Development of Techniques to Relate Radon Levels in Homes in the Dayton Area to Local Geology and Fill Material

摘要

A Lucas cell was built and calibrated for measuring radon emanation from fill material and a procedure was developed to find the radium content of fill material. Studies to determine the best radon source for a radon chamber were also made. Radon diffusion properties of three polyethylene-type materials were studied for possible use as moisture barriers in the charcoal canisters or as radon source covers. The radon measurements taken showed a higher percentage of elevated radon measurements above 6.0 pCi/l in homes to the north and east of Dayton. This was based on 107 first floor measurements and 76 basement measurements. Radon chamber studies were conducted on several radon sources including radium in HCl solution and evaporated sources. A clear advantage is demonstrated for the evaporated radon source. The ability of the glovebox to maintain a build-up of radon was also shown. Radon emanation from fill material was measured using a Lucas cell modified to hold fill material in the cell. The ability of the Lucas cell to determine radon emanation is clearly demonstrated with an equilibrium time of just over two weeks. A procedure for determining the radium content of fill material was developed using a NaI detector. Before the procedure can be used, however, an efficiency for the fill material in the geometry used must be measured since it was not done in this study.