Traces of radioactive ¹³¹I in rainwater and milk samples in Romania

Measurements of ¹³¹I (T_1/2 = 8.04 days) activities have been performed in the IFIN HH (Horia Hulubei National Institute of Physics and Nuclear Engineering) underground laboratory situated in Unirea salt mine, Slănic-Prahova, Romania. The rainwater samples were collected starting on 27 March from Braşov and Slănic-Prahova. Also sheep and goat milk samples were collected in the Slănic, Braşov and Iaşi areas and measurements were subsequently made on them. The measurements on the samples were made at the IFIN HH's underground laboratory in an ultra-low radiation background, using a high resolution gamma-ray spectrometer equipped with a GeHP (hyperpure) detector having a full width at half-maximum of 1.80 keV at 1332.48 keV for the second ⁶⁰Co gamma ray and a relative efficiency of 22.8%. The results show a specific activity of ¹³¹I from < 0.063 to 0.75 Bq l ^{− 1} for rain. In the milk samples the specific activity varied from < 0.12 to 5.2 Bq l ^{− 1}.