Measurement of radon exhalation rate and radiation doses in fly ash samples.

Coal based thermal power plants contribute about ~ 72% of the power generation in India. Indian coal is of bituminous type, having a high ash content with 55–60% ash. Due to considerable environmental importance the collected fly ash has become a subject of worldwide interest in recent years. In the present study radon exhalation rate and the activity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K radionuclides in fly ash samples from Kasimpur Thermal Power Plant, Aligarh, Uttar Pradesh, India have been measured by 'Sealed Can technique' using LR-115 type II detectors and a low-level NaI (Tl)- based gamma-ray spectrometer, respectively. Radon exhalation rate has been found to vary from 57.1 ± 5.3 to 119.4 ± 7.7 mBq m⁻² h⁻¹ with an average value of 87.3 ± 5.8 mBq m⁻² h⁻¹. Activity concentration of ²²⁶Ra ranged from 20.0 ± 8.5 to 30.0 ± 9.7 Bq kg⁻¹ with an average value 23.4 ± 9.0 Bq kg⁻¹, ²³²Th ranged from 17.0 ± 9.9 to 69.0 ± 13.8 Bq kg⁻¹ with an average value of 46.5 ± 12.1 Bq kg⁻¹ and ⁴⁰K ranged from 130.0 ± 7.2 to 332.0 ± 11.1 Bq kg⁻¹ with an average value of 177.0 ± 8.1 Bq kg⁻¹. [ABSTRACT FROM AUTHOR]