RD&D-Programme 2004 - SKB

During the initial step E, which was concluded in 2002, a combined but non-site-adapted design
of the deep repository facility’s surface and underground parts was carried out and a reference
design was devised for them. A facility description, Layout E, has been prepared with drawings
showing the function, size and scope of the facility. The facility description has been published
in three versions with alternative accesses: Straight ramp with two operating areas /11-6/, spiral
ramp with one operating area /11-7/, and shaft alternative with one operating area /11-8/.
A study was conducted in 2003 as a basis for the different access alternatives ramp and/or shaft
/11-9/. The result is a recommendation to build both ramp and shaft, and SKB has devised a
schematic design of the deep repository, see Figure 11-2, that includes a ramp that is used for
transporting heavy loads, a skip shaft for transport of rock much and backfill, and three ventilation
shafts.
In designing the underground part, it is important to adapt it to the geological conditions on the
site. Adaptation means that the layout and placement of tunnels, shafts and rock caverns and
positions for canister deposition are adjusted as increasingly detailed and deeper knowledge
concerning the conditions in the rock becomes available. The methodology is sometimes called
information-based design and entails that the underground part is designed for the interpretation
of the conditions in the rock that is judged to be most probable, but that variants are also devised
for alternative interpretations. When the conditions have been determined with greater accuracy
during the construction phase, the available information is used for e.g. final placement of
deposition tunnels and individual deposition holes.
Figure 11-2. Schematic design of the deep repository.
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