Description

After full water saturation and when the hydrostatic water pressure is reached, the plug has no sealing function and very little water will flow past the plug due to the low hydraulic gradient. The plug will thus be an integrated part of the backfill and will have one very tight section with the bentonite seal and two highly permeable sections (the filter and the concrete plug). However, the permeable sections are only local and will not influence the overall hydraulic behaviour of the tunnel backfill.

SKB Number

SKB FEP Number

Pg04

Main Category

Main category for FEP

Internal process

System Component

System component to which the FEP applies

Tunnel plugs

Handling

Explanation of how the FEP is treated

Intact canister, Resaturation/ "thermal" period: Assumed to be part of the tunnel with high hydraulic conductivity. Intact canister, Long-term after saturation and "thermal" period: Assumed to be part of the tunnel with high hydraulic conductivity.

References

Bibliographic references to obtain more information

SR-Site Buffer, backfill and closure process report, TR-10-47, Section(s) 2.4.3, 5.2.2