MIT team discovers new family of materials with best performance yet for oxygen evolution reaction; implications for fuel cells and Li-air batteries
19 September 2013
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| A diagram of the molecular structure of double perovskite shows how atoms of barium (green) and a lanthanide (purple) are arranged within a crystalline structure of cobalt (pink) and oxygen (red). Grimaud et al. Click to enlarge. |
MIT researchers have found a new family of highly active catalyst materials that provides the best performance yet in the oxygen evolution reaction (OER) in electrochemical water-splitting—a key requirement for energy storage and delivery systems such as advanced fuel cells and lithium-air batteries.
The materials, double perovskites (Ln0.5Ba0.5)CoO3−δ (Ln=Pr, Sm, Gd and Ho), are a variant of a mineral that exists in abundance in the Earth’s crust. Their remarkable ability to promote oxygen evolution in a water-splitting reaction is detailed in a paper appearing in the journal Nature Communications. The work was conducted by Dr. Yang Shao-Horn, the Gail E. Kendall Professor of Mechanical Engineering and Materials Science and Engineering; postdoc Alexis Grimaud; and six others.
The performance of this family of materials, Shao-Horn says, is a step forward from the previous record-holder for a catalyst that promotes electrochemical water-splitting—a material that Shao-Horn and her team reported in a paper in Science two years ago. (Earlier post.) In addition, while the earlier material quickly changes structure during water-splitting, the new material is stable.
The discovery of new cost-effective and highly active catalysts for electrochemical energy conversion and storage is of prime importance to address climate change challenges and develop storage options for renewable energy production. Among the electrochemical processes, the oxygen evolution reaction (OER) on water oxidation is efficiency-limiting for direct solar and electrolytic water splitting (H2O → H2 + ½ O2), rechargeable metal-air batteries (MxO2 → Mx + O2) and regenerative fuel cells. Transition metal oxides such as ABO3 perovskites composed of rare and alkaline earth (A) and 3d transition metal cations (B) are of particular interest as they have intrinsic activities comparable to the gold standards of OER catalysts such as IrO2 and RuO2.
Here we report that the intrinsic OER activities of (Ln0.5Ba0.5)CoO3−δ are among the highest reported to date, with the most active (Pr0.5Ba0.5)CoO3−δ in the series exhibiting activities greater than BSCF, the most active cubic perovskite. Unlike BSCF, these double perovskites are stable under OER conditions based on measurements from cyclic voltammetry (CV), galvanostatic testing and transmission electron microscopy (TEM) imaging. The physical origin of the high activity and stability of these Co-based double perovskites is compared with Co-based pseudocubic perovskites and discussed in term of eg filling of Co ions and the O p-band centre relative to the Fermi level as predicted from density functional theory (DFT).
—Grimaud et al.
Electrochemical water-splitting is well understood in principle, but to make it economically viable researchers must find catalysts that are inexpensive, easily manufactured and efficient enough to carry out the conversion without losing too much of the original power. The new finding could be a significant step in that direction, the MIT researchers say.
The specific compounds used in this research were made by combining a lanthanide (praseodymium, samarium, gadolinium or holmium) with barium, cobalt and oxygen. These compounds form a crystal structure with one distinct site for barium and another for the lanthanide. “There’s lots of flexibility in the chemistry and structure,” Shao-Horn says, allowing for a wide variety of potential materials.
While Shao-Horn and her team had previously reported the effect of transition-metal ions such as cobalt or iron on a water-splitting reaction, this work demonstrates how changing the specific lanthanide element has a strong effect on how rapidly oxygen is produced from the catalyst, Shao-Horn says.
| Video shows the strong activity of the new catalyst material (dark circle at center) in promoting the oxygen evolution reaction when submerged in water, as revealed by the bubbles of oxygen forming on its surface. Source: MIT. |
In their tests so far, the catalyst using praseodymium had the greatest activity level of any material tested to date, the researchers report. And, unlike most of the other materials tested in this reaction, tests indicate that this one is stable under repeated use.
In addition, because this represents a new family of compounds for water-splitting, the MIT researchers predict that further research could lead to more-active catalysts.
The pseudocubic perovskites and double perovskites...not only have the highest OER activities in alkaline solution but also exhibit the highest activities for surface oxygen exchange kinetics upon oxygen reduction at elevated temperatures, which highlights the importance of the oxide electronic structure on oxygen electrocatalysis. Future spectroscopic experiments of these oxides are needed to verify the computed O p-band centre trend in this study, and seek activity and stability descriptors that can be measured experimentally. Our study highlights the importance of controlling a transition metal oxide having the O p-band close to the Fermi level as a promising strategy to create highly active oxide catalysts for OER to enable the development of efficient, rechargeable metal-air batteries, regenerative fuel cells and other rechargeable air-based energy storage devices.
—Grimaud et al.
“We figured out what physical parameters could control the activity and stability” of the compounds, Grimaud says, providing guidance for future research. These compounds could find use in fuel cells, advanced rechargeable metal-air batteries, and direct-solar splitting of water, they say.
The first perovskite was discovered in 1839, Shao-Horn says, but her group “combed back through the studies” and found that surprisingly little is known about how to tune these oxides for water-splitting. Their work “highlights a new path to potentially connect basic oxide physics with the activity and stability of these perovskites,” she says.
“We know little about the surfaces of these oxides and how they may change under water-splitting conditions,” Grimaud adds, “and what are the active sites.” Future work will be needed to connect oxide bulk properties with oxide surface chemistry and catalytic activities under operating conditions.
Jean-Marie Tarascon, a professor at the University of Picardie in France and director of its laboratory on reactivity and chemistry of solids (who was not involved in this work), says, “This work is significant as it offers an alternative to costly noble-metal catalysts” for the OER. That’s important, he says, because “there is a huge demand for an OER catalyst for direct solar and electrolytic water-splitting. Personally, I think that the true impact of this work is on the fundamental level. The fact that these double perovskites are surface-stable is a great advance.”
The team also included MIT graduate students Kevin May and Wesley Hong; affiliates Christopher Carlton and Yueh-Lin Lee; postdoc Marcel Risch; and Jigang Zhou of Canadian Light Source Inc. in Saskatoon, Saskatchewan. The work was supported by the US Department of Energy’s Hydrogen Initiative Program and the Office of Naval Research.
Resources
Alexis Grimaud, Kevin J. May, Christopher E. Carlton, Yueh-Lin Lee, Marcel Risch, Wesley T. Hong, Jigang Zhou & Yang Shao-Horn (2013) Double perovskites as a family of highly active catalysts for oxygen evolution in alkaline solution. Nature Communications 4, Article number: 2439 doi: 10.1038/ncomms3439
This kind of research illustrates why I am not a fan of picking winners at our present level of knowledge.
Clearly this would, if practical and cheap, shift the balance towards fuel cell cars, and also to renewables, as it would provide storage against their intermittency.
A lot of folk who are dead set against fuel cell vehicles are also, strangely, advocates of something near a renewables only energy supply.
That is pretty difficult anyway, and impossible without far better energy storage than we have currently.
Personally I am a fan of nuclear, which is ideally suited to battery cars, but I don't allow that to make me a battery only advocate.
Technology is far too complex and likely to develop in unexpected directions to make sweeping visions of the 'perfect' way of powering transport remotely practical, and a more fragmented view, assessing technologies for their respective strengths and weaknesses uninfluenced by grandiose overarching ideologies works a heck of a lot better.
Posted by: Davemart | 19 September 2013 at 04:54 AM
This is progress, but enough to make the RE/hydrogen economy feasible? I'm inclined to doubt it.
I'm a strong advocate of nuclear + battery because they work, today. Those things which work sell product, and profits from sales drives R&D. That's bound to push things forward... unless hare-brained policy decisions prevent it. (Germany and Obama, I'm looking at you.)
Oxygen evolution catalysts have their own set of uses, and will be developed regardless. For instance, any economy which has lots of electricity but discourages fossil-fuel use will look to electrolytic production of ammonia for fertilizer, with the evolution of oxygen at the anode. But the development of carbon-free systems cannot wait for these things to be ready.
Posted by: Engineer-Poet | 19 September 2013 at 07:50 AM
@EP:
If I ruled the world, I would certainly simply do a massive build out of nuclear, which can most economically power battery cars.
Since I don't I am stuck with what is happening in the world, and rapid progress is being made in hydrogen production and fuel cells, which are in any case very closely related to advanced batteries such as metal air, as the article says.
Mainly, I want us to move on from the combustion engine and oil, and I ain't too fussy on how we do it.
I welcome advances in hydrogen production, in fuel cells, in batteries, in inductive charging, whatever.
Posted by: Davemart | 19 September 2013 at 08:56 AM
In a rational world, nuclear would be the default choice for power generation in most cases. In the real world, the cheapest, cleanest power source in So. Cal. is shuttered after a trivial release of mildly radioactive tritium that didn't harm anyone, to be replaced by more burning of fossil fuels, with all the attendant health and climate consequences.
Clear thinking is in very short supply, and vision and imagination seem to be almost non-existent. Nevertheless, I believe nuclear power, and especially newer designs (SMRs, MSRs) will eventually win the day, although it may take much longer than it should.
Posted by: Nick Lyons | 19 September 2013 at 09:31 AM
Math is about as rational a system as one can find.
Math is closing nuclear reactors and not building new ones.
Emotion has wanted SONGS closed for a long time but emotion did not cause SONGS's closure. SONGS was closed when the cost of the electricity it would have produced post repairs was not competitive.
The three other US reactors which have closed or announced closure have all done so because of the math.
If we priced carbon then existing reactors would probably stay around longer as the price of using natural gas increased. But due to the rapidly falling prices of wind and solar their days are limited. Affordable storage will drive the stake though their hearts.
It's the math.
Posted by: Bob Wallace | 19 September 2013 at 11:16 AM
But in any story problem if you write out the wrong equation even a correct solution will give you the wrong answer.
No, vicious discrimination against nuclear power by both regulators and electricity buyers, plus accounting rules which allow decommissioning funds to be added to corporate "revenues" when a plant is closed, are responsible. There's no other reason for destruction of an asset to be more "profitable" than operating it, and in the rest of the world it isn't.
Wind is by far the cheaper of the two, but if wind had to pay carbon taxes for the 70% gas-fired power that actually winds up delivered to the grid, it would be unable to compete against nuclear.
Wrong again. Storage becomes "affordable" depending how much of it you need. A "renewable" system which requires sufficient storage to buffer weekly cycles will find things a lot less affordable than a nuclear-base load grid which can operate on daily cycles and needs about 1/7 as much.
Posted by: Engineer-Poet | 19 September 2013 at 12:24 PM
Affordable storage will drive the stake through their hearts. And unicorns will prance in my garden tonight. That is to say, what affordable storage? Not to mention the cost of wind and solar, which are still much higher than the conventional alternatives. Since you need something like 3-4X the capacity plus storage to make wind and solar functionally equivalent to fossil, hydro or nuclear, I don't see how the economics are going to work in my lifetime, if ever.
Nuclear power cap-ex is high only because of over regulation in this country. Compare $/kW for new nuclear in China, for instance. New (or revived) concepts such as MSRs are potentially cheaper yet.
Posted by: Nick Lyons | 19 September 2013 at 12:32 PM
@Nick, EP:
Just to clarify, of course I am aware that notions of taking already expensive wind or solar, then only utilising electrolysers part time to convert the surplus to hydrogen are economic lunacy and wasteful of capital and energy.
However, cheap NG and possibly coal bed methanation and maybe the use of methane hydrates should keep the overall cost down to something which is affordable, and energetically there are still massive savings to be made against the present use of fossil fuels.
Dedicated plants, perhaps the Chinese PBR or maybe artificial photosynthesis together with electrolysers operating full time are a different matter, and likely affordable even if sub-optimal.
There are up sides to the use of hydrogen, as it could effectively provide virtually identical performance to ICE much cleaner and more energy efficiently, although it couldn't do heavy transport long distance.
So I think hydrogen and fuel cells will be part of the mix going forward.
Posted by: Davemart | 19 September 2013 at 02:37 PM
The cost of nuclear energy produced from overhauled and/or new facilities is not going down but up. Basically, it's more a question of $$$ than regulations and non-acceptance by the general public.
More reators have been closed than commissioned in the last 20 years or so.
Posted by: HarveyD | 19 September 2013 at 04:55 PM
@Harvey: Current nuclear has big up-front costs (in USA, anyway--not so high in China) but low and stable operating costs. Carbon emissions are minimal, safety and health impacts are much better than any fossil solution. It is a question of regulations, because the high cap costs are mostly a result of over-regulation. What if coal plants had to set aside money to deal with their huge waste streams (not to mention pay for all the other externalities from mining, transportation and toxic emissions)? How many years to license a new gas-fired power plant vs a new nuclear plant?
Right now cheap natural gas is king in North America, due to the fracking revolution. How strict are the regulations for new fracking? We don' even require the gas companies to reveal what toxics they are injecting into the ground. Compare that regulatory model to the hoops a new nuclear plant has to go through.
In the current regulatory environment, new conventional nuclear, with high up-front costs, doesn't pencil out short term, I agree. (This assumes gas will be cheap for the life of a power plant, a dubious proposition.) I would prefer to see more investment in SMRs, which can be built in factories and shipped to a construction site, significantly lowering construction time and financing risk. Longer term, new types of reactors can be the safest, lowest-cost as well as lowest-carbon solutions--if we let them. The fuel is dead cheap--uranium is relatively abundant, and thorium is currently thrown away as waste from the mining of rare earth elements.
Posted by: Nick Lyons | 19 September 2013 at 05:34 PM
During 2011 and 2012 the average PPA for wind generated electricity was 4 cents per kWh. Add back in the subsidy and that means production costs were no more than 5 cents.
The federal subsidy is 2.2 cents per kWh and lasts for only the first 10 years of production. So over a 20 year PPA that's about a penny per kWh of subsidy.
And the PPA price includes not only the LCOE, it also includes real estate, tax, transmission and owner profit costs.
Many of our existing, paid off nuclear plants have operating expenses 5 cents per kWh or higher.
We are now installing utility scale solar for roughly $2/Watt. Europe is installing for $1.50/Watt. China is installing for $1/Watt. Within a few years (before a new reactor could be built) we should have our price down to where China is now. That means solar as cheap as wind.
You can argue all you like about how we should build more nuclear reactors but the math simply does not work.
We've seen no evidence that new nuclear could produce for even 10c/kWh. Previous bids have ranged from 15c to 20c/kWh.
If you can generate most of your electricity for about 5c and store for less than 10c there's no way that nuclear can be a player.
That's just the math.
Posted by: Bob Wallace | 19 September 2013 at 08:32 PM
Lots of people are doing their own math -- they are called investors. I don't see them lining up to build nuclear. And for good reason. The high up front costs are unlikely to be recovered by low operating costs when competing technologies are developing rapidly. The risk is just too high. Even if you accept the premise that the math works for nuclear under current conditions, the risk is too high as is the investment threshold. Much more certain to put up a wind turbine in months than a nuclear reactor in decades.
Posted by: JMartin | 19 September 2013 at 08:47 PM
SONGS was closed because the retrofit designers miscalculated on the cooling system numbers, excessive vibration caused premature wear.
Posted by: SJC | 19 September 2013 at 09:35 PM
Harvey said:
'The cost of nuclear energy produced from overhauled and/or new facilities is not going down but up. Basically, it's more a question of $$$ than regulations and non-acceptance by the general public.'
You are not distinguishing between costs inherent in the technology and costs imposed by regulation and, for instance, renewables mandates.
If inherent costs were rising, that would apply around the world.
That is not happening, it is in Western Europe and the US that costs are rising.
The costs are going up in those locations because the anti-nuclear lobby controls the legislation.
Mandates to take renewables etc hit hard to what the power can be sold for, at its most extreme in Germany, where conventional power sources of all types are being bankrupted by fiddled markets which are compelled to take, in particular, solar which is ludicrously expensive there, and almost unavailable in the winter, so that you end up with electricity at $0.30 kwh as in Germany.
More reators have been closed than commissioned in the last 20 years or so.
And you claimed:
'More reators have been closed than commissioned in the last 20 years or so. '
Which shows the thought and research you put into your pronouncements.
Why don't you find out something about a subject, and then develop opinions, instead of basing them on faulty premises?
Reactors around the world are increasing in numbers, and even more in capacity, not decreasing.
The effect of the anti nuclear campaign in the West will be to ruin their industries, and accelerate the rise of countries such as China who don't load stupid costs on nuclear and know perfectly well that it is the key to a low carbon, prosperous future.
That is why from China to Russia to South-East Asia to the Middle East reactor building programs are being greatly expanded.
Posted by: Davemart | 19 September 2013 at 11:36 PM
JMartin said:
'Lots of people are doing their own math -- they are called investors. I don't see them lining up to build nuclear. And for good reason.'
Yeah, for instance Germany closing their reactors overnight at the investors cost, and imposing huge new burdens on the remaining reactors with early closure forced, has something to do with it, as does places like California's cost loading on reactors.
We have seen these sorts of fiddled economics many times before, and that is the way to ruin the economy, distort investment and export jobs.
Given a level playing field nuclear would wipe out the fossil fuel industry and most renewables, except peak load solar.
That is why for the past 40 years from Carter on the anti nuclear movement in collusion with the fossil fuel industry have gamed the market against nuclear.
Posted by: Davemart | 19 September 2013 at 11:42 PM
Put a different way, repairing SONGS would have cost so much that it could not pay its bills.
That math thing again.
"Dominion announced in October it would shut Kewaunee, even though its operating license does not expire until 2033, after failing to find a buyer for the plant due to economic reasons related in part to low natural gas and power prices.
Kewaunee, a pressurized water reactor, entered service in 1974 and is located on the shore of Lake Michigan, about 27 miles (43 km) southeast of Green Bay, Wisconsin.
Kewaunee is the second U.S. reactor to be retired this year. The last group of reactors was retired in the late 1990s.
Earlier this year, Duke Energy Corp said it would retire its 860-MW Crystal River 3 reactor in Florida, due in part to the uncertain cost of replacing the unit's containment structure."
http://www.reuters.com/article/2013/05/07/utilities-dominion-kewaunee-idUSL2N0DO1OT20130507
"The Vermont Yankee nuclear reactor, one of the oldest nuclear plants in the country and the subject of heated battles over the decades, will close late next year, the company that owns it announced on Tuesday, less than two weeks after winning a protracted legal fight against the State of Vermont to keep it open.
The company, Entergy, said a long depression in natural gas prices had pushed the wholesale price of electricity so low that it was losing money on the reactor, which is on the Connecticut River in Vernon just north of the Massachusetts border.
So far this year, owners have announced the retirements of five reactors, with the low price of gas being cited as a factor in all of the cases. Three of the five have substantial mechanical problems. "
Math.
"Exelon Corp. (EXC), the largest U.S. nuclear plant operator, would consider closing its Oyster Creek station before the plant’s planned 2019 decommissioning, Chief Executive Officer Christopher Crane said.
Exelon would accelerate plans to close Oyster Creek in Forked River, New Jersey, if it faced unexpected new capital costs at a time when depressed power prices and cheap renewable energy are squeezing nuclear generation margins, Crane said in an interview yesterday.
Exelon already has deferred plans to boost capacity at its LaSalle nuclear station in northern Illinois and Limerick plant in Pennsylvania, saving $1.2 billion in the near-term, the chief executive said.
The Chicago-based company also plans to refuel its Clinton nuclear plant annually instead of every two years in a bid to boost profitability at the hardest-hit plant in Exelon’s 17- reactor system, he said."
More math. Paid off reactors are going broke. Building new reactors is, well, the math says "Fail".
Posted by: Bob Wallace | 19 September 2013 at 11:45 PM
Bob:
Since the figures you churn out in no way take account of the cost to the grid to cover the intermittency of wind and solar, which is why they have to be mandated or not a single bird killer would be built, they are utterly meaningless.
Renewables are excellent ways of maintaining a very high fossil fuel input into the grid for decades, which is why there is a coalition between the 'greens' and fossil fuel interests.
Opposition to nuclear and slowing its roll out has not only killed countless people through air pollution, but is the primary cause of global warming.
Stupidity kills, and so does Greenpeace.
Posted by: Davemart | 20 September 2013 at 03:25 AM
What Davemart said. Nuclear is the safe, clean, low-cost future--just not in the USA until we come to our senses.
And BTW, I have solar panels on my roof.
Posted by: Nick Lyons | 20 September 2013 at 07:50 AM
Just to set the record straight, I am not opposed to nuclear. I just don't think it will will grow unless the Government takes on the risk and accepts the costs down the road. China is willing to do that for obvious reasons -- they need energy to grow their economy and need a short term fix to air pollution.
I don’t disagree that regulation can make or break an industry, but every government picks winners and losers all the time. After all, we subsidize oil don’t we? All this argument over whether nuclear is better of cheaper is pointless. The market (with some type of regulation, rational or not) will decide.
Posted by: JMartin | 20 September 2013 at 08:13 AM
SONGS was told to shut down, it was not an economic choice. I am not an expert on this, but I have been following it closely for years. Just to say it was a purely economic choice is misleading.
Posted by: SJC | 20 September 2013 at 09:13 AM
Davemart -
"Since the figures you churn out in no way take account of the cost to the grid to cover the intermittency of wind and solar, which is why they have to be mandated or not a single bird killer would be built, they are utterly meaningless."
In case you fail to read all the way to the bottom, Dave, it costs the grid more to integrate nuclear and large fossil fuel plants than wind and solar.
And $0.50/MWh to integrate wind is $0.0005/kWh.
"In ERCOT’s calculations for 2011, Goggin said, “the total cost for integrating wind came out at about $0.50 per megawatt-hour.” And, he added, without 2011’s anomalies in July and August that accounted for 80 percent
“Newer research suggests systems can go to 40 percent renewables with no problem,” Goggin said, “using the very efficient grid operating practices being applied by MISO, ERCOT, the California Independent System Operator (CAISO) and others."
“They do very fast interval dispatch of all energy resources,” Goggin continued. “because load is continuously changing, the output of fossil-fired plants is continuously changing, and, of course, wind is continuously changing, too.” The closer system operators are to real-time dispatch, he explained, the more effectively supply and demand can be balanced without the use of reserves.
“They also have pretty large balancing areas,” Goggin added. “If one wind project is going off, another is probably going on somewhere, providing an overall more stable output. Larger areas also simply have more resources to accommodate variability. In MISO, wind’s variability is just something in the noise. It is not showing up in their reserve needs.”"
"
Studies show nuclear and large fossil plants actually have “far higher integration costs than renewables,” Goggin said. “Contingency reserves, the super-fast acting energy reserve supply required of grid operators in case a large power plant shuts down unexpectedly, are a major cost. Comparing the incremental cost of wind to those costs that ratepayers have always paid, the wind cost looks even more trivial.”
The fundamental issues are more or less the same with integrating solar...."
“Relative to wind, solar has more minute-to-minute variability, which increases the cost. But forecasting the sun is easier because it is clear when the sun will come up and go down and when the peak is, and that reduces the cost. But grid operators who use efficient operating methods are finding it is no more of a challenge or cost than wind.”
http://www.greentechmedia.com/articles/read/Grid-Integration-of-Wind-and-Solar-is-Cheap
Posted by: Bob Wallace | 20 September 2013 at 09:19 AM
SJC -
"SONGS was told to shut down, it was not an economic choice. I am not an expert on this, but I have been following it closely for years. Just to say it was a purely economic choice is misleading."
The owners looked at the repairs needed, the testing and paperwork required to go back in service, and decided to shut it down.
The lack of an ability to make a profit. That's why SONGS is gone.
About a fourth of our nuclear reactors are walking a thin line between staying in operation and going bankrupt. A significant repair can easily push them over the edge. That's what happened not only with SONGS but also Crystal River and Oyster Creek. It causing upgrades to be canceled.
Over half of our reactors are safe for now. Some are profitable in today's market, some are in regulated markets in which they don't have to compete with cheaper generation.
We should expect to see a continued string of reactor closures due to repair needs and, as solar continues to decrease in price, increased price competition.
China apparently is now installing utility scale solar for about $1/watt. That makes solar almost as cheap as wind and would kill a lot of merchant reactors once we reach that price point.
Things look bleak in nuclear land....
Posted by: Bob Wallace | 20 September 2013 at 10:01 AM
Furthermore, let's revisit the magnitude of the Fukushima nuclear disaster to see the inherent danger in nuclear power. See the following link:
http://www.psr.org/environment-and-health/environmental-health-policy-institute/responses/costs-and-consequences-of-fukushima.html
The following is an excerpt of the above link:
"The destruction of the Fukushima Daiichi nuclear power plant in March 2011, caused by an earthquake and subsequent tsunami, resulted in massive radioactive contamination of the Japanese mainland. In November 2011, the Japanese Science Ministry reported that long-lived radioactive cesium had contaminated 11,580 square miles (30,000 sq km) of the land surface of Japan.[i] Some 4,500 square miles – an area almost the size of Connecticut – was found to have radiation levels that exceeded Japan’s allowable exposure rate of 1 mSV (millisievert) per year.
About a month after the disaster, on April 19, 2011, Japan chose to drastically increase its official “safe” radiation exposure levels[ii] from 1 mSv to 20 mSv per year – 20 times higher than the US exposure limit. This allowed the Japanese government to downplay the dangers of the fallout and avoid evacuation of many badly contaminated areas.
However, all of the land within 12 miles (20 km) of the destroyed nuclear power plant, encompassing an area of about 230 square miles (600 sq km), and an additional 80 square miles (200 sq km) located northwest of the plant, were declared too radioactive for human habitation.[iii] All persons living in these areas were evacuated and the regions were declared to be permanent “exclusion” zones.
The precise value of the abandoned cities, towns, agricultural lands, businesses, homes and property located within the roughly 310 sq miles (800 sq km) of the exclusion zones has not been established. Estimates of the total economic loss range from $250[iv]-$500[v] billion US. As for the human costs, in September 2012, Fukushima officials stated that 159,128 people had been evicted from the exclusion zones, losing their homes and virtually all their possessions. Most have received only a small compensation to cover their costs of living as evacuees. Many are forced to make mortgage payments on the homes they left inside the exclusion zones. They have not been told that their homes will never again be habitable.
Radioactive cesium has taken up residence in the exclusion zone, replacing the human inhabitants. Cesium-137 has a half-life of 30 years, and since it takes about 10 half-lives for any radionuclide to disappear, it will maintain ownership of the exclusion zone for centuries.
Once a large amount of radioactive cesium enters an ecosystem, it quickly becomes ubiquitous, contaminating water, soil, plants and animals. It has been detected in a large range of Japanese foodstuffs, including spinach, tea leaves, milk, beef, and freshwater fish up to 200 miles from Fukushima. Radioactive cesium bioaccumulates, bioconcentrates, and biomagnifies as it moves up the food chain. Routine ingestion of foods contaminated with so-called “low levels” of radioactive cesium has been shown to lead to its bioaccumulation in the heart and endocrine tissues, as well as in the kidneys, small intestines, pancreas, spleen and liver. This process occurs much faster in children than in adults, and children are many times more susceptible than adults to the effects of the ionizing radiation their internal organs are then exposed to..."
Of course, most nuclear plants in the world are not in tsunami nor earth quake zone. However, in cases of wars, including civil wars and other internal conflicts leading to neglect or sabotage or deliberate attacks on any of these nuclear plants, the effects similar to Fukushima can be expected. A modern nuclear plant may be designed to have passive fail safe in case of neglect, however, cannot be designed to be invulnerable against deliberate attacks by bunker-busting bombs or other highly penetrating explosives of massive power that is available in the world's arsenals of today. Countries with a lot of nuclear plants are thus extremely vulnerable to conventional high explosive weapons. Their enemies simply need to concentrate bombing with cruise missiles with conventional explosives onto those nuclear sites in order to provoke nuclear disasters. Or, commandos can be airlifted by stealth helicopters and descended secretely to a nuclear plant and rigged up the damanges similar to that suffered by the Fukushima plant, and we will have another nuclear disaster of similar or even greater magnitude. Several equivalence of Fukushima disasters in dispersed zones at once and a country is toasted! The magnitude of the damage to a country may be even greater than even if nuclear bombs are used, yet, no nuclear bomb nor any overt aerial bombing needs be used!
Posted by: Roger Pham | 20 September 2013 at 01:05 PM
One by one, the cost barrier to seasonal-scale H2 storage implementation is broken, paving the way for full implementation. Scarce and very expensive Platinum will no longer be necessary!
Posted by: Roger Pham | 20 September 2013 at 01:21 PM
@Bob
Great points.
@Davemart and other nuclear proponents
You massively over-exaggerate the cost and technical challenges of integrating wind and solar into current grids.
Grid operators need to manage huge unplanned disruptions in any case and distributed, smaller plants are much smaller of a problem for them, than huge, gigawatt-sized fossil/nuclear plants.
Research of the current grid and advanced modelling has already proven that renewable generation which is geographically dispersed has a low variability even if the individual generating plants are highly intermittent. The EU already has huge interconnects between its countries and it is continuously being upgraded. This will probably happen in the US in sync with renewable investment.
This and the coming of cheap grid-scale storage will eliminate any resistance at generators against renewables and as a result, fossil/nuclear investment will practically stop. Some of the next-gen grid-storage solutions are already in the commercialization phase (EOS, GE Durathon) you sound silly when you refer to them as fairy-tales. Heck, GE already sells wind turbines with integrated storage (built-in Durathon batteries in the turbine tower).
Posted by: soltesza | 20 September 2013 at 01:25 PM