DIN EN ISO 21909-2 Beiblatt 1:2024-05

This Supplement applies to passive dosimetry systems for neutron radiation that work with albedo dosimeters with thermoluminescent detectors (TLD albedo dosimeters) and supports the implementation of DIN EN ISO 21909-2 (VDE 0492-3-909-2):2023-12 for this specific application. Together with DIN EN ISO 21909-2 (VDE 0492-3-909-2):2023-12, it replaces DIN 6802-4:1998-04. The standard differs from DIN 6802-4:1998-04 as follows: a) the normative requirements can be found in DIN EN ISO 21909-2 (VDE 0492-3-909-2):2023-12; see there for changes compared to DIN 6802-4:1998-04; b) detailed description of the procedure with TLD albedo dosimeters can be found in this Supplement. The official German personal dosimetry services use TLDs based on LiF. In this case the neutron- and photon-sensitive TLD element is enriched with approximately 95% of the isotope ⁶Li. Neutrons are detected via the reaction ⁶Li(n,α) ³T. The other TLD element mainly contains the isotope ⁷Li, and the ⁶Li content is so low that it is practically insensitive to neutrons. The four areas of application specified in DIN 6802-4 have been adopted. When assigning a TLD albedo dosimeter to a monitored person, the radiation protection officer shall inform the measuring service of the correct N factor (from N1 to N4) so that the correct dose can be calculated. The assignment of typical monitoring fields to different application areas N1 to N4 for personal monitoring with TLD albedo dosimeters is shown in tabular form in the Supplement.