A Passive Radon Dosemeter Suitable for Workplaces

Abstract

The results obtained in different international intercomparisons on passive radon monitors have been analysed with the aim of identifying a suitable radon monitoring device for workplaces. From this analysis, the passive radon device, first developed for personal dosimetry in mines by the National Radiation Protection Board, UK (NRPB), has shown the most suitable set of characteristics. This radon monitor consists of a diffusion chamber, made of conductive plastic with less than 2 cm height, containing a CR-39 film (Columbia Resin 1939), as track detector. Radon detectors in workplaces may be exposed only during the working hours, thus requiring the storage of the detectors in low-radon zones when not exposed. This paper describes how this problem can be solved. Since track detectors are also efficient neutron dosemeters, care should be taken when radon monitors are used in workplaces, where they may he exposed to neutrons, such as on high altitude mountains, in the surroundings of high energy X ray facilities (where neutrons are produced by (gamma, n) reactions) or around high energy particle accelerators. To this end, the response of these passive radon monitors to high energy neutron fields has been investigated.

Study on the influence of CR-39 detector size on radon progeny detection in indoor environments

“…For this dosimeter a calibration factor F = (2.8 ± 0.2) tracks.m 3 cm -2 .kBq -1 .h -1 was employed [14] in order to obtain the liquid radon activity in air inside the rooms.…”

Assessment the Health Hazard from 222Rn in Old Metalliferous Mines in San Luis, Argentina

“…The CR-39 plastic track detectors (1.7 cm 2 area and 0.9 mm thick) were enclosed in a radon diffusion chamber (NRPB/SSI type monitors) (Orlando et al 2002). They were deployed at 14 locations within the adits of the La Carolina gold mine and 20 locations of the Los Cóndores wolfram mine, as illustrated in Figs.…”

Application of a “Sealed Can Technique” and CR-39 detectors for measuring radon emanation from undamaged granitic ornamental building materials

“…Each sample was ICRER 2011 placed inside a plastic cylindrical container facing a CR-39 track detector into a diffusion chamber model NRPB/SSI [13] (Fig. 2).…”

“…The container was then sealed for approximately three months. After exposure, the detectors were etched during 5.5 hours with a KOH 30% solution at 80˚C [13], and readed under a Zeiss optical microscope [14].…”

“…(cm −2 .Bq −1 .h −1 ) [13]. The surface exhalation rate of radon E in x , Bq.m −2 .h −1 , was calculated as follows:…”