The worldwide NORM production and a fully automated gamma-ray spectrometer for their characterization
Xhixha, G. (Università di Ferrara. Dipartimento di Fisica)
Bezzon, G. P. (Istituto Nazionale di Fisica Nucleare (INFN). Legnaro National Laboratory)
Broggini, C. (Istituto Nazionale di Fisica Nucleare (INFN). Padova Section)
Buso, G. P. (Istituto Nazionale di Fisica Nucleare (INFN). Legnaro National Laboratory)
Caciolli, A. (Istituto Nazionale di Fisica Nucleare (INFN). Padova Section)
Callegari, I. (University of Siena. Center for GeoTechnologies)
De Bianchi, Silvia (Università di Ferrara. Dipartimento di Fisica)
Fiorentini, G. (Università di Ferrara. Dipartimento di Fisica)
Guastaldi, E. (University of Siena. Center for GeoTechnologies)
Kaçeli Xhixha, M. (University of Sassari. Botanical, Ecological and Geological Sciences Department)
Mantovani, F. (Università di Ferrara. Dipartimento di Fisica)
Massa, G. (University of Siena. Center for GeoTechnologies)
Menegazzo, R. (Istituto Nazionale di Fisica Nucleare (INFN). Padova Section)
Mou, L. (University of Siena. Center for GeoTechnologies)
Pasquini, A. (University of Siena. Center for GeoTechnologies)
Rossi Alvarez, C. (Istituto Nazionale di Fisica Nucleare (INFN). Padova Section)
Shyti, M. (Università di Ferrara. Dipartimento di Fisica)
Istituto Nazionale di Fisica Nucleare (INFN). Ferrara Section
Agricultural University of Tirana. Faculty of Forestry Science

Data:	2013
Resum:	Materials containing radionuclides of natural origin and being subject to regulation because of their radioactivity are known as Naturally Occurring Radioactive Material (NORM). By following International Atomic Energy Agency, we include in NORM those materials with an activity concentration, which is modified by human made processes. We present a brief review of the main categories of non-nuclear industries together with the levels of activity concentration in feed raw materials, products and waste, including mechanisms of radioisotope enrichments. The global management of NORM shows a high level of complexity, mainly due to different degrees of radioactivity enhancement and the huge amount of worldwide waste production. The future tendency of guidelines concerning environmental protection will require both a systematic monitoring based on the ever-increasing sampling and high performance of gamma-ray spectroscopy. On the ground of these requirements a new low-background fully automated high-resolution gamma-ray spectrometer MCA_Rad has been developed. The design of lead and cooper shielding allowed to reach a background reduction of two order of magnitude with respect to laboratory radioactivity. A severe lowering of manpower cost is obtained through a fully automation system, which enables up to 24 samples to be measured without any human attendance. Two coupled HPGe detectors increase the detection efficiency, performing accurate measurements on small sample volume (180 cm3) with a reduction of sample transport cost of material. Details of the instrument calibration method are presented. MCA_Rad system can measure in less than one hour a typical NORM sample enriched in U and Th with some hundreds of Bq kg−1, with an overall uncertainty less than 5 %. Quality control of this method has been tested. Measurements of three certified reference materials RGK-1, RGU-2 and RGTh-1 containing concentrations of potassium, uranium and thorium comparable to NORM have been performed. As a result, this test achieved an overall relative discrepancy of 5 % among central values within the reported uncertainty.
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Publicat a:	Journal of Radioanalytical and Nuclear Chemistry, Volume 295 (2013) , pp. 445-457., ISSN 1588-2780

DOI: 10.1007/s10967-012-1791-1

Post-print 22 p, 540.4 KB

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