Download presentation
Presentation is loading. Please wait.
Published byBertram Adams Modified over 9 years ago
1
Distribution of radionuclides in soils in surroundings of Bratislava, capital of the Slovak Republic. II. Man-made radionuclides Mátel Ľ., Rosskopfová O., Rajec P., Galanda D.,Švec, V., Department of Nuclear chemistry, Faculty of Science, Comenius University, Mlynská dol. CH-1, 842 15 Bratislava, Slovakia
2
The actual distribution of the concentrations man-made radionuclides in soil from the area of Podunajske Biskupice is presented. The monitoring was located 12 km south east from Bratislava centre. Documentation is based on the collection of soil and analysed for 137 Cs, 90 Sr, 239,240 Pu, and 241 Am
3
The soils were analysed using gamma spectrometry - ( HPGe detector with relative efficiencies 28 %, Ortec ) - 137 Cs. Analytical procedures involve total dissolution of the samples, followed by radiochemical separation and purification using solvent extraction ( Aliquat-336 - 239,240 Pu; TBP - 90 Sr ), calcium oxalate precipitation and extraction chromatography an Eichrom TRU Resin - 241 Am
4
Separation scheme for the simultaneous determination of Pu, Sr ( A ); Pu, Am ( B ) - soil, sediment ashing add tracers 236 Pu ( 242 Pu ), 243 Am and carriers ( Ba, Pb, Sr, Y ) acid leaching with 8 M HNO 3 - H 2 O 2 ( autoclave, 180 0 C, 3 times ) plutonium oxidation state adjustment ( NaNO 2 ) extraction with equal volume 30 % Aliquat 336 in toluene ( in nitrate form )
5
A aqueous Am, Cm,Y organic Th, Pu, U evaporate washing with 8 M HNO 3 ( U ) dissolution in HNO 3 10 M HCl (Th ) organic Pu aqueous extraction with TBP (Y ) ( discard ) stripping Pu with H 2 C 2 O 4 - HCl organic Y aqueous (discard ) stripping with H 2 O micro precipitation with NdF 3 precipitation of oxalates ( pH = 2-3 ) Alpha spectrometry of Pu Beta counting of Y-90 ( Sr-90 )
6
B aqueous Am, Cm organic Th, Pu, U evaporate washing with 8 M HNO 3 ( U ) 10 M HCl ( Th ) dissolution in 12 M HCl organic Pu aqueous evaporate (discard ) dissolution in 1M HCl stripping Pu with H 2 C 2 O 4 - HCl ( NH 2 OH.HCl, Ca 2+ ) calcium oxalate precipitation destroy oxalate dissolved in 2 M HNO 3 /0,5M Al(NO 3 ) 3 extraction chromatography ( TRU.Spec Resin ) convert to Cl - form with 9 M HCl 4 M HCl - Am Micro precipitation of Pu, Am with NdF 3 Alpha spectrometry of Pu, Am
8
The interval of specific activity (Bq.kg -1 ) are 137 Cs: 14,1 - 83,8 90 Sr:3,8 - 29,2 239,240 Pu: 0,130 - 2,904 241 Am: 0,704 - 0,580
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.