The tsunami which hit Fukushima was 43-49 feet tall. For seismic originated tsunamis, this is near the upper limit.

Not all tsunamis are caused by earthquakes though. On July 9th, 1958, there was a rockfall in Lituya Bay, Alaska. A cliff face broke off, and fell 3000 feet into the ocean. This resulting in a tsunami which stripped vegetation at up to 1720 feet in the surrounding areas.

https://geology.com/records/biggest-tsunami.shtml

In Japan? Maybe. Globally? Not even close. As recently as 2004, there was a tsunami in the Indian Ocean that caused over 200,000 casualties (compared to the 15,000-20,000 casualties of the 2011 Japanese tsunami).

Sorry if it seemed insensitive, I didn't mean the most harmful, but the most powerful in terms of physics, as an engineering reference point if you will.

Death toll really isn't a good number to use for gauging the risk to nuclear reactors. Indonesia was more vulnerable to tsunami damage and deaths than Japan for basically the same reasons why Japan has nuclear power plants and Indonesia doesn't.