U-series radionuclides and ¹³⁷Cs in sediment

This method specifies the minimum requirements and laboratory methods for simultaneously measuring multiple U-series nuclides, including ²³⁸U, ²¹⁰Pb, ²²⁸Th, ²²⁸Ra, ²²⁶Ra, ⁴⁰K, and ¹³⁷Cs.

Samples are collected using crab sampler or gravity sampler, sealed on board and finally kept at -18°C. Post processing will take place in the land laboratory by freeze-dry and measuring using gamma-spectrometry. Isotope decay corrections are applied to some specific radionuclides (such as ²¹⁰Pb, ²²⁸Th, ²²⁸Ra, and ¹³⁷Cs) if the time gaps between sampling and measurement introduce discernible variations in activities.