Yet another unexplained spike in airborne radioactivity has been detected in Europe. This is the second reported spike in radioactive particles in Europe this year.
According to the Federal Office for Radiation Protection, elevated levels of the isotope Ruthenium-106 have been reported in Germany, Italy, Austria, Switzerland and France since September 29. Ruthenium-106 is a radionuclide of artificial origin. It is a fission product from the nuclear industry used in the medical field for brachytherapy treatments and sometimes in radioisotope thermoelectric generators (RTGs) as a source of energy for satellites.
IRSN, French public expert in nuclear and radiological risks, said in yesterday's press release that the radionuclide has been detected by several European networks involved in the monitoring of atmospheric radioactive contamination, at levels of a few milliBecquerels per cubic meter of air.
The agency has undertaken investigations since October 3, 2017 to carry out an in-depth assessment of the measurements of ruthenium levels in France and to identify the possible origins of the situation encountered.
"In France, IRSN has mobilized all its measurement stations for atmospheric monitoring and undertook the analysis of their filter samples. At this stage, only the filters of the stations of Seyne-sur-Mer (Var) and Nice (Alpes-Maritimes) show the presence of Ruthenium-106 at trace levels (respectively 7.4 and 6.8 micro-Bq/m3). The results of measurement of the filters of the other stations of IRSN do not show the presence of this radionuclide," it said.
Based on calculations carried out by IRSN, the levels of atmospheric contamination of the order of those observed in Europe are not likely to generate health effects.
"By combining levels of contamination observed and numerical simulations performed by IRSN, it appears that the contaminated air masses measured in Europe originate from the southern regions of the Urals. Given the amount of Ruthenium-106 that may be at the origin of the air pollution observed in Europe, it appears that measures of protection of the populations could have been necessary in the vicinity of the site of the releases. It should be noted that the detection of ruthenium alone excludes the possibility of an accident on a nuclear power plant, which would result in the presence of other radionuclides. Ruthenium can occur in nuclear fuel cycle installation, in facilities manufacturing radioactive sources or in RTG's (Radioisotope thermoelectric generators) used for the power supply of satellites. Discussions with BfS, the German counterparts of IRSN, show that they reach similar conclusions," IRSN said.
"At this stage, we do not have information to confirm the end of the releases and we continue our efforts to monitor the level of ruthenium in the territory and its calculations to clarify the origin of the releases and their characteristics," the institute concluded.
According to the RT, the Russian state atomic energy corporation Rosatom said the radiation situation around all Russian nuclear facilities is within the norm and corresponds to natural background radiation.
Their statement also noted the data of Roshydromet, Russia’s meteorology service, indicated that Ruthenium-106 hasn’t been detected on Russian territory, only excluding St. Petersburg, from September 25 to October 7. However, the Ruthenium-106 concentration in St. Petersburg last week was 'insignificant,' and was four times lower than the allowed level, it added.
Russian nuclear facilities cannot be seen as the source of the reported release, Rosatom said, calling the speculation about a Russian origin 'invalid.'
In January 2017, a radionuclide of anthropogenic origin, Iodine-131, has been detected in the ground-level atmosphere across Europe. Since Iodine-131 is a radionuclide with a short half-life (8 days) its detection suggested a rather recent release. You can read more about that event at the following link: Spike in radioactive Iodine-131 levels detected across Europe
Featured image: Composite image of Europe at night, 2016. Credit: NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA's Goddard Space Flight Center