Complex System of Radon Diagnosis Methods and Specific Experimental and Theoretical Procedures Applied in the Indoor Building Environment

The paper is aimed at different measuring techniques and methods practically used for a classification of buildings in the context of radiation protection requirements. Specific experimental and theoretical diagnostic procedures designed for identification and quantification of indoor radon entry characteristics are proposed and discussed in detail (continuous simultaneous radon concentration monitoring, blower door technique, infrared Thermography imaging system, continuous soil gas radon measurement, air-exchange rate assessment – tracer gas measurement, visual inspections of buildings, build-up curve numerical analysis, air infiltration parameters assessment etc.). The given system of radon diagnosis was applied and verified on a set of dwellings, covering practically all types of family houses with regards to different types and quality of radon protection measures. INTRODUCTION Instantaneous values of indoor radon concentration fluctuate in time and simultaneously feature the significant space variations within the individual compartments of buildings. Generally, the indoor radon concentration is a result of two competing driving processes, the radon entry rate (Bq.s) respectively air-exchange rate (s). For the purpose of the individual dose estimation due to radon and its decay products exposure, the annual mean indoor radon concentration assessments derived from the solid-state nuclear track detectors measurements are generally provided. The weather conditions and residential habits, including a habitual behavior of occupants, staying time, number of inhabitants, ventilation and heating regime, ventilation and an air-conditioning systems operation etc., are considered as the most significant influencing factors for the indoor radon measurements and radon exposure assessment. In respect of buildings classification related to preventive and remedial measures efficiency against the radon entry from the subsoil, short-term radon concentration measurements under conservative exposure conditions are usually applied. The measurement conditions are set-up to minimize the false positive results and to avoid misinterpretation accordingly. In this context, a defined range of temperature and pressure field gradient during the measurement is required. The summary overview of radon diagnosis results focused on the ineffective preventive measures against radon penetration has been presented (Neznal, 2006). Proceedings of the American Association of Radon Scientists and Technologists 2008 International Symposium Las Vegas NV, September 14-17, 2008. AARST © 2008 ACKNOWLEDGEMENT The reported research activities were supported by the research project No. 10/2006 “A development and an application of measuring and diagnostic methods and methodologies for an exposure evaluation to natural radiation in buildings”. 41 ( ) ) e 1 ( ) ( ) ( ) ë ( d ) ( d