Lets consider a rather large "bad thing": The Fukushima Disaster last year. Supporters of nuclear power and TEPCO themselves like to fall back on the "unpredictability" of the event as their primary defence.
Sadly, the record proves them wrong.
An AP report from March 27 2011 gets to the crux of the issue1. In summary, in 2001 papers were first published detailing the geological information that was building up about the Jogan/Sanriku earthquake and tsunami of 869 indicating that it was both more dangerous than previously thought and that there appeared to be evidence of an 800 to 1100 year cycle period for it. This made the possibility of a similar earthquake happening soon increasingly likely as we moved into the 21st century. TEPCO's response was to ignore the evidence, going as far as to try and argue it was "unreliable":
In a 2007 paper published in the peer-reviewed journal Pure and Applied Geophysics, two Tokyo Electric Power Co. employees and three outside researchers explained their approach to assessing the tsunami threat to Japan’s nuclear reactors, all 54 of which sit near the sea or ocean.In other words, when the facts don't fit our version of reality, discard.
To ensure the safety of Japan’s coastal power plants, they recommended that facilities be designed to withstand the highest tsunami “at the site among all historical and possible future tsunamis that can be estimated,” based on local seismic characteristics.
But the authors went on to write that tsunami records before 1896 could be less reliable because of “misreading, misrecording and the low technology available for the measurement itself.” The Tokyo Electric Power Co. employees and their colleagues concluded, “Records that appear unreliable should be excluded.”
This would almost be excusable in a: "Well, that's big business for you", sense of apathy if not for further reporting by the New York Times last week2. In this article, the Times spells out how the regulatory agencies were executing similar dances with presentations of data related to the Jogan earthquake as well:
One of those whose warnings were ignored was Kunihiko Shimazaki, a retired professor of seismology at the University of Tokyo. Eight years ago, as a member of an influential cabinet office committee on offshore earthquakes in northeastern Japan, Mr. Shimazaki warned that Fukushima’s coast was vulnerable to tsunamis more than twice as tall as the forecasts of up to 17 feet put forth by regulators and Tepco.Ahh, government happily falling back on: Hear No Evil, See no Evil.
Minutes of the meeting on Feb. 19, 2004, show that the government bureaucrats running the committee moved quickly to exclude his views from debate as too speculative and “pending further research.” None of the other 13 academics on the committee objected. Mr. Shimazaki’s warnings were not even mentioned in the committee’s final report two years later.
At this point, we could stop and go: "Well, no one wanted to hear it. What do you expect?", but... at the tail end of the article we find out that TEPCO finally ran the numbers in house in 2008... promptly shat themselves, and then sat on the stinking pile for a year... releasing some of the revised numbers to the regulators in 2009... threw a tarp over the rest and fled the room for another two years before finally releasing what would happen if a 50' wave of the kind that eventually crippled the plant to regulators on March 7th 2011: 4 days before the fatal blow, and 3 years after they knew they were going to need to do something to address this.
Here's where we hit the "stop" button on the "unpredictable" argument folks: people knew this was coming but they also knew what this was going to cost to fix. However, instead of paying that bill, they rolled the dice that it wouldn't happen "soon" and now we've got a 30 Km exclusion zone in north-east Japan to show for it. When it comes to failing at craps, I wouldn't let these guys within a 1000 KM of Vegas in order to ensure Japan stays a sovereign nation and not a wholly owned subsidiary of Trump Inc.
Compare and contrast with this3 LA Times story from village of Murohama in the affected area: when the Jogan tsunami ravaged the area 1000 years ago many residents in the town went to the lower of two hills and were swept away by the waves. The survivors built a shrine on that hill and the story was passed down through generations of what happened that day. When the earthquake hit on March 11th 2011, the populace instead moved en mass to the taller hill this time and watched the other be inundated by the waves.
Imagine that: learning from and responding to history. Perhaps TEPCO should've done the same and then they wouldn't be in a position where they have to try and hand wave it.
1."Japan utility used bad assumptions to conclude nuclear plant was safe from tsunami": March 27, 2011, AP.
2. "Nuclear Disaster in Japan Was Avoidable, Critics Contend": March 9th, 2012, NYT.
3. "Japan's 1,000-year-old warning": March 11, 2012, LA Times.