Rapid fusion method for determination of plutonium isotopes in large rice samples

Abstract

Keywords: rapid, separation, plutonium, isotopes, food, rice, emergency AbstractA new rapid fusion method for the determination of plutonium in large rice samples has been developed at the Savannah River National Laboratory (Aiken, SC, USA) that can be used to determine very low levels of plutonium isotopes in rice. The recent accident at Fukushima Nuclear Power Plant in March, 2011 reinforces the need to have rapid, reliable radiochemical analyses for radionuclides in environmental and food samples. Public concern regarding foods, particularly foods such as rice in Japan, highlights the need for analytical techniques that will allow very large sample aliquots of rice to be used for analysis so that very low levels of plutonium isotopes may be detected.The new method to determine plutonium isotopes in large rice samples utilizes a furnace ashing step, a rapid sodium hydroxide fusion method, a lanthanum fluoride matrix removal step, and a column separation process with TEVA Resin™ cartridges. The method can be applied to rice sample aliquots as large as 5 kg. Plutonium isotopes can be determined using alpha spectrometry or inductively-coupled plasma mass spectrometry (ICP-MS). The method showed high chemical recoveries and effective removal of interferences. The rapid fusion technique is a rugged sample digestion method that 2 ensures that any refractory plutonium particles are effectively digested. The MDA for a 5 kg rice sample using alpha spectrometry is 7E-5 mBq g -1 . The method can easily be adapted for use by ICP-MS to allow detection of plutonium isotopic ratios.

Analytical Methods for the Determination of 90Sr and 239,240Pu in Environmental Samples

“…Compared with the soil surface, the transfer factor (TF) absorbed by roots was 0.032 ± 0.014 (Bq·kg −1 fresh grass mass)/(Bq·kg −1 dry soil mass), and the TF of forage grass in the literature was in the range of 5 × 10 −5 –0.7. Sherrod et al [ 30 ] determined the activity of 239 Pu in rice samples as 11.8 Bq·kg −1 . Lee et al [ 74 ] measured Pu and Am isotopes in the volcanic soil of Jeju Island and the Korean Peninsula.…”

“…In addition, the melting method is sometimes used in the sample pretreatment process [ 30 ], such as processing the insoluble residues in the wet-digestion method, accelerating the isotope exchange balance between the tracer and the target nuclide, etc. The melting method can treat kilogram samples, and the treatment effect depends on flux, temperature, and so on.…”

Alpha-particle spectrometry for the determination of alpha emitting isotopes in nuclear, environmental and biological samples: past, present and future

“…AS is important for the determination of all anthropologically introduced a-emitters in the environment [85][86][87][88][89] (e.g., soil, vegetation, water, etc.) due to mining and exploration, nuclear electricity production, nuclear fuel reprocessing, handling and storage of nuclear wastes, unfortunate nuclear reactor accidents like Chernobyl (Russia) and Fukushima (Japan), atmospheric weapon tests, and accidents of satellites with a nuclear power source of 238 Pu.…”

Elemental and Isotopic Mass Spectrometry

“…This method can easily allow detection of plutonium isotopic ratios [119]. For example, a rapid fusion method was developed in order to determine very low levels of plutonium isotopes in large rice samples.…”