Strålningsmätning

Kommittébeteckning: SIS/TK 424 (Kemiska vattenundersökningar)
Källa: CEN
Svarsdatum: den 8 apr 2019
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This document specifies a test method for the determination of gross beta activity concentration in non-saline waters. The method covers non-volatile radionuclides with maximum beta energies of approximately 0,3 MeV or higher. Measurement of low energy beta emitters (e.g. 3H, 228Ra, 210Pb, 14C, 35S and 241Pu) and some gaseous or volatile radionuclides (e.g. radon and radioiodine) might not be included in the gross beta quantification using the test method described in this document.

This test method is applicable to the analysis of raw and drinking waters. The range of application depends on the amount of total soluble salts in the water and on the performance characteristics (background count rate and counting efficiency) of the counter used.

It is the laboratory’s responsibility to ensure the suitability of this method for the water samples tested.

Kommittébeteckning: SIS/TK 424 (Kemiska vattenundersökningar)
Källa: CEN
Svarsdatum: den 11 apr 2019
Se merSe mindre
 

This document specifies a method for the measurement of 210Po in all types of waters by alpha spectrometry.

The method is applicable to test samples of supply/drinking water, rainwater, surface and ground water, marine water, as well as cooling water, industrial water, domestic, and industrial wastewater after proper sampling and handling, and test sample preparation. A filtration of the test sample is necessary.

The detection limit depends on the sample volume, the instrument used, the background count rate, the detection efficiency and the chemical yield. The method described in this document, using currently available alpha spectrometry apparatus, has a detection limit of approximately 5 mBq.l-1, which is lower than the WHO criteria for safe consumption of drinking water (100 mBq·l-1). This value can be achieved with a counting time of 24 hours for a sample volume of 500 ml.

The method described in this document is applicable in the event of an emergency situation.

The analysis of 210Po adsorbed to suspended matter is not covered by this method.

It is the user’s responsibility to ensure the validity of this test method for the water samples tested.

If suspended material has to be removed or analysed, filtration at 0,45 μm is recommended. The analysis of the insoluble fraction requires a mineralization step that is not covered by this document (see NF M 60-790-4[13]). In this case, the measurement is made on the different phases obtained. The final activity is the sum of all the measured activity concentrations.