Radioactivity in polymetallic nodules from the Clarion-Clipperton Zone
Description
In this study we present, for the first time, specific activities of all long-lived alpha, beta and gamma emitters from the natural decay chains of Uranium-238, Uranium-235 and Thorium-232, in bulk and surface material of the same nodules obtained from 10 locations within the Clarion-Clipperton Zone. The results show elevated specific activities for the nuclides Th-230, Ra 226, Pb-210, Po-210, as well as Pa-231 and Ac-227 in accordance with prior reported activities. However, in contrast to assumptions made in previous studies, our analyses show that Pa-231 is not in equilibrium with its daughter nuclide Ac-227.
Files
Steps to reproduce
Data were obtained from bulk and surface samples of manganese nodules. Surface samples were scraped off the nodules to a depth of 1 mm. Specific activities were determined by gamma spectrometry and alpha spectrometry. Partly, alpha spectrometric results were calibrated using results of gamma spectrometry.