METHOD FOR DETERMINING SPECIFIC ACTIVITY OF RADIONUCLIDES Pu IN SOLID SAMPLES AND VEGETATION Russian patent published in 2025 - IPC G01T1/00 

FIELD: measurement technology.

SUBSTANCE: invention relates to methods of determining activity of radionuclides of transuranium elements of technogenic origin in different types of samples. Method proposes simultaneous determination of beta-emitting nuclides ²⁴¹Pu and alpha-emitting nuclides ^238,239+240Pu based on ion chromatographic method, their extraction from samples with subsequent determination of specific activity of radionuclides. Sample is dried, ground and quartered, a weighed portion of 1–2 g is taken, dissolved in a mixture of hydrofluoric and 7.5 N acids while heating, solid and liquid phases are separated, 1–2 ml of the solution is taken and the approximate activity of the Pu radionuclides is determined for the quantitative assessment of the radioactive label of Pu, it is added to the solution, which is evaporated to dryness, the dry residue is dissolved in 7.5 N nitric acid, evaporated to wet salts, treated with oxalic acid, sodium nitrite is added to change the valence of Pu, filtering the obtained solution through a chromatographic column filled with ion-exchange resin AB-17 in NO³⁻ form, washing successively with 7.5 N nitric acid and 9 N hydrochloric acid to remove impurities, Pu is eluted with 0.2 N hydrochloric acid, the eluate is evaporated to dryness and calcined on an electric hot plate. Dry residue is dissolved in 7.5 N nitric acid in the presence of hydroperit, evaporated and dissolved in 0.2 N nitric acid. After cooling, a counting sample is prepared by mixing with a scintillation cocktail, then measurement is carried out on a liquid-scintillation beta-, alpha-radiometer and activity of extracted ^{238,239+240,241}Pu radionuclides is calculated.

EFFECT: high sensitivity of the method with reduced measurement error and shorter analysis time.

1 cl, 1 dwg