Remeasurement of ²³⁴U Half-Life

The half-life of ²³⁴U has been measured using a novel approach. In this method, a uranium material was chemically purified from its thorium decay product at a well-known time. The ingrowth of the ²³⁰Th daughter product in the material was followed by measuring the accumulated ²³⁰Th daughter product relative to its parent ²³⁴U nuclide using inductively coupled plasma mass spectrometry. Then, the ²³⁴U decay constant and the respective half-life could be calculated using the radioactive decay equations based on the n(²³⁰Th)/n(²³⁴U) amount ratio. The obtained ²³⁴U half-life is 244 900 ± 670 years (k = 1), which is in good agreement with the previously reported results in the literature with comparable uncertainty. The main advantages of the proposed method are that it does not require the assumption of secular equilibrium between ²³⁴U and ²³⁸U. Moreover, the calculation is independent from the ²³⁸U half-life value and its uncertainty. The suggested methodology can also be applied for the remeasurement of the half-lives of several other long-lived radionuclides.