Occupational radiation exposure due to norm in a rare-earth compounds production facility.
In India, rare-earth compounds are produced from the beach sand mineral monazite. Caustic digestion of the mineral followed by selective acid extraction is the method used to separate composite rare-earth fraction. The composite rare-earth chloride contains low levels of natural radionuclides and is the starting material for individual rare-earth compounds which have wide applications. Activity concentrations in composite rare-earth compounds such as chlorides, fluorides, carbonates and oxides of Ce, Nd, Pr, Sm, Gd, etc. are presented in this paper. The external gamma exposure rates and airborne activity due to thorium and thoron progeny in the occupational environment are studied. The activity levels in liquid effluent are presented. The potential individual occupational dose is estimated to be 1.9 mSv per annum.
Haridasan
P P
PP
Environmental Assessment Division, Bhabha Atomic Research Centre, Health Physics Unit, Indian Rare Earths Limited, Udyogamandal, Alwaye 683501, Kerala, India. haripadmam@gmail.com
Pillai
P M B
PM
Tripathi
R M
RM
Puranik
V D
VD
D000395:Air Pollutants, Occupational / Q000032:analysis*; D000396:Air Pollutants, Radioactive / Q000032:analysis*; D005720:Gamma Rays; D006801:Humans; D007194:India; D008674:Metals, Rare Earth; D016273:Occupational Exposure; D011829:Radiation Dosage; D011850:Radioactive Waste / Q000032:analysis; D011886:Radon / Q000032:analysis*; D013910:Thorium / Q000032:analysis*
D000395:Air Pollutants, Occupational; D000396:Air Pollutants, Radioactive; D008674:Metals, Rare Earth; D011850:Radioactive Waste; D013910:Thorium; D011886:Radon