Discovered radioactive source in a railway wagon, loaded with scrap metal, in Stomana Industry” S.A.

Site with SIR or place of the event: “Stomana Industry” S.A, Pernik

Event description:

During the entrance check of a scrap-loaded railway wagon in “Stomana Industry” S.A. (town of Pernik) a source, containing Ra-226, representing a panel with control devices on it, with luminous dials, has been discovered.

The NRA emergency centre was notified that on 25th July 2010 the portal radiation monitoring system of the “Stomana Industry” S.A. – town of Pernik detected elevated radiation level in a scrap-loaded railway wagon. The railway wagon has been stationed on a separate track on a special platform on site and has been put under surveillance.

The measurements have shown slightly elevated radiation levels, up to 0.9 µSv/h, on the surface of a small area on the top of the wagon. As a reference, the values of the natural gamma background in the area of Pernik are between 0.07 and 0.11 µSv/h. Following a field spectrometric analysis, the presence of the radioactive isotope Ra-226 (radium-226) has been identified.

The wagon has been partly unloaded. The detail, causing the elevated radiation levels, has been discovered and removed from the scrap. The later represented a panel with 3 control devices on it (weighted about 500 g in total), with luminous dials. The measured values of the gamma dose-rate at 1 m have been about 0.3 µSv/h and in contact – up to 8.6 µSv/h. The isotope Ra-226 has been included as an ingredient of a luminous paint.

The source has been packed and put in a safe place for temporary safe storage. After additional measurements the railway wagon has been released for unloading.