Abstract:
This research aims to measure the radon emanation rate from gypsum board that contained the different contents of phosphogypsum. The emanation rate was measured by hermetically closing the sample in chamber and allowing the radon activity to build up with time until it reaches the equilibrium before doing the measurement. The radon concentration in the chamber was measured by 2 methods; activated charcoal adsorption and radon gas instrument, namely RAD7. The result of mass emanation rate from gypsum boards containing 30, 35 and 38% were 21.707+ and - 3.45, 38.34 + and - 6.10, 23.213 + and - 3.59 Bq.kg. superscript-1S superscript-1, respectively, where charcoal adsorption method was applies. While the level of emanation rate measured by using RAD-7 instrument gave 14.5-15% higher than the level obtained by the charcoal adsorption method. In addition, the radon emanation fraction was also calculated and the highest value was found to be 11% in gypsum board containing 30% phosphogypsum