Radiological study of transport and processing of naturally occurring radioactive materials

Abstract

Background: Recently the European Commission is recasting the Euratom Basic Safety Standards (BSS) in order to further limit the exposure of the public and workers to radioactivity1. The new BSS is expected in 2015 and contains a broad list of industries, processing Naturally Occurring Radioactive Material (NORM), that will become subject to more strict regulation. The list contains, among others, zirconium, thorium, and titanium processing plants, phosphate-ore industries and oil and gas extraction facilities. In addition the new BSS provides additional regulation for the incorporation of residues of NORM (fly ash, phosphogypsum, phosphorus/tin/copper slag, red mud, …) in building materials and for building materials from natural origin.

Materials & methods: A large scale radiological study of the container traffic in the port of Antwerp was conducted by means of portal monitors2,3. Geometry corrected in-situ measurements were performed on materials in industrial processes with LaBr3(Ce) and NaI(Tl) probes. These results were compared with lab analysis of samples by means of a HPGe detector. For a detailed comparison of the properties of LaBr3(Ce) and NaI(Tl) probes see Milbrath et al.4.

Results: (1) A database of the NORM traffic through the port of Antwerp (2008 – 2010) was constructed. (2) Through measurements at the port of Antwerp and at companies a new user-friendly method for the determination of the activity concentration was developed. The activity concentrations of shipped goods and several building materials are determined with several detectors and the results are compared to the BSS limits. (3) In case-studies dose on workers was assessed. (4) Initial results of the measurements on building materials are shown.

Outlook: Ongoing research focuses on the treatment strategies for NORM contaminated waste, soil and water. IAF and NuTeC organize the 4th EAN-NORM workshop in Hasselt, Belgium (Nov 29th – Dec 1st 2011). The workshop focuses on transportation of NORM, measurements strategies and building materials (http://www.ean-norm.net/).