Purification and accurate concentration determination of 231Pa

This work presents the combination of two chemical separation methods to purify protactinium (Pa) oxide from its decay daughter chain. It combines precipitation and basic to neutral washing with ion exchange to reach radiochemical pure 231Pa. The method is suitable to purify 231Pa in milligram scales. Precipitation and washing of Pa hydroxide removes most of the daughter activity and the dose rate. Losses of Pa occurs predominantly in the precipitation stage and are dependent on the conditions used. The subsequent ion exchange procedure showed essentially no losses of Pa and is efficient to fully remove all decay products leaving less than 0.4 % of the Th as an impurity in the purified Pa solution. Full radiochemical purity was obtained by repeating the separation procedure. The radiochemical pure Pa solution was characterised by an alpha ratio method by addition and mixing of a known Cm spike. The specific activity and concentration of 231Pa was determined with an uncertainty of 1 % (coverage factor k = 2).

MALMBECK Rikard;  BANIK Nidhu; 

2022-09-08

SPRINGER

JRC124793

0236-5731 (online),   

https://link.springer.com/article/10.1007/s10967-021-07699-8,    https://publications.jrc.ec.europa.eu/repository/handle/JRC124793,   

10.1007/s10967-021-07699-8 (online),