The Belgian nuclear waste agency ONDRAF/NIRAS developed the concepts of supercontainer and monolith for packaging nuclear waste of category C and B for disposal in a geological repository excavated in the Boom Clay formation. The presence of metal components in the supercontainer, monolith, and primary package of the waste, as well as in the waste itself poses a risk of gas problems. Anaerobic corrosion of these metals results in the production of hydrogen gas (H2), which will dissolve in the near field pore water. This report deals with the estimation of the gas source term due to anaerobic corrosion of metals for the spent fuel (SF) waste stream, for both direct disposal and reprocessing scenarios. In the latter, the contribution of the vitrified high-level waste (VHLW) package and of the compacted wastes (hulls, endpieces, etc… compacted into compaction cans of which 8 are placed into a CSD-C canister) are evaluated. In addition, the contribution of the MOSAIK casks used for packing waste arising from the dismantling of lower core internals of Belgian PWRs is also estimated. For each waste type, stepwise time variations of the gas production rate are obtained.
|Number of pages
|Published - Apr 2012
|Studiecentrum voor Kernenergie