Environmental radiological impact of monazite mining and mineral separation by IREL Manavalakurichi- a brief report

Monazite (CePrNd Pm SmGdEuTpDyHoEr Tm Yb Lu - Th U P₂O₅) and Zircon (ZrSiO₄) are two radioactive minerals present in beaches of Indian Peninsula. Monazite contains 7.5-8% thorium (300-320Bq/g) and 0.3% uranium (36Bq/g). Zircon at Manavalaurichi region contains 250-300 ppm of natural uranium (3Bq/g) and traces of thorium (0.5Bq/g) as crystal lattice trapped element. Health Physics Unit under Health Physics Division, Bhabha Atomic Research Centre is responsible for environmental radiological monitoring of plant premises and environment of Indian Rare Earths Limited (IREL) engaged in mining and separation of beach sand heavy minerals including monazite and zircon. This paper discusses environmental impact assessment of continuous operation of Mineral Separation Plant, Manavalakurichi and show that average 6-10 fold reduction in environmental dose rate due to mining and separation of monazite. (author)