But you are right about Three-Mile Island.
I myself thought just that until recently after investigating it.
What makes nuclear power unsafe is human error more than technical failure. That's the aspect the naive technocrats (like the guy who wrote this article) always ignore.
"Models predict that by 2065 about 16,000 (95% UI 3,400–72,000) cases of thyroid cancer and 25,000 (95% UI 11,000–59,000) cases of other cancers may be expected due to radiation from the accident, whereas several hundred million cancer cases are expected from other causes. Although these estimates are subject to considerable uncertainty, they provide an indication of the order of magnitude of the possible impact of the Chernobyl accident. It is unlikely that the cancer burden from the largest radiological accident to date could be detected by monitoring national cancer statistics. Indeed, results of analyses of time trends in cancer incidence and mortality in Europe do not, at present, indicate any increase in cancer rates—other than of thyroid cancer in the most contaminated regions—that can be clearly attributed to radiation from the Chernobyl accident."
"But other reputable scientists researching the most radiation-contaminated areas of Russia, Belarus and Ukraine are not convinced. The International Agency for Research on Cancer, another UN agency, predicts 16,000 deaths from Chernobyl; an assessment by the Russian academy of sciences says there have been 60,000 deaths so far in Russia and an estimated 140,000 in Ukraine and Belarus.
Meanwhile, the Belarus national academy of sciences estimates 93,000 deaths so far and 270,000 cancers, and the Ukrainian national commission for radiation protection calculates 500,000 deaths so far."
He's not right about TMI, either. The results of TMI are debated to this day with some studies claiming minimal or no adverse health affects and some studies claiming significant adverse health affects.