Description
Corrosion of the copper canister under repository conditions.
SKB Number
SKB FEP Number
C11
Main Category
Main category for FEP
Internal process
System Component
System component to which the FEP applies
Cast iron insert and copper canister
Handling
Explanation of how the FEP is treated
Intact canister. Generally, corrosion is modelled based on mass balance and transport capacity considerations whereas reaction rates are disregarded.
Sulphide in buffer and backfill modelled.
Microbially generated sulphide in buffer pessimistically bounded by supply of nutrients for microbes.
Initial oxygen in buffer: Pessimistically assumed that all oxygen corrodes copper neglecting oxygen consumption by buffer pyrite and rock.
Initial oxygen in tunnel backfill: Consider consumption by rock and microbes.
Potentially intruding oxygen: Integrated handling of rock, backfill and buffer conditions.
Pitting (oxygen corrosion): Described as uneven general corrosion.
Corrosion due to radiation: Negligible corrosion depths.
Chloride assisted corrosion: Neglected if pH>4 and [Cl-]<2M.
Corrosion effects on cold worked material neglected due to small consequences, if any.
Corrosion by water modelled as "what-if-case"
Failed canister. Not relevant.
References
Bibliographic references to obtain more information
SR-Site Fuel and canister process report, TR-10-46, Section(s) 1.10, 3.5.4