Print View Posted on: 25 May 2022
On February 8, 2022 an alarm from a radiation portal monitoring system was activated at the metal scrap yard in Dąbrowa Górnicza. The alarm was triggered by a courier parcel. The services of the regional governor were directed to the site in order to take radiometric measurements. The parcel contained elements of a chromatograph with radioactive source. The measurement 10 cm from the outer surface of the parcel was 4 µSv/h, identification of the isotope was unsuccessful. The National Atomic Energy Agency (PAA) was notified of the incident, but did not receive any information about the damage of the chromatograph elements and the source. It was recommended to secure the objects and hand them over to the Radioactive Waste Management Plant (ZUOP) for disposal.On February 16, 2022 a dosimetry team from PAA was sent to the site to perform additional measurements. The parcel was opened on the site, it turned out that the source is out of shielding container and is damaged. The measurement of unshielded source was 98 mSv/h from 10 cm, identification of the isotope was still not possible. No contamination was detected on the surface of the package. The dosimetry team took wipe samples from the source. Due to identified contamination, the dosimetry team was directed to the place of living of the people who sent the package. It turned out the chromatograph was cut and sent by courier to the metal scrap yard by two young men. In the place of disassembly (shed), the dosimetry team took measurements that indicated dose rate between 4 µSv/h to 100 µSv/h (measured with β/γ probe). Items such as the table, tools, and waste container were contaminated. In addition, contamination was detected on the grass in the back yard, clothes, and single points inside the houses of young people.ZUOP in cooperation with the regional governor decontaminated the site and buildings. Decontamination process was performed until natural background radiation level was reached. The contaminated objects were secured and transported to ZUOP for disposal.On March 7,2022 PAA received results of the sample taken by the dosimetry team which indicated that the source was Sr-90. Source activity was estimated at 48,7 MBq.Exposure assessment of one of the young man (the other refused to be tested) has been conducted in the National Centre for Nuclear Research and in the Institute of Nuclear Chemistry and Technology. On April 13, 2022 PAA received results of abovementioned assessment from which it appeared that received whole body absorbed dose based on biological dosimetry is estimated in range of 100 to 300 mSv.