Radionuclide fluxes at a plant manufacturing dicalcium phosphate for domestic animals

Research output: Contribution to journalArticle


We have studied a phosphate rock plant which produces dicalcium phosphate (DCP), used as a source of calcium and phosphorus for domestic animals. A by-product in the manufacturing process is calcium chloride which is used in the oil industry, the food industry and as road-salt. The objectives of our study were to describe the fluxes of radionuclides from the U-238 decay series and to estimate the radiation doses to workers at the plant. The radionuclides in the phosphate rock were found to be in secular radioactive equilibrium with U-238, With an average activity concentration of 837 Bq kg(-1). Separation and concentration processes were observed at different stages in the plant. Most of the Ra-226 was found in the calcium chloride, while the major part of the U-238, about 950 Bq kg(-1), was found in the dicalcium phosphate. The annual occupational effective dose to the workers was found to be below the 1 mSv limit recommended by ICRP (1991a) for the public. This study has shown a good example of an important non-nuclear industry with a high input of natural radionuclides with several conceivable pathways to man.


  • Torbjörn Gäfvert
  • Elis Holm
  • Per Roos
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Environmental Sciences


  • Calcium chloride, Dicalcium phosphate, Phosphate industry, Natural radioactivity
Original languageEnglish
Pages (from-to)61-73
JournalJournal of Environmental Radioactivity
Issue number1
Publication statusPublished - 2001
Publication categoryResearch