Measurement procedures for large masses to determine whether radiation levels are below the low limiting values required for release from the control region
The dismantling of nuclear facilities requires proof that the radioactivity of materials to be released from restricted areas remains below limit values. The specific radioactivity of parts with smooth, plane and open surfaces is at present estimated manually by analysing representative samples or by measuring the surface of the part with beta sensitive, large-area gas flow detectors. These measurements require large amounts of time and staff and are very costly. Measurements to prove that radiation levels have fallen below radioactive limit values are difficult on parts with complex geometries. To keep the cost of measurements low, NIS has developed a measuring device which enables the examination of large amounts of dismantled and potentially releasable components by a fast, automated procedure. The device, with nearly 4-pi detector geometry, measures the gross gamma-radiation, which has a higher penetration capacity into the material than beta-radiation. The measuring tunnel is 1.2 m wide and 1.2 m high and can handle parts up to 4 m long and one metric ton in weight.
Bibliographic Reference: EUR 13438 DE (1991) 86 pp., FS, ECU 8.75
ISBN: ISBN 92-826-0586-8
Record Number: 199110925 / Last updated on: 1994-12-02
Original language: de
Available languages: de