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MIT Designs Tsunami Proof Floating Nuclear Reactor
First time accepted submitter Amtrak (2430376) writes "MIT has created designs for a nuclear plant that would avoid the downfall of the Fukushima Daiichi plant. The new design calls for the nuclear plant to be placed on a floating platform modeled after the platforms used for offshore oil drilling. A floating platform several miles offshore, moored in about 100 meters of water, would be unaffected by the motions of a tsunami; earthquakes would have no direct effect at all. Meanwhile, the biggest issue that faces most nuclear plants under emergency conditions — overheating and potential meltdown, as happened at Fukushima, Chernobyl, and Three Mile Island — would be virtually impossible at sea."
They power nuclear subs, nuclear icebreakers etc. Stick a transformer on it and connect it to the grid, Bingo, floating nuclear power plant.
If you gave me a choice between a printer and a giraffe with explosive diarrhoea, i'll get my ladder and my raincoat
It's perfect! Unsinkable? Unthinkable!
No Homer will ever be allowed, and all the regulators will be objective and unbowed!
"Flyin' in just a sweet place,
Never been known to fail..."
Compare the relative frequency of major hurricanes/typhoons to that of major earthquakes. Add to that the various potential problems that any floating structure has (springing a leak and sinking comes to mind here).
Then, consider that in Japan, the nuclear plant closest to the quake epicentre actually survived unscathed. Because the people designing it did not stick with the minimum legal specs for the seawall height like the geniuses at Fukushima had, but did some research on their own. And simply made the seawall much higher.
Conventional plants are not that bad, if they are designed by competent people. If you put them on barges, though, as these dudes are proposing, you are just adding to the potential failure modes, while not avoiding any that are impossible to handle. Not a good thing.
Convince the career politicians. Step 3. Convince the tax payers. There is no step 4.
Convincing the taxpayers gets rather easy when it is career politicians ensuring alternative (or traditional) fuel costs continue to rise by placating lobbyists. They sure as hell aren't getting cheaper over time as resources continue to be depleted and we refuse (for whatever illogical or corrupt reason) to accept nuclear power in its place.
This is why we need to switch to LFTRs
No pressure vessel to worry about.
Not in my back ocean!
You missed it. Reprocessing.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
subsurface water carries the contamination away, contaminating water supplies forever and at an ever increasing distance. yucca mountain was one of the rare places where that was not true.
We could stop wasting the fuel you call waste, and using it completely instead. What we do now is like bringing in oil, burning off the diesel and ignoring the gasoline, kerosene, and all the other fuels it contains.
http://www.nei.org/Issues-Poli...
On the other hand, thorium reactors are even more efficient, and the leftover is nearly inert.
We already have very advanced containment systems. There's nothing about them that would be unsuitable for oceanic use, aside from requiring a whole lot of floatation. The containment system at Fukushima wasn't even close to modern, yet it did a pretty good job anyhow. Hell, the system at Three Mile Island contained nearly all the radioactive material, and that was 35 years ago.
With even the Mark 1 containment building found at Fukushima (which was 40 years old; the same age as TMI), an incident like Chernobyl (which had *no* containment building) wouldn't have been nearly as bad. Compared to modern containment buildings though, Mark 1 isn't even *last* generation; it's outright obsolete.
There's no place I could be, since I've found Serenity...
Simply being at sea doesn't prevent the cooling problem. Remember, Fukushima was right on the ocean. The problem is that the cooling system has to have at least two loops. An internal loop of coolant (usually water, though salt has also been used) actually travels inside the reactor. Consequently it picks up some residual radioactivity from being exposed to all those neutrons flying around. You cannot just use this single loop for cooling, or else you're releasing this radioactive coolant into the environment.
A second external loop of coolant cools the internal loop via a heat exchanger. This external loop picks up nowhere near as much radioactivity, and the coolant (water) is safe to dump back into the environment.
If it were just one loop, you could come up with a clever design using thermal expansion to make the water flow through it to provide passive cooling in the event of a pump failure. But with two loops (and the inner loop being closed), you're pretty much reliant on active pumping to remove heat from the reactor core. The problem at Fukushima was that power to these pumps failed, and backup generators designed specifically to supply power in that scenario were flooded and their fuel source contaminated.
I don't see how putting the plant on a floating platform helps in this scenario, unless you're willing to open up the primary cooling loop to the environment and just dump water straight into the reactor (with the resulting steam carrying both heat and radioactivity out). Which was pretty much what they ended up doing at Fukushima. If they'd done it before the cladding on the fuel rods melted, we'd only be dealing with a small amount of radioactive water (deuterium, tritium, etc) being released into the environment as steam, instead of fission byproducts being directly released. So I don't see how being by vs on the ocean makes any difference for this scenario.
Maybe you could design the steel containment sphere to act as a heat sink, allowing sufficient cooling when submerged? But the containment's primary job is to contain what happens inside. That's why it's a sphere - it encloses the largest volume for the least amount of material and surface area, and its mechanical behavior under stress are very easy to predict. This is precisely the opposite of what you want from a heat sink. You want the most surface area for a given enclosed volume. Which makes me suspect that the steel containment could only operate as a heat sink if you're willing to compromise its protective strength somewhat.
The other problem I see is that putting it out at sea hinders accessibility. Meaning more mundane events like a fire, which are trivial to handle on land, become much more problematic at sea.
Objects floating in the ocean are EXPOSED, they are easily damaged by weather, can be attacked easily, are hard to secure, and VERY expensive to operate.
On top of all this the article is silly. Nobody at MIT has 'designed' a reactor, they just made a proposal that is barely more than just saying "build it on an oil rig!" with a few pictures. They talk about reactors anywhere from 50MW up to 1000MW which means basically "Gosh, you could float almost any nuclear reactor!". However it is not AT ALL clear that a 1,000 MW reactor would be made safe by passive seawater cooling in the event of say the whole thing sinking to the bottom of the ocean. Consider the effects of Fukushima COMBINED with the McCondo well blow-out... Its not a pretty picture to imagine a meltdown in 100 meters of water not too far offshore. Yes, the ocean would probably make this less totally disasterous than on land, but it might also be IMPOSSIBLE to quell or clean up. Statements on the lines of "it must be safe in the ocean" are exactly what goeth before a fall in engineering.
Anyway, it will seriously have to be studied, though I suspect others have done so already. As they said, the Russians have been working on this concept for years. That's one of the interesting things about it though, working on it for years, but where's the beef? Its probably not quite so easy as it sounds.
"Malo periculosam, libertatem quam quietam servitutem." -- Jefferson
People are so terrified of previous generation nuclear technology that they're not willing to even look at what an actual modern reactor would offer. It's like dragging up the combat specs of a Sopwith Camel and claiming that there's no place for aircraft in modern warfare.
Like, say, placing the emergency generators on the hills right next to it, nothing bad would have happened. Of if they had spend the extra $100.000 that would have cost for hydrogen valves, the buildings would not have exploded.
The problem is not that nuclear cannot be made safe. The problem is that the people doing nuclear cannot make it safe. And as these are also the people doing waste storage, this will remain a serious issue for the next, say, 1 million years or so. The combination of greed and stupidity found in nuclear planners is absolutely staggering.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
While that sentiment is accurate, no one wants to pay for decommissioning old reactors. Say we build a bunch of modern reactors, in 50 years will anyone want to pay for decommissioning them?
And it is still a non-issue. When it is 30 years later and you can still store it on-site then it is not a lot of waste. Compare that to any other energy source, the amount of toxic waste, even solar panel manufacturing and you have your answer.
Make them finance the decommissioning at build time. I believe they did this in the 70s with Vermont Yankee, though clearly they screwed up. Presumably we can do better with the actuarial stuff now that some of these older plants are shutting down.
The main problem is that no one can justify building one right now. Hell, it is hard to justify the _operation_ of one. Natural gas is cheap, and even coal plants are shutting down because they cannot compete.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Reprocessing has not been done because Peanuthead declared it to be illegal. Meanwhile there is no rush to reprocess because new fuels is so cheap from bot mined supply and recycled from Cold War weapons through the Megatons to Megawatts program. While we wait for reprocessing to get cheaper and fuel to get more expensive, there's storage at Yucca Mountain, which is finished and waiting to be opened.