Method development in support of recertification of plutonium CRMs 136, 137, and 138

Amounts typically used for separations prior to analysis by thermal ionization mass spectrometry for plutonium isotopic analysis at LANL are typically about 20 micrograms of plutonium. We performed a scaled-up separation experiment using 20 milligrams, in an effort to check the separation efficiency using the larger amounts. Results from this separation experiment demonstrated that Pu decay products (²⁴¹Am, and ²³⁴U, ²³⁵U, ²³⁶U isotopes produced from the decay of ²⁴¹Pu, ²³⁸Pu, ²³⁹Pu, and ²⁴⁰Pu) can be cleanly separated using the same columns we use for separation of the 20 µg quantities. The results of the scaled up separation experiments, funded through NBL as part of the DOE Office of Science project are discussed. LA-UR-22-22151. (author)