Measurement of 238U and 232Th radionuclides in ilmenite and synthetic rutile

International Nuclear Science, Technology and Engineering Conference 2017

原子能学

Idris, M.I.^1 ; Siong, K.K.^1 ; Fadzil, S.M.^1

School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM, Bangi, Selangor Darul Ehsan

43600, Malaysia^1

关键词: Activity levels;    Dose rate;    Radiation Exposure;    Regulatory exemptions;    Residential areas;    Safety precautions;    Safety standard;    Synthetic rutile;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/298/1/012010/pdf
DOI  :  10.1088/1757-899X/298/1/012010

来源: IOP

【 摘 要 】

The only factory that currently processes ilmenite to produce synthetic rutile is Tor Minerals in Ipoh, Perak, Malaysia. These two minerals contain radioactive elements such as uranium and thorium. Furthermore, this factory was built close to the residential areas. Thus, the primary issues are radiation exposure attributed to the decay of the radionuclides. Hence, the objectives of this study are to measure the dose and to evaluate activity levels of uranium and thorium. Dose rates from surrounding area of factory indicate the normal range for both on the surface and 1 meter above the ground (0.3-0.7 μSv/hr) lower than the global range of 0.5-1.3 μSv/hr set by UNSCEAR. The mean activity levels of uranium and thorium for ilmenite are 235 Bq/kg and 503 Bq/kg while for synthetic rutile are 980 Bq/kg and 401 Bq/kg, respectively. The result shows that uranium activity levels of synthetic rutile is 4 times higher than ilmenite but it is still lower than the regulatory exemption limit of 1000 Bq/kg set by IAEA Basic Safety Standards. Even though the dose rates at the factory and the activity levels are within safe limits, safety precautions must be followed by the factory management to prevent any unwanted accident to occur.