Posts belonging to Category nuclear reactor



How To Detect Nuclear Device

How to keep U.S. ports of entry safe and secure by detecting and interdicting illicit radioactive or nuclear materials? A team led by Northeastern’s Swastik Kar and Yung Joon Jung has developed a technology that could go a long way toward achieving that goal.

nuclear radiation

Our detector could dramatically change the manner and accuracy with which we are able to detect nuclear threats at home or abroad,” says Kar, associate professor in the Department of Physics. It could also help streamline radio-medicine, including radiation therapies and scanning diagnostics, boost the effectiveness of unmanned radiation monitoring vehicles in mapping and monitoring contaminated areas following disasters, and revolutionize radiometric imaging in space exploration. Made of graphene and carbon nanotubes, the researchers’ detector far outpaces any existing one in its ultrasensitivity to charged particles, minuscule size, low-power requirements, and low cost.

All radiation, of course, is not harmful, and even the type that may be depends on dosage and length of exposure. The word “radiation” refers simply to the emission and propagation of energy in the form of waves or particles. It has many sources, including the sun, electronic devices such as microwaves and cellphones, visible light, X-rays, gamma waves, cosmic waves, and nuclear fission, which is what produces power in nuclear reactors. Most of the harmful radiations are “ionizing radiations”—they have sufficient energy to remove electrons from the orbits of surrounding atoms, causing them to become charged, or “ionized.” It is those charged particles, or ions, that the detectors pick up and quantify, revealing the intensity of the radiation. Most current detectors, however, are not only bulky, power hungry, and expensive, they also cannot pick up very low levels of ions. Kar and Yung Joon’s detector, on the other hand, is so sensitive it can pick up just a single charged particle.

Our detectors are many orders of magnitude more sensitive in terms of how small a signal they can detect,” says Yung Joon, associate professor in the Department of Mechanical and Industrial Engineering. “Ours can detect one ion, the fundamental limit. If you can detect a single ion, then you can detect everything larger than that.”

Source: http://news.northeastern.edu/

How To Process Nuclear Waste

In the last decades, nanomaterials have gained broad scientific and technological interest due to their unusual properties compared to micrometre-sized materials. At this scale, matter shows properties governed by size. At the present time, nanomaterials are studied to be employed in many different fields, including the nuclear one. Thus, nuclear fuels production, structural materials, separation techniques and waste management, all may benefit from an excellent knowledge in the nano-nuclear technology. No wonder researchers are on the constant lookout for better ways to improve their production.

nuclear radiation

Scientists from Joint Research Center have come up with a way to do just that. Olaf Walter, Karin Popa and Oliver Dieste Blanco, have devised a simple access to produce highly crystalline, reactive actinide oxide nanocrystals. The shape of the crystals, together with their increased reactivity, enables the consolidation of homogeneous nanostructured mixed oxides as intermediates towards very dense nuclear fuels for advanced reactors. Moreover, such materials can be used as precursors for the production of compounds with special properties, which mimic structures those are found in spent nuclear fuel, and will also be of great use in the study of how such radioactive material migrates in nearby geological environments.

This new process could enable scientists further research on the properties of these types of materials. Surprisingly, this new route proved uncomplicated, fast, and reproducible. It contains fewer procedural steps than typical oxalate precipitation-decomposition processes, allowing for production using a single vessel and under continuous flow.

The article, published recently in Open Chemistry may lead to the development of a process to remove uranium from wastewater at the front-end of the nuclear fuel cycle, or even extracting natural uranium from sea water.

Source: https://www.degruyter.com/

Nanoparticles Detect Dirty Nuclear Bomb

One of the most critical issues the United States faces today is preventing terrorists from smuggling nuclear weapons into its ports. To this end, the U.S. Security and Accountability for Every Port Act mandates that all overseas cargo containers be scanned for possible nuclear materials or weapons.

Detecting neutron signals is an effective method to identify nuclear weapons and special nuclear materials. Helium-3 gas is used within detectors deployed in ports for this purpose. The catch? While helium-3 gas works well for neutron detection, it’s extremely rare on Earth. Intense demand for helium-3 gas detectors has nearly depleted the supply, most of which was generated during the period of nuclear weapons production during the past 50 years. It isn’t easy to reproduce, and the scarcity of helium-3 gas has caused its cost to skyrocket recently — making it impossible to deploy enough neutron detectors to fulfill the requirement to scan all incoming overseas cargo containersHelium-4 is a more abundant form of helium gas, which is much less expensive, but can’t be used for neutron detection because it doesn’t interact with neutrons.

A group of Texas Tech University researchers led by Professors Hongxing Jiang and Jingyu Lin report this week in Applied Physics Letters, from AIP Publishing, that they have developed an alternative materialhexagonal boron nitride semiconductors — for neutron detection. This material fulfills many key requirements for helium gas detector replacements and can serve as a low-cost alternative in the future. The group’s concept was first proposed to the Department of Homeland Security’s Domestic Nuclear Detection Office and received funding from its Academic Research Initiative program six years ago. By using a 43-micron-thick hexagonal boron-10 enriched nitride layer, the group created a thermal neutron detector with 51.4 percent detection efficiency, which is a record high for semiconductor thermal neutron detectors.

nuclear radiation

“Higher detection efficiency is anticipated by further increasing the material thickness and improving materials quality,” explained Professor Jiang, Nanophotonics Center and Electrical & Computer Engineering, Whitacre College of Engineering, Texas Tech University. “Our approach of using hexagonal boron nitride semiconductors for neutron detection centers on the fact that its boron-10 isotope has a very large interaction probability with thermal neutrons,” Jiang continued. “This makes it possible to create high-efficiency neutron detectors with relatively thin hexagonal boron nitride layers. And the very large energy bandgap of this semiconductor — 6.5 eV — gives these detectors inherently low leakage current densities.

The key significance of the group’s work? This is a completely new material and technology that offers many advantages. “Compared to helium gas detectors, boron nitride technology improves the performance of neutron detectors in terms of efficiency, sensitivity, ruggedness, versatile form factor, compactness, lightweight, no pressurization … and it’s inexpensive,” Jiang said.

This means that the material has the potential to revolutionize neutron detector technologies.

Beyond special nuclear materials and weapons detection, solid-state neutron detectors also have medical, health, military, environment, and industrial applications,” he added. “The material also has applications in deep ultraviolet photonics and two-dimensional heterostructures. With the successful demonstration of high-efficiency neutron detectors, we expect it to perform well for other future applications.”

The main innovation behind this new type of neutron detector was developing hexagonal boron nitride with epitaxial layers of sufficient thickness — which previously didn’t exist. “It took our group six years to find ways to produce this new material with a sufficient thickness and crystalline quality for neutron detection,” Jiang noted. “It’s surprising to us that the detector performs so well, despite the fact that there’s still a little room for improvement in terms of material quality,” he said. “These devices must be capable of detecting nuclear weapons from distances tens of meters away, which requires large-size detectors,” Jiang added. “There are technical challenges to overcome, but we’re working toward this goal.”

Source: https://publishing.aip.org/

Nuclear Hazard: Major Step To Cure Radiation Sickness

At the labs of the biotech firm Pluristem Therapeutics in Haifa (Israel), researchers have developed an injection of cells from the placenta that can treat radiation exposure. Cells from the donated placentas are harvested to create a cocktail of therapeutic proteins.

nuclear radiationCLICK ON THE IMAGE TO ENJOY THE VIDEO

With these cells, we are injecting these cells to the bodies’ muscles and over there they capture stress signal from the body and they start secreting factors like… that will help the bone marrow to recover after radiation“, says Esther Lukasiewicz, Vice President (Medical Affairs)  at Pluristem Therapeutics.
The treatment is currently undergoing trials in Jerusalem and the United States. Animals exposed to radiation during testing have shown nearly a 100 percent recovery rate. The company says it’s most effective if injected within 48 hours of exposure to radiation, which could make it a vital tool in emergencies.

Yaky Yanay, President at Pluristem Therapeutics and  comments: “So it will be very easy to use, off-the-shelf and readily available. We designed it to be simple to treat it in the combat field or in case of the catastrophe itself, you just have to take the vial, take the cells out and inject it into the patients muscle so we will be able to treat or the agencies will be able to treat a lot of people in a short time.” The meltdown at Japan’s Fukushima Daiichi nuclear plant following an earthquake and tsunami in March 2011 is one such scenario. Pluristem Therapeutics is now working with Fukushima Medical University to treat people in case they are exposed to radiation.

When the Fukushima disaster happened it inspired our feeling that we have to do it stronger and quicker and we developed an aggressive plan in order to bring the product into awareness and today with NIH (National Institute of Allergy and Infectious Diseases) support and the cooperation of the Fukushima center we strongly believe that we can bring the product to cure many patients“, says Zami Aberman, Chairman and CEO at Pluristem Therapeutics.
Further trials are currently underway, and the company says the U.S. is keen to stockpile the treatment in case of emergency. They’re now developing similar treatments for disorders like Crohn’s Disease and other disorders of the central nervous system.

Source: http://www.pluristem.com/
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http://www.reuters.com/

Fusion Power Is Close

Fusion power is the Holy Grail of energy production – seen by some as a silver bullet for a carbon-neutral future. The failure of the multi-billion dollar ITER project to produce reactor relevant fusion has disappointed scientists and environmentalists. But a batch of small firms like Tokamak Energy believes they’re close to cracking the mystery. The UK firm says its reactor‘s spherical shape and magnets made using high-temperature superconductors means it could be two years from reaching 100 million degrees Celsius. That’s seven times hotter than the sun’s core and the temperature necessary to achieve fusion.

fusion powerCLICK ON THE IMAGE TO ENJOY THE VIDEO

We’ve got a slightly different shape from traditional fusion and this allows us to get a higher plasma pressure for a given magnetic field. It’s a measure of efficiency called beta“, says Dr  Bill Huang, Senior engineer for Tokamak Energy.
Fusion is how stars produce energy. Investors are spending millions on small-scale fusion projects. Vast potential return makes them attractive, as does the fact that multiple methods of achieving fusion could all be profitable.  “First of all they can be constructed in a factory, so you’re talking about economies of scale; and the second key thing is the way in which the grid itself, the future grid, is likely to be more dispersed” , says Mark White, of  Rainbow Seeds, and investor.
Tokamak Energy is constructing its third reactor and hopes the fifth generation can transfer energy to the grid by 2030.  Dr David Kinghan, CEO of Tokamak Energy. adds: “If it could be harnessed, could be scaled up rapidly to be deployed world-wide by 2050 and could make a very big difference from 2050 onwards.”
With world leaders meeting in Paris to hammer out a deal to limit global emissions, fusion power may help them meet those promises.

Source: http://www.tokamakenergy.co.uk/
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http://uk.reuters.com/

How To Improve Efficency Of Power Plants

Most of the world’s electricity-producing power plants — whether powered by coal, natural gas, or nuclear fission — make electricity by generating steam that turns a turbine. That steam then is condensed back to water, and the cycle begins again.
But the condensers that collect the steam are quite inefficient, and improving them could make a big difference in overall power plant efficiency.
Now, a team of researchers at MIT has developed a way of coating these condenser surfaces with a layer of graphene, just one atom thick, and found that this can improve the rate of heat transfer by a factor of four — and potentially even more than that, with further work. And unlike polymer coatings, the graphene coatings have proven to be highly durable in laboratory tests.
The findings are reported in the journal Nano Letters by MIT graduate student Daniel Preston, professors Evelyn Wang and Jing Kong, and two others. The improvement in condenser heat transfer, which is just one step in the power-production cycle, could lead to an overall improvement in power plant efficiency of 2 to 3 percent based on figures from the Electric Power Research Institute, Preston says — enough to make a significant dent in global carbon emissions, since such plants represent the vast majority of the world’s electricity generation. “That translates into millions of dollars per power plant per year,” he explains.
MIT-Graphene-Coating
An uncoated copper condenser tube (top left) is shown next to a similar tube coated with graphene (top right). When exposed to water vapor at 100 degrees Celsius, the uncoated tube produces an inefficient water film (bottom left), while the coated shows the more desirable dropwise condensation (bottom right)
We thought graphene could be useful,” Preston says, “since we know it is hydrophobic by nature.”
They found that the single-atom-thick coating of graphene did indeed improve heat transfer fourfold compared with surfaces where the condensate forms sheets of water, such as bare metals. Further calculations showed that optimizing temperature differences could boost this improvement to 5 to 7 times. The researchers also showed that after two full weeks under such conditions, there was no measurable degradation in the graphene’s performance.

Source: http://newsoffice.mit.edu/

Graphene soaks up Carbon, Cause of Global Warming

Chemists and engineers at Oregon State University (OSU) have discovered a fascinating new way to take some of the atmospheric carbon dioxide that’s causing the greenhouse effect and use it to make an advanced, high-value material for use in energy storage products.This innovation in nanotechnology won’t soak up enough carbon to solve global warming, researchers say. However, it will provide an environmentally friendly, low-cost way to make nanoporous graphene for use in “supercapacitors” – devices that can store energy and release it rapidly. Such devices are used in everything from heavy industry to consumer electronics.

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There are other ways to fabricate nanoporous graphene, but this approach is faster, has little environmental impact and costs less,” said Xiulei (David) Ji, an OSU assistant professor of chemistry in the OSU College of Science and lead author on the study. “The product exhibits high surface area, great conductivity and, most importantly, it has a fairly high density that is comparable to the commercial activated carbons. “And the carbon source is carbon dioxide, which is a sustainable resource, to say the least,” Ji said. “This methodology uses abundant carbon dioxide while making energy storage products of significant value.”

The findings were just published in Nano Energy by scientists from the OSU College of Science, OSU College of Engineering, Argonne National Laboratory, the University of South Florida and the National Energy Technology Laboratory in Albany, Ore. The work was supported by OSU.

Source: http://oregonstate.edu/

Solar Plant produces twice more Than Nuclear Power Plant

A solar energy project in the Tunisian Sahara aims to generate enough clean energy by 2018 to power two million European homes. Called the TuNur project; developers, including renewable investment company Low Carbon and solar developer Nur Energie, say the site will produce twice as much energy as the average nuclear power plant. But instead of using typical photovoltaic cells that only generate power during the day; they’re using Concentrated Solar Power. Using a vast array of mirrors to concentrate and  reflect the intense Saharan sun to a central tower, water or molten salt is heated to over 500 degrees Celsius. The steamced powers a turbine which in turn generates electricity. This, says Nur Energie‘s CEO Kevin Sara, means the plant will produce electricity even when the sun is down.

 

solar power plant

 “The technology that you can deploy in the desert is baseload renewable power; that means you can actually replace fossil fuel power plants because we can generate 24-7 using solar power,” says Kevin Sara, CEO of Nur Energie. Transmission lines will take the electricity to the Tunisian coast where a dedicated undersea cable will connect it to the European grid via a hub in northern Italy. Over ten millions euros has already gone into identifying the best location in the Tunisian Sahara to harness the intense solar radiation. “It’s quite large; it’s 10,000 hectares – a hundred square kilometres. But there’s nothing there, it’s just sand and a few bushes.

With energy security a big concern, Sara says the project has the potential to help end Europe’s reliance on fossil fuels using ‘desert power‘. “We believe that this is really opening a new energy corridor. This could be the first of many projects, and we could gradually de-carbonise the European grid using desert power, using this solar energy with storage from the Sahara desert and linked to Europe with high-voltage DC cables which are very, very low in their losses.” Sara added.
Tunisia is seeking to bolster its stability following the 2011 uprising, with lack of jobs and growth contributing to the unrest. The team behind the TuNur project hope the Saharan sunshine will be a shining light not only for renewable energy, but for the future of Tunisia.

Source: http://www.reuters.com/

Stronger Microbes To Clean Up Nuclear Waste

A microbe developed to clean up nuclear waste and patented by a Michigan State University (MSU)researcher has just been improved. In earlier research, Gemma Reguera, MSU microbiologist, identified that Geobacter bacteria’s tiny conductive hair-like appendages, or pili, did the yeoman’s share of remediation. By increasing the strength of the pili nanowires, she improved their ability to clean up uranium and other toxic wastes. In new research, published in the current issue of Applied and Environmental Microbiology, Reguera has added an additional layer of armor to her enhanced microbes. The microbes also use the pili to stick to each other and grow a film on just about any surface, similar to the bacterial film that forms on teeth. The Geobacter biofilm, encased by a network of nanowires and slime, gives the bacteria a shield and increases their ability to neutralize even more uranium. The improvement also allows the bacteria to survive longer even when exposed to higher concentrations of the radioactive material. Geobacter immobilizing uranium can be described as nature’s version of electroplating. The beefed-up microbes engulf the uranium and turn it into a mineral, preventing the toxic material from leaching into groundwater.
nucelar waste
The results surpassed our most optimistic predictions,” Reguera said. “Even thin biofilms immobilized uranium like sponges. They reduced it to a mineral, all while not suffering any damage to themselves, for prolonged periods of time.
Source: http://msutoday.msu.edu/

How Bonds Fracture

Looking at the molecular level, in order to understand how bonds fracture, from airplane wings to dental crowns, this is the purpose of a MIT research team. Materials that are firmly bonded together with epoxy and other tough adhesives are ubiquitous in modern life — from crowns on teeth to modern composites used in construction. Yet it has proved remarkably difficult to study how these bonds fracture and fail, and how to make them more resistant to such failures.
Now researchers at MIT have found a way to study these bonding failures directly, revealing the crucial role of moisture in setting the stage for failure.

airplane wingsThe bonding problem is a general problem that is encountered in many disciplines, especially in medicine and dentistry,” says Buyukozturk, whose research has focused on infrastructure, where such problems are also of great importance. “The interface between a base material and epoxy, for example, really controls the properties. If the interface is weak, you lose the entire system.”
The composite may be made of a strong and durable material bonded to another strong and durable material,” Buyukozturk adds, “but where you bond them doesn’t necessarily have to be strong and durable.”
Their findings are published in the journal Proceedings of the National Academy of Science in a paper by MIT professors of civil and environmental engineering Oral Buyukozturk and Markus Buehler; research associate Kurt Broderick of MIT’s Microsystems Technology Laboratories; and doctoral student Denvid Lau, who has since joined the faculty at the City University of Hong Kong.
Source: https://newsoffice.mit.edu/

Self-regenerating Objects Used In Daily Life

When a chair leg breaks or a cell phone shatters, either must be repaired or replaced. But what if these materials could be programmed to regenerate-themselves, replenishing the damaged or missing components, and thereby extend their lifetime and reduce the need for costly repairs? That potential is now possible according to researchers at the University of Pittsburgh Swanson School of Engineering, who have developed computational models to design a new polymer gel that would enable complex materials to regenerate themselves.
Self-Regenerating polymer gel2
Animation of the Self-regenerating Composites

This is one of the holy grails of materials science,” noted Principal investigator Anna C. Balazs, PhD, the Swanson School’s Distinguished Robert v. d. Luft Professor of chemical and petroleum engineering. “While others have developed materials that can mend small defects, there is no published research regarding systems that can regenerate bulk sections of a severed material. This has a tremendous impact on sustainability because you could potentially extend the lifetime of a material by giving it the ability to regrow when damaged.

The article, “Harnessing Interfacially-Active Nanorods to Regenerate Severed Polymer Gels” (DOI: 10.1021/nl403855k), was published November 19 in the American Chemical Society journal Nano Letters.
Source: http://www.engineering.pitt.edu/

How To Cool Fusion In Nuclear Reactors

Particles suspended in cooling water could prevent hotspots in nuclear plant cooling systems and electronics. Cooling systems generally rely on water pumped through pipes to remove unwanted heat. Now, researchers at MIT and in Australia have found a way of enhancing heat transfer in such systems by using magnetic fields, a method that could prevent hotspots that can lead to system failures. The system could also be applied to cooling everything from electronic devices to advanced fusion reactors, they say. Hu, associate director of MIT’s Nuclear Reactor Laboratory, says the new results are the culmination of several years of research on nanofluids — nanoparticles dissolved in water.

nuclear-reactor
“The magnets attract the particles closer to the heated surface” of the tube, greatly enhancing the transfer of heat from the fluid, through the walls of the tube, and into the outside air, says Hu.

Without the magnets in place, the fluid behaves just like water, with no change in its cooling properties. But with the magnets, the heat transfer coefficient is higher, she says — in the best case, about 300 percent better than with plain water. “We were very surprised” by the magnitude of the improvement, Hu says.
The system, which relies on a slurry of tiny particles of magnetite, a form of iron oxide, is described in the International Journal of Heat and Mass Transfer, in a paper co-authored by MIT researchers Jacopo Buongiorno and Lin-Wen Hu, and four others.
Source: http://www.mit.edu/