Dose assessment to workers in a dicalcium phosphate production plant
The production of dicalcium phosphate (DCP) uses phosphate rock (PR) as a raw material. Sedimentary phosphate rocks are enriched with relevant concentrations of natural radionuclides from the 238U decay chain (around 103 Bq·kg-1), leading to the need of controlling potential exposures to radiation o...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/100957 |
| Acceso en línea: | https://hdl.handle.net/2117/100957 https://dx.doi.org/10.1016/j.jenvrad.2016.09.018 |
| Access Level: | acceso abierto |
| Palabra clave: | Industrial safety - Península Ibèrica Aerosols Calcium phosphate Dicalcium phosphate plant NORM Ambient dose equivalent H*(10) Radon Occupational effective dose Seguretat en el treball - Península Ibèrica Fosfat de calci Àrees temàtiques de la UPC::Economia i organització d'empreses::Seguretat industrial::Prevenció de riscos laborals Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Degradació ambiental::Contaminació atmosfèrica |
| Sumario: | The production of dicalcium phosphate (DCP) uses phosphate rock (PR) as a raw material. Sedimentary phosphate rocks are enriched with relevant concentrations of natural radionuclides from the 238U decay chain (around 103 Bq·kg-1), leading to the need of controlling potential exposures to radiation of workers and members of the public in accordance with IAEA safety standards. Indeed, phosphate industries are classified as Naturally Occurring Radioactive Material (NORM) industries. Thus, the aim of this work is to assess the radiological risk of the workers in a DCP production plant located in the Iberian Peninsula (South-West Europe), which digests PR with hydrochloric acid. In the present study 238U, 230Th, 222Rn, 210Pb and 210Po concentrations in aerosols (indoor and outdoor areas) are reported. Aerosols showed concentrations between 0.42–92 mBq·m-3 for 238U, 0.24–33 mBq·m-3 for 230Th, 0.67–147 mBq·m-3 for 210Pb and 0.09–34 mBq·m-3 for 210Po. Long-term exposure (four months) of passive 222Rn detectors provided concentrations that ranged from detection limit (< DL) to 121 Bq·m-3 in outdoor areas and from < DL to 211 Bq·m-3 in indoor areas, similar to concentrations obtained from short-term measurements with active detectors from < DL to 117 Bq·m-3 in outdoor areas and from < DL to 318 Bq·m-3 in indoor places. 226Ra accumulation in ebonite and pipe scales were the most important contributions to the ambient dose equivalent H*(10), resulting in 0.07 (background)–27 µSv·h-1 with a median value of 1.1 µSv·h-1. Average 222Rn air concentrations were lower than the 300 Bq·m-3 limit and therefore, according to European Directive 2013/59/EURATOM, 222Rn concentration is excluded from the worker operational annual effective dose. Thus, considering the inhalation of aerosols and the external dose sources, the total effective dose determined for plant operators was 0.37 mSv·y-1. |
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