GAMMA-SPECTROMETRY AND ALPHA-SPECTROMETRY FOR NATURAL RADIOACTIVE NUCLIDES IN THE SPA WATERS OF EXTREMADURA (SPAIN)

Gamma and alpha spectrometry of waters from several spas of Extremadur a (Spain) were performed in order to determine their radioactivity. Fo r the gamma spectrometry, the sample was measured directly using an Hp Ge detector with a Marinelli beaker. The nuclide Rn-222 was determined by measuring the emissions from its daughters (214)pb and Bi-214 and assuming transient equilibrium . Each sample was measured for several days in order to check that Pb-214 and Bi-214 decay with the half-life of Rn-222. Concentrations of Rn-222 ranged from om 3.5 to 234 Bq/l. A lpha spectrometry of uranium, thorium and Ra-226 was performed by chem ical separation of these elements from the samples and then using PIPS detectors for the measurement of the sources. Uranium concentrations were in general below 1 mu g/l (with one exception), thorium specific activities were of the order of 10-5 Bq/l, and Ra-226 activity ranged from 4.5 to 71 mBg/l. These results allow some conclusions to be estab lished about the environmental behaviour of these radionuclides.