Estimation of 222Rn release from the phosphogypsum board used in housing panels

Phosphogypsum board is a popular construction material used for housing panels in Korea. Phosphogypsum often contains 226Ra which decays into 222Rn through an α transformation. 222Rn emanated from the 226Ra-bearing phosphogypsum board has drawn the public concern due to its potential radiological impacts to indoor occupants. The emanation rate of 222Rn from the board is estimated in this paper. A mathematical model of the emanation rate of 222Rn from the board is presented and validated through a series of experiments. The back diffusion effect due to accumulation of 222Rn-laden air was incorporated in the model and found to have a strong impact on the 222Rn emanation characteristics.