Application of gamma-ray spectroscopy to the differentiation between mobile and deposited fission products in pipes
In order to study the effects of fission product release under severe accident conditions, a method is required which differentiates between fission products flowing along a pipe and deposit on the inside pipe wall. A gamma-spectroscopic method utilises combinations of collimators to provide the required discrimination. A systematic examination was made of gamma-radiation obtained from gases and deposits in pipes of different diameter for a number of collimator combinations. This was used to optimise collimator/pipe parameters to cover a range of possible applications. The Monte-Carlo modelling code MCNP was used to provide a calibration in situations where it was not possible to make separate measurements of gas and deposit contributions. The results were found to be broadly in agreement with a series of laboratory measurements. It was demonstrated that gamma-spectroscopic techniques can be used to discriminate satisfactorily between flowing and deposited fission products in pipes. In addition, consideration was given to the effects of movement between pipe and collimator which may arise if significant heating of the pipe occurs.
Bibliographic Reference: EUR 13215 EN (1990) 24 pp., FS, ECU 5
ISBN: ISBN 92-826-1939-7
Record Number: 199110479 / Last updated on: 1994-12-02
Original language: en
Available languages: en