Countries which have had nuclear leaks or meltdowns: 15.
Number of nuclear leaks and meltdowns since 1952 (only those which resulted in loss of human life or >US$50K property damage): ~100.
About 60% of those have been in the USA, allegedly the most advanced country in the world.
Note that the USA requirements for nuclear reactor waste (yes, they produce toxic waste; they are not clean), last time I checked, required the canisters to be able to survive for 300 years. The waste lasts longer than 300 years.
Two years ago the USA had a leak which spilled ~400,000 gallons of radioactive water into a major river system, and it was covered up for two years.
Finally: If you are not willing to have a nuclear reactor right beside your house, but are willing to have one beside someone else's house, you are a coward and are not really in favour of nuclear power.