Can a pebble bed reactor survive: The complete & total loss of any supporting structures which keep the fuel pebbles at a distance, the simultaneous loss of its cooling system, and the complete loss of *every single control system in place*? Plus the complete failure of humans not to do *exactly the wrong thing in every single instance in a crisis*? Or to not be able to do anything at all? (Say chemical weapon attack?) Not hours, not days, not weeks, indefinitely -- without being a risk to those living in the surrounding community?
That is the real test. These aren't toys, and its no small danger we live with. I live next to something with the potential to destroy the 1/3 of the agricultural capacity of the United States, and make areas of 3 states unlivable for generations to come.
I'm a big believer in multiple event scenarios, and in the tremendous overconfidence in tables for how strong something really is & narcissistic egos of engineers that have killed numerous people with their pronouncements of "that is simply an impossible scenario" ..only to watch it happen.
I'm a big believer in incredible amounts of human error, and a tremendous decline in the quality of the education system; to the point that a fair number of those with even advanced degrees aren't worth their salt. If it can't be run, and maintained by people with a 70 IQ, it just might be a problem. Never underestimate the effect of those 50 bonus points on the hiring test for minorities, social promotion in schools, and future government mandated quotas for degrees, and management promotion.
If your reactor can be screwed up because the maintenance person Tyrone puts in the wrong size bolt after a hard night of celebrating his/her recent casino win with an all nighter of amphetamine, cocaine, alcohol, and sex with random strangers (possibly for money) ... You know what? It will probably happen. If your reactor can be screwed up because Susie decided she needed to have an excuse not to come home so she is able to cheat on her husband by smashing the levee that feeds the water to your plant ...you know what? It will probably happen. (The few of you who live in or near Machens, Missouri, and West Alton, Missouri know why I reference such an event.)
We are reasonably near the New Madrid fault line. I really do not believe a pressurized water reactor like they have at Callaway would survive a seismic event even remotely close to what Japan experienced. The propaganda minister at Ameren tells us:
Emergency Safety Systems include six emergency power sources:
â 2 Ameren power lines to the site
â 2 Emergency Diesel Generators (onsite)
â 1 power line from local Rural Co-op
â 4 Standby Diesel Generators (offsite)
Additional Emergency Safety Features:
âSteam powered cooling water pump with DC battery powered controls system
âA 30-day cooling water supply stored on-site in a seismically designed retention pond.
All well, and good. Except in my scenario, the upwind rail line has a pair of trains passing at the exact same time of the seismic event. Each of the trains has tanker cars filled with a total of half a million gallons of things that react to cause long lasting fire, and/or creating a poison gas cloud that kills everyone downwind (meaning every single nuclear plant employee, including recent big winner at the casino Tyrone) for miles around. The twin events or the earthquake, and train accident make the area inaccessible due to chemical contamination, numerous bridge collapses, and the rerouting of surrounding rivers (not unprecedented). The water feeds for the plant are now broken, as are any power lines from anywhere else underground or otherwise. Due to problems with the communications system, and widespread power outages -- outside authorities remain unaware of the situation, and are mobilized to other areas before the extent of the crisis is realized.
The capacitors that Ameren saved $1.20 a piece on fail in the control panel, the beer Tyrone was drinking on the job completes the circuit for the two battery terminals in an impressive explosion of sulfuric acid, and molten lead. The bolt that was holding the flywheels in both of the generators was replaced by drunken Tyrone celebrating his recent casino win, as was the welding job on the pipes for the steam generator that cracked during the earthquake ... The person who calculated both the strength of the levees containing the water supply, and the amount of water needed for the holding ponds (which I'll grant, amazingly don't fail) was admitted to the university due to his potential to increase the offense of the university football team. His 2.0 GPA is a reflection of help along the way, but he does have a piece of paper. He is also the right color to get those bonus 50 points on the application with a wink, and nod from the: diversity hire herself, bottom of her class, human resources manager who thinks he is kind of cute, and wonders if she can get him to come to the casino with her, and Tyrone.
Almost everything in my above scenario happened at the nuclear power plants in Japan. (Minus the chemical trains, and the lawsuit enforced diversity policy many US utilities live with). Almost every item of human stupidity, and failure in that scenario has happened at US nuclear power facilities (minus the chemical trains, and chemical weapons attack of course). The average IQ in Japan is quite a bit higher than here. They are also the best in the world at building bridges, and facilities to survive earthquakes; the bright Japanese, all of their precision craftsmanship, and all of their l33t engineering sk!11s couldn't contain a multiple event scenario with (not exact) the 2nd most popular reactor design in the US, and one not completely dissimilar from the one at Callaway. Do you really think we wont be get burned here eventually? I just don't have the kind of faith that some of you have in several things not going wrong at once.
How much tolerance do pebble bed reactors really have in a worst case scenario to all of the above? Even to human sabotage? Never forget that there are people who would willfully cause such an event, and they may not have to strike from outside of the facility! He may well be the one depressed out of his gord, who really needs those antidepressants that they wont allow him to take, and keep his job. Or the one who does it anyway, and has a psychotic break where he feels you are all better off not here, and shoots everyone in the control room ...
Sometimes an engineer can't fix a problem that someone else fixes or builds: 12 city blocks burned down due to having the wrong thread screw, and wrong washer installed on an antistatic device in a grain elevator.
Engineers have tunnel vision when they design things, e.g., the shutdown of an entire billion dollar auto manufacturing plant due to a defect in a single bearing in Normal, Illinois (thank you quality engineer who didn't think of something so simple, or a way to figure out where the stoppage is quickly, or the ability to shut one part down, without fully stopping everything). The launching of hundreds of tanks of gasses due to a combination of heat, and the failure of a single common safety device that the engineer thought would be safer at a gas supplier in St Louis. O-Ring, one word: Challenger (which makes me really leery that they want to launch nuclear reactors to power devices in space)... Or the hard drinking Russian employee manning the control room in a nuclear reactor in Chernobyl during multiple systems failures, who ignored dozens of warnings...
For those who think the train scenario unlikely, some recent history examples of similar enough incidents:
1992 - June 30 - Superior, Wisconsin - Burlington Northern freight train derails. Three tank cars plunge into Nemadji River. An environmental disaster occurs when one of the cars ruptures spilling chemicals into the river. The river spills into Lake Superior. Over 40,000 people evacuated when a chemical cloud envelopes the cities of Superior and Duluth, Minnesota.
1986 - July 8, fifteen cars of a forty-four-car CSX train derailed near Miamisburg, Ohio. Some of the cars that derailed contained phosphorus. When ignited, phosphorus releases poisonous gas. Shortly after the derailment, city officials ordered thousands of Miamisburg residents to evacuate their homes. The next day, officials allowed these people to return, only to have the phosphorus ignite. One Miamisburg resident described the resulting vapor cloud as "real heavy stuff, hugging right on the ground, like fog. People had their lights on, it was so dark." A second evacuation occurred, with approximately twenty thousand people seeking shelter at Dayton, Ohio, at the University of Dayton and the Dayton Convention Center. This was the largest evacuation to occur in Ohio's history. By July 10, all but two hundred families had returned home, as most of the phosphorous had burned. Over three hundred people sought treatment at area hospitals due to respiratory problems.
Norfolk Southern had more than 100 train accidents caused by switches in the wrong place in the last three years, including head on collisions of trains. In their own words: We have a 99.997% safety record ... (Statement made after trains collided carrying 120,000lbs of chlorine that killed a whole lot of people in the ensuing toxic cloud. Roughly 2004 in Texas.)
I don't want to hear "we run our reactor with a 99.997% safety record".