Canister transfer in access tunnel. Lay-out, system and operation description

In this report the alternative of canister transfer by a vehicle is examined, the principle and the plans are shown in those details that differ from the canister-transfer-throughshaft alternative. In vehicle-transfer alternative the disposal canisters are transferred with a freely steered motor vehicle from ground surface to the repository at level 400 to 500 m below ground surface. The vehicle is a crawler type heavy-load transfer vehicle. The disposal canisters are loaded into the shield cylinder of the vehicle at the encapsulation plant. Canisters are transferred with the vehicle from encapsulation plant to the mouth of the repository ramp, then through the ramp to the repository level underground and finally through central tunnels to the disposal tunnel and disposal hole. Radiation effects of the canister can be detected only in the close vicinity of the vehicle. Transfer route in the site area shall be selected in a way that heavy traffic areas are avoided and the roads used should be even and passable. Underground, the canister transfer proceeds always in the controlled area. The access ramp is declared to be controlled area temporarily in four sections as the transfer proceeds through the ramp. The ventilation is temporarily closed in the controlled area section during canister transfer. To transfer the vehicle from access ramp to the technical rooms of the controlled area of the repository level a construction of a by-pass tunnel is planned. This is made for avoiding disturbance of the simultaneous uncontrolled area operations on the repository level. In two-storey alternative, a by-pass tunnel access is needed also on the lower level of the repository. In case of one-storey repository alternative, the vehicle transfer of the disposal canister does not cause any changes in the order of use of the disposal tunnels or in the organization of controlled and uncontrolled area. In case of two-storey repository, the order of the use of some disposal tunnels is changed. (orig.)