Recent developments in the analysis of transuranics (Np, Pu, Am) in seawater

A procedure is described to extend the current radiochemical method of seawater analysis for Pu and Am including Np. Short-lived Np-239 tracer was prepared by separation from its Am-243 parent. Irish Sea Water reference material (IAEA-381) containing known concentrations of Np-237, Pu isotopes and Am-241 was used to test the procedure for small water volumes. Inductively-coupled plasma mass spectrometry (ICP-MS) was used in addition to alpha spectrometry for measurement of Np-237 in the purified final Np fractions.