Not unsafe? The likelyhood of failure is higher than you think! Trying to contain the atomic dragon is a fools errand. The story dosent end with safe operation, even if that was possible? The waste products are still a major unsafe factor! Radioactive metals contain much more power than you realize. Not unsafe, tell that to the people affected by ionizing radiation, everyone on earth has an increased risk of cancer due to the atomic age! Don't be fooled by lack of published data linking it up! Radiation in your body from fusion isotopes are detectable! No where on the planet remains unaffected.
All of humanities activities carry with them a certain degree of danger. The more energy involved, the more dangerous they become. A significant amount of effort must be placed in decreasing those dangers, but there will always be danger.
Unless you plan to give up your computer, car, mass transit, pretty much all mass produced goods, and go back to an egrarian lifestyle, you will have to deal with industrial accidents. Engineers are pretty good at preventing known types of accidents from re-occuring, but the unknown will always cause bad things to happen. Claiming that Nuclear is worse than the alternatives just betrays your own ignorance. Indeed, we had all been largely ignorant of fossil fuels consequences for decades, but the use of Oil, Gas and Coal may have had far more dire consequences for the future of humanity than all of the radiation disasters put together. The liklihood that something else, we have been doing since the dawn of the industrial revolution, will be the death of us all is greater than the chance that nuclear will be our downfall.
In the end, so called "renewable" resources may be our best bet, but they are not sufficient for our needs currently, and may never be, and who knows what genie those technologies have bottled up for the future.
In the far distant future, mankind will have solved universe spanning power production using some technology we cant comprehend yet. In 1000 years, who knows what breakthrough power generation system we will use, but holding our breath waiting for a breakthrough will overwhelmingly likely end with all of us sitting in the dark. In 500 years, we most likely won't be using fossil fuels anymore because we probably wont have any more to use), and I'd give long odds that if we still have a global economy by that time, the underpinnings will be a fission or fusion power grid. Nothing else has the where-with-all to produce the power we have come to demand.