Guidelines for comparing cost assessments for geological repository projects
The working group has defined some tools and basic guidelines for the comparison of cost assessments of geological repositories:
- The definition of a standardised fact sheet. This is a collation of high-level data including project timing, disposal inventory, repository dimensions and main cost elements which form the basis of the cost assessment. The working group considers the selected data as the principal cost drivers for a geological repository project.
- The alignment of the available undiscounted cost figures by eliminating incorporated contingencies, by escalating the price levels to the same financial reference year and by converting them to the same currency unit on the basis of purchasing power parities (PPPs).
- The break-down of the cost estimations in a standardised costing matrix that compares significant scopes of the programme consistent with the phases of the programme. This break-down allows comparing the economic aspects of the different programmes.
- The distribution of the cost data over the involved quantities of SF, HLW and ILW, according to keys based on dimensions data of geological repositories.
The distribution of the cost data over SF, HLW and ILW is important, as some countries only dispose spent fuel, while some countries only dispose high-level (vitrified) and intermediate level waste and other countries co-dispose of SF, HLW and ILW.
In general we can conclude that a simplified comparison of cost assessments for geological repository projects is not possible or would produce distorted conclusions. A sound comparison implicates a ‘deconstruction’ of the cost estimates and a good knowledge of the related waste inventories.