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View document| NKS Programme Area: | NKS-B | | Research Area: | Measurement Strategy, technology and QA | | Report Number: | NKS-85 | | Report Title: | Co-ordination and modernisation of methods for AGS and CGS measurements of multi-nuclide contamination. Report from a seminar | | Activity Acronym: | | | Authors: | Uffe Korsbech, Eldri Naadland Holo, Bent Lauritzen, Helle Karina Aage, Simon Karlsson, Mark Smethurst, Svein Thorshaug, Olof Karlberg, Mikael Moring, Teemu Siiskonen | | Abstract: | Earlier projects within NKS have unveiled that Nordic teams performing Airborne or Car-borne Gamma-Ray Spectrometry (AGS and CGS) used different definitions and methods for data processing and presentation. The differences were clarified and proposals for how to obtain consistent results in the future were suggested. The investigations almost all concerned caesium-137 being the only artificial nuclide that today could be measured in the environment with ordinary AGS and CGS equipment. Therefore it was decided to initiate within NKS an examination of how to map other fall-out nuclides with AGS and CGS. As a first step a seminar was arranged on 17-18 October 2002. Here the participants presented how they would handle the mapping of four pre-defined fall-out scenarios. The presentations and discussions at the seminar showed that carrying out the measurements for some of the scenarios would be difficult or even impossible with ordinary equipment and data processing techniques presently used by some of the teams. Mapping of very high levels of contamination could be a problem. Also mapping of a mixed-nuclide fall-out with iodine-131 at a concentration close to the action/no-action levels could be difficult. The seminar resulted in a list of problems deserving attention. Among those was the question on when to prefer high sensitivity NaI detectors and when to prefer high resolution HPGe detectors. A common definition on "detection levels" was also needed. Here the generation of sets of spectra with different levels and combinations of fallout nuclides was proposed. Among the outcomes of the seminar were two proposals for future NKS projects; one concerned mapping of low levels of iodine, and the other was a method for generation of strip factors from ordinary survey spectra. | | Keywords: | Mapping; contamination; AGS; CGS; fallout; multi-nuclide; iodine-131; Caesium-137; dose rates; detector saturation | | Publication date: | 01 Febr 2003 | | ISBN: | ISBN: 87-7893-143-6 | | Number of downloads: | 2374 | | Download: |  NKS-85.pdf |
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