EE Times: Failed Risk Analysis that Felled Fukushima
Failed Risk Analysis that Felled Fukushima
Junko Yoshida
3/8/2016 00:01 AM EST
<snip>
Now, five years later, we've followed up on the issue by scouring the Japanese media and government reports issued in recent months.
We also talked to Prof. Rodney Ewing, earth scientist at Stanford University, and chair of the U.S. Nuclear Waste Technical Review Board. In addition to the lessons weve learned from the disaster, we asked him specifically, where the so-called experts have gone wrong (and if they could still go wrong) when it comes to risk or safety assessments in the science and engineering world.
<snip>
Failed safety analysis
Meanwhile, last week, Stanford University issued a news report on the lessons from the Fukushima disaster, which focused on testimony by Rodney Ewing, a professor of geological sciences in Stanford's School of Earth, Energy & Environmental Sciences.
Ewing has emphasized that the Fukushima tragedy was not an accident. He specifically cited the lack of protection Tepco provided for backup power at Fukushima. Placed low along the coast, the backup power systems the diesel generators for reactors 1 through 5 were swiftly flooded and could not cool the reactors. They could have been located farther back and higher, like they were at reactor 6. Ewing believes that these were clearly failures in design, not an accident.
The late Ulrich Beck, a German sociologist known for his risk society theory, last year anticipated Ewings position. The argument that the catastrophe was caused by a natural disaster is ... categorically a mistake, Beck told Asahi Shimbun, a Japanese daily newspaper. The decision to build an atomic industry in the area of an earthquake is a political decision.
<snip>
First, Ewing noted that the assessment has failed to capture the real impact of the Fukushima disaster. Because the Japanese governments assessment focuses only on deaths the quantity of lives lost it has missed the point, he said.
<snip>
The Fukushima disaster triggered the displacement of more than 100,000 people. They are still displaced, Ewing said. That element of the disaster is not captured in the risk assessment. For those Japanese people who lived in small villages, Ewing said, My understanding is that losing homes and being placed somewhere else is not a small inconvenience. It has serious consequences.
Keeping a narrow view only on the number of people killed must be called into a question, he said.
<snip>
Instead of a typical risk assessment that usually only considers the fate of a single reactor at a specific location, "You could ask, 'What if I have a string of reactors along the eastern coast of Japan? What is the risk of a tsunami hitting one of those reactors over their lifetime, say, 100 years?'" he said. "In this case, the probability of a reactor experiencing a tsunami is increased, particularly if one considers the geologic record for evidence of tsunamis."
Wilms
(26,795 posts)And great question regarding confirming safety measures instead of determining if it's really safe.
But was it an engineering failure, or one of management? I thought I read that an engineer protested the ill-advised placement of back-up generators.
The Challenger loss, and I think the Columbia disaster as wll, were management failures. The engineers knew!
Baobab
(4,667 posts)Its a weakness with almost all current reactor designs, they need a continuous flow of cold water. We really need to understand there is an imminent risk of global catastrophe inherent to the current reactor designs in a coronal mass ejection event, and we know now that we very narrowly missed a Carrington class CME event in 2012. there is a roughly one in eight chance every decade (very hard to know, that is an estimate) That's way way too high.
Had we had a CME that hit Earth, 'we would still be picking up the pieces" - and that is actually an understatement.. it could cause a global catastrophe as power grids were knocked out of service by electromagnetic surges - that would make the power distribution transformers blow up and the loss of power, as it did in Fukushima, could drive multiple nuclear meltdowns - many of them all around the planet, at the same time.
Due to "loss of the ultimate heat sink".
See:
http://lasp.colorado.edu/home/wp-content/uploads/2011/07/lowres-Severe-Space-Weather-FINAL.pdf
http://www.resilientsocieties.org/images/Petition_For_Rulemaking_Resilient_Societies_Docketed.pdf
http://www.resilientsocieties.org/initiatives.html
Wilms
(26,795 posts)Wow.
Thank you, Baobab
shadowmayor
(1,325 posts)A nuke plant is a highly complex piece of machinery designed to simple boil water that creates a waste stream which mankind will be pondering for millennia. While capable of boiling water, what they really seem to do best is discovering hitherto unknown geological faults. They make great markers for fault lines all over the globe.