10 posts categorized "Nuclear Accidents"

07/10/2012

Nuclear Accidents: Preventable ‘Man-Made’ Disasters

Fukushima-622

A report released by the Fukushima Nuclear Accident Independent Investigation Commission has concluded that the Japanese nuclear accident and meltdown last year could and should have been prevented.

The exhaustive 641-page report was sharply critical of the Japanese government and plant operator’s claims that the accident was the unavoidable result of an unpredictable double-disaster of a severe earthquake followed by a tsunami. In fact, the report noted that given the high number of earthquakes in Japan (and the well-known association of tsunamis with earthquakes), much more could have been done. Basic safety measures were ignored, backup systems were not implemented and government regulators who were charged with enforcing safety standards did not follow through.

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Fukushima is the second preventable nuclear crisis in history. Though sometimes considered a technological failure, the nuclear meltdown at Russia’s Chernobyl power plant was a man-made disaster caused by human error. In 1986, a group of scientists intentionally deactivated several safety systems in order to test a cooling system at reactor 4. The experiment failed, leading to the worst nuclear accident of all time. There are several psychological and social factors common to both Chernobyl and Fukushima.

Underestimating Risk

In both nuclear accidents, the public and those running the reactors were assured that the risk of any accident -- much less a full-fledged core meltdown -- was so remote that it need not be of concern.

As a New York Times story noted, “Tepco [the plant’s operator] has contended that the plant withstood the earthquake that rocked eastern Japan, instead placing blame for the disaster on what some experts have called a ‘once in a millennium’ tsunami that followed. Such a rare calamity was beyond the scope of contingency planning, Tepco executives have suggested, and was unlikely to pose a threat to Japan’s other nuclear reactors in the foreseeable future.”

By portraying the risk of accident as unimaginably rare (“once in a millennium”), Tepco officials overstated its safety. As Zhores Medvedev notes in his book The Legacy of Chernobyl (1990, W.W. Norton), the same minute risk mentality pervaded the culture at Chernobyl; one plant operator said that “in the classrooms of their institutions [nuclear reactor technician students] had beaten into their heads: a reactor cannot explode.... And it was only in October 1986 that the regulations were changed to include the grim warning: ‘When there are fewer than 30 [nuclear reaction dampening] rods the reactor goes into a situation of nuclear danger.’”

The irony is that in both cases the risk of accident actually was very remote -- assuming that established safety protocols were followed.

Culture of Complacency

In both nuclear accidents there was an entrenched culture of complacency. Corners were often cut and safety procedures ignored. At Chernobyl the danger of a nuclear meltdown was systematically downplayed and rules became lax. Igor Kazachkov, one of the shift operators at Chernobyl, stated “We didn’t have any foolproof safeguards against this particular thing happening... There are lots of safeguards but nothing that controls the number of rods. We have often had less than the required number of rods [controlling the reaction] and nothing happened. No explosion, everything proceeded normally.”

HOWSTUFFWORKS: How a Nuclear Reactor Works

In other words, the plant had operated safely and things turned out okay when safety rules were ignored, so operators became complacent. This is human nature, and can be seen in the psychology of drunk drivers who think, “Well, the last few times I drove home safely, so I can do it again.” Getting away with breaking the rules -- especially repeatedly -- makes the action seem less dangerous.

The Fukushima Nuclear Accident Independent Investigation report also contained pointed criticism of the Japanese culture and its role in creating the disaster and failing to mitigate its aftermath. Kiyoshi Kurokawa, chairman of the commission, stated that “What must be admitted -- very painfully -- is that this was a disaster ‘Made in Japan.’ Its fundamental causes are to be found in the ingrained conventions of Japanese culture: our reflexive obedience; our reluctance to question authority; our devotion to ‘sticking with the program’; our groupism; and our insularity.” The problem was so pervasive, Kurokawa noted, that “Had other Japanese been in the shoes of those who bear responsibility for this accident, the result may well have been the same.”

After each high profile accident there are reports and investigations calling for changes to be implemented to make sure it “never happens again.” The nuclear power industry did not learn lessons from Chernobyl, and likely will not learn lessons from Fukushima. There will be future nuclear accidents of this scale--and probably worse. Not because the technology isn't improving, for it surely is, but because humans are the weak link, and human nature will continue to endanger us all.

Photo: The underground water storage tank installation at Fukushima Daiichi nuclear power station as seen on June 18, 2012. Credit: Tepco / Jana Press




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04/07/2012

Walk This Way: Japanese Heels Auto-Plant Seeds

Seed_Heels

Addressing nuclear fallout never looked so painfully stylish. A Japanese shoe designer is developing sky-high heels that automatically deposit seeds in the ground as the wearer walks in them. The shoes are part of a project to help rebuild Fukushima.

Designer Masaya Kushino's imaginative shoes usually sport wild, Dada-esque heels. He's adorned them with horns, fake ponytails, peacock feathers and ornate gold framing. So it wasn't a big stretch to add a component for distributing seeds.

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Kushino's "Healing Fukushima (Nanohana Heels)" were conceptualized in partnership with Japanese artist-designer Sputniko!, who came up with the project idea. Fukushima remains contaminated with nuclear waste following the earthquake and tsunami that struck the power plant there early last year. Sputniko! visited temporary housing there a number of times and learned about efforts to plant rapeseed in the region.

Some varieties of rapeseed, known in Japan as "nanohana," remove the radionucleotides caesium-137 and strontium-90 from the soil. The plant stores them in its stalk and seed coat, but not its seeds, which can be processed into industrial lubricants and cooking oil. Scientists in Belarus made the discovery after the Chernobyl disaster, according to the International Atomic Energy Agency.

The mechanical heels, which are still a work in progress, sink back when the wearer walks. Pressure from the movement causes a tube within the heel to emerge. The compartment containing rapeseeds turns and, similar to a BB gun, a single seed emerges from the end of the tube. Lifting the foot starts the process again:

Despite the heels' apparent functionality, the towering work of art is intended to be a catalyst for discussion about rebuilding Fukushima rather than a practical farming tool. This summer the artists say they plan to release a new video about their work.

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Based on his website's gallery, it looks like Kushino also designs accessories. Maybe he can come up with gloves so novice gardeners like me can automatically plant seeds simply by dipping fingertips into potting soil. Proceeds could go to the rapeseed replanting effort in Japan.

Photo: "Healing Fukushima (Nanohana Heels)" by Masaya Kushino. Credit: Takuya Shima.



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01/26/2012

Caging Radioactive Gas

MOFs
One of the challenges of nuclear energy is that the spent fuel emits dangerous, radioactive gasses. Not only is such a gas harmful to humans, but it makes storage and reprocessing difficult.

Now chemists at Sandia National Labs have found a way to isolate iodine gas from other molecules in nuclear fuel by trapping it in a kind of molecular cage. The metal-organic framework, known as an MOF,  is a crystalline and porous substance in which a metal atom binds to organic molecules.

BLOG: Scientists Build Self-Replicating Molecule

The team got the idea for an MOF from zeolite, a common material used in industry as an absorbent (and shows up in laundry detergent as well). Zeolite is made of minerals that take on a porous structure, allowing it to absorb other molecules relatively easily. A form laced with silver atoms can take up radioactive iodine quite well, for example, because the silver and iodine combine to form silver iodide. But silver is expensive.

So the scientists turned to other materials. They found that if you put zinc in the center of a frame made of organic molecules (methyl imidazolate for aficionados) that the ores in it that are just about the size of an iodine molecule. That allows them to absorb the iodine and trap it in the molecular framework. What’s left can be incorporated into glass and stored safely.  

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One big advantage to this kind of stuff is that it can be made into pellets or powders. The latter can blow around and that’s more efficient for cleaning up after a nasty spill. Pellets are good for getting iodine out of a controlled waste stream – the pellets retain a lot of surface area and are stable.

This is the first time anyone has used a zeolite-like substance in this way, and it means that other, similar molecules could be made to absorb other dangerous chemicals as well. 

Image: Sandia Laboratories





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12/15/2011

Small May Be Beautiful For Nuclear Power

Gundremmingen_Nuclear_Power_Plant

Small Is Beautiful is the title of a book often cited by environmentalists, but it could the concept also be applied to nuclear power plants?

A study by the University of Chicago’s Energy Policy Institute says that small, modular reactors may be the future of the nuclear power industry in the United States.

Small, modular reactors (SMRs in industry parlance) are designed to generate 600 megawatts or less; by contrast the smallest current designs from nuclear power plant builders start in the 1100-megawatt range.

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Nuclear plants generally require a huge up-front financial investment, which is one reason that only regulated utilities or government-owned monopolies have built them. The big costs involved incentivize owners to build big plants in order to get a better return on investment. More power equals more revenue.

However, the EPI study says it might be worth rethinking that assumption, and looking at what would happen if nuclear plants could be built smaller, with standardized parts that would be mass-produced. The report claims that the costs of electricity per kilowatt-hour from the SMRs compare favorably to those of wind and solar, coming in at about 9 cents per kilowatt-hour. That's about half the cost of solar photovoltaic (18 cents) and 36 percent that of solar thermal (25 cents). Wind energy would cost about the same, and biomass ranges from 9 to 18 cents.

The cost savings would be from the efficiencies gained by standardizing the manufacturing of parts (something similar to this was done in France, which generates 76 percent of its electricity with nuclear).  

Another big advantage would be the lead time. A new nuclear power plant can take a decade to come on-line, between the construction and regulatory approvals. A smaller-scale facility with simpler parts could be built much more quickly, on the order of a few years.

Smaller reactors could also be built to be safer. Robert Rosner, the EPI’s director and one of the report’s authors, said in a statement that many of the new designs allow the reactor to be passively air-cooled, via convection, rather than with pumping water. That simplifies the design. Some, he said, could even go through an accident with no human intervention because they would be able to throw off their heat load before melting down.

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The nuclear accident at Fukushima, as well as that at Three Mile Island in 1979 and the 1986 disaster at Chernobyl were all caused by failures of the cooling systems, which allowed the nuclear fuel in the reactor cores to overheat. In the case of Fukushima the result was water with radioactive contamination being released into the ocean.

Building a whole lot of small reactors will still run into challenges. Besides the safety concerns with new designs, there are the economics. The report admits that for a full-on program of building nuclear plants to replace coal, for example, government subsidies would likely be needed. Probably the government would end up being an early customer. There is also the waste disposal, which remains a hot-button issue.

A copy of the study is available here.

Image: Felix König / Wikimedia Commons




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11/15/2011

Will You Survive A Nuclear Attack?

Nuke-blast-zone-622

Nabokov once described the region where I'm from in the Midwest as the three states beginning with "I." My adopted home state, Missouri, is widely regarded as a "fly-over state." And if you're erudite New York Times columnist, David Carr, the only waltz we know is the "dance of the low-sloping foreheads."

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But I've got news for you jet-setting city-slickers looking down on us from the first class cabins of your coast-to-coast red-eyes. Once the nukes start dropping on metropolis, you just might find yourself knocking on the doors of us milquetoast Midwesterners. How come? Why not take gander at Google Maps-inspired website, Would I Survive A Nuke, and see how you and your fellow metropolitans will fair perhaps a 50 megaton Tsar Bomba detonates downtown.

If you survived, congratulations. If not, how about considering a move to my neck of the woods in Columbia, Missouri? Sure the website says I "live in the middle of nowhere," but at least I survived the Tsar Bomba attack on St Louis. However, with the oncoming nuclear winter, I'll need to brush up on my skiing techniques.

BLOG: Urban Nuclear Attack Scenarios Examined

Bad news, though, should a dinosaur-ending meteor score a direct hit. In that scenario, we're pretty much all toast.

[Via Gizmodo]

 



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10/11/2011

iPhone Powers Radiation Detector

RDTXRDTX: $275

As if radiation weren’t scary enough, imagine having to track levels of it everywhere you go. For some in Japan, this may become a reality. Japanese accessory maker Scosche created RDTX, a Geiger counter that plugs into iPhone or iPod Touch and works with the radTEST app to measure radiation levels all the time. It’s predecessor, RDTX-Pro sold out quickly, but the RDTX will be available next month. A home Wi-Fi version is set for release next year, but like all the detectors, it will only be available in Japan.

NEWS: Why Radiation Is So Scary

The calibrated device turns its host’s screen into a meter display that indicates radiation levels in three different colors: green for safe, yellow for elevated and red for dangerously high. It also has a digital display that provides measurements in more detail like, micro Sieverts per hour and dose received. If the desire to share your possible contamination levels with friends hits, results can be shared on Facebook, Twitter and Google Maps.

Via: CNET

Credit: Scosche




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03/24/2011

Computers, Electronics and Autos Hit by Japan's Tsunami

Japan-cleanup-650

As the rest of the world waits, watches and hopes for Japan's recovery from the suffering and devastation caused by the March 11 tsunami, it's beginning to experience the reverberations of the destruction from afar. For various reasons, ranging from damage to buildings to lack of available staff,  several technological and manufacturing firms in Japan have halted production of computer and automobile components, causing disruptions to worldwide supply chains.

For example, a Nissan engine factory in Iwaki, located in the same prefecture as the Fukushima nuclear plant, doesn't have enough water, electricity or gas to operate. This has already impacted 40 of Nissan's Japanese component suppliers.

CRISIS IN JAPAN: Get the latest coverage

Most affected is the automaker's engine factory in Iwaki, which is in the same prefecture as the stricken Fukushima Daiichi nuclear power plant. The factory doesn't have enough water, electricity or gas. Nissan may need to ship engines from a plant in Tennessee depending on how long it takes to get the Iwaki facility back in production.

What does this mean for you? You might not be able to buy that new iPad or the latest models of Prius when you wanted to, and when those items are available, they may be more expensive than ever.

Japan is a hub of technological manufacturing. According to Credit Suisse, the country makes 72 percent of the world's silicon wafers, 32 percent of the world's cars, and 74 percent of the navigation systems that go in all cars.

Companies in neighboring South Korea are feeling the immediate impacts, since they depend on Japan firms to supply LCD glass, silicon chips, semiconductor components, steel for building ships, reports China Daily.

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But the United States is not immune. A General Motors in Louisiana had to temporarily shut down for lack of Japanese-made auto parts. The San Jose, Calif.-based solar panel maker SunPower Corp could be affected, too, as it gets 20 percent of its supplies from a Japanese firm. And Boeing is on alert. About 35 percent of the 787s and 20 percent of the 777s come from Japanese companies, such as Jamco, Mitsubishi Heavy Industries, Fuji Heavy Industries, and Kawasaki Heavy Industries.

According to the news agency Reuters,the following Japanese companies have been affected by tsunami in some way.

  • Toyota
  • Honda
  • Mazda
  • Suzuki
  • Fuji Heavy Industries
  • Sony
  • Toshiba
  • Cannon
  • NEC
  • Nikon
  • Panasonic
  • Renesas
  • Shin-Etsu Chemical
  • Jamco

There's a partial list of the latest plant shutdowns here. We hope that Japan gets back on its feet soon.

Destroyed cars and trucks are seen outside a shopping mall on March 18, 2011 in Ishinomaki, Japan. Credit: Chris McGrath/Getty Images




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03/22/2011

Volunteers Report Radiation Levels Online

Radiation-map

More than a week after a 46-foot tsunami devastated parts of northeast Japan, engineers are still working to regain control of a damaged nuclear reactor facility. Reports of higher-than-normal levels of radiation in milk and some vegetables are popping up in areas not far from the Fukushima reactor, and meteorologists have measured small levels of radiation wafting over the United States on very high altitude winds.

Wide Angle: Japan in Crisis

So far, it doesn't appear that anyone living in the United States is in danger. An announcement from the Food and Drug Administration yesterday reported that no products are being exported from the affected region of Japan, since people there are still dealing with the heavy damage from the quake and tsunami. Nonetheless, the agency says it's paying special attention to any shipments that may arrive from companies in the affected area.

But how can you know if any radiated particles are in your local air?

Plume-278x225 You can watch the winds on the University of Maryland's website, which uses information from NOAA to calculate the movement of hazardous material through the atmosphere.

Or you can visit the website Radiation Network, which reports to the public the radiation levels in most locations throughout the 48 contiguous United States. It's a grass-roots effort managed by backyard radiation watchers equipped with hand-held Geiger counters.  Volunteers who sign up for monitoring download a software program developed by Tim Flanegin, who runs the site, and then use the radiation detectors, which are connected to laptops, to upload information in near real time. Read more about do-it-yourself radiation monitoring in this article from the Washington Post.

So far, measured levels over the United States are being reported as very low and harmless, since any radiation gets diluted in the air by wind and rain as it travels across the globe.




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03/18/2010

Is Nuclear Energy Safe?

Is-nuke-energy-safe-278x225 With a financial push from the Obama administration (and even Bill Gates), nuclear energy is out in front as an alternative to generating electricity with fossil fuels.

Nuclear power plants –- and there are 104 operating in the United States today -- work much like natural gas or coal plants: An energy source heats water to make steam; steam turns a turbine; the turbine generates electricity. But a nuclear reactor differs from fossil fuel-based plants in that it doesn’t burn anything and doesn’t produce any carbon-dioxide emissions. Zero.

However, it’s based on radioactive materials and it produces radioactive waste. That’s where the concerns lie. I think it’s fair to say that whenever the topic of nuclear energy comes up, the question of its safety is high on the list of discussion points.

It’s a complicated topic, but to give you some food for thought, I interviewed a person from either side of the issue. First, I spoke with Tom Kauffman, senior media relations manager for the Nuclear Energy Institute in Washington, D.C. Kauffman has been in the industry for more than two decades, held a senior reactor operator license and was at Three Mile Island when the accident occurred in 1979. Out of that conversation, I came up with a list of questions, which I emailed to Edwin Lyman.

Lyman is a senior staff scientist at the Union of Concerned Scientists in Washington, D.C. His research focuses on the prevention of nuclear proliferation and nuclear terrorism, and prior to working at the UCS, he was the president of the Nuclear Control Institute. Lyman emailed his answers.

Below are Kauffman’s and Lyman’s responses to some of the main safety concerns hovering over the future of nuclear energy. Neither one saw the other’s answers, as I did not want them to debate each other, but rather provide information about these issues from their point of view. Since I spoke with Kauffman first, I’ll put his answers first. Here are their responses to this controversial issue:

Oftentimes the topic of Chernobyl comes up when nuclear energy is mentioned. Could a Chernobyl-type accident happen in the United States at a nuclear power plant?

Kauffman: No. A Chernobyl-type accident can’t happen in the United States. It’s physically impossible. The reactor was a completely different design. All of the U.S. nuclear plants are self-limiting. They can’t run out of control and explode. The Chernobyl reactor wasn’t self-limiting. That design is banned in the United States and in most other nations. People who bring it up are using it as a scare tactic. My Subaru is as likely to blow up like Chernobyl as one of our nuclear reactors.

Lyman: The short answer is yes. An accident resulting in a large radiological release to the environment comparable to or worse than that of Chernobyl could definitely occur at a U.S. nuclear power plant. While the particular accident mechanism resulting in a catastrophic release of radioactivity would be different for a U.S. light-water reactor than for a Chernobyl-type reactor, the outcome could be similar. The Nuclear Regulatory Commission has a policy that if a core-melt accident occurs (such as the one at Three Mile Island in 1979), then the probability that the event could result in a large radiological release should be less than 10 percent.

According to computer simulations, some U.S. reactors would comfortably meet this limit, while it is less clear for others. Some reactor-containment buildings could be ruptured by a hydrogen explosion, for example. In addition, when a plant is down for a refueling outage, the containment building is open to the environment, but the fuel remains hot and is still vulnerable to melting if cooling is interrupted. And finally, terrorists with the tactical skill to attack a nuclear plant would find it fairly easy to blow a hole in the containment building.

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Do people who work or live near nuclear power plants get exposed to radiation? And is that level safe? What's an unsafe level and how does it compare to our everyday exposure?

Kauffman: There have been commercial plants operating in the United States for more than 50 years, and collectively they have amassed more than 3,000 reactor years of operations. After all of those years and experience, there have been no deaths or negative health effects linked to the nuclear power plants in the public. There has never been a radiation-caused death of any of the workers. According to the Bureau of Labor Statistics, it’s safer to work at a nuclear power plant than it is to work at a bank or a grocery store or in real estate. The industry’s record shows that it has performed very safely and reliably for decades.

It’s a myth that there is no safe dose of radiation. If that were true, you couldn’t breathe the air or drink water or eat food. Every human being is continuously exposed to different forms of radiation, from outer space, the Earth, water, food and air. The risk associated with low doses of radiation from natural sources and manmade sources is extremely low.

The use of radiation to make electricity, in medicine to diagnose and treat disease or treating food for bacteria has improved, extended or saved the lives of millions of Americans.

Lyman: First of all, there is no such thing as a "safe" level of radiation. Reputable scientific bodies like the U.S. National Academy of Sciences have reviewed all the evidence and concur that even a single particle of ionizing radiation is capable of causing the genetic damage that could result in cancer. But the risk is proportional to the dose, so the higher the dose the greater the risk.

Many people who work at nuclear plants get exposed to radiation as part of the job. There is a federal limit for the maximum exposure a nuclear plant worker can receive over the course of a year, but the U.S. standard is 2.5 times the international standard. This limit is set so that the occupational risk incurred by radiation workers is comparable to that of other workers in hazardous industries.

People who live near nuclear plants also receive some routine radiation exposure. It is very hard to accurately project these doses, and they are extremely variable with respect to time and location. The Nuclear Regulatory Commission requires licensees to make estimates of these doses and show that they do not exceed regulatory limits. Regulatory limits are set so that the doses received by the public from anthropogenic radiation are a fraction of the radiation received from the natural background. But the public dose limit is the same for everyone, and doesn't take into account that certain subpopulations may be more susceptible to radiation exposure, such as children.

Do nuclear power plants leak? If so, what does that mean and can those leaks be dangerous?

Kauffman: We’ve had some leaks, like at Vermont Yankee. But that was self-identified by on-sight monitors. They notified everyone and actively found the sources, isolated them and mitigated the consequences. It has not gotten into drinking water nor has it threatened the safety or the health of the public around the plant. None of the leaks ever have.

We’re working hard to prevent these things. But when they do happen, we take the initiative to self-identify and let everyone know, and then mitigate those events.

Lyman: I interpret a "leak" to mean an unauthorized release of radiation. Nuclear plants emit some radioactivity into the air and water during normal operation, but those releases are regulated by the Nuclear Regulatory Commission. However, there have been several examples over the past few years of unauthorized and uncontrolled releases of tritium and other radionuclides to groundwater. Vermont Yankee is a case in point. So far, very few of these have resulted in detectable increases in radioactivity in public drinking water sources. However, these leaks may be troubling signs of unanticipated corrosion problems at aging nuclear plants and could lead to more serious problems if left uncorrected.

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How vulnerable are nuclear power plants to terrorist attacks?

Kauffman: Nuclear power plants are some of the most highly protected facilities in the nations. They are up there with Fort Knox. They are built to withstand the impact of a jet liner. They are guarded and protected 24 hours a day, 7 days a week, 365 days a year with security equipment and personnel armed with automatic weapons. These are fortified, highly secure, and well-protected facilities. The multiple layers of security make them less of target of terrorism than other, less-secure facilities.

Lyman: Nuclear plants are intrinsically vulnerable to terrorist attacks because they are delicate systems that can be easily disrupted through violent means. At some U.S. plants, detonation of an explosive device at a single location could be sufficient to result in a core meltdown. As a result, plants require extensive security measures to protect against both external violent assaults and insider sabotage.

However, these measures are cumbersome and expensive, and post-9/11 security requirements have been resisted by the utilities. Even today, nearly half of U.S. nuclear plants have not completed security upgrades mandated by Nuclear Regulatory Commission after the 9/11 attacks. And these measures are not foolproof. Currently, the Commission statistics reveal that about 10 percent of plants fail their "force-on-force" security inspections, in which a team of mock adversaries attack a plant to assess the quality of the security force response.

How vulnerable are shipments of new or used radioactive materials? Could they be blown up or crash and release radioactive materials that could harm people?

Kauffman: There have been more than 3,000 shipments of used fuel and highly radioactive materials since the 1960s that have totaled 1.7 million miles on our roads and railways, and in that time, there have been nine accidents. None have caused any radiation exposure. There were no leaks or environmental impact. No radiological impacts. No damage or impact to the public. That’s an excellent safety record.

A fuel-shipping container can withstand a direct hit by high-speed locomotive going 80 miles per hour. It can withstand a 1,475-degree Fahrenheit fire for 30 minutes, a direct hit by projectile 30 times more powerful than an anti-tank weapon, and 600 feet of water pressure.

Lyman: Some types of concentrated nuclear material are extremely hazardous and considerable care must be taken when they are transported. Spent nuclear fuel, plutonium and high-level nuclear wastes are the most dangerous categories. The Nuclear Regulatory Commission has requirements for transportation packaging and for transport safety and security measures, but the efficacy of these measures is --- and has been --- extensively debated for decades.

There is always a tradeoff between safety and the cost of transport. Transportation of nuclear material is the stage of the nuclear fuel cycle that is most vulnerable to terrorist attack. However, there is very limited information about the potential consequences of sabotage attacks on transportation casks. It simply isn't well known how much material could be released into the environment. But a sabotage attack does have the potential to spread radioactive contamination over a wide area.

Is finding a storage solution the responsibility of the federal government or the power plant? The fact of the matter is, even if no other plants are built in the United States, we still have operating plants that must dispose of waste. What in your opinion is, or are, some alternatives to safely storing radioactive waste?

Kauffman: Storage of used fuel is by law, the responsibility of the federal government to have a solution, but they haven’t fulfilled this obligation. When I was being trained in the late 1970s, the used fuel would go into storage pools and then it was supposed to be shipped off to reprocessing to be reused. But Carter stopped all development and research on reprocessing.

The Obama administration stepped up saying we need a plan in place for these materials and we need to consider developing technologies for reprocessing used fuel. President Obama doesn’t favor the Yucca Mountain option, but he’s recognized that we need a comprehensive, long-term plan. He and Energy Secretary Steven Chu established a blue ribbon commission that begins meeting this month and is charged with developing recommendations within two years.

The industry has made some recommendations, too. We would like to see centralized, interim storage. We have plants that have been decommissioned. Remove the used fuel from those decommissioned plants so that the sites can be made green and used for other purposes. To reduce the risk of proliferation, we want proliferation-proof ways to recycle the used fuel considered. It would be a tremendous waste to bury it somewhere.

Yucca Mountain and the used fuel issue were mired in politics for years, and now we see some very positive movement forward.

Lyman: By law, the federal government has the responsibility for the final disposal of commercial spent nuclear fuel, but the funding for carrying out this responsibility comes from electricity ratepayers. The government has not honored this responsibility and as a result is now defending itself from numerous utility lawsuits, and now that it has cancelled the current geologic repository program, it is likely going to continue to lose in court.

In our view (and the view of most experts), there is no alternative for nuclear waste disposal in an underground geologic repository. The government will have no choice but to restart the siting process that was originally started in the 1980s and culminated in the selection of Yucca Mountain. And there is no technical means to destroy nuclear waste so that a repository would not be necessary.

Some people advocate reprocessing spent fuel and assert that this technology would have benefits for nuclear waste management. However, this is absolutely not the case. Reprocessing greatly increases the volume of nuclear waste requiring secure disposal, releases considerable radioactivity into the air and water, and produces separated plutonium, which is a material that can be stolen by terrorists and used to make nuclear weapons. Therefore, reprocessing is the most dangerous option for dealing with spent nuclear fuel.

Photo: Getty Images/David McGlynn

03/12/2010

Designing an Unmanned Chopper for Nuclear Disasters

Rmax This is Yamaha's RMAX unmanned aerial vehicle, which according to the company's website is "to be used in agriculture for the purpose of crop dusting, and also to serve...for observation/monitoring." Now, the Virginia Tech Autonomous Aerial Robotic Team is modding these choppers out with specialized equipment that would take them far beyond the realm of crop-dusting. The idea, horrible as it is to think about, is to make these vehicles capable of entering difficult areas in difficult situations. One possible scenario that has been put forward: The choppers could be deployed after a nuclear strike, or a dirty bomb explosion, to search for survivors, monitor radiation levels, and assess damage. The team leader at Virginia Tech is Dr. Keven Kochersberger. Despite the fact that some of the work is classified (the research is being funded by the US government), Dr. Kochersberger agreed to an interview via email. 

1) Tell me a little bit about the background of this project -- how did it come about? What was the goal, and has that goal changed as the project progressed? 


The Unmanned Systems Lab has built a capability in operating VTOL (vertical takeoff and landing) aircraft for autonomous payload delivery through previously funded projects and collegiate competitions such as the International Aerial Robotics Competition (IARC). The IARC event has served to train undergraduates in the use of software tools, as well as the design and fabrication of electrical and mechanical hardware which is critical to building lightweight and low power systems. In 2008, the Virginia Tech IARC team placed 2nd and took home $17,700 in prize money. Those students that stay on for a graduate degree hit the ground running which gives the lab a distinct advantage. 

 2) The Yamaha-built UAV RMAX helicopter -- can you tell me a bit more about this vehicle

This helicopter was designed by Yamaha as a low-cost, remote controlled crop dusting aircraft to be used on small rice fields in Japan. A few were exported to the U.S. for research purposes, but in 2005 the Japanese government ceased exports and so the helicopter currently has only limited support from the manufacturer. It can carry about 50 lbs. of payload for 45 minutes, and flies no faster than 20 MPH when carrying our custom-designed payloads. It has been upgraded to be fully autonomous and requires FAA approval to fly in the National Airspace. 

SRNLflight  3) What modifications have you made to the vehicle, and why? 

The helicopter has a commercial autopilot installed, and a VT-designed electronics box, or E-box, mounted to the belly which contains a mission computer, payload radio, and custom designed power and communications printed circuit boards. A gimbaled camera and stereo camera system are additional permanent installations which are powered and controlled through the E-box. The mission computer operates the payloads and provides high level control to the air vehicle system. 

4) How do you envision the use of this modified UAV? I understand that it could, for example, go into a city after a nuclear attack

I have to be very vague about this.  The system is designed so that a minimal crew can rapidly deploy the helicopter configured with its mission-specific payload. 

5) Are there other scenarios, though, where it could prove useful? 

Yes. There is nothing in the design of this air-vehicle system that is specific to sampling in a blast site. For instance, the helicopter could be configured to locate lost hikers, send images back to the ground station and accurately drop supplies via a tether

6) And the UAV you're working on is largely autonomous, right? 

It can be operated fully autonomously, however we are manually taking off and landing (through remote control) to provide an added margin of safety. Once airborne, the flight control computer is engaged and the helicopter proceeds on its mission. This system is designed to be fault tolerant, and in the event that a radio link is lost, the helicopter will return to its home waypoint. Manual control can be regained at any time during the mission via a safety pilot who is continuously observing the helicopter as it flies (for our research purposes only – in an actual mission the visual line of sight of the helicopter would be lost). 

7) How would the vehicle itself deal with high radiation levels, dust, dirt, etc? 

The electronics have undergone preliminary radiation and environmental testing. As the project progresses, we will be more focused on developing a fully deployable system that will work in all possible conditions.

8) What's the timeline for testing and deployment? 

The press release says we will be mission-ready in 3 years. In the meantime, we will conduct frequent research flights near Virginia Tech and provide larger demos to the sponsor on a less-frequent basis.

(Top photo courtesy of Yamaha. Bottom photo courtesy of Virginia Tech)

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