Discovered radioactive source in a railway wagon, loaded with scrap metal

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

Event description:

The Emergency centre of the NRA was notified that on 23rd January 2009 the portal radiation monitoring system of the “Stomana Industry” S.A. – 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 detailed measurements have shown elevated radiation levels, up to 3,7 µSv/h above the natural background, 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 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 scap. The latter represented a control device and the radiation originates from the luminous paint coating, used for the dial, containing the isotope of Ra-226. The measured values of the gamma dose rate at 10 cm have been up to 9,3 µSv/h.

After additional measurements the wagon has been released for unloading. The source has been put in a safe place for temporary safe storage, and latter will be disposed as radioactive waste by the State Enterprise “Radioactive Waste”.