I'm sure I'm missing something here, but why can't we drill down in a geologically stable area (like Australia) far below any water table and bury it? I'm imag

I'm sure I'm missing something here, but why can't we drill down in a geologically stable area (like Australia) far below any water table and bury it? I'm imagining a bored out cylinder in solid bedrock just wide enough to stack barrels made of some kind of space-age material, like 15,000' down. I don't know much about the drilling tech, so it might be totally impossible.