Dose assessment at a phosphate industry landfill using solid state detectors

Abstract

The industrial landfill “Racó de la Pubilla” is located at Flix (Tarragona, Spain) and contains residues from a factory that produces bicalcium phosphate using phosphorite. The main aim of the study was the determination of the environmental radiological conditions in the landfill in order to estimate the effective dose received by workers and the potential impact on the surrounding area. With these objectives in mind, a system based on LiF:Mg,Cu,P thermoluminescent detectors (TLD) and electrets was used. The main dosimetric characteristics of the TLD system are presented (LID, energy response, isotropy, etc.), as well as the results of the influence of environmental conditions on the electrets. The evaluation of the gamma ambient dose equivalent measured at the landfill by the TLD technique gives a maximum value of approximately 200 nSv/h, but most of the measurement points were close to the unaltered site (80 nSv/h). In addition, average radon concentrations of 30 Bq / m 3 were measured, slightly higher than the reference value. The effective dose due to the natural radioactive components of the waste is lower than 1 mSv/year. The use of LiF:Mg,Cu,P, with a sensitivity 30–40 times higher than LiF:Mg,Ti, and electrets for radon measurements allow short measurement periods, thus providing an easy assessment of the radiological risk of the studied facility.