title: First intercomparison among laboratories involved in COST Action-TU1301 "NORM4Building": Determination of natural radionuclides in ceramics.
abstract: This work describes the outcomes of the COST Action-TU1301 "NORM4Building" intercomparison on the determination of natural radioactivity in ceramics. Twenty-two laboratories involved in the intercomparison are evaluated for their performance using robust statistics. The reference values of226Ra (214Bi and214Pb) are determined to be 122 ± 11 Bq kg-1and 124 ± 14 Bq kg-1, respectively and in secular equilibrium in the uranium chain while the reference values of232Th (228Ac) is determined to be 61 ± 6 Bq kg-1and that of40K was determined to be 955 ± 40 Bq kg-1. Although the aim of the exercise was to determine the activity concentration of226Ra,232Th and40K and evaluation of the "Activity Concentration Index", laboratories were asked to report complete characterization of natural radionuclides. The results of this exercise pointed out a good performance among laboratories since the percentage of the acceptable results were above 90% for the radionuclides of interest. Based on these results, considering the systematic rejection of the results reported from a few laboratories we emphasize the need for quality control procedures.
authors.affiliation: Legnaro National Laboratory - National Institute of Nuclear Physics (INFN), Via dell'Università, 2 - 35020 Legnaro, Padova, Italy; Department of Physics, Faculty of Natural Sciences, University of Tirana, Blv. Zogu I, 1001 Tirana, Albania. Electronic address: xhixha@fe.infn.it.
authors.forename: Gerti
authors.initials: G
authors.lastname: Xhixha
authors.affiliation: Unit of Environmental Radioactivity and Radiological Surveillance, CIEMAT, Avda de la Complutense, 40 - 28040 Madrid, Spain.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Trinidad
authors.affiliation: Unit of Environmental Radioactivity and Radiological Surveillance, CIEMAT, Avda de la Complutense, 40 - 28040 Madrid, Spain.
authors.forename: Catalina
authors.initials: C
authors.lastname: Gascó
authors.affiliation: Departments of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1 - 44122 Ferrara, Italy; INFN Ferrara Section, National Institute of Nuclear Physics (INFN), Via Saragat 1, 44122 Ferrara, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Mantovani
mesh_terms: D002516:Ceramics / Q000032:analysis*; D011197:Potassium Radioisotopes / Q000032:analysis*; D011834:Radiation Monitoring / Q000379:methods*; D011886:Radon / Q000032:analysis*; D013910:Thorium / Q000032:analysis*
chemical_list: D011197:Potassium Radioisotopes; D013910:Thorium; D011886:Radon
keywords: Activity concentration index; Building materials; Ceramics; Intercomparison exercise; Natural radioactivity