Inter-comparison of radon detectors for one to four week measurement periods.

Seven different types of radon detectors (Atmos 12 dpx, RAD7, RStone, Sun Nuclear 1028, Ramon 2.2, Canary and CR-39) were compared for exposure periods of 1, 2, 3 and 4 weeks. The comparison was conducted under two conditions: (a) in a purpose-built radon chamber with an average radon concentration of 2560 Bq m(-3) (b) in a home environment with a radon concentration of 57 Bq m(-3), in both cases measured by the reference detector (Atmos 12 dpx) with a ±10% uncertainty range. In (a) 5 out of 8 detectors recorded radon concentrations within the Atmos uncertainty range and all detectors recorded within ±15%; in (b) 3 out of 9 detectors recorded within the Atmos uncertainty range and 6 out of 9 measured within ±20%, for a 4 week measurement. The results from this study show that radon surveys can be conducted for shorter periods than the recommended 3 months where a rapid indication is needed of whether the radon concentration is above the reference level, such as when assessing the concentration during and after remediation work.

An outdoor radon survey and minimizing the uncertainties in low level measurements using CR-39 detectors.

Long term outdoor radon measurements were recorded in Ireland using CR-39 track etch detectors. A measurement protocol was designed for this study, which was optimized for the relatively low radon concentrations expected outdoors. This protocol included pre-etching the detectors before exposure to allow radon tracks to be more easily distinguished from background. The average outdoor radon concentration for the Republic of Ireland was found to be 5.6 ± 0.7 Bq m(-3). A statistically significant difference between inland and coastal radon concentrations was evident but no difference between mean radon concentrations on the east coast and those on the west coast was observed.

Investigation of occupational radiation exposures to NORM at an Irish peat-fired power station and potential use of peat fly ash by the construction industry.

Annually, approximately 15% of Ireland's electricity requirement is provided through the combustion of 3 x 10(6) tonnes of peat. While the literature on coal-fired power generation is quite abundant, studies on the peat-fired power generation industry from a radiological point of view are scarce. A study of the largest Irish peat-fired power plant was initiated to review the potential occupational radiation exposures arising from the occurrence of naturally occurring radioactive material (NORM) at different stages of the industrial process and to investigate any radiological health consequences that may arise should peat fly ash be used as a component of building materials. Ambient gamma dose rate measurements, radon measurements, quantification of the occupational exposure from inhalation of airborne particles (personal air sampling) and gamma spectrometry analysis of peat, peat ash and effluent samples from the ash ponds were undertaken. The results indicate that the radiation dose received by any worker involved in the processing of the peat and the handling of the ash resulting from peat combustion does not exceed 150 microSv per annum. Regulatory control of the peat-fired power generation is therefore unnecessary according to the Irish legislation with regards to NORM. The potential use of peat fly ash as a by-product in the building industry was also found to have a negligible radiological impact for construction workers and for members of the public.

Natural radioactivity in building materials in the Republic of Ireland.

This paper presents the findings of a study undertaken to determine the natural radioactivity present in building materials in the Republic of Ireland. A total of 70 samples of commonly used building materials were collected from various manufacturers and suppliers throughout the country and analyzed using a HPGe gamma ray spectrometer. The specific activities of 226Ra, 232Th, and 40K were measured in all samples, and results ranged from minimum values of <1, <1, and 4 Bq kg(-1) to maximum values of 139, 57, and 1,977 Bq kg(-1), with mean values of 32, 18, and 353 Bq kg(-1), respectively. Results obtained were compared with relevant national, EU, and international legislation and guidance, and with the results of similar studies undertaken in other countries. These activities would suggest that the use of such building materials in the construction of domestic dwellings or workplaces in Ireland is unlikely to give rise to any significant radiation exposure to the occupants. In general, these activities were comparable to the results of similar studies undertaken in other countries. 137Cs activity was also detected in some samples.