Underground nuclear storage is not the only way to store nuclear material. Economically speaking, it is more expensive, but likely much safer to store nuclear waste above ground in facilities that can be easily monitored and dealt with. Unlike in underground storage facilities, should something go wrong above ground, it can be responded to quickly and efficiently and it is likely that problems will be detected earlier as well.  Further, widely implementing underground nuclear storage would also encourage states to be more cavalier with their nuclear energy policies. Specifically, whilst nuclear energy generation may result in zero carbon emissions, the mining and milling of uranium that initially starts the process is environmentally damaging.1  ISN Security Watch. “Europe’s Nuclear Waste Storage Problems.” Oilprice.com 01/06/2010