After Fukushima, it seems obvious that the nuclear industry needs to get a better handle on what can happen in these "unlikely" scenarios.  The tactic of professing to have confidence that something is so unlikely you might as well say it can't happen loses its credibility the instant all hell breaks loose.  

Human credibility is just quirky that way. The industry needs a better plan.  

A "loss of pool coolant event" was held to be "so unlikely that no specific action was warranted" beyond the existing design of reactor sites such as Fukushima, before the event.  This was the conclusion of the Nuclear Regulatory Commission in discussion with the panel that came up with the most authoritative source Congress has for such information, i.e. the National Research Council, part of the National Academy of Sciences who reported on what could be expected to happen in one of these events in 2006.  

They'll never say that again.  

Why can't the nuclear industry be more reassuring at a time like the height of the crisis at Fukushima?  

I wonder if Stephen Chu, perhaps inadvertently, pointed to an answer in one of his recent speeches.  Eg:  he wants to "to bring computer simulation to reactor design".  Chu thinks a computer model may one day actually be able to accurately model a given reactor design, so "scientists and engineers will be able to stand in the center of a virtual reactor, observing coolant flow, nuclear fuel performance, and even the reactor's response to changes in operating conditions", and after they build the reactor, they’ll find out the simulation was correct.  He set up a nuke R&D Bell "lab-let" to create the capacity to do just this and funded it with stimulus money.  He’s bringing "some of our nation's brightest minds to work under one roof" to get it done.

Now that we’ve had our Fukushima, its time to think about putting people like this to work simulating meltdowns and loss of pool coolant events in specific reactor designs and installations.  

This is just a thought.  I'm wondering where this line of reasoning goes. It could be time to ramp up the new builds of new designs and phase out these old plants in an orderly manner as the new ones come online. But if politics merely intensifies rather than changes over this, we're stuck with those old plants for as long as we can hang on to them.   Consider:  ten years of the most costly and aggressive solar subsidy program in the world resulted in about one reactor's worth of power to the grid in Germany, and the cost was in excess of $40 billion.  See: George Monbiot, former wild eyed Green who stared at climate change so long he became a pro nuke, in his column,  in The Guardian  And after all this, the power is available only when the sun is up or if you add cost and store it.  

Other industries are rolling out successful computer simulators now.  Cummins, a major provider of diesel engines for long haul trucks just built a new design diesel engine without building prototype after prototype, each with slight modifications, by using simulation.  The project surprised senior executives because it was a success.  

 What's wrong with the nuclear industry?  

We can simulate atomic weapons and certify them to be safe to store and use yet we can't figure out what could happen in an event like this?  Or is it the case that we already can?  Does this event show the uninitiated that Tokyo could have been rendered uninhabitable until the cesium decayed?  

Excuse me.  I must have drifted off there.   Getting back to Chu's speech:  

"Just as advanced computer modeling has revolutionized aircraft design-predicting how any slight adjustment to a wing design will affect the overall performance of the airplane, for example",

We should be able to enter data into a model, i.e. lets see... Fukushima Daiichi plant Unit 4, spent fuel pool, force 9 seismic, tsunami has taken out all backup electricity, hydrogen explosion, high radiation level drives off workers in droves, how many rods removed at which date arranged in what manner, one pool wall reduced to being just the stainless liner due to the concrete backup "falling away", the kitchen sink, whatever, 1/2 water gone, 30 hrs to projected complete loss of water, crank the lever, watch all the flashing lights while the machine works, and get an answer.  

 At least we could come up with an assessment of the probable magnitude of the event as published in something like the NRC 2006 assessment for Congress that people could refer to as definitive.  

That report is worth reading just to see how uncertain it is.  When a city the size of Tokyo is feeling a little shaken, perhaps even threatened, what is the best public assessment available doing lying around saying the possible consequences could be "worse than Chernobyl", fleshed out with specifics like a possible consequence is "loss of tens of thousands of square kilometers of land" due to cesium contamination, plus, at no extra cost, "hundreds of billions of dollars" lost, and an estimate of deaths which is more of a guess depending on how effective evacuation proved to be. 

What this industry needs is a better idea of what the real threat from these unlikely scenarios is.  The report itself contains references to people in the industry who rejected at least some of the possible "offsite consequences" of such an event as highly unlikely or impossible, but the fact that this discussion remains classified leaves anyone reading the public sections with the certainty that this industry is either not unified in its understanding of what can happen, or this industry is sure that what is known is better kept secret.  

Pro nuclear types are downplaying this report in the light of what happened at Fukushima by calling it the result of an unrealistic computer model, and the tendency is to attack anyone talking about "what if" referring to this as someone who is a fear monger or who has as their only concern a desire to attack or destroy the nuclear industry.  I've come under fire for posting direct quotes, because by quoting it directly I must be "reading into" the report things that are not there.  Pro nukes don't like it to be generally known that there are high level discussions that involve their creations about whether scenarios laying waste to thousands of square miles of land in highly populated regions are credible.    

That 2006 report also cited ongoing studies that were not completed by the time the report had to be finalized.  

It is a bit hard for me to understand how it could possibly be that the best assessment of the latest computer modelling work was not conveyed to the senior authorities during the worst of the Fukushima uncertainty.  Its either the case that state of the art computer modelling could not rule out what was feared at Fukushima or the industry was blundering around panicking people for no good reason.  If leaders were confident about the pools, they could have rolled the results of their latest and best modelling into public view and appealed for calm. 

Whether it ultimately is proven that a propagating zirconium cladding fire was the threat the 2006 US national laboratory computer simulations that are publicly available indicated it could be, or if this possibility is eventually proven to be not credible, the fact is that after Fukushima, more data will be demanded by many.  

I think the industry will have to find a way to provide it.   If confidence cannot be secured by computer simulation, it will come down to large scale testing of reactors as they melt down, and spent fuel pools sitting without water, on a large enough scale to convince.  

Otherwise the anti nukes have a point.  Nothing shows 1. this industry does not have confidence in its downplayed assessments of what can happen in extremis at reactor sites, or 2. that the doomsday scenarios such as the "worse than Chernobyl" assessment published in National Research Council 2006 study “Safety and Security of Commercial Spent Nuclear Fuel Storage: Public Report” are absolutely true or 3. that even worse was actually seen by the responsible authorities as a result of the latest, classified, modeling to be in store,  than what we've seen at Fukushima.  What is this industry doing blundering around without confidence in its own assertions this long after TMI? 

 Why can we simulate atomic weapons and certify them safe to store and use and we can't figure out to the point responsible people can agree on what can happen in an event like this?  Or is it the case that this event shows the uninitiated that Tokyo could have been rendered uninhabitable until the cesium decayed?  

Sorry, I drifted off again there.  

 

 

Postscript:  

 "Safety and Security of Commercial Spent Nuclear Fuel Storage: Public Report (2006)

A bit fuller description of the worst case scenario it presented is here. Note:  The word "tsunami" does not appear in the document.  The greatest threat a spent fuel pool would face was described as a "beyond-design-basis seismic event"  

Photo by alfredo-9.