Quality assurance of individual radon measurements

The 96/29/EURATOM guideline and its national transformations demand the application of radiation protection measures if the presence of radon and radon decay products leads to a significant increase in exposure of workers. The requirements of the aforementioned EURATOM guideline were met by the amendment to the German Radiation Protection Ordinance in 2001. Presently, a national guideline for the transformation of the legal rules into practice is being implemented to guarantee an effective but appropriate protection against natural radiation. The guideline regulates the responsibilities of the authorities as well as the setting-up of appropriate means and measures to be taken by the employers. Additionally, it will demand from the laboratories carrying out measurement tasks a program for quality assurance and the participation in measurement inter-comparisons. For the evaluation of laboratory inter-comparisons and for the authorization of personnel radon monitors, uniform accuracy criteria have been developed. Around the relevant limit of the measured potential alpha-energy exposure of 14 mJ h m(-3), an over- and under-estimation of the true value by a factor of 1.8 is accepted. Monitors for exposure to radon can be applied at workplaces with equilibrium factors within a range from 0.2 up to 0.7. Measurement uncertainty around the relevant limit of 6000 kBq h m(-3) is 20%.