Canister spacing in high-level radioactive nuclear waste repository

One of the core problems of waste canisters layout in high-level radioactive waste repository is the evolution of the temperature field. On basis of the layered thermal analysis model for single waste canister, the expression of temperature increment at any location in surrounding rock in the repository was obtained by the superposition principle. The initially estimated value of the canister spacing (CS) was determined according to the temperature design criterion. Finally, the influence of relevant parameters on the canister surface temperature (CST) was analyzed. The results were drawn as follows: (a) Taking thermal conductivities of 2.4 and 2.8 W/(m × K) for the rock as examples, the appropriate CS is 12.2 and 13.5 m under the tunnel spacing of 40 m, respectively. (b) The greater the CS, the greater the thermal conductivity of bentonite and rock, the smaller the CST would be. (c) The thicker the buffer layer, the less the heat flux inside the canister would spread out.