DIN Standards Committee Materials Testing
DIN ISO 2889 Beiblatt 3
Sampling airborne radioactive materials from the stacks and ducts of nuclear facilities; Supplement 3: Estimation of aerosol particle penetration and depositional losses in sample lines
Probenentnahme von luftgetragenen radioaktiven Stoffen aus Kanälen und Kaminen kerntechnischer Anlagen; Beiblatt 3: Abschätzung von Übertragungsgraden und Abscheideverlusten von Aerosolpartikeln in Probenentnahmeleitungen
Overview
DIN ISO 2889:2012-07 describes the requirements for the sampling of airborne radioactive materials from the stacks and ducts of nuclear facilities. Through a series of supplements - currently 5 are intended - the application of the standard shall be supported and information for special aspects shall be given. So far the following supplements have 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 3: Estimation of aerosol depositional losses in sample lines - Supplement 4: Sampling methods - Supplement 5: Method for determination of the performance of sampling devices. The methods for collection of radioactive substances attached to particle samples shall be selected according to their physical and chemical characteristics. Distinction is made between methods for collection of aerosol particles with or without size selection. Furthermore, Supplement 3 contains supplementary information for estimation of aerosol depositional losses in sample lines which shall support the application of DIN ISO 2889. Supplement 3 deals in particular with the following: - interaction of aerosol particles with the wall surface; - deposition in a straight tube by sedimentation, turbulence and diffusion deposition as well as depositions by electrostatic forces and thermophoresis; - depositon in a bent pipe (manifold); - deposition of cross section of the pipe and flow velocity changes; - deposition losses in sampling probes; - deposition of gaseous iodine compounds. 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, Joint Committee with the Radiology Standards Committee (NAR).
