 |
|
Separating uranium from plutonium
August 08, 2003Moscow researchers have made the supercritical carbon dioxide work. Saturated with special reagents, carbon dioxide first extracts uranium from the spent nuclear fuel waste, then extracts plutonium and then flies away into the atmosphere.
As a matter of fact, the spent nuclear fuel consists of multiple elements. First of all, this is uranium that did not burn out and plutonium obtained as a result of nuclear reaction and numerous fission fragments, both radio-active and non-radio-active. Uranium and plutonium are extracted first of all: on the one hand, they are very dangerous, and on the other hand, they can be used to produce new heat-generating elements for atomic power-plants.
The so-called Purex process is used worldwide to extract uranium and plutonium. Purex process is applied not because it is perfect, but because nothing better has been invented so far. The essence of the process is as follows: old fuel elements get dissolved in the nitric acid and a special reagent - tributylphosphate - catches what is required.
As a result, two solutions are obtained based on the poisonous acid. One of the solutions contains almost the entire uranium and plutonium. The other contains the residuum: some uranium and plutonium, fission elements and corrosion products. The volume of these liquids is measured by thousands of tons.
The method proposed by the researchers under the guidance of Academician Miasoyedov, Vernadsky Institute of Geochemistry and Analytical Chemistry (GEOKHI), Russian Academy of Sciences, is revolutionary as compared to the Purex process. The reason is that the solid residual (zirconium, caesium, strontium and other fission elements) and two aqueous solutions are received at the output. One solution contains uranium salts, the other - plutonium salts. On top of that, it contains carbonic acid gas that returns back to the atmosphere. When this gas is condensed and slightly heated (up to + 35 degrees C), it passes to the supercritical condition and becomes as powerful dissolvent as, for instance, acetone. Utilization of supercritical CO2 gas is considered one of the major directions in green chemistry, which has been already evolving for several decades at a rush pace.
This particular supercritical technology extracts uranium at the first phase. To this end, the spent nuclear fuel is placed into the sealed chamber and poured with supercritical carbon dioxide under pressure, a special reagent being dissolved in the carbon dioxide. Uranium forms a complex with it and dissolves, and plutonium and fission elements - do not. They settle on the bottom of the chamber.
Then the pressure is decreased and the carbonic acid gas is passed through water. Uranium remains in the water in the form of salts solution, and pure carbonic acid gas flies away. It is interesting to note that this method allows to extract uranium practically to full extent.
The second phase is separating the residuum, i.e. the plutonium/uranium fission products mixture. To extract plutonium, the researchers want to repeat the process but with a different substance. It will react only with plutonium and will disregard other components of the mixture.
"We are proactively handling this phase of the process now, says Academician Miasoyedov. The extragent has already been found. By the way, scientists all over the world are trying to address the problem, however, the first results on separating uranium and plutonium have been achieved in Russia. Another issue is how to use plutonium for peaceful purposes. The future of nuclear power lies in fast reactors. These reactors require mixed fuel - uranium and plutonium. So, in this case the element we extracted will be helpful."
Informnauka (Informscience) Agency
As a result, two solutions are obtained based on the poisonous acid. One of the solutions contains almost the entire uranium and plutonium. The other contains the residuum: some uranium and plutonium, fission elements and corrosion products. The volume of these liquids is measured by thousands of tons.
The method proposed by the researchers under the guidance of Academician Miasoyedov, Vernadsky Institute of Geochemistry and Analytical Chemistry (GEOKHI), Russian Academy of Sciences, is revolutionary as compared to the Purex process. The reason is that the solid residual (zirconium, caesium, strontium and other fission elements) and two aqueous solutions are received at the output. One solution contains uranium salts, the other - plutonium salts. On top of that, it contains carbonic acid gas that returns back to the atmosphere. When this gas is condensed and slightly heated (up to + 35 degrees C), it passes to the supercritical condition and becomes as powerful dissolvent as, for instance, acetone. Utilization of supercritical CO2 gas is considered one of the major directions in green chemistry, which has been already evolving for several decades at a rush pace.
This particular supercritical technology extracts uranium at the first phase. To this end, the spent nuclear fuel is placed into the sealed chamber and poured with supercritical carbon dioxide under pressure, a special reagent being dissolved in the carbon dioxide. Uranium forms a complex with it and dissolves, and plutonium and fission elements - do not. They settle on the bottom of the chamber.
Then the pressure is decreased and the carbonic acid gas is passed through water. Uranium remains in the water in the form of salts solution, and pure carbonic acid gas flies away. It is interesting to note that this method allows to extract uranium practically to full extent.
The second phase is separating the residuum, i.e. the plutonium/uranium fission products mixture. To extract plutonium, the researchers want to repeat the process but with a different substance. It will react only with plutonium and will disregard other components of the mixture.
"We are proactively handling this phase of the process now, says Academician Miasoyedov. The extragent has already been found. By the way, scientists all over the world are trying to address the problem, however, the first results on separating uranium and plutonium have been achieved in Russia. Another issue is how to use plutonium for peaceful purposes. The future of nuclear power lies in fast reactors. These reactors require mixed fuel - uranium and plutonium. So, in this case the element we extracted will be helpful."
Informnauka (Informscience) Agency
Nuclear Current Events and Nuclear News RSSScientists watch as peptides control crystal growth with 'switches, throttles and brakes'
By producing some of the highest resolution images of peptides attaching to mineral surfaces, scientists have a deeper understanding how biomolecules manipulate the growth crystals. This research may lead to a new treatment for kidney stones using biomolecules.
Genetic analysis helps dissect molecular basis of cardiovascular disease
Using highly precise measurements of plasma lipoprotein concentrations determined by nuclear magnetic resonance spectroscopy (NMR), researchers led by Daniel Chasman at Brigham and Women's Hospital and Harvard Medical School in Boston, MA, the Framingham Heart Study in Framingham, and the PROCARDIS consortium in Stockholm, Sweden and Oxford, England performed genetic association analysis across the whole genome among 17,296 women of European ancestry from the Women's Genome Health Study.
Is global warming unstoppable?
In a provocative new study, a University of Utah scientist argues that rising carbon dioxide emissions - the major cause of global warming - cannot be stabilized unless the world's economy collapses or society builds the equivalent of one new nuclear power plant each day.
Nuclear weapons: Predicting the unthinkable
If a nuclear weapon were detonated in a metropolitan area, how large would the affected area be? Where should first responders first go? According to physicist Fernando Grinstein, we have some initial understanding to address these questions, but fundamental issues remain unresolved.
An atomic-level look at an HIV accomplice
Since the discovery in 2007 that a component of human semen called SEVI boosts infectivity of the virus that causes AIDS, researchers have been trying to learn more about SEVI and how it works, in hopes of thwarting its infection-promoting activity.
Proton's party pals may alter its internal structure
A recent experiment at the Department of Energy's Thomas Jefferson National Accelerator Facility has found that a proton's nearest neighbors in the nucleus of the atom may modify the proton's internal structure.
Chromosomes dance and pair up on the nuclear membrane
Meiosis - the pairing and recombination of chromosomes, followed by segregation of half to each egg or sperm cell - is a major crossroads in all organisms reproducing sexually.
Nanotech in Space: Rensselaer Experiment To Weather the Trials of Orbit
Novel nanomaterials developed at Rensselaer Polytechnic Institute are scheduled to blast off into orbit on November 16 aboard Space Shuttle Atlantis.
The bizarre lives of bone-eating worms
The females of the recently discovered Osedax marine worms feast on submerged bones via a complex relationship with symbiotic bacteria, and they are turning out to be far more diverse and widespread than scientists expected.
SNM applauds House action to build medical isotopes reactor in the US
SNM applauds the U.S. House of Representatives for its passage of H.R. 3276-the American Medical Isotopes Production Act of 2009.
More Nuclear Current Events and Nuclear News Articles
 |
History of Nuclear Weapons - The Ultimate Weapons (2-DVD Set) Directed By: A2ZCDS.com The Ultimate Weapons DVD set from A2ZCDS is both disturbing and fascinating at the same time. Its historical significance can not be overrated – nor can the quality of these incredibly preserved vintage films from the dawn of the nuclear era. Over the course of the two DVDs you get a full picture of the development of the first nuclear weapons – that would spearhead the end of World War II – up through advanced nuclear testing in the late 1950s. If you are looking for films of nuclear bombs exploding, you will not be disappointed. You see the effects of the bomb on houses constructed at test sites, and also learn how the government planned to deal with the psychological effects of nuclear weapons. The Bikini Atoll test films are included and there is some exciting footage of... |
 |
The Nuclear Express: A Political History of the Bomb and Its Proliferation by Thomas C. Reed (Author), Danny B. Stillman (Author) This is a political history of nuclear weapons from the discovery of fission in 1938 to the nuclear train wreck that seems to loom in our future. It is an account of where those weapons came from, how the technology surprisingly and covertly spread, who is likely to acquire those weapons next and most importantly why.
The authors’ examination of post-Cold War national and geopolitical issues regarding nuclear proliferation and the effects of Chinese sponsorship of the Pakistani program is eye opening. The reckless “nuclear weapons programs for sale” exporting of technology by Pakistan is truly chilling as is the on again off... |
 |
3M Performance Plus 8979N Nuclear Grade 48-Millimeter-by-54.8-Meter Duct Tape, Slate Blue by 3M 8979N Nuclear Grade is designed for both permanent and temporary applications both indoors and outdoors. 8979 provides clean removal with little or no adhesive residue from most opaque surfaces up to 6 months after application. It offers sunlight/UV r |
 |
Day One Starring: Brian Dennehy, Alan Scarfe, John Pielmeier, Ken Pogue, David Strathairn Directed By: Joseph Sargent This Emmy® winning, historically accurate drama tells the complex and moving story of the Manhattan Project. Racing against the Nazi war machine and enduring intense military and political pressure, Allied scientists wrestle with the challenge of creating the ultimate weapon. Leading the superb cast are Michael Tucker (L.A. Law) as Hungarian physicist Leo Szilard, David Strathairn (Good Night, and Good Luck.) as mission chief J. Robert Oppenheimer, Brian Dennehy (Death of a Salesman) as General Leslie Groves, and David Ogden Stiers (MASH) as FDR. Also featuring Hal Holbrook (Mark Twain Tonight!), Hume Cronyn (12 Angry Men), and Tony Shalhoub (Monk). Before the bomb can be perfected, Hitler's death and Germany's surrender remove one enemy from the equation. But Japan remains. Day... |
 |
Power to Save the World: The Truth About Nuclear Energy (Vintage) by Gwyneth Cravens (Author), Richard Rhodes (Introduction) An informed look at the myths and fears surrounding nuclear energy, and a practical, politically realistic solution to global warming and our energy needs. Faced by the world's oil shortages and curious about alternative energy sources, Gwyneth Cravens skeptically sets out to find the truth about nuclear energy. Her conclusion: it is a totally viable and practical solution to global warming. In the end, we see that if we are to care for subsequent generations, embracing nuclear energy is an ethical imperative. |
 |
Nuclear Energy in the 21st Century: World Nuclear University Press by Ian Hore-Lacy (Author) The onset of the 21st century has coincided with mounting scientific evidence of the severe environmental impact of global energy consumption. In response, governments and environmentalists on every continent have begun to re-evaluate the benefits of nuclear power as a clean, non-emitting energy resource. Today nuclear power plants operate in some 30 countries, and nuclear energy has become a safe and reliable source of one-sixth of the world's electricity. This base has the potential to be expanded widely as part of a worldwide clean-energy revolution. Nuclear Energy in the 21st Century is an authoritative resource for educators, students, policy-makers and interested lay-people. This balanced and accessible text provides: * An inroad into nuclear science for the... |
 |
Trinity & Beyond - The Atomic Bomb Movie Starring: William Shatner, Edward Teller, Frank H. Shelton, Randall William Cook, Hubert H. Humphrey Directed By: Peter Kuran Trinity & Beyond… The Atomic Bomb Movieis the top secret, strange and visually compelling history of the design, production and testing of Atomic Hydrogen bombs. In this special 60th Anniversary Diamond Edition, renowned special effects filmmaker Peter Kuran (Star Wars, Star Trek II & V, Robocop) offers up amazing film footage chronicling the top secret, strange and visually compelling history of the design, production and testing of Atomic Hydrogen bombs by the United States. With the development and use of award-winning new film restoration systems, Kuran has perfectly preserved these haunting images for generations to come. Narrated by William Shatner (Boston Legal, Star Trek), Trinity & Beyond features extremely rare film segments from top secret government archives and... |
 |
Nuclear War Card Game by Flying Buffalo A humorous card game with a tongue-in-cheek view of international diplomacy, propaganda, and finally: holocaust! Two to six players engage in touchy negotiations until a warmonger pushes the button! This hilarious card game is easy to learn and fast to play. But watch out: if everyone is wiped out -- nobody wins! |
 |
Defcon: Strategic Nuclear War by Encore It's the End Of the World as You Know It! Inspired by the 1983 cult hit, War Games, Defcon puts you right in the middle of the Cold War era. Your success and our ultimate survival are on the line. Can you dominate or will you crumble under the pressure and paranoia? Compete as 1 of 6 superpowers embroiled in the largest military conflict imaginable! The only game that allows players to rain nuclear death on the enemy and rack up kill counts in the 10s of MILLIONS! |
 |
Nuclear Weapons: What You Need to Know by Jeremy Bernstein (Author) Nuclear Weapons is a history of nuclear weapons. From their initial theoretical development at the start of the twentieth century to the recent tests in North Korea, the author seeks to, at each point in the narrative, describe the basic science of nuclear weaponry. At the same time, he offers accounts and anecdotes of the personalities involved, many of whom he has known firsthand. Dr. Bernstein writes in response to what he sees as a widespread misunderstanding throughout the media of the basic workings and potential impact of nuclear weaponry. |
| © 2009 BrightSurf.com |