In the future, nuclear clean-up workers may be getting help from some surprising sources. None of these three methods are in widespread use right now, but they show promise:
1) Algae
Scientists have discovered that a type of algae can precipitate strontium into crystals. This could lead to better nuclear clean-up techniques, potentially sequestering radioactive strontium-90 from tainted water into crystalline form, which is easier to contain.
The algae, called C. moniliferum, collects strontium in sulfate-rich vacuoles, and because strontium and barium have low solubility in sulfate solutions, they precipitate out of solution as crystals.
What’s the Context: The danger of strontium-90 is that it is chemically similar to calcium, and so can be taken up into milk, bones, and other tissues. Nuclear waste and spills can contain significant amounts of strontium; C. moniliferum is especially helpful because it can precipitate strontium but leave calcium alone (calcium is different enough from barium that the bacteria doesn’t crystallize it).
Not So Fast: Scientists don’t yet know how well the algae can withstand radioactivity, which could potentially put a damper on this clean-up method. Now, the scientists would like to find ways of increasing sulphate levels in the environment, which may in turn increase the ability of the algae to crystallize strontium.
Reactor 3 at the Fukushima Daiichi plant, on March 24
What’s the News: A non-peer-reviewed study (pdf) publicized last week by radioactivity-detection expert Ferenc Dalnoki-Veress suggests that nuclear fission reactions continued at Japan’s Fukushima nuclear power station well after the plant’s operators had allegedly shut down the reactors there. The paper says there may be what are called “localized criticalities” have occurred in the plutonium and uranium left in the reactors—little pockets of fuel that have gone critical, propagating the nuclear chain reaction and generating potentially harmful radiation. The existence of criticalities is controversial: some researchers say there are certainly none; Dalnoki-Veress himself says it’s only a possibility.
80beats has covered Japanese robotic wonders such as the first robot marathon runners and catwalk-strutting robots as well. (If you’re wondering why such a tech-savvy, robot-friendly country didn’t deploy robots earlier, Reuters has a couple of guesses: old, robot-unfriendly reactor design, and a surprisingly anachronistic tendency to leave humans in charge of some easily automated tasks, “such as operating elevators and warning motorists of road construction.”)
Update (March 15): Shortly after this post was originally published, the situation at the Fukushima Daiichi facility worsened dramatically: there was an explosion at a third reactor, which may have damaged the containment unit there, along with a new fire. Reports elsewhere now suggests that more radioactive material escaped, but the extent of the risk of further release of radioactivity is not yet clear. The title of the post has been edited to reflect the changing situation. (Original title: “Relax: Fears Of Japan’s Radioactive Leakage Are Overblown”)
A second explosion hit Japan’s Fukushima Daiichi nuclear power plant today and authorities are preparing to pump seawater into a third imperiled reactor. But considering that Friday’s earthquake was seven times more powerful than the maximum limit they were designed to withstand, we’re lucky the situation isn’t much worse. Japan’s scenario is a far cry from Chernobyl: Any radioactive leakage that has occurred is low, and unlikely to affect anyone outside the local area (if that).
What Happened
Both today’s explosion (in reactor No. 3) and the one on Saturday (reactor No. 1) have the same cause: a breakdown in the cooling system as tsunami waters swamped generators. Specifically, today’s explosion was caused by hydrogen gas, which builds up as the seawater that’s pumped in to cool the reactor also heats up. From video footage, the explosion looks devastating, and while 11 people were injured, the steel and concrete containment shell around the nuclear reactor was not damaged—which is the main reason why authorities say the situation is mostly under control. “There is no massive radioactive leakage,” Cabinet Chief Cabinet Secretary Yukio Edano told the New York Times. Here’s a rundown on the risks in the leakage that has occurred:
What Is Escaping (and How)?
The root problem is heat: Even though the nuclear chain reaction is safely stopped in all of Japan’s nuclear reactors, that doesn’t stop heat from building up.
The uranium “stopped” the chain reaction. But a number of intermediate radioactive elements are created by the uranium during its fission process, most notably Cesium and Iodine isotopes, i.e. radioactive versions of these elements that will eventually split up into smaller atoms and not be radioactive anymore. Those elements keep decaying and producing heat. Because they are not regenerated any longer from the uranium (the uranium stopped decaying after the moderator rods were put in), they get less and less, and so the core cools down over a matter of days, until those intermediate radioactive elements are used up. [The Energy Collective]
Between murders and leaked documents, there’s disarray and intrigue all around Iran’s burgeoning nuclear program.
Yesterday, two prominent nuclear scientists in Iran were attacked in car bombings.
According to [Iranian new service] Fars, scientists Majid Shahriari and Fereydoun Abbasi were parking their cars in separate locations near the university campus about 7:45 a.m. local time when they were attacked.Witnesses said each car was approached by a group of men on motorcycles, who attached explosives to the vehicles and detonated them seconds later, the news agency reported. Shahriari was killed instantly. Abbasi was wounded. Both men were with their wives, who were also wounded. [Washington Post]
Unsurprisingly, Iranian President Mahmoud Ahmadinejad quickly pointed the finger of blame at the West and Israel. Both of the targeted scientists are reportedly connected to the Iranian nuclear program, which the government maintains is for the purpose of energy, but the United States and other nations oppose out of fear of an Iranian bomb.
Abbasi-Davani, whose handful of publications on neutron physics are mainly in Iranian journals, is a key figure in Iran’s nuclear programme. He is reported to be a scientist at the country’s defence ministry, and a member of Iran’s revolutionary guards since the 1979 Islamic Revolution. He was also named as being among “Persons involved in nuclear or ballistic missile activities” in the 2007 UN Security Council Resolution 1747, which imposed sanctions on Iran over its refusal to stop enrichment of uranium. [Nature]
It was late September when the world got wind of Stuxnet, the complex piece of malware that appeared to specifically target Iranian nuclear sites. Now, analysis of Stuxnet suggests it was almost perfectly designed to corrupt nuclear centrifuges, according to David Albright of the Institute for Science and International Security.
On Wednesday, Mr. Albright and a colleague, Andrea Stricker, released a report saying that when the worm ramped up the frequency of the electrical current supplying the centrifuges, they would spin faster and faster. The worm eventually makes the current hit 1,410 Hertz, or cycles per second — just enough, they reported, to send the centrifuges flying apart. In a spooky flourish, Mr. Albright said in the interview, the worm ends the attack with a command to restore the current to the perfect operating frequency for the centrifuges — which, by that time, would presumably be destroyed. [The New York Times]
Computer experts don’t know Stuxnet’s origin for sure, though the Times’ story drops a few cryptic hints of Israeli involvement. And further study of the attack shows that although Stuxnet appears calibrated to disrupt centrifuges, it could be easily adapted to seize the reins of other systems.
The widespread interconnection of corporate networks and use of SCADA systems [supervisory control and data acquisition] means that industrial infrastructure is increasingly vulnerable to software attack. Such control systems are used in virtually every industry—food production, vehicle assembly, chemical manufacturing—and are commonly exposed to insecure networks. This leaves them vulnerable to tampering, such as with Stuxnet, as well as intellectual property theft. [Ars Technica]
Rovers that roll are so 2004. This year’s designers are bringing the heat with fashionable Mars hopper designs, dreaming of explorers that can go the distance one half-mile hop at a time.
The British team that described its design in the journal Proceedings of the Royal Society A isn’t the first to suggest a hopper. But unlike previous designs, this hopper wouldn’t rely on solar power for fuel, but would instead by powered by radioactive isotopes and the plentiful carbon dioxide in Mars’s atmosphere.
The ability to hop from place to place would enable the new explorers to cover more of the Martian landscape, and visit rough terrain that earlier rovers couldn’t handle. The 2004 rover Opportunity is just hitting 15 miles of surface driving after almost seven years on Mars.
Dr Richard Ambrosi [who worked on the project], at the Leicester Space Research Centre, commented: “The improved mobility and range of a hopping vehicle will tell us more about the evolution of Mars and of the Solar System and may answer questions as to whether there was life in the past, whether Mars was wetter in the past and if so where that water went.” [Press Release]
After decades of development, Iran’s first nuclear power plant is close to operational. This week the country’s TV service announced that engineers have begun loading the fuel rods into the core of the Bushehr plant in southern Iran.
The 1,000-megawatt Bushehr plant has been under construction since before Iran’s 1979 Islamic Revolution. It was first contracted to a company that later became German industrial giant Siemens; more recently work was done with the help of Russia’s state-owned atomic energy company. [Los Angeles Times]
Iran‘s power plant was reportedly one target of the Stuxnet computer virus that emerged several weeks ago, but apparently that didn’t impair the final steps of preparing Bushehr.
A quarter-century after the catastrophe, Chernobyl can’t stay out of the news.
When fires broke out in Russia this month, people worried that the flames would spread to areas still affected by the radiation, with unknown consequences. And this week, we learned that Chernobyl-related radiation is actually on the rise somewhere else: in German boars.
Shahram Amiri is at the Pakistani embassy in Washington D.C. Unless he’s not.
The missing Iranian nuclear scientist is no stranger to intrigue and indecision: Last month we covered dueling YouTube videos in which two men, both claiming to be Amiri, say that either he was being held against his will in the United States or was studying freely and happily here. Today his case took more strange turns, as government officials in Pakistan claimed that Amiri is currently at their embassy in Washington, awaiting a return trip to Iran.
Today Amiri was quoted by Iranian official media as claiming that the US government had intended to return him to Iran to cover up his kidnapping in Saudi Arabia. “Following the release of my interview in the internet which brought disgrace to the US government for this abduction, they wanted to send me back quietly to Iran by another country’s airline,” he told state radio from the Iranian interests office in Washington. “Doing so, they wanted to deny the main story and cover up this abduction. However, they finally failed” [The Guardian].
Have you seen this man? If so, please ask him to make up his mind.
Shahram Amiri, a 32-year-old Iranian nuclear scientist, is at the center of an episode of United States-Iran intrigue that just got weirder, thanks to YouTube. Amiri disappeared during his pilgrimage to Saudi Arabia last year, and anonymous U.S. officials confirmed that he defected, presumably bringing information about Iran’s nuclear program. Now he—or someone purporting to be him—appears in two contradictory videos that claim he was either abducted and tortured by the United States or is living happily here and going about his studies.
The first video:
The dark-haired man, appearing unshaven and disheveled, said he was being held against his will in Tucson. “I was kidnapped in a joint operation by the American intelligence, CIA terror and kidnap teams, and Saudi Arabia’s Istikhbarat” spy service, the man said in a grainy video aired in Iran on Monday night. He said he had been drugged before being smuggled out of Saudi Arabia, adding that he had been subjected to “severe torture” and “psychological pressures” [Washington Post].
A very different Amiri showed up in a second video today. He, or someone like him, appears in a professionally shot video sitting in front of some parlor with a globe and a chess board, as if he wants to have a few minutes of our time to talk about life insurance.
Let’s give Bill Gates some credit: Retiring from Microsoft with all the free time and money in the world, Gates could have launched any number of Montgomery Burns-ian schemes for world domination. Instead, the multi-billionaire went the philanthropist route, becoming one of DISCOVER’s 10 most influential people in science through the health work his foundation funds. But a tinkerer is never done tinkering: In the last year Gates has patented an anti-hurricane device, given a few million dollars to fund geoengineering research, and then this week went public with his newest project: small-scale nuclear power.
A Gates-backed start-up company called TerraPower in talks with Toshiba to develop traveling-wave reactors (TWRs), which are designed to use depleted uranium as fuel and thought to hold the promise of running up to 100 years without refueling [FoxNews.com]. TWRs, which scientists have been playing with on and off for decades, need enriched uranium to get going, but are advantageous because they can use normal or even depleted uranium once the fission reaction is underway (and depleted uranium is something the United States has in great quantity). The technique requires bombarding uranium with a neutron to convert it to an unstable form of the element, which decays into neptunium and then fissile plutonium.
Toshiba’s already been working on mini reactors that run for about 30-40 years, and they believe that about 80% of the technology used in those can be used in the traveling-wave reactors [DVICE]. One of the challenges, though, is that if you’re that efficient at burning fuel, you need materials that can withstand that many years of constant radiation. TerraPower has completed the conceptual designs for both small units that produce electricity in the hundreds of megawatts, and a gigawatt-sized reactors that could power a city. But that’s the drawing board. In other words, this is very early days. And as with any new energy technology, expectations that energy supplies will be transformed in the near future should … take a rest [Financial Times].
Are these the first steps to a nuclear renaissance? Yesterday the White House said it would give more than $8 billion in loan guarantees to make sure that construction of two new nuclear power plants gets under way in Georgia. If these plants go ahead, they would be the first new nuclear plants built in the country in more than three decades.
The loan guarantee is conditional. It hinges on the utility, the Southern Co., receiving a license from the US Nuclear Regulatory Agency to build and operate the new reactors. Based on the current timeline, the utility expects to receive its license during the second half of 2011, says David Ratcliffe, its chairman and chief executive officer [Christian Science Monitor]. The two reactors would each produce more than 1,000 megawatts, and would work with two existing reactors at a site near Waynesboro, Georgia.
The loan guarantees will allow Southern Co. to get massive construction loans from its bankers without assuming the risk; if the power plants aren’t profitable and if the company defaults on its loans, the federal government will pay back the money to the banks instead. Despite the government support, the new Georgia reactors are far from a done deal: their design has not yet been fully approved by the Nuclear Regulatory Commission, whose staff has raised questions about whether changes made to harden the plant against aircraft attack had made it more vulnerable to earthquakes [The New York Times].
How on Earth did the moon come into being? If you subscribe to the latest theory, the moon was born out of a nuclear explosion on Earth that sent a chunk of mass flying from the planet’s core into orbit, where it finally became the moon. But cool as that sounds, some killjoy scientists are pooh-poohing the hypothesis, calling it “unnecessary,” “nonsensical,” and “not physically sensible.”
The standard theory of the moon’s origin holds that a giant space object, possibly an asteroid, banged into Earth and sent a large piece of the planet flying into space. That piece eventually became the moon. But the composition of the moon doesn’t seem to support this theory. Researchers say if an asteroid or some such object smashed away part of the Earth, the Moon ought to be composed of about 80 percent of that object’s constituent material and about 20 percent of the Earth’s. But the makeup of moon rock closely mirrors that of the Earth [Popular Science].
An alternate theory, known as the fission theory, suggests that the moon spun out of the rapidly spinning blob of molten rock that would later become Earth [Popular Science]. But no one has been able to explain what caused a huge chunk of earth to spin away and become the moon. Now, researchers Rob de Meijer and Wim van Westrenem have proposed in an online paper that centrifugal forces may have concentrated heavy, radioactive elements like uranium and thorium at the boundary between the Earth’s mantle and its core. Then, they propose, a massive nuclear explosion occurred at the edge of Earth’s core, flinging red-hot, liquid rock into space. The orbiting detritus gradually congealed into what is now our planet’s lone satellite [Discovery News].
Such “georeactors” have existed on Earth before, albeit on a smaller scale than these researchers propose. But de Meijer and van Westrenem have gotten little support for their hypothesis, and plenty of scorn.
The hunt for fusion energy is one that has been plagued by false starts and overly-optimistic announcements. This week, however, researchers at the National Ignition Facility in California announced a major new step: firing all of its 192 lasers together for the first time, and channeling the beam into an area no bigger than a pencil eraser.
That tiny target is called the hohlraum. It’s a gold-plated cylinder intended to contain the hydrogen isotopes deuterium and tritium, which would fuse together during a potential fusion reaction. In this test, documented in the journal Science this week, the 192 lasers heated up the hohlraum to “only” about 6 million degrees Fahrenheit. But, team member Jeffrey Atherton says, the NIF is working its way up to the really powerful reactions. “The point is that we were doing it at a scale that’s about 20 times larger than has been done, with a laser power that accordingly is about 20 times higher than has been done, with a precision and efficiency that hasn’t been done before,” he said [MSNBC].
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].
What’s the News: Japan has finally 
Between murders and leaked documents, there’s disarray and intrigue all around Iran’s burgeoning nuclear program.
It was late September when 
After decades of development, Iran’s first nuclear power plant is close to operational. This week the country’s TV service announced that engineers have begun loading the fuel rods into the core of the Bushehr plant in southern Iran.
A quarter-century after the catastrophe, 
Shahram Amiri is at the Pakistani embassy in Washington D.C. Unless he’s not.
Have you seen this man? If so, please ask him to make up his mind.
Let’s give Bill Gates some credit: Retiring from Microsoft with all the free time and money in the world, Gates could have launched any number of Montgomery Burns-ian schemes for world domination. Instead, the multi-billionaire went the philanthropist route, becoming one of 
Are these the first steps to a nuclear renaissance? Yesterday the White House said it would give more than $8 billion in loan guarantees to make sure that construction of two new 
How on Earth did the 
The hunt for fusion energy is one that has been plagued by false starts and overly-optimistic announcements. This week, however, researchers at the National Ignition Facility in California 
