Why was Benj Clarke trying to blow up Iceland?

Ra couldn't assume that Laura would have the ability to resurrect Rachel. If that isn't an option, what is the next course of action for Shard-Ra to resurrect Sun-Ra? One of the main advantages of the key is the access to the massive amounts of energy. Shard-Ra probably already had the programming needed to reactivate, as demonstrated with the quine. Thus the only thing it needed was a massive energy packet of thaumonuclear proportions.