Year
1983
Abstract
A method for the simultaneous d e t e r m i n a t i o n of americiura and plutonium in reprocessing solutions using an automated on—line c o n c e n t r a t i o n monitor has been developed and evaluated. The q u a n t i t a t i v e assays for plutonium were based on the intensities of the characteristic gamma rays of 238Pu, 239Pu, 240Pu, and 2U1Pu in the 120 keV to 210 keV region of the solution spectra. The assay peaks for americium were the 59.5 keV and 125 keV lines of 2 t t lAm. The method is capable of measuring americium (1 to 1500 ppm) in p l u t o n i um (5 to 50 g/L) solutions with an accuracy b e t t e r than ±5% using the 59.5 keV peak of 2 4 1Am. The observed americium data were compared with those obtained by alpha spectrometry and the values derived from the calculated 241Am (125 keV)/2 3 9Pu (129 keV) ratios of the test solutions. An overall average deviation of 1% for 239Pu and 3% each for 238 Pu, 240 Pu, and 21+1Pu from the mass spectrometry data was noted for the isotopic d i s t r i - bution of p l u t o n i u m . The elemental p l u t o n i um abundances compared very well with those measured by i s o t o p e d i l u t i o n mass s p e c t r o m e t r y and control led—potential coulometry.