I would hope that a disaster of this magnitude can promote some serious lessons learned both from the standpoint of future nuclear reactor designs as well as disaster recovery best practices. Given that most of these plants are aging, particular those in the U.S., this event should prompt some serious rethinking and reengineering of many of these plants' core structures. Whether there's money to be had to fund these retrofits, which no doubt will be costly, is another story.
Based on my experience working with firms in Japan I can only say that they are fast learners. It is true that the government may delay many of the changes and recommendations, but the next plant will be over-protected. I do not thibk that they will allow same errors in such an important application where lives of so many people are affected.
In my opinion, nuclear engineers lost a lot of credibility in this latest fiasco. The mantra of nuclear engineers for many years has been, "we have redundant safety systems" and "an accident cannot happen" because we have thought of everything. The only reason those plants even had a problem was due to the generstors being built too low. Really? In my opinion, if you build a plant in an eatrthquake zone where tsunamis regularly happen and you don't provide for multiple redundant power backup systems, you might want to find a new calling. This never should have happened. Shame on the planners of this plant.
The single most important thing that should NEVER be done with nuclear reactors is to build a bunch of them at one sight. If one has a problem, the radiation level and other effects make you abandon ALL of them. Storing waste material near the reactor makes it even a bigger problem.
I LIKE nuclear power...but storing and not re-processing fuel is a big mistake, and if you can't clean the litter-box, you shouldn't own a cat.
It's not just Engineers who need to learn these valuable lessons, it's their leaders who often slash the budgets the engineers have to work with, and force what was a good design into a compromise between cost and capability. I run into this situation all too often, where the managers of engineers are finance people by background, and they just don't get it. It's amazing how many times I've have to explain why the codes and standards are what they are to someone who doesn't understand why they need to spend the $$ I'm asking for.
Although in this case...point taken. It couldn't have cost much more to install the generators on high ground, duh.
It's a shame that the Fukishima disaster occurred on several fronts. First off, the hardships incurred by the Japanese is eclipsed, perhaps, only by the Ukrainian nuclear disaster. Second, this disaster seriously-compromised the future of nuclear power generation. Last, because its future is compromised, pressures to develop renewable energy sources will escalate to levels that may, in fact, result in the deployment of inferior solutions, simply to appease those who are abnormally-frightened about nuclear power generation.
The world actually needs more nuclear power generation to serve as a logical bridge between conventional power generation, and renewable generation. People have a distorted view of renewable power generation: thinking that all one has to do is to erect a wind turbine, or assemble a photo-voltaic array, tie them into the grid, and call it a day. The reality of renewable energy generation is that we still do not have viable, long-term storage, and until science develops such a break-through in stationary batteries - batteries that can deliver relatively-constant DC for several weeks at a time, while not requiring an enormous land mass to implement - practical renewable energy generation is still 15 - 20-years down the road.
I'm always concerned with redundancy & in Japan the backup pumps were not protected. They could have been used earlier to pump seawater as a coolant.
Spent fuel rods should never be present at a powerplant. They should be recycled immediately after use. Jimmy Carter stopped recycling of spent fuel rods and must take part of the responsibility for the tragedy in Japan. Japan copied our technology & followed the Carter no-recyle plan.
France recycles spent fuel & stores the resulting less toxic material in a closet in Marsailles. We should also be recycling fuel in the USA.
Any environmentalist with a proliferation "concern" should be told to store spent fuel in their back yards or turn off their lights & go off grid.
I am reasonably confident that the Japanese culture will remedy the current issues uncovered with Nuclear plants in new and remedial work. A look at the systematic, incremental improvements they made in autos demonstrates this.
I am seriously concerned that the US culture of not spending a penny more than we need to to obtain a benefit will hamper us from doing the same with expedited timing. Some suggestions for our activities: (1) For flooding, earthquake , tsunami, and wave action where are the tall berm walls to break up the waves and encircle plants and diesel genertors. Should we add redundant powered pumps inside the berm walls that can come on immediately? Should we reloacate the genertors to high ground? Should we have redundant bare bones control rooms at the edge of the site or offsite? (2) For offsite power should we have reduadant offsite power from 2 diverse locations? Should it be located underground and protected from both terror and natural interruption? (3) Should we over ride the no preemptive shutdown policy of utilities in the interest of national security? How many dollars can compensate for human lives put at risk? Now that we have seen the creative ugly face of terrorism, we should rethink the entire issue for Nuclear and fossile plants and see is we can sufficiently isolate units from each other as well as the nearby neighborhood. (4) I noted a few new safety systems in Japanese plants that were not in US nuc plants when I wrote FSARs 20 years ago, we need to evlauate how well they worked and which ones to incorporate. (5) We need to coordinate military protection for national assets like this and train with special forces to defend the plants. Use redundant diverse communications. Even the spent fuel pool can be a contamination problem. (6) We need a national spent fuel reprocessing and storage faciklity and policy to get the spent fuel safe from accidental and deliberate compromises and away from populated areas. If we can isolate and protect missile silos, we can protect spent fuel. (7) We need a major initiative to inspect plants from corrosion and other silent dangers. Then make a list of infrastructure that needs replacementand do so on a schedule. How can a small utility have the expertise to know where to look for problems and how often, especially in rooms that are only entered once every year or two?
I want to see us do better, we are capable, but really need fresh eyes. The world has changed since the assumed risks were written down in the 1960s and 1970s and we need to evaluate the landscape again.
It seems that as the plants come up for re-licensing here in the US we should seriously consider retiring the older designs and replacing them with new ones.
There are many good points in the article and in the comments. Separating plants physically, removing spent fuel and reprocessing it, and replacing older reactors with new modern and safe designs seems like a no brainer.
It is interesting to note how many of these problems and issues are the result of poor decisions made in the past. Not reprocessing the fuel is a good example. But we can go even further back and ask why we are using uranium fueled reactors instead of thorium? The reason is you cannot make a bomb from thorium. The US wanted the uranium technology to support the defense requirement for nuclear weapons.
One thing I have learned is the sooner one corrects the mistakes made the sooner one can obtain the benefits of doing it right. Unfortunately the NRC has also become the poster child for what is known as "Regulatory capture". The NRC is not so much regulating and providing oversight as they are promoting and acquiescing to the industry demands.
The smartest thing to do is to look at the entire industry and the energy requirements it is intended to support and come up with a national (even international) energy policy. The policy should correct the errors of the past and provide a carefully thought out and well engineered solution for the future. I just don't see that coming from the Federal government and the Department of Energy. I might blame the oil companies for part of this.
People involved with the very strong march 11 seism evaluation feature this : strength 9.1, duration : 3 minutes. The Fukushima NPP is designed for 7.x strong seism. With that duration and the big power difference larger than 100 times of the seism (more than 2 logarithmic point between 7 and 9.1) no chance the Fukushima design can resist. Bringing on the top of the mountain the generators is of no use. The whole vessel design was off well before the tsunami impact. I fear no one can design a NPP to sustain such a powerful and sustained earthquake, the energy ratio is in the range of thousands above the current design ratings. Now the corium is out of containment and the TMI disaster is a gentle affair compared to Fukushima. The whole planet is concerned, no customs for radioactivity. Can we longer rely on nuclear energy : only 2.6% of final energy used by humanity and each big accident cost so large it nullifies spares from the origin of nuclear era energy.
Linear guides are one of the most important components required for the development of automated or computer-controlled equipment. Aluminum profile extrusions, used for these guides in machine design, can enable designed-in functional features.
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