Rapid method to determine 89Sr/90Sr in large concrete samples

Abstract

A new rapid method has been developed that provides high quality low-level measurements of 89,90 Sr in concrete samples with an MDA (Minimum Detectable Activity) of <1 mBq g-1. The new method is fast, meets new decommissioning regulatory limits and is robust even if refractory particles are present. The method utilizes a rapid fusion to ensure total dissolution of samples and rapid preconcentration and separation of 89,90 Sr from 5-10 g concrete samples. When, the 89 Sr/ 90 Sr ratio is high, Sr can be isolated from up to 5g concrete samples, total 89/90 Sr measured, and then 90 Sr determined via 90 Y separated after a period of ingrowth. Another approach allows the immediate determination of 90 Sr in 10 g concrete aliquots without waiting for 90 Y ingrowth, in instances where the shorter lived 89 Sr is unlikely to be encountered.

Fusion and chemical separation of Am, Pu and Sr from barite-concrete

“…When shielding concrete is reinforced by BaSO 4 , the resulting density of the concrete is higher than 3 g/cm 3 . Therefore, conventional dissolution techniques, such as leaching or microwave digestion, will not succeed in fully decomposing the material.…”

“…For most purposes, leaching or partial microwave dissolution is sufficient to get the elements of interest into solution. Si is a prominent component of barite-concrete; therefore hydrofluoric acid (HF) is often used to remove SiO 2 , since SiO 2 can have an influence on radionuclide separation and purification [3]. A most common fusion technique for shielding concrete is the sodium hydroxide fusion using Zr crucibles and an additional step with HF to remove Si [4].…”

Recent Development on Determination of Low-Level 90Sr in Environmental and Biological Samples: A Review

“…Another pretreatment method for solid environmental samples is alkaline fusion, in which fusion flux such as Na 2 CO 3 and Na 2 O 2 , NaOH or LiBO 3 is mixed with the solid sample and melted at a high temperature, e.g., 300-1000 • C [70][71][72][73][74][75]. Jurecic et al [72] compared conventional acid digestion using a mixture of HNO 3 , HClO 4 and HF, microwave-assisted digestion using HNO 3 and HF, and alkali fusion with Na 2 CO 3 and Na 2 O 2 .…”

Rapid method to determine 89/90Sr in steel samples

“…[6] Consistent with this need, a sodium hydroxide fusion method for complete dissolution of 10g concrete samples was recently published by this laboratory. [8] Similar sodium hydroxide fusion methods have been used with great success for soil, concrete, vegetation and other solid samples. However, steel samples cannot be adequately dissolved with sodium hydroxide fusion.…”

“…The search for more rapid analyses has also led some to pursue inductively-coupled plasma mass spectrometry (ICP-MS) to measure 90 Sr. [14] While ICP-MS offers a simplicity that may be appealing, it suffers from poor detection limits when compared with beta emission measurement methods [8] due to the relatively short half-life of 90 Sr (28.9 years). Additionally, the measurement of 90 Sr by ICP-MS is affected by the 90 Zr isobaric interference and often requires effective matrix removal to produce samples suitable for injection into an ICP-MS instrument.…”