Poor design, ignored warnings, mismanagement, missing disasters (Typhoon Nina intersecting acold fron and stalling over the dam, dumping 1060mm of rain in 24 hours), poor communications, inadequate disaster and response plan, no public emergency bulletin system, no emergecy transport, rescue, recovery, or supplies & infrastructure capabilities, and a 40-year cover-up. Read the Wikipedia article. It is good.

Only about 26,000 people died of the immediate flooding itself. Over 150,000, six times as many, died from disease or starvation. All of those deaths could have been avoided, even with total dam failure, given land-use planning, warnings, diversion dikes, and refuge shelters elevated only modestly from the floodplain, plus an immediate R&R andaid mission.

Virtually all the failures had nothing to do with the underlying power conversion process itself. All are intrinsic to any large, complex, institutional engineering project. None can simply be engineered away: they require continual human process management. All are equally intrinsic to nuclear power operations.

Most significantly, the risk book on Banqiao has been closed, and was within a few weeks or months, at most, from the isaster. There is no residual disaster risk. Unlike Hartford, or Chernobyl, or Fukushima, or other nuclear disaster sites, there is no multi-century exclusion zone with a glowing heap of deadly slag at its centre. None of these sites have final management plans in place, in cases decades on.

Banqiao is now home to tens of millions of inhabitants, and a few memories of what went wrong.

https://en.wikipedia.org/wiki/Banqiao_Dam

Proponents of nuclear power assume that we can assess risks with tails not of the decade or so of Banqiao, but of 100, 1,000, 1 million years. Utterly outside the scope of any human institutions, or of the human species itself.

Our models of risks and of costs fail us....

The problems with nuclear power are massive, long-tailed, systemic and potentially existential. The same cannot be said of a wind farm or solar array. There is no significant 10,000 year threat from wind power, or solar power. We're not risking 30 - 60 km exclusion zones, on an unplanned basis, of which we've created at least four in the half-decade of significant nuclear energy applications: Hanford, Washington, Three Mile Island, Pennsyvania, Chernobyl, Ukraine, and Fukushima, Japan. And this is with a global plant of some 450 operating nuclear power plants as of 2017....

If the total experience has been, say, 500 reactors, over 50 years, or 25,000 reactor-years of experience, and we've experienced at least four major disasters, then our failure rate is 0.016%.

The global share of nuclear power generation in 2012 was about 10%.[4] Which means that without allowing for increased electrical consumption within existing or extending to developing nations, the plant count would have to increase tenfold.

Holding the reactor-year failure rate constant would mean 80 core meltdowns per century. Reducing that to the present rate of four meltdowns/century would require reducing the failure rate to 0.0008%. That's five nines, if anyone's counting.

Five nines on a process involving weather, politics, business, social upheaval, terrorism, sabotage, individual psychology, group psychology, climate, communications, response, preparedness....

https://old.reddit.com/r/dredmorbius/comments/6rmupo/open_th...

https://old.reddit.com/r/dredmorbius/comments/2awjj2/thought...

https://news.ycombinator.com/item?id=14896581