Elevated radiation level detected in a scrap-loaded railway wagon, entering “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 device form aircraft, containing Ra-226, was discovered.

The NRA emergency centre was notified that on 6^th October 2011 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 was stationed on a separate track on a special platform on site and was put under surveillance.

The measured dose rate was up to 0.7 µSv/h, on the surface of a small area on the side of the wagon (the natural gamma background in the area is between 0.07 and 0.11 µSv/h). Following a field spectrometric analysis, the presence of the radioactive isotope Ra-226 (radium-226) was identified.

The wagon was partly unloaded and the item, causing the elevated radiation levels, was discovered and removed from the scrap. The later represented a device from aircraft – compass (diameter of 80 mm, height of about 120 mm, weighted about 200g), containing Ra-226. The measured values of the gamma dose-rate at 10 cm were about 4.1 µSv/h and in contact – up to 10.3 µSv/h. Probably the isotope Ra-226 was included as an ingredient of a luminous paint.

The removed object was packed and put in a safe place for temporary safe storage. After additional measurements the railway wagon was released for unloading.