Wouter Schroeyers

Measurement of NORM

Abstract This chapter describes the most important measure methods to determine the activity concentration of gamma emitting radionuclides, the measurement of dose rates, and the determination of radon concentrations as well as radon exhalation rates. Several aspects concerning sampling, detector calibration, and uncertainty estimation are discussed.

From NORM by-products to building materials

Abstract The cementitious materials and ceramic industries are frequently looked as targets for the recycling and valorization of several wastes, residues, and by-products, generated from a wide variety of industries. In general, only technical (and chemical) aspects are covered on each attempt for recycling a waste in a particular product, while radiological features are rarely considered. This chapter aims to give new and more complete insights on the recycling of several industrial wastes, on four groups of construction materials: (1) construction materials based on Portland cements (both as cement itself and as concrete), (2) construction materials based on alkali-activated binders, (3) ceramics and glass-ceramics, and (4) gypsum. For each by-product a separate section will describe (1) the technical (and chemical) aspects of the use as part of a construction material and (2) the resulting radiological properties of the designed product, when they are available. Some ceramic industries also use radiologically active components, namely zircon and zirconia (in glazes, refractories, etc.). The radiological consequences of their production, further use/manipulation by other industrial sectors (e.g., ceramic glazes and frits production), and on the final costumers are also briefly reported.

From raw materials to NORM by-products

Abstract Naturally occurring radionuclides are present in the Earth crust; however, their distribution is not homogeneous. When primary or secondary raw materials containing relatively low concentrations of naturally occurring radionuclides are introduced in an industrial process then the radionuclides can become more concentrated in the produced (by-)products. For example, during the production of purified metals, throughout the purification process, also other elements, such as naturally occurring radionuclides, become concentrated in the by-products. In order to assure radiation protection of the population, it is important to map the potential exposure for workers and the general public. There is an extensive literature available regarding the presence of naturally occurring radionuclides in various by-products; however, it can be hard to review and even to interpret for the regulators and members of the industry in order to assure the safe use of by-products for example in construction. To solve this problem data mining and text processing have been applied to the ever-increasing numbers of publications (More than 39,000 filtered publications have been processed up to the Jan. 6, 2017), and the NORM4Building database has been compiled based on the analysis of the collected data. Based on this database using text analysis methods the most NORM prone raw materials and industries have been identified. This chapter gives a concise overview on the parameters to be considered during the selection of NORM by-products as feedstock for the construction industry, specifically for the production of cement, concrete, and ceramics. In the frame of this chapter the technical and radiological properties of the most representative industrial processes (such as coal mining and combustion; iron and steel production; the alumina, the zirconia, and the phosphate industry; etc.) and their by-products are discussed, especially considering the needs of the construction industry and the new European Basic Safety Standards.

Special issue: Natural radioactivity in construction

Kovler, K (reprint author), Technion, Fac Civil & Environm Engn, Haifa, Israel. cvrkost@technion.ac.il; wouter.schroeyers@uhasselt.be

Nontechnical aspects that influence the reuse of NORM in construction industry

This chapter deals with the most important nontechnical aspects that will determine whether reuse options for NORM by-products in construction are viable or not. Potential traps and problems involved in attempts to achieve reuse for NORM by-products are addressed.

General conclusion and the way forward

The final conclusions and perspectives of the COST network NORM4Building regarding the use and evaluation of the use, of NORM by-products in construction materials.

4 – Legislative aspects

In this chapter the evolution of the EU legislative approach regarding natural radioactivity in building materials is presented. In addition, an overview of regulations already in force in some EU Member States and in other countries is presented. Finally, a section of this chapter is also devoted to a review of the Activity Concentration Indexes elaborated in different EU and non-EU countries to evaluate the radiological impact of building materials.

Leaching assessment as a component of environmental safety and durability analyses for NORM containing building materials

Abstract In addition to direct exposure to radiation, inhalation of radon or inhalation of dust, other pathways of exposure need to be considered, such as release of naturally occurring radionuclides (NOR) by leaching to soil and groundwater used as sources of drinking water. Evaluation of naturally occurring radioactive materials (NORM) and NORM containing construction products by leaching has been extensively addressed. However, actual NOR measurements in eluates are very limited. The evaluation of release of dangerous substances from construction products is a topic dealt with by national legislators in Europe, in European standardization (CEN) and by US EPA, which has led to recently finalized leaching standards that are leading to the comparable results between EU and the United States. Given the physical aspects of leaching and the chemical behavior of radionuclides is the same as for their stable counterparts, it is logical to address questions about leaching of NORM and NORM containing construction products in same way. In this chapter results for a range of NORM and NORM containing products are presented, which implies that the experience gained in assessing release of stable elements is directly applicable for NORM and NORM containing construction products.

A low-energy set-up for gamma-ray spectrometry of NORM tailored to the needs of a secondary smelting facility

A measurement station dedicated for quantitative radiological characterisation of naturally occurring radionuclides in a metallurgical company and based on gamma-ray spectrometry was developed. The station is intended for performing quality control of final non-ferrous metal products and for radiological checks of incoming materials. A low-background point-contact HPGe-detector was used and the signal was split in two branches to enable collecting simultaneously spectra with high amplification (for gamma-ray energies below 250keV) and low amplification.