The 2012 NATO/PFP SIRA Exercise in Evaluation of Gamma Spectra with Varying Complexity : official Swedish contribution to EAPWP 2012 conducted under the auspices of NATO/JCBRND-CDG/SIBCRA

As part of a continuing program to improve NATO/PFP ability to interpret results obtained in sampling and monitoring activities, the NATO SIBCRA subgroup has conducted a radiological laboratory exercise. In this exercise, FOI CBRN Defence and Security (Umeå) distributed by email a set of six gamma spectra for analysis and provided simple scenarios with each spectrum. The spectra were sent to 22 laboratories from 16 participating nations from NATO and PFP. 21 of the 22 laboratories reported results after 8 h of analysis and 10 of these laboratories made minor to significant changes and additions in their 2-week reports. All laboratories that reported results also completed an exercise evaluation. The results of the participating laboratories ranged from fair to excellent. As expected, very few laboratories had problems with the high-resolution spectra as these are the types of spectra they deal with almost on an everyday basis. Also, most of the laboratories easily dealt with the single radionuclide low-resolution spectrum, which contained 192Ir, whereas only a few were able to correctly identify both radionuclides in the multiradionuclide spectrum. To discern the unique 154Eu peaks hidden in a 152Eu low-resolution spectrum turned out to be difficult. Similarly, the complex laboratory measurement exercises also caused problems for the participating teams. While most teams easily identified 241Am, they found it more difficult to quantify the activity from the given information. The medical isotope task caused similar problems for the participating teams and only a third identified all three radionuclides and estimated activities correctly. Overall, there was little difference between the 8-hour and 2-week responses. Many teams only needed, or allocated, one day for the exercise. It was clear that some of the smaller teams unsurprisingly needed longer time to analyse all spectra and benefitted most from the longer response time, but some larger teams also needed more time for analysis of the most complex tasks. The exercise evaluations brought up several ideas well worth discussing that may assist the standardisation of procedures or results across NATO/PFP laboratories. A forum for such discussions has in the past been the NATO/JCBRNCDG/SIBCRA RTOE. Until the reorganisation of the structures under the JCBRNCDG is settled and finished, it is recommended to bring ideas for discussion to the attention of JCBRND CDG for coordination of further cooperation in this area.