Community Research and Development Information Service - CORDIS


If radioactive waste is to be stored in deep ocean sediment beds, it will be sealed into a torpedo-shaped device (a penetrator) which, when dropped into the sea, will bury itself to a considerable depth in the sediment. It is essential that the hole made by the entry of the penetrator closes up again to form an effective seal. This report describes the second phase of work on the development of an impedance antenna to detect and measure hole closure. It is shown that a suitable dynamically stable antenna-float combination can be designed, which gives a terminal velocity of 30 m/s, and which prevents the antenna doubling up on the surface of the sediment. The mechanical design meets the buoyancy and strength requirements. Antenna impedance measurement electronics have been developed compatible with the IOS 3.5 kHz acoustic transponder system. A computer model which predicts electric field distribution around the electrodes has been used to determine measurement sensitivity at varying distances. A measurement evaluation program can provide axial and radial position information on sediment resistivity and is capable of locating several holes occurring simultaneously at different locations.

Additional information

Authors: FORTESCUE T R, Thurning Instruments Ltd., Wootton Fitzpaine, Bridport, Dorset (GB)
Bibliographic Reference: EUR 12777 EN (1991) Phase II, 119 pp., MF, ECU 8, blow-up copy ECU 16.25
Availability: (2)
Record Number: 199110414 / Last updated on: 1994-12-02
Original language: en
Available languages: en