DIN ISO 2889 Beiblatt 5:2014-09

DIN ISO 2889:2012-07 describes requirements for sampling airborne radioactive materials from the stacks and ducts of nuclear facilities. The application of the standard is supported by a series, 5 are currently scheduled, of supplements which give information about special aspects. The following supplements have yet been published: - Supplement 1: Distribution of activity via the diameter of aerosol particles; - Supplement 2: Assessment of the changes in the concentration of aerosol particles due to non-isokinetic sampling; - Supplement 4: Sampling methods; - Supplement 5: Estimation of the activity-related correction factors: activity-related total-loss factor and activity related tube factor. Monitoring of activity releases of radioactive substances in the effluent air of nuclear facilities is performed for the following reasons: 1) on the one hand, level and changes of activity releases of radioactive substances provide information to the operator about the quality of emission controls and changes in the operating condition; 2) on the other hand, monitoring of the activity releases serves the balancing of released activities, the proof that none of the limits prescribed by the regulator are exceeded, and as a basis for calculating radiation exposure of the population. In nuclear plants, monitoring and balancing of activity releases of radionuclides with the effluent air is performed according to the Emission and Immission Guideline (REI) and according to KTA 1503.1. Since, for the purpose 1), only approximate values of activity releases and, in particular, the changes of these values over the time are important, higher uncertainties of measurement are permissible. For the purpose 2), namely balancing of activity releases, the uncertainties of measurement shall be as low as possible. Therefore, all influences which might lead to a corruption of values have to be considered and reduced or corrected as far as possible. This Supplement 5 provides terms and definitions and suggestions for the estimation of the activity-related correction factors for the procedures used when determining activity releases of radionuclides attached to particles for balancing. The responsible committee is DKE/GUK 967.2 "Aktivitätsmessgeräte für den Strahlenschutz" ("Radiation protection instrumentation") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE, collaborating with the Radiology Standards Committee (NAR).