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 control device with a luminous dial, has been discovered.

The NRA emergency centre was notified that on 04^th April 2010 the portal radiation monitoring system of the “Stomana Industry” S.A. – Pernik detected elevated radiation level in a scrap-loaded railway wagon, supplied from the railway station Ilientsi (Sofia). A written notification for the case was received in the NRA on 12^th April. 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 on 06^th April 2010 have shown elevated radiation levels, up to 3.1 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 control device with a luminous dial. The measured values of the gamma dose rate at 1 m have been up to 0.3 µSv/h. Probably 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, and latter will be disposed as radioactive waste by the State Enterprise “Radioactive Waste”. After additional measurements the railway wagon has been released for unloading.