Disequilibrium in the uranium and actinium series in oil scale samples

We have investigated the disequilibrium of the uranium and actinium series and have found both ²²⁶Ra (90,200 ± 4300 Bq/kg) and ²²⁸Ra have activity concentrations orders of magnitude higher that ²³⁸U (1.83 ± 0.36 Bq/kg) and ²³²Th (7.0 ± 0.4) which are at the head of the decay series. As well the activity concentration of ²¹⁰Pb (24,400 ± 1200 Bg/kg) was about 3.6 times less than ²²⁶Ra. Once an efficiency curve was constructed summing corrections for specific isotopes in the decay change also needed to be taken in consideration. Furthermore, self-attenuation of the photons especially the 46.5 keV belonging to ²¹⁰Pb was calculated to be 78% since the scale had elevated elemental concentrations of high-Z elements such as barium and strontium.