§ Dr. Roger Thomas
asked the Secretary of State for the Environment, in the proposals for the disposal of nuclear wastes by deep burial, what materials are being considered for backfilling and sealing the shaft and repository.
§ Mr. Fox
The research into feasibility of geological disposal of nuclear wastes includes study of materials for backfilling and sealing repositories and shafts. The materials under consideration, which may be used singly or in combination, include cement mixes, crushed rock, bentonite clay, polymers, pulverised fly ash, asphalt and salt.