RD&D-Programme 2004 - SKB

10.7 KBS-3 with horizontal deposition
The KBS-3 method is based on the multiple barrier principle. The possibility of modifying the
reference method and depositing the canisters horizontally in a row in long horizontal deposition
drifts instead of vertically in deposition holes with one canister in each has been discussed
since the early 1990s /10-14 to 10-17/. The above-ground part, accesses and central area under
ground can be designed independently of what the actual deposition area looks like. The
fundamental difference between the reference method (KBS-3V) and a KBS-3 repository with
horizontal deposition (KBS-3H) is shown in Figure 10-5. The canister and buffer are the same
in both variants.
Conclusions in RD&D 2001 and its review
In RD&D 2001, SKB described the initiated work of devising a research, development and
demonstration programme for KBS-3H, which was then termed Medium Long Holes.
In its review of RD&D 2001, SKI pointed out that it is gratifying that SKB presented an alternative
with horizontal deposition, but that a decision regarding e.g. horizontal deposition may have
to be made relatively soon. Further, SKI noted that a demonstration of the horizontal deposition
technique is required.
Newfound knowledge since RD&D 2001
In 2001, SKB published a research, development and demonstration programme for a KBS-3
repository with horizontal deposition /10-18/. The programme, which is being carried out
stepwise in cooperation with Posiva during the period 2002–2010, includes feasibility study,
conceptual design, manufacture of equipment, demonstration and field tests at the Äspö HRL,
plus an evaluation. The programme has been fitted as much as possible into SKB’s reference
timetable for the deep repository.
The feasibility study, which was conducted in 2002, mainly dealt with technical matters such as
technology for rock excavation, handling equipment for deposition and design of a deposition
container. The study showed that the concept is technically feasible. The work of devising a
conceptual design was carried out during 2003. The purpose of this phase of the project was to
identify critical points with regard to long-term safety in the programme. The work has involved
three areas: technical development, preparations for a demonstration, and initial studies of
Figure 10-5. Fundamental difference between the reference method KBS-3V (left) and KBS-3H
(right).
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