"Don’t Know Squared: “It’s What You Don’t Know You Don’t Know” that can bring down any system designed by humanity."

Michael Schlesinger, an engineer and climate scientist at the University of Illinois, Urbana-Champaign, provided this comment on my Dot Earth post rounding up reader views on next steps for nuclear power in the wake of Japan’s extraordinary nuclear emergency following the great quake and tsunami. His full comment is below. My Dot Earth post on “Complexity and its Discontents" following the Gulf oil gusher explores these issues, as well.

"The out-of-control status of the 6 Fukushima nuclear reactors and their stored spent fuel rods is a textbook example of "Don’t Know Squared – It’s What You Don’t Know You Don’t Know" that can bring down any system designed by humanity. In the present case, the reactor behaved as designed to scram (= emergency shutdown) during an earthquake. But the cooling system for both the reactor cores and the onsite-stored spent fuel rods was not designed to withstand a "once-in-a-millennium" tsunami.

While we can and will learn from this disaster, there will still – and always – be “Don’t-Know-Squared Events” that can and will occur that will render any human-constructed system less than foolproof. This is the primary lesson that must be learned from Fukushima: We humans cannot foresee, and thus cannot protect against, all the awful events that can and will impact our best world-class-designed systems. Accordingly, we should not construct any additional nuclear reactors until and unless we devise a way to render the spent fuel therefrom harmless = not be more radioactive than the world Mother Nature has created in which we live. This is such a tall order that it may not be possible for humanity to accomplish it.”