Rapid Norm Analysis Capabilities

The Client

Mining, Oil and Gas Industries

The Challenge

Radium 226 and Thorium 230 can be concentrated in waste materials related to mining, oil and gas operations. These isotopes are of interest due to their relatively high radiotoxicity and potential exposure to workers and the public.  GEL has developed rapid techniques to handle screening for these isotopes in soil, sludge, slag and other materials when time restrictions apply.

GEL Labs Services Provided

Samples are processed “as received” in order to meet a rapid turnaround.  Depending on the project needs, results can be delivered in 24-48 hours.  The “as received” designation implies that drying and bulk homogenization procedures, which would typically add 2-3 days to the process, are bypassed .  A sample of approximately 120-200 grams (depending on sample density) is added to a 100 cc aluminum can, which is then hermetically sealed.  Samples are counted on a high purity germanium detector for 1-2 hours to ensure detection limits are achieved of 0.15 Bq/g for Ra226 and 0.5 Bq/g for Th230.

The Result

GEL has successfully provided rapid results for Radium 226 and Thorium 230.  Radium is determined by  monitoring the signature gamma line at 186 kev.  Data reviewers evaluate alternate lines for correlation and potential for interferences.  For example, if a soil is largely in secular equilibrium, the Bi214 line will be used as a validation cross reference. If maximum sensitivity is needed, GEL can hold the can for recounting after 14-21 days to evaluate Ra226 by the ingrowth of Bi214, which can reduce the detection limit by a factor of 10.

Th230 is determined along with Ra226 by its direct gamma line at 68 kev.  This region of the gamma spectrum can be difficult due to Compton effects and other natural isotopic activity.  GEL offers  alpha spectroscopy as a cross check technique if needed, that would reduce the detection limit to 0.05 Bq/g.