Handling interferences in 89Sr and 90Sr measurements of reactor coolant water: A method based on strontium separation chemistry

摘要: Measurements for determining the activity of Sr-89 and Sr-90 in reactor coolant water are associated with limitations due to interferences from radionuclides similar chemical properties beta(-)-energies. From a measurement bias point-of-view these would result mainly an overestimated concentration Sr-90. In order address interference problem, common well-known method was used show need sufficient decontamination. An improvement achieved by taking sample through two initial strontium separations increase decontamination factor. This determines Sr-90, via its daughter nuclide Y-90, Cherenkov counting. work is primarily based on theoretical calculations strontium-, yttrium- other potential interfering radionuclide ratios after instant fission. The done confirm were carried spiked standard solutions fresh water. known contain at composition resembling that detection limit double separation calculated 0.17 Bq/kg 0.38 Sr-89. When using methods solely rely resins, this paper shows factor (DF) significantly higher when than single separation. also DF as effective it comes removing high ratio both Sr- Ln-resin (EiChrom Technologies, Inc., 2003; Tovedal at, 2009b). However, 'old' samples, where e.g. Ba-140 has decayed, does not benefit Furthermore, samples low either, seeing more time consuming separations.