Separation and activity standardization of Ra by 4πα liquid scintillation counting.

The Ra standardization method is based on the removal of Rn by intensive venting and subsequent separation of radon daughter decay products on a column packed with lead filings, Ra remains in the eluate. The eluate was repeatedly measured by LSC, and the measured values were corrected for the increase in the activity of the Ra daughter products since the separation was completed. The method was applied to EB type solutions from CMI production. The Ra activity was determined with an uncertainty better than 0.6.