I support the use of nuclear energy and I understand that there are risks. However technology is improving at a rapid pace so I believe many of the issues in the past won't happen again. All the people involved in those projects do not wish to see these accidents.
As you said, it may be costly to build and start these plants, the amount of clean energy produced is amazing. Especially since we do not produce enough renewable energy from wind or solar at this point in time. Also I think diversification in energy sources is a good thing as you never know when you will have issues with one source.
RE: Why countries gamble on nuclear energy to combat climate change?