Environmental effects of radon and its progeny from uranium waste rock piles. Pt. 1. Measurements by passive and continuous monitors

The radon concentration in atmosphere on and around the uranium waste rock pile sites has been measured by integrating passive monitors since 1989. In fiscal 1996, except for the Katamo-shimo 1, the average concentration of radon on the sites, around the sites and in control areas, ranged from 11 to 194 Bq/m3 (average: 45 Bq/m3), from 8 to 75 Bq/m3 (average: 26 Bq/m3), and from 9 to 77 Bq/m3 (average: 30 Bq/m3), respectively. Additionally, the typical daily and seasonal variations of radon concentration, radon progeny concentration and radon exhalation rate are observed with continuous or automatic monitors. According to the measurement results by passive monitors and continuous monitors, the environmental effects of radon and its progeny from the waste rock pile sites are estimated small in residential regions around the sites. (author)