Development of a methodology for measuring the radon source strength of large surfaces and evaluation of the radon insulation effects of various coverings. Final report

Knowledge of the intensity of large-surface radon exhalation, ie. of the source strength, is an important prerequisite for activities for preparing the knowledge base for decisions on the radiological remediation of abondoned mining sites, the radiological clearance of such sites for construction projects, and the assessment of radiological hazards in the context of site examination work. The method currently applied for determination of the radon exhalation (box method) yields only a snapshot of the radon exhalation process, which does not permit to derive information on the long-term processes which are influenced by meteorological and soil physics conditions. The general objective of the project reported is to develop a feasible methodology for determining the long-term source strength of large-surface radon exhalation sources. The specific project objectives are: develop concepts, models and basic approaches; - perform radon measuring campaigns at selected sites and standard samples with sophisticated electronic equipment permitting integrated data acquisition, including the calibration work for subsequent applications for the given purpose; - modelling and evaluation of the results obtained; - development of a feasible method for determining the long-term radon exhalation from lare surfaces. (ori./CB)