DIN ISO 18589-7:2014-12

In situ gamma spectrometry is an effective means of making rapid assessments of radioactivity in soil and the dose rates generated by a given radionuclide. It is a powerful measurement method for nuclide specific determination of gamma emitting radionuclides in or on soil. It is a direct measurement method without time consuming and labour-intensive sampling. The quantitative analysis of the recorded line spectra presumes the selection of suitable areas for the measurement, however. Furthermore, it is required to know the physicochemical properties of the soil and the distribution of the radionuclides in the soil. DIN EN ISO 18589-7(VDE 0493-4-5897) applies to portable in situ gamma spectrometry systems with germanium and scintillation detectors for fast activity determination of artificial and natural radionuclides in or on soil. It can also apply for activity determination by clearance procedures in nuclear plants, for example buildings and floor space. The standard is applied for measurement of both artificial and natural radionuclides existing on the surface or in soil. In situ gamma spectrometry covers further applications such as measurement of contaminated soils (contaminated sites) and for environmental restoration, identification of airborne artificial radionuclides, determination of exposure levels inside buildings or during waste disposal operations. Generally, the method can no longer be applied when the spatial distribution of the radionuclides in the environment is not precisely known (influence quantities, unknown distribution in soil) or in situations with very high photon flux (dead time problem). The following significant modifications have been made with respect to DIN 25462:2000-10: a) the measurands and conversion factors have been updated; b) regarding the determination of the decision threshold and detection limits, implementation of DIN ISO 11929; c) regarding the measurement uncertainty, implementation of ISO/IEC Guide 98-3:2008: Uncertainty of measurement - Part 3: Guide to the expression of uncertainty in measurement (GUM); d) the measurement of the ambient dose equivalent rate is not part of the in situ spectrometer and is therefore no longer subject of this standard; e) the description of the hardware components has been adjusted to the state of the art; f) the illustration of the collimator has been corrected; g) the entire document has been restructured and the allocation of individual paragraphs to the clauses, subclauses and annexes has been corrected, respectively. The responsible committee is DKE/GUK 967.2 "Aktivitätsmessgeräte für den Strahlenschutz" ("Activity meters for radiation protection") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.