Architecture and management of a geological repository - Andra

5 – Repository ModulesFigure 5.3.14Longitudinal section through type CU1 and CU2 cellsThe temperature change of the wall of the clay buffer between 0 and 600 years (see Figure 5.3.15)shows that, for the dimensioning indicated in the table above, the temperature returns below the 70°Cthreshold well before 1 000 years, which meets the long-term thermal criterion.Température (C°)90807060504030CU2CU1 court shortCU1 long200 40 80 120 160 200 240 280 320 360 400 440 480 520 560 600Nombre Number d'années of aprés years after la mise disposal en stockageFigure 5.3.15Clay buffer wall temperature for spent fuelsThe dimensioning shown leads to a more rapid decrease in the temperature inside the argilite than intype C waste. This result may appear paradoxical, given the slower decrease in the heat rating of spentfuels; it is due to the large distances between packages imposed by the short-term thermal criterion.• Specific mechanical and thermo-mechanical dimensioning characteristics of spentfuel cellsThe sleeves of cells must maintain functional clearances that retain the capability to withdraw thepackages, for a period in the order of a few centuries. The dimensioning calculation is identical to thatfor type C waste, in both its purpose and assumptions. The only difference is the larger diameter of thecells.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM245/495