The US has performed almost 10,000 nuclear tests, one can assumethat the USSR has also performed a similar number. No othercountries have performed more than a couple hundred nucleartests.Not all of these tests produced a nuclear explosion (e.g. somefailed, some were "safety tests" designed to prove that safetysystems would prevent an unwanted explosion, some were subcriticaltests), but even then we are talking about many thousands ofnuclear explosions. Much of this information is still classifiedand thus not publicly available.Then there were the three bombs exploded during World War 2: theTrinity Test in New Mexico and the two bombs dropped in combat overJapan (Hiroshima & Nagasaki).