Technetium and rhenium in volcanic soils by ICPMS

Technetium-99 (99Tc) and rhenium (Re) were determined in volcanic tuff muck rock, from the potential repository at Yucca Mountain and in nuclear bomb cavity samples from the Nevada Test Site (NTS). These analyses were performed in order to test the feasibility of using high resolution inductively couple plasma mass spectrometry (HR-ICPMS) for the determination of 99Tc. Six 20 gram tuff samples were analyzed in duplicate for 99Tc and Re following separation using an anion exchange resin to remove potential interferences. Four nuclear bomb cavity samples were analyzed using one gram samples. A 99Tc method detection limit (MDL) of 33 pg/kg (parts per quadrillion (ppq)) was achieved, however the tuff samples analyses results were all less than this concentration. The average Re concentration of the six tuff samples was 23 ng/kg (ppt) with an average relative standard deviation (RSD) of 7.5%. The nuclear bomb cavity samples 99Tc analyses results ranged from 330 to 11,900 pg/kg (ppq).