METHOD OF DETERMINING VOLUMETRIC ALPHA-ACTIVITY OF PLUTONIUM IN PROCESS MEDIA OF NUCLEAR POWER PLANTS Russian patent published in 2015 - IPC G01T1/167 

FIELD: chemistry.

SUBSTANCE: invention can be used to monitor content of plutonium in process media of nuclear power plants. A method of determining volumetric alpha-activity of plutonium in process media of nuclear power plants comprising collecting a sample, filtering the sample at a rate of 0.1-4 l/h through cellulose acetate membrane with pore diameter of 0.1-1.3 mcm, impregnated with hydrated manganese oxide, followed by drying with an air current generated by evacuation, and radiometric measurement of alpha-activity. The analysed sample is pretreated with nitric acid and stripped to dryness, then dissolved in 7.5 M nitric acid solution with addition of 2.5-3.0 g/l sodium nitrate and held at 40-45°C until the release of nitrogen oxides in the form of brown gas ceases; the cooled solution is filtered through a strongly basic anionite, e.g. AB-17, at a rate of (7-10)·10^-3 l/h, after which plutonium is eluated with a resin with a solution of 14-15 g/l ammonium iodide in 10 M hydrochloric acid at a rate twice less than the filtering rate, neutralised with ammonia to pH=6-10 and fed for filtration through a membrane.

EFFECT: high accuracy of determining volumetric alpha-activity of plutonium in process media of nuclear power plants.

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