Discovered radioactive source in a track with trailer, loaded with scrap metal

Site with SIR or place of the event: “Kremikovtzi” S.A. - Sofia

Event description:

The Emergency centre of the NRA was notified that on 4^th September 2008 the portal radiation monitoring system on the Check point No. 9 of the “Kremikovtzi” S.A .detected elevated radiation level in a scrap loaded track with trailer.

The measurements have shown elevated radiation levels, up to 10 µSv/h, on the surface of a small area low down on the right hand board of the trailer. As a reference, the values of the natural gamma background in the area are around 0,22 µSv/h. The track has been returned to the site of the owner company and has been put under surveillance.

On 5^th September 2008 the radioactive source Emergency team Emergency team compost by representative from the NRA, Ministry of Health and General Department “Civil Protection” – Ministry of Emergency Situations partly unloaded the trailer. A source of ionising radiation was discovered and separated. The latter presents a metal frame (18 x 15) cm with built in 2 glass tubes crossing each other by a 90 degrees angle, filled with liquid. The most probably the source had been served as a part of an instrument for vertical and horizontal levelling (libella). The maximum measured value of the gamma dose rate was about 15 µSv/h (the natural values for the area are about 0,10 µSv/h). Following a field spectrometric analysis, the presence of the radioactive isotope Ra-226 (radium-226) has been identified. Probably the latter is included inside the luminous coating, assuring the possibility for night usage of the device.

After additional measurements the wagon was released for unloading. The source was packed and put in a safe place for temporary safe storage, before their disposal as radioactive waste by the State Enterprise “Radioactive Waste”.