Japan nuclear body says radioactive water at Fukushima an 'emergency'

http://preview.reuters.com/2013/8/5/fukushima-radioactive-water-likely-breached

by yapcguy • 13 years ago

93 125 13 years ago

preview.reuters.com

mpyne5• 13 years ago

More details would be nice. As the article notes, tritium itself is almost innocuous (its decay is via a weak beta particle emission, about the only way it could hurt you is if you ingested a lot of it).

Either way the problem with radioactive materials relates to the concentration in solution of radioactive materials more than the binary "radioactiveness" of the material. After all the human body itself is 'radioactive' if only from the K-40 and C-14 that are present.

Without knowing the concentration of radioactive contaminants like Co-60 and radiocesium that might leak into the sea it's hard to know how much of an 'emergency' we'd be looking at. All we'd know for sure is that TEPCO is incompetent... but then what else is new?

ChuckMcM3• 13 years ago

It would be hugely better to actually have details.

Water, aka H2O, doesn't activate so it is not radioactive, it can however carry radioactive isotopes in solution. Is the groundwater flowing from the neighbouring area? (implied) then the it is carrying cesium from the environment away (good thing if you want to move back into the neighbourhood) is it picking up new contaminants from a broken reactor vessel?

I wonder if anyone has a better source for data here.

khuey• 13 years ago

Water can be radioactive if some of those hydrogen atoms are really tritium.

akiselev3• 13 years ago

Water, aka H2O, doesn't activate so it is not radioactive, it can however carry radioactive isotopes in solution.

What? Tritium is an unstable hydrogen isotope that is radioactive, no matter what molecule it is found in. Combine that with acid-base chemistry which revolves around the disassociation of hydrogen from water and that tritium can end up as a beta emitter anywhere in the body, including in actual strands of DNA [1]. What radioactive isotopes the water carries as a solute is irrelevant to the presence of tritium in the molecules.

[1] http://www.ncbi.nlm.nih.gov/pubmed/11130944

mpyne5• 13 years ago

Water can activate (much more so than you think in fact, though I can't discuss further maybe someone with a civilian background in nuclear physics can fill in).

Certainly the long-term danger is more from what the water will carry in solution than from the water itself though.

jlgreco2• 13 years ago

its decay is via a weak beta particle emission, about the only way it could hurt you is if you ingested a lot of it

Well, it is water contamination they're talking about. People have the tendency to ingest large amounts of water.

Of course, as you say, knowing the concentration is vital to understanding the risk posed. You could drink gallons of water laced with a gamma emitter if the concentration were low enough (well, not gallons. You'd get water intoxication ;).

mpyne5• 13 years ago

Well I don't think people ingest large amounts of seawater. :)

Perhaps fish and other seafood (assuming that the tritium concentrates in the seawater around Japan and doesn't get dispered into the wider Pacific). But then the tritium would be mostly "fixed" within the flesh of the fish and end up being mostly self-shielding. Perhaps the ATP w/ tritium and similar products get carried into cells but by that point we're talking about nothing worse than the day-to-day problems of life under the sun, eating bananas, breathing the sweet sweet scent of brick-induced radon, etc.

nknighthb2• 13 years ago

I'm not sure that Reuters didn't misunderstand something. The tritium mention seems oddly out of place. A lot more than tritium has leaked from this plant, and I would be surprised if the water they're leaking now is contaminated solely with tritium.

Also, I think with regard to tritium spilling into the sea, they're probably less concerned about a direct effect on people than on the fish swimming around in it.

mzs• 13 years ago

Back in '07 the Canadian Nuclear Safety Commission couldn't get a limit from Japan:

http://nuclearsafety.gc.ca/eng/readingroom/healthstudies/tri...

yk3• 13 years ago

But Tritium can be quite ugly if it gets into the body, since it can replace hydrogen. (And can therefore accumulate in the body.) This depends on the molecules tritium is attached to.

And on a further note, I believe that websites which need JS to scroll text are malicious.

VLM8• 13 years ago

Ah its not so bad. If you have to take something radioactive, thats the one element I'd take because I'd pee most of it out in about a week.

The phrase no one on HN has mentioned yet is "biological half life". There's a pretty decent wikipedia article at

http://en.wikipedia.org/wiki/Biological_half-life

Whats important is the ratio of biological half life to radiological half life. Superficially it sounds like you're WAY better off with contaminated water, with a bio half life of about a week, than plutonium around 100 years, a difference of about 4 ords of magnitude. However the half life of 3H is in the 10s of years range and non-RTG Pu is about 20K years range or about 3 ords of magnitude lower activity. So the net effect is it hangs around 4 ords of magnitude longer, but specific activity is 3 ords of magnitude lower, so given X number of atoms, Pu is only about 10 times worse for you than 3H.

All bets off for the Pu RTG isotope that is so short half life it self-melts pretty easy, or that one Pu isotope thats mostly harmless but its decay product is icky (I think 241pu to 241Am where the 241Pu if it wouldn't decay is mostly harmless but the 241Am is icky)

brianbreslin• 13 years ago

Has anyone done tests to see how the radioactive water and other contaminants have affected the pacific as a whole? how about the fish stock near japan?

http://www.grida.no/images/series/vg-climate/large/32.jpg

akiselev3• 13 years ago

It's extremely difficult to do such a study because the entire system is just so complex and there's no way to control for many of the variables.

There have, however, been limited studies about bioaccumulation of tritium in phytoplankton and how it can move up the food chain [1]. As another poster said, tritium decays by beta radiation which isn't necessarily harmful but if it accumulates in the food chain, it might be dangerous (just like heavy metals and fish, for example). Tritium's half life is about 12 years so its not inconceivable.

It's a different environment but you can probably draw some conclusions about the impact/spread of radioactive particles by looking at Chernobyl.

Edit: [1] http://www.ncbi.nlm.nih.gov/pubmed/22863967

toomuchtodo• 13 years ago

Does this mean we have to start equipping undersea seismic sensors and surface buoys with geiger counters? :(

Bjoern3• 13 years ago

The dilution of the radioactive content by the ocean is probably high. Overall the risk is low for significant contamination due to the overall ocean volume.

The issues are so-called hot-spots which cause certain fish to be extremely radioactive and streams causing concentrations of radioactive materials highly contaminating only certain regions and fish.

That being said, there are so many pollutants in the oceans that I'm confused why people are not more outraged about ocean pollution.

Vice Documentary about garbage streams. e.g. https://www.youtube.com/watch?v=D41rO7mL6zM

Finally, its certainly not acceptable to have on-going ocean pollution, which is probably happening in Fukushima Daiichi.

VLM8• 13 years ago

One interesting problem with "stuff" near Japan is according to western coverage, the only thing that happened was a nuclear accident.

However what actually happened was a huge disaster. So right off the coast lets say around 100K cars were destroyed, and the average car has a twenty gallons of liq petrochems like gasoline, used motor oil, and all the various hydraulic and coolant fluids... all floating in coastal water now.

Its like a live retro experiment of what if junkyards and the like were totally unregulated for awhile. There was a time when you'd just dump that stuff in a river instead of proper disposal and recycling, and we've got an interesting live example of what happens if we try it again...

So is the two headed fish because of modest radio contamination, or because it grew up next to a puddle of used motor oil, or the warehouse full of insecticide that washed into the ocean, or...

hannibal53• 13 years ago

It all boils down to bioaccumulation. Radioactive stuff that just floats around is diluted fast into nothingness.

Chernobyl was bad, but most of the fallout landed on forests and lakes that are not significant source of human food chain (mushrooms, fish in lake and animals in the forest still have traces left).

Fukushima did not blow stuff into the atmosphere, most of the leak is from water leaking to the soil and to the sea. Almost everything living in the sea is important part of the human food chain.

Bjoern3• 13 years ago

Fukushima did not blow stuff into the atmosphere

Well, that is actually not right. During the accident radioactive water vapor and other gases were released into the atmosphere due to the explosions. Its correct though that, most of it was washed out by rain quickly being diminished into the ground water or carried away onto the ocean.

More importantly a significant portion of the radioactive water seeped into the groundwater, which will have unknown effects in the future.

jasonwatkinspdx2• 13 years ago

I don't have the specific links on this computer (sorry) but one of the major oceanographic research institutes published a fairly detailed report of their own measurements last year.

The general flavor of the report is that the pacific as a whole is in no danger. Despite the toxicity of what's been released, the pacific is very, very, big. They expressed concern for local waters near the plant, but weren't able to study that as freely due to Tepco and the Japanese government. Accumulation of isotopes in predator species is still a very real concern.

marze11• 13 years ago

Anyone can correct me if I'm wrong, but I believe for two years Tepco has been dumping about 150 tons of water a day on the melted cores at the bottom of the reactor buildings (or wherever they are), and pumping 100 tons of it out to filter and reuse.

Obviously, 50 tons/days has disappeared every day for 2+ years. Since that water came in contact with the melted cores is extremely radioactive (not just tritium). Measurements of the water filling the lower levels of turbine buildings supports this thinking (something like 1 Seivert/hr).

Since TEPCO has not allowed any independent measurements of the ocean within kilometers of the site, nor independent ground water measurements, and the independent ocean measurements taken at large distance from the site do not show a decrease in contamination vs. time, it appears likely they've been leaking substantial amounts of cesium and other radionuclides into the ocean for >2 years.

If so, an impressive coverup. The math is simple, water in minus water out, and where did the missing water go.

VLM8• 13 years ago

Hmm we'll lets run this thru the engineering filter and see how much is reasonable.

Well, something that can't run forever, stops, and its been close enough to forever that you can assume we're evaporating away 50 tons/day. Where else could it be going? But is that a reasonable evap rate from an engineering perspective?

50 tons is about 50K kilograms. Takes about a KWH to boil away a kilo of water so we're looking at about 50K KWH or 50 MWH per day. Now there's about 25 hours in a day so thats about 2 MW continuous boiling away water, or at least on long term average.

A big reactor runs in the GW range but decay heat starts around 10% and slowly drops over time. Actually a couple years in, most should be gone although the long tail is pretty long. So it was dumping out tens of MW continuously and now maybe much less. So we're looking at a couple MW generated, vs a couple MW to make that much water vapor. Seems reasonable. So I'm willing to believe from an engineering estimate, aside from solar heating and whatever, that 50 tons of water simply evaporates away.

We can argue volumetric, if a ton is about 1K kilos and 1 L water is about 1 Kg, that would strongly imply a ton of water is about a 1K liters or about one cubic meter. I suppose we could have gotten to this same point by talking about mL vs cubic centimeters vs grams. Anyway you're claiming a cube of water a meter on a side, stacked 50 tall each day, for a couple years. I say that most of that has to have evaporated away otherwise you'd have 50 meters deep of water covering the entire site after a thousand or so days.

marze11• 13 years ago

All good, but there is no boiling.

Just evaporation from the surface of the pooled water flooding the buildings, which will not be significant, even if it wasn't at a humid oceanside location.

api9• 13 years ago

Fukushima converted me away from being a supporter of nuclear, or at least conventional nuclear. Maybe something like LFTR or WAMSR could re-open the debate in my mind, but the debate for conventional solid-phase reactor cores is pretty much closed.

Not because I buy into all the fear mongering about radiation, but for a much simpler reason: it showed that conventional nuclear is not cost-effective vs. the alternatives and is not scalable.

In any system, accidents will happen. Worst case accidents will happen. The frequency may be low, but Fukushima shows that one singular bad accident can completely obliterate the economic rationale for nuclear power in a given country. Fukushima is going to be a billions-a-year money pit for Japan for at least the next decade and a half.

Given those costs plus the fact that nuclear without accidents is not substantially cheaper than alternatives, it just seems more rational to invest the money and R&D effort required to solve the energy storage and distribution problems associated with solar and wind energy.

In the end, provided we can back them up and distribute the power efficiently, there is actually more energy available from the sun and the wind than there is from any actionable real-world plan for scaling nuclear that I've ever seen. Renewables also have many other benefits including:

- Very low risk... basically no more dangerous than any other construction or manufacturing.

- No fuel, so little to no real sustainability concerns. This means that once we make them work they will work forever and we won't have to worry about energy anymore.

- Small incremental investment cost. Wind and solar can be deployed in small increments, and it's exponentially easier to raise small increments of money than large ones.

- Less politically centralized. Nuclear demands centralized regulation and huge centralized financial control, and nuke plants are central points of failure for the entire industrial system built around them. Were we to rely on them exclusively they would become easy "off switches." Renewables by contrast open up the potential for a "PC revolution" in energy.

It just seems like a no brainer for me. Nuclear is a boondoggle, at least for most uses.

nazgulnarsil2• 13 years ago

We have spent decades and hundreds of billions chasing a particularly poor form of nuclear because of the US and Russian military industrial complexes. Dismissing nuclear because of horrible past decisions seems unwise.

api9• 13 years ago

Perhaps so, but at this point I'm starting to wonder if the point is moot. Solar is experience Moore's Law type effects in terms of cost per kW of installed capacity, and there is now immense R&D muscle behind energy storage due in part to the electronics industry.

The awesome power of exponential tipping points is not to be underestimated. When the cost/kWh curves intersect, it could happen fast. Look at the adoption of the Internet and smart phones for examples. Solar could go from <1% of our energy to >25% in 5-10 years. That might be conservative.

I'm seeing nuclear as a niche technology. In a post-fossil world I can see it for radionucleotide production (e.g. for nuclear medicine and space probes), maybe for a few really heavy industrial needs, and for some locations with very poor local renewable energy availability. But for the most part I see it as obsolescent.

I do think it might find its killer app somewhere else though: Mars. There are many reasons it would make more sense there.

x0x02• 13 years ago

can't wait to find out what new failure modes your new "but it's really safe guys... this time I promise!" reactors have

tptacek5• 13 years ago

I don't understand how an empirical analysis, such as this purports to be, could get around the fact that "conventional" power generation kills far more people than nuclear ever has.

x0x02• 13 years ago

I don't understand how people who keep bringing up that conventional power generation kills more people than nuclear ever has (yet!) get around having their nose rubbed in the fact that we haven't experienced a worst case nuclear incident yet and that we keep getting lucky and scraping past worst cases -- at least according to what I read about all those old fuel rods stored at Fukushima. People keep ignoring safety precautions and we keep getting lucky, but luck and hope is not an acceptable strategy when you can irradiate large chunks of countries as a worst case scenario.

@SuperChihuahua: I can't find the articles now, but just one failure case is there were pools with spent nuclear rods in them that required active cooling. Failure to do so produces a plume of radiation straight into the air. Of course you're never supposed to store that many fuel rods, yet somehow safety wasn't important and there we where with tons of fuel rods in pools that required active cooling and no real plan for what to do if, say, we couldn't actively cool them.

marze11• 13 years ago

In deciding what to build next, you would compare nuclear with the other future options, which do not include coal.

No one argues that solar or wind will kill anyone.

And, the real problem with nuclear is that it isn't cost effective. If the free market was operating, no plants nuclear plants would be built in the US. It is only with govt. subsidies making 90% the up-front cost risk-free there has been even a nibble of interest from free market investors. And even that interest has petered out.

VladRussian25• 13 years ago

"conventional" power generation kills far more people than nuclear ever has.

and don't start on how many people cholesterol in burgers is killing

dredmorbius2• 13 years ago

Two reasons why this is a red-herring argument:

1. False alternative. There are multiple alternatives to nuclear power, and I'm not aware that there are higher levels of death associated with most of them, coal being the notable exception.

2. The risk profile of nuclear power is not well-understood. Humans have hundreds to tens of thousands of years of experience with fire, water, and wind power. We've been toying with atoms for about three-quarters of a century, with commercial electrical generation for only about half of that. In that time large areas of land have been contaminated, and a number of serious plant or reactor accidents have occurred, several of them contaminating large areas of land until at least 2050 (64 years after the accident), possibly longer. The effects of the Fukishima disaster are still being revealed.

3. Few conventional power plants (natural gas plants with significant on-site storage being a potential exception) have catastrophic failure modes with more than a very small affected region. In terms of both longevity of effects and area, acute impacts are limited. By contrast, when things go wrong with a nuke, then tend to go very phenomenally wrong, and it can be unclear, even after a significant period of time, what the full consequences and extent of damage are.

marze11• 13 years ago

Worse case accident for solar:

Ow. I dropped the solar panel on my foot.

For nuclear:

Oops, we destroyed $270B of real estate.

SuperChihuahua3• 13 years ago

Can solar panels survive an earthquake?

cobrausn2• 13 years ago

Actual worst case for solar:

Oops, we spent $270B on solar panels that can't provide enough power.

hannibal53• 13 years ago

The risks are small, but they are not so small that nuclear plants could get normal insurance from free markets. They have actuaries that can do the math. It all boils down to the expected value (= value*risk). Even if the risk is incredibly small the cost when the risk actualizes is so massive that it's deal breaker (alternatively, the cost of insurance from free markets makes nuclear energy too expensive)

This is why every country with nuclear plants subsidies nuclear energy with laws that limit the amount of compensation.

marze11• 13 years ago

Ask the 80000 people made homeless by the Fukushima meltdowns how much the government or power company gave them.

It was a laughably small amount. I wouldn't expect any other 1st world country to much better.

jessriedel4• 13 years ago

Even if the risk is incredibly small the cost when the risk actualizes is so massive that it's deal breaker (alternatively, the cost of insurance from free markets makes nuclear energy too expensive)

Do you have a cite for this? My understanding is that the risks from nuclear are simply too high variance (i.e., concentrated in a few huge events) for an insurance company to absorb, not that the expectation value of the cost is high.

ori_b5• 13 years ago

Fukushima was an outdated design that was not safe under passive cooling (ie, it was physically possible for it to melt down). It's construction predated Chernobyl, and it's design was even older, and designed around a weaponizable fuel.

Fukushima doesn't represent the state of the art. It didn't even represent the state of the art a quarter of a century ago.

marze11• 13 years ago

Hmm, if it is so outdated, should we close all 45 of the identical General Electric-design reactors operating in US cities soon?

Or, we could extend their operating license each for 20 years and see if they can handle it.

akiselev3• 13 years ago

To restore faith in nuclear: http://ntrs.nasa.gov/search.jsp?R=19710050022

Researched as a rocket engine (but equally effective for terrestrial power) over 40 years ago. Instead of taking 20,000 kg of fuel (which is about how much each Fukushima reactor had) and trying to prevent it from overheating, the nuclear lightbulb reactor (or rocket engine) takes 20kg of fuel, compresses, and heats the fuel to the point where it is a self sustaining critical reaction. If the chamber ruptures or power is cut, the core (which at this point is about 10,000 Kelvin and a black body radiator in UV-vis) expands, cools, and reacts with oxygen to quickly precipitate. If you combine this with a plasma window separated vacuum chamber with graphite or another neutron moderator, the second power is cut the entire chamber including the nuclear core is sucked into a safety chamber (plasma windows require multiple kilowatts of power per inch diameter so any failure causes it to die). Of course there are some material science problems to go over but with the progress we (Corning alone, really) made in the last 40 years, it is achievable.

Food for thought: the worst power-generation related disaster was by far Deep Water Horizon, which is turning the entire Gulf of Mexico into a deadzone (you could even see the oil from space! [1]). Hell, BP's fuck up wasn't even the worst case scenario (earthquake or something causing the entire subterranean pipe to expand past the point of closing with conventional cement) and we will be dealing with the aftermath for many decades.

[1] http://en.wikipedia.org/wiki/File:Deepwater_Horizon_oil_spil...

jessriedel4• 13 years ago

A massive natural disaster hit Japan causing 15,883 deaths, 6,145 injured, and 2,667 people missing. It cost $235 billion dollars, making it the costliest natural disaster in world history. The nuclear power plant damage results in zero deaths (other than a handful of deaths from emergency crews unrelated to radiation) and a few billion in clean-up costs (the large majority of which is due to hysteria-provoked safety requirements which are vastly too strong).

And you take this as evidence against nuclear power? Not only that, you consider this so obvious that the debate is pretty much closed. I'm just baffled.

api9• 13 years ago

That's a non sequitur. The tsunami was a natural disaster, and was probably unavoidable.

The Japanese now have a 20-year radiation-spewing money pit, which was avoidable.

My post was mostly about the future. Why build more potential multi-billion-dollar 20-year money pits when there are alternatives that are almost ready and that could be brought to readiness with what are likely comparable R&D expenditures and infrastructure costs?

Daniel_Newby2• 13 years ago

... one singular bad accident can completely obliterate the economic rationale for nuclear power in a given country.

The anything-but-nuclear policy has caused fossil fuel wars costing hundreds of thousands of lives and trillions of dollars.

The parent comment is not merely wrong, it is the opposite of correct. Having a Fukushima-size meltdown every few years would be an economic bargain.

api9• 13 years ago

This is simply unrelated. Fossil fuels are worth a lot of money and are frequently located in areas controlled by unstable regimes, hence wars. There are also wars over water, diamonds, gold, arable land, and any other high-value commodity located where the local political environment is unstable.

Using a lot of nuclear power would not alter this picture in the slightest. It might alter the landscape in terms of supply and demand, perhaps shifting fossil fuel demand from heavy nuclear users toward developing or lower-tech countries, but the basic equation of high value resources plus political instability remains intact.

California is highly oil-dependent and Texas has a lot of oil. So far California has not invaded Texas. That's because both are politically stable.

ctdonath6• 13 years ago

We're not using much in the way of renewable energy for good reasons. Simply: low and inconsistent output.

Solar: The absolute maximum upper limit is 1.3kW/m^2, the total solar energy hitting the Earth's disc. Realistically, you'll max out around 130W/m^2 under ideal conditions, dealing with atmospheric absorption, night, clouds, conversion efficiency, breakage, etc. Realistic norm is somewhere around even a tenth of that. Output storage & buffering is problematic, batteries using environmentally unfriendly materials requiring manufacture & replacement over a less-than-you-want lifespan. By the time an installation has become cost-effective, it's done and you'll have to re-install diminishing-return components. On a large enough scale to compete with other energy sources, you're performing "solar strip-mining" on the local environment.

Wind: Big turbines are costly, last about 20 years, annoy neighbors (I almost had a wind farm dropped on my town), and by the time those huge expensive generators wear out or burn up (!) nobody will have a financial interest in replacing/dismantling them. Likewise, inconsistent power output is a problem few seriously address. Converting large amounts of atmospheric movement to heat will itself result in "manmade global warming" type issues.

Old-form nuclear sucks. Between lousy ancient designs and sheer paranoia over "weapons-grade" phases, coupled with vast construction handling high-pressure extreme-danger contents, yeah there's a disaster waiting to happen - and as noted it just takes one to make the savings moot.

New-form nuclear has real potential. Small sealed units incapable of self-destructing, highly resistant to deliberate damage, and easy to transport make it entirely possible for a community to purchase one turnkey reactor and run from that for decades.

Oil/coal will remain a major contender precisely because the energy has already been gathered into convenient pumpable-haulable form, is shelf-stable over usage fluctuations, and has little discernible waste.

Renewables are just not viable, at least not yet. Despite huge piles of money thrown at it (by the current US administration in particular), nothing of marketable substance has emerged. If it were viable, it would be in widespread production. I'm looking to run my HVAC off solar if you disagree.

The bashing of nuclear is mostly limited to old-school hot-water active-cooling designs. Yes, they suck. Get over it and move on to modern designs held back mostly by regulatory concerns which apply those fears to inapplicable reactors without further consideration.

api9• 13 years ago

True-- for now.

The question is: is it better to spend billions researching new generations of nuclear reactors or to spend billions working on energy storage?

The former will lead to a switch from older, less concentrated fossil fuels to a newer, more energy-dense fossil fuel. But it's not without well-known problems.

The latter will result in a permanent, eternal solution to the energy problem.

There are limits to how much solar and wind is available, but those are orders of magnitude beyond our civilization's current energy requirements. Other limits to growth -- arable land, decreasing fertility with increasing wealth -- will likely prevent us from ever even approaching those limits.

Solve the energy storage problem and the industrial revolution becomes as permanent as the agricultural revolution. Nuclear power won't do that. So energy storage technology is IMHO a more prudent, higher dividend investment than better nuclear reactors.

phaemon4• 13 years ago

Converting large amounts of atmospheric movement to heat will itself result in "manmade global warming" type issues.

This single statement clearly indicates you have absolutely no clue whatsoever about anything regarding energy production. At all. It's like saying that you can't have an LED display on a space rocket because running it would use up all the fuel. Except, that doesn't even capture the scale of the energy disconnect. I can't actually think of an analogy that accurately demonstrates the level of sheer ignorance in that comment...

BrandonMarc• 13 years ago

Toshiba may have a decent answer for nuclear power, as described by one of the writers who investigated Three Mile Island, and whose friends helped battle Chernobyl many moons ago. A writer who just happens to not write under the name Mark Stephens ... namely, Robert X Cringely.

Here's what he wrote about Toshiba [0], ~ 2.5 years ago when Fukushima lit up:

But the new plants also have to show they can survive an 8.9 earthquake and reduce the number of critical failure points. Toshiba's 4S reactors, which have been around for several years now, though not yet commercially successful, do all that quite easily.

4S reactor cores are like nuclear building blocks, built on a factory production line and transported by truck to be installed 30 meters under the ground. Each 4S puts out 10 megawatts of electricity or enough for 2000 Japanese homes. Following this path means the lost 1000 megawatt reactors will need 100 4S's each to replace them or a total of 1200 4S reactors. 4S's are fueled at the factory, put in place to run for 20 years then returned to the factory for refueling. They are sodium-cooled and pretty darned impossible to melt down. If the cooling system is compromised they automatically shut down and just sit there in a block of sodium.

I admit I haven't followed the Toshiba 4S model's progress in the intervening time, but was fascinated at the idea when I read about it before. Cringely isn't a nuclear engineer, but he's no slouch, either. It's all worth a read.

----------

[0] http://www.cringely.com/2011/03/13/is-anything-nuclear-ever-...

... and here's more of RXC's writing on the topic. Fascinating stuff:

http://www.cringely.com/2011/03/11/flea-powder-may-be-saving...

http://www.cringely.com/2011/03/16/who-ya-gonna-call-superta...

http://www.cringely.com/2011/03/30/plutonium-is-forever/

http://www.cringely.com/2011/09/20/truth-about-fukushima-dai...

http://www.cringely.com/2012/05/24/the-next-japanese-nuclear...

carsonreinke• 13 years ago

`Tepco's "sense of crisis is weak"`, ultimately the problem.

Bjoern3• 13 years ago

The infamous Atomic Village problem, particularly Tepco's corruption is quite well known and paradoxically accepted by the society.

https://www.youtube.com/watch?v=pGsYdDpUSzg

(turn on captions)

LolWolf• 13 years ago

But what was leaked is really not all that much. Recall that 1Bq is a disintegration per second, and, although a few trillion is quite a bit, this is over a massive volume. Now, there's nothing stated in terms of how much leaked into water sources, so, there's little judgment that can be made. But I believe it's little to truly worry about.

Japan nuclear body says radioactive water at Fukushima an 'emergency'

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