237 Np analytical method using 239 Np tracers and application to a contaminated nuclear disposal facility

Abstract

Environmental Np analyses are challenged by lowNp concentrations and lack of an available yield tracer; we report a rapid, inexpensive Np analytical approach employing the short livedNp (t = 2.3 days) as a chemical yield tracer followed by Np quantification using inductively coupled plasma-mass spectrometry.Np tracer is obtained via separation from a Am stock solution and standardized using gamma spectrometry immediately prior to sample processing. Rapid digestions using a commercial, 900 W "Walmart" microwave and Parr microwave vessels result in 99.8 ± 0.1% digestion yields, while chromatographic separations enable Np/U separation factors on the order of 10 and total Np yields of 95 ± 4% (2σ). Application of this method to legacy soil samples surrounding a radioactive disposal facility (the Subsurface Disposal Area at Idaho National Laboratory) reveal the presence of low level Np contamination within 600 m of this site, with maximumNp concentrations on the order of 10 times greater than nuclear weapons testing fallout levels.

RAPID: The Development and Application of a Hybrid High Pressure Ion Chromatography and Inductively Coupled Plasma Mass Spectrometry Method for the Direct Analysis of Irradiated Materials

“…In the early 2000's, IC-ICPMS methods were developed to analyze actinides, lanthanides, and other metals in samples such as "urban road dust" and atmospheric particles [22], National Institute of Standards and Technology (NIST) standards of soil and a human lung [23], environmental samples [24,25], uranium materials [26], and spent nuclear fuel [27][28][29][30]. More recently, work has been done to isolate and determine the concentrations of elements such as Np [31], Mg [32], Sr [33,34], Cs [35], Pu [36,37], Nd [38], Bk/Cf [39], Sm [40], and various other metals [41,42] through IC-ICPMS analysis.…”