New radionuclide specific laboratory detection system for metallurgical industry

One of the main outputs of the European Metrology Research Programme (EMRP) project 'Ionising radiation metrology for the metallurgical industry' (MetroMetal) was the recommendation on a novel spectrometric detection system optimized for the measurement of radioactivity in metallurgical samples. The recommended system, prototypes of which were constructed at two project partner's laboratories, was characterized by using Monte Carlo (MC) simulations. Six different MC codes were used to model the system and a range of cylindrical samples of cast steel, slag and fume dust. The samples' shape, density, and elemental composition were the same as the ones of the calibration standards developed within the project to provide traceability to end-users. The MC models were used to calculate full-energy peak and total detection efficiencies as well as true coincidence summing correction (TCSC) factors for selected radionuclides of interest in the metallurgical industry: ⁶⁰Co, ¹³⁷Cs, ¹⁹²Ir, ²¹⁴Bi, ²¹⁴Pb, and ²⁰⁸Tl. The MC codes were compared to each other on the basis of the calculated detection efficiencies and TCSC factors. In addition, a 'Procedural guide for calculation of TCSC factors for samples in metallurgical industry' was developed for end-users. The TCSC factors reached in certain cases up to 32% showing that the summing effects are of high importance in the close measurement geometries met in routine analysis of metallurgical samples. (authors)