There are arguments to be made on both sides of this question.
On the one hand, nuclear power brings with it a vast potential for disaster. Serious incidents like those at Fukushima or Chernobyl cause the need for large scale evacuations. They could also lead to the deaths of many people. These impacts also last for a long time, leaving areas such as that around Chernobyl uninhabitable for the foreseeable future. This would argue for the elimination of commercial nuclear power.
On the other hand, these sorts of disasters are not certain to happen. By contrast, the problems caused by burning fossil fuels are almost certain. These effects could be just as harmful to various areas, particularly if rising sea levels submerge large areas of land, making them even less inhabitable than areas that received radioactive fallout.
There is, then, no objective way to make this decision. We must decide between horrific consequences that could happen and consequences that are much more certain but are less devastating to human beings.