiological environmental monitoring of the pre-operation phase of the ESS started in 2017.The current report presents additional results of 3 H in precipitation, air humidity and sewage sludge, gamma radionuclides in sewage sludge and 14 C in vegetation.The sewage sludge sample collected in the summer showed a low level of 3 H (2.30.4Bq L -1 , MDA = 1.6 Bq L -1 ) which was similar to the one measured on the winter and spring of the same year on the same location.The results of the tritium measurements in air humidity and precipitation were generally below the detection limit.The sewage sludge sample collected for analysis of gamma emitting radionuclides indicated presence of 131 I (115.74.3Bq kg -1 ).It is important to note that the measured sample is an average sample of the month (consisting of sub-samples that were collected during each working day of the month) and that the administered e.g. 131I activity at SUS Lund, that endup in the sewage sludge, is influenced by many different factors (e.g.number of patients, residence of these patients, physical decay).Other natural ( 40 K, 226 Ra, 228 Ac) and anthropogenic ( 137 Cs) radionuclides were observed at small and expected concentration levels for this type of sample.The samples of crops had activity concentrations of gamma emitting radionuclides below the MDA for the measurement time (approx.24 h), except for 40 K (131.816.6 and 183.414.0Bq kg -1 , respectively).The 20 analysed samples of vegetation showed no signs of anthropogenic contamination of 14 C.The average 14 C activity concentration from year 2018 was not significantly different from the data obtained in year 2017.