Investigation into the behaviour of highly compacted dry low-level radioactive waste under repository conditions
Supercompaction is a process in which drums containing low-level radioactive waste are compressed at a high axial pressure of up to 70 MPa, resulting in a significant saving in the volume of a repository built to store such waste. Recent practice has been to compact waste which has been placed in a sealed primary container, typically a 200-litre steel drum. During the process of compaction the drum is squashed with its contents into a flat pellet; the compaction ratio may reach as high as 20:1. The primary objective of this project was to investigate the physical and some of the chemical characteristics of such supercompacted pellets. All the work was carried out on full-scale 200-litre drums of simulated, but non-radioactive, waste. The compaction ratio reached ranged from 5 to 21, depending on the type of waste. On completion of compaction, all drums exhibited a tendency to expand. The magnitude of ultimate expansion for dry storage was of the order of 1 mm only, whereas under wet storage conditions values were up to about 10 mm. As the presence of moisture can significantly increase the expansion of compacted waste drums or stress developed due to restraint, it is recommended that the waste repository be made water/vapour-tight.
Bibliographic Reference: EUR 13558 EN (1991) 53 pp., FS, ECU 6.25
ISBN: ISBN 92-826-2824-8
Record Number: 199111050 / Last updated on: 1994-12-02
Original language: en
Available languages: en