In a Powell's review of Hermann Scheer's Energy Autonomy: The Economic, Social and Technological Case for Renewable Energy, April Placencia says,

Scheer does not consider nuclear energy to be a viable alternative to fossil fuels or renewable energy. He contends that nuclear energy is too dangerous because peaceful civilian uses are so closely tied to military applications. In addition, nuclear energy production consumes resources such as water, divides global society into the "haves" and the "have-nots," requires a significant amount of backup capacity, and creates waste that is hazardous and difficult to deal with. In the chapter "Sun or Atom," he writes at length about the "nuclear crisis," the high costs of atomic energy, and the less-than-stellar payoff of nuclear energy.

This point about peaceful civilian uses being closely tied to military applications is one highlighted in most of the cautions countering the latest NIE regarding Iran's nuclear development. From what I understand, the big shift between the old intelligence and the new is not exactly what Iran is doing, but why; there seems to be more belief that they really are working on civilian uses. The point to draw from Scheer is that if nuclear power were not seen as a perfectly reasonable way to obtain energy, Iran would have more difficulty claiming it is not looking for a military application. Admittedly, conservative immediately sneer that any country with lots of oil couldn't possibly be looking for an alternative energy source. But I can believe that Iran foresees a future in which it will be making such whopping profits on oil export that domestic use will be priced out, so it had better find something affordable for its own people's use while other nations gobble its oil. That I can believe it, however, doesn't mean I think it's actually true with regard to Iran's current leadership.

But even if the U.S., EU, Russia, China and other major nations came to a consensus that nuclear energy shouldn't be used, I don't know of a way to enforce that on other countries. Nuclear energy has environmental effects, so perhaps there would be a treaty like the Stockholm Convention restricting DDT, except the Convention was signed by only 98 countries. Iran is very unlikely to sign such a document now, and as we have seen in the case of even the U.S. itself, having a government of a nation sign an agreement does not mean that future governments of the same country won't withdraw.