This paper present the results of a test programme to validate the Dutch pre-normative protocol NVN 5623 ‘Radioactivity measurements: Determination of the activity of gamma-ray emitting nuclides in a counting sample by means of semi-conductor gamma-spectr
Radon concentration in outdoor air and in buildings is very variable, showing diurnal and seasonalvariations. Long term measurements with track etch detectors lasting up to one year give the mostprecise one year averages. It arrives, however, that we are obliged to get results much sooner e.g. forscreening measurements. How long should we measure radon concentration to get proper results? Wehave studied the problem of selecting proper time interval on the basis of our six long-termmeasurements in Krakw using AlphaGUARD PQ-2000 ionization chamber.
Measurements of 210Po embedded in glass have been performed with passive detectors in houses ofthree rural communities of Yugoslavia. Field work has been initiated and carried out by the VincaInstitute, Belgrade and analyses have been conducted by SSI (Sweden), UCD (Ireland), NRPA(Norway) and CRR (Italy). Based on 210Po concentration assessments, radon retrospective estimateshave been produced. Fairly good agreement amongst laboratories resulted both for polonium andradon determinations.
Rad Elec Inc., located in Frederick, MD, USA is the only commercial producer of electret ionchambers (EIC) systems. These are distributed under the brand name of E-PERM, electret-passiveenvironmental radon monitors. Different versions of these are used in various applications, whichinclude: measurement of indoor/outdoor radon, thoron (220Radon), radon flux, radon in water, radiumin soil/building materials, environmental gamma radiation, tritium in air and on surfaces, alphacontamination on surfaces and in soil.
A method is developed to measure 222Rn exhalation rate on soil surfaces using an ionizationchamber radon monitor (AlphaGUARD PQ2000, Genitron Instruments GmbH, Frankfurt,Germany) in passive-diffusion mode.We have developed a compartmental model to describe time variation of radon concentration in theionization chamber. This model consists of two compartmens, one for the external radon field, andone for the ionization chamber.
The application of a radon model is useful to understand the processes that drive the radon gasbehaviour from its sources to its accumulation indoors. Since in a given inhabited house the detailedknowledge of the values of all the parameters that affect indoor radon levels is not available, theresponse of the model has to be explored in a reference site in which all the parameters are supposedto be known. We call this site the reference configuration.
Radon goes through four stages from its formation until it reaches a living environment: i) itsgeneration in the source medium, ii) its migration in the source medium, iii) its entry into a dwelling,and iv) its accumulation indoors. Many parameters of different origin take part at each stage, and mostof them are time-dependent. In this paper we discuss the requirements that an ideal model, whichconstitutes a Global Dynamic Radon Model (GDRM), should fulfil to predict indoor radon levels inliving areas of inhabited houses.
The radon concentrations in indoor air and in soil air vary both on short term (daily, weekly) and onlong term (seasonal). The radon level and its changes depend on a few parameters, which may bedifferent from one building to another and from one type of soil to another. It is important to know theseasonal variation of the indoor radon levels if the level is to be compared with the national upperlimits in Europe for indoor radon concentrations.
In situ gamma spectroscopy is widely utilised to determine the outdoor gamma dose rate from the soiland to calculate the natural and artificial radionuclide concentration and their contribution to the doserate. The application of in situ gamma spectroscopy in indoor environments can not supplyquantitative information about activity concentration of radionuclides in buildings materials, but thistechnique can provide interesting information about building materials as radon source.
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