A new set of Large Size Dried (LSD) Spikes for the determination of uranium and plutonium by isotope dilution mass spectrometry in solutions of spent fuel from reprocessing plants has been prepared and certified for uranium and plutonium isotopic contents. The methodology followed was similar to that of previous batches. The solution, made by dissolution of the starting materials in nitric acid, was dispensed directly into individual penicillin vials.
This new batch of large size dried spikes contains ca. 50 mg of uranium (235U abundance = 19.7%) and ca. 1.8 mg of plutonium (239Pu abundance = 97.8%) in each individual vial, covered with a light layer of organic material (cellulose acetate butyrate) as stabilizer.
The U and Pu amount content was certified based on values from mass metrology. Verification of the amount contents of the spike was done by IDMS at IRMM. The values measured for the batch solution and of the dried covered spikes agreed well with those calculated from the weights of starting materials dissolved and the weights of the final solution.JRC.D.4-Isotope measurement
