Radiological Monitoring of Waste Treatment Plant

Scheduled waste in West Malaysia is handled by Concession Company and is stored and then is incinerated. It is known that incineration process may result in naturally occurring radioactive materials (NORM) to be concentrated. In this study we have measured three samples consist of by-product from the operation process such as slag, filter cake and fly ash. Other various environmental media such as air, surface water, groundwater and soil within and around the plant have also been analysed for their radioactivity levels. The concentration of Ra-226, Ac-228 and K-40 in slag are 0.062 Bq/g, 0.016 Bq/g and 0.19 Bq/g respectively. The total activity (Raeq) in slag is 99.5 Bq/kg. The concentration in fly ash is 0.032 Bq/g, 0.16 Bq/g and 0.34 Bq/g for Ra-226, Ac-228 and K-40 respectively resulting in Raeq of 287.0 Bq/kg. For filter cake, the concentration is 0.13 Bq/g, 0.031 Bq/g and 0.33 Bq/g for Ra-226, Ac-228 and K-40 respectively resulting in Raeq of 199.7 Bq/kg. The external radiation level ranges from 0.08 μSv/h (Administrative building) to 0.35 μSv/h (TENORM storage area). The concentration level of radon and thoron progeny varies from 0.0001 to 0.0016 WL and 0.0006 WL to 0.002 WL respectively. For soil samples, the activity ranges from 0.11 Bq/g to 0.29 Bq/g, 0.06 Bq/g to 0.18 Bq/g and 0.065 Bq/g to 0.38 Bq/g for Ra-226, Ac-228 and K-40 respectively. While activity in water, except for a trace of K-40, it is non-detectable.