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:

A SIR, containing Th-232, representing hemispherical, transparent, plastic detail, mounted on a circle metal plate, with diameter of 4 cm and weight about 25 g, was discovered in a railway scrap loaded wagon in “Stomana Industry” S.A.

The NRA emergency centre was notified that on 19th July 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 slightly elevated radiation levels, up to 0,62 µSv/h, on the surface of a small area on the side 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 Th-232 (thorium-232) has been identified.

On 20th July 2009 the wagon has been partly unloaded. The detail, causing the elevated radiation levels, has been discovered and removed from the scrap. The later represented hemispherical transparent plastic detail, mounted on a circle metal plate with diameter of 4 cm and weight about 25 g. The measured values of the gamma dose rate at 10 cm have been up to 28 µSv/h and in contact on the surface – up to 330 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”.

There is no any danger for the population and the environment.