A New Class of Nuclear Reactors 560
prunedude tips this quote from a post at Freakonomics about Japan's nuclear crisis:
"The folks over at IV Insights, the blog associated with Nathan Myhrvold's Intellectual Ventures, point out that it was the complete loss of power that disabled the cooling systems protecting the plant's reactors. Which raises the question: Is there nuclear technology that could withstand such a catastrophe? Possibly. TerraPower, an Intellectual Ventures spin-off that also boasts Bill Gates as an investor, is working on a new reactor design called a traveling wave reactor that uses fast reactor technology, rather than the light water technology used at the Fukushima Daiichi plant. The two biggest advantages of the fast reactor design is that it requires no spent fuel pools and uses cooling systems that require no power to function, meaning the loss of power from the tsunami might not have crippled a fast reactor plant so severely."
Um, don't safe reactors already exist? (Score:4, Interesting)
Safe nuclear does exist -- it is spelled LFTR (Score:2, Interesting)
http://www.telegraph.co.uk/finance/comment/ambroseevans_pritchard/8393984/Safe-nuclear-does-exist-and-China-is-leading-the-way-with-thorium.html
http://www.wired.com/magazine/2009/12/ff_new_nukes/
CANDU (Score:5, Interesting)
I'm not saying that's the only solution, I'm just saying that a known good solution that's been working for decades is probably better than a new one.
Re:Dumb question... (Score:3, Interesting)
They do power their own cooling.
Alas, when you shut the plant down, it stops providing power for its own cooling. Which they did here.
Note that the kneejerk response (earthquake, therefore shutdown the reactor!!!!), was, in this case, absolutely the worst thing that could be done. If they'd left the reactor running but begun a slow shutdown (as opposed to a SCRAM), they'd likely have had enough power to keep things under control.
And if it turned out an emergency shutdown was needed, well, that option would still be on the table.
It is probably worth noting also that there's a pretty good chance of lot of reactor plant operations manuals are going to be revised as a result of this little adventure. With an eye toward keeping the reactor operational at lower power output until it absolutely, positively needs to be shutdown right the fuck now!
Re:Toshiba 4S reactor (Score:4, Interesting)
Or we could put the panels in the desert and let the people live where ever they like. I know crazy idea.
Sure nukes have a place, but at this point they are more heavily subsidized than any other power generation method. I say that because cleanup costs always come from the tax payer. Solar thermal plants in our deserts and Wind where that fits can be a large part of our power needs. Nukes will still be needed, but unless something can be done about their high costs, coal will sadly stay in use.
Re:Pebble bed reactor (Score:5, Interesting)
These are only the size of a shipping container and are a self contained unit. They would be a great way to bypass the NIMBYism associated with nuclear power plants. They are also much safer. If these can be bought by people with a bit of cash in the attic and installed in the countryside unknown to the neighbours we can all enjoy cheap nucular energy while everyone is blisfully oblivious to the fact that the neighbours little 'storage' container is actually a nucular power plant
It turns out that pebble beds aren't quite so maintenance free. Although the helium used as a coolant doesn't become radioactive, the graphite in the pebbles absorb radioactive metals and spread it around in graphite dust particles. Both the the AVR and HTR reactors in germany had big problems with contamination of the reactors due to this and due to the inability of the pebbles to contain radioactive isotopes.
Also, the pebble bed itself can't be instrumented so it becomes a black box resulting in unexpected hot currents of gas that can be significantly (200+K) warmer than expected. This resulted in maintenance issues in the two reactors in Germany (I don't think there is information on other experimental or production reactors using a pebble bed design). These problems might be surmountable but right now they're pretty big issues.
Wikivertisement (Score:3, Interesting)
The Wikipedia article [wikipedia.org] has been hijacked by their marketing dept, it's the closest things I've seen to an advertisement in Wikipedia.
Re:Doesn't Matter (Score:2, Interesting)
Telling them that Nuclear powers is safe enough might not convince them.
How about giving them the numbers of killed because of hydro power?
Here are a few. You can spend a few days and try to track down more incidents if you want to. You can probably fill a book with reports of dam breaks.
Bilberry reservoir - causing the deaths of 81 people.
Gleno Dam - killing at least 356 people.
Fujinuma Dam - Eight people were missing and four bodies were discovered after searches began at dawn.
Edersee Dam - About 70 people died
Coedty Reservoir - The resultant flood caused the loss of 17 lives in Dolgarrog.
Dale Dyke Dam - destroyed 800 houses, and killed 270 people
Kurenivka mudslide - The estimated number of casualties varies from 1,500 to 2,000, but only 146 people were officially recognized as such.
Banqiao Dam - 26,000 people died from flooding and another 145,000 died during subsequent epidemics and famine.
Gusau Dam - killing 40 people and destroying 500 homes.
We can have afford to have 10 more chernobyls without even being close to the kind of death and destruction that hydro power causes.
Some might, but some wouldn't: (Score:5, Interesting)
That's not entirely true.
For example. Amory Lovins, one of the notables of the anti-nuclear movement was asked in an interview what he thought of a truly cheap clean energy source. He said it would be a disaster. Why? Because he believes that whenever humans are given concentrated sources of power, they use it to destroy nature. Thus humans need to be limited to diffuse and limited sources of energy.
Quite often the waste and radiation questions are arguments used against nuclear power, when some of the motivation would have problems with any concentrated source of energy.
Needless to say, I disagree with that viewpoint, but it is one that can be argued and is not totally without merit.
Jimmy Carter worked on a Melt Down at Chalk River (Score:3, Interesting)
As long as we have Jimmy Carter around, I'm not worried bout no meltdowns.
THORIUM is the answer. You just aren't asking the right question.
"On Dec. 12, 1952, the NRX reactor at Atomic Energy of Canada’s Chalk River Laboratories suffered a partial meltdown. There was an explosion and millions of litres of radioactive water ended up in the reactor building’s basement. The crucial reactor’s core was no longer usable. With the Cold War then in full swing, and considering this was one of the first nuclear accidents in the West, the Americans took a great interest in the cleanup. Mr. Carter was a young U.S. Navy officer based in Schenectady, New York, who was working closely with Admiral Hyman Rickover on the nuclear propulsion system for the Sea Wolf submarine. He was quickly ordered to Chalk River, joining other Canadian and American service personnel. “I was in charge of building the second atomic submarine and that is why I went up there,” said Mr. Carter. “There were 23 of us and I was in charge. I took my crew up there on the train.” Once his turn came, Mr. Carter, wearing white protective clothes that probably, by today’s standards, provided little if any protection from the surging radiation levels, was lowered into the reactor core for less than 90 seconds."
http://ottawariverkeeper.ca/news/when_jimmy_carter_faced_radioactivity_head_on/ [ottawariverkeeper.ca]
Re:Dumb question... (Score:5, Interesting)
It should perhaps be noted that I'm a former reactor plan operator. I have a clue.
Yes, cooling the daughter isotopes is exactly the issue. You generate fewer of them when you reduce output from commercial levels to self-sustaining levels.
And when you reduce power (but not shutdown completely), the decay products begin to decay down toward the new steady-state level. Which is a LOT less than steady state when you're operating at 90%+.
Every minute that goes by with the reactor operating at a reduced output is another minute you don't have to find an external power source to cool things down. And another minute farther from a core meltdown.
As was, by doing a hard shutdown immediately, the reactor was placed into a position such that the only possible way for a "good" outcome would be for the national electrical grid to stay completely intact during the next few days. There's no way that the battery back-up they had could keep cooling that plant for the next couple days by itself.
Which leaves as your only real option to try to use the reactor's output to maintain cooling while you burn through the decay products for as long as possible. After all, you can always scram the reactor later, if things don't work out.
Re:Doesn't Matter (Score:2, Interesting)
If you're trying to convince an environmentalist that hydro is bad, it's probably best not to lead with human death figures. When it comes to saving the environment, the vast majority of human beings are part of the problem, not the solution. Animals deaths are good (evidence), because their numbers are pretty well regulated by hunter-prey dynamics and things like nuclear waste interfere with that natural regulation. But our almost complete lack of predators and our ability to import food from anywhere on the globe make our population dependent on other factors.
Of course, you can always talk about the number of trees and plants that die when you flood a previously-unflooded area. All those dead plants give off a ton of CO2, which makes hydro one of the dirtiest green power sources. For the finishing blow, get some pictures of the area before and after the dam was built. For instance, by most accounts, the Hetch Hetchy Dam destroyed an area that look very similar to Yosemite Valley. Pictures like that are like porn to an environmentalist.