Thursday, May 21, 2009

MIT: Slow growth of nuclear could harm climate efforts

The rate of deployment of new nuclear power plants around the world has been much slower than needed in order to combat climate change, the Massachusetts Institute of Technology (MIT) said in an update of its in-depth study on the future of nuclear power.
K.S.Parthasarathy



WNN
Energy And Environment
MIT: Slow growth of nuclear could harm climate efforts
21 May 2009

The rate of deployment of new nuclear power plants around the world has been much slower than needed in order to combat climate change, the Massachusetts Institute of Technology (MIT) said in an update of its in-depth study on the future of nuclear power.

The 2003 edition of the Future of Nuclear Power report said "that in order to make a serious contribution to alleviating global climate change, the world would need new nuclear plants with a total capacity of at least a terawatt [1000 gigawatts] by 2050."

In its updated study, MIT says, "Since the 2003 report, interest in using electricity for plug-in hybrids and electric cars to replace motor gasoline has increased, thus placing an even greater importance on exploiting the use of carbon-free electricity generating technologies."

It added, "With regard to nuclear power, while there has been some progress since 2003, increased deployment of nuclear power has been slow both in the United States and globally, in relation to the illustrative scenario examined in the 2003 report."

MIT noted, "While the intent to build new plants has been made public in several countries, there are only few firm commitments outside of Asia, in particular China, India, and Korea, to construction projects at this time. Even if all the announced plans for new nuclear power plant construction are realized, the total will be well behind that needed for reaching a thousand gigawatts of new capacity worldwide by 2050."

In its updated study, MIT says that, compared to 2003, "the motivation to make more use of nuclear power is greater, and more rapid progress is needed in enabling the option of nuclear power expansion to play a role in meeting the global warming challenge." It added, "The sober warning is that if more is not done, nuclear power will diminish as a practical and timely option for deployment at a scale that would constitute a material contribution to climate change risk mitigation."

Construction costs up

The latest study noted that, "Since 2003 construction costs for all types of large-scale engineered projects have escalated dramatically. The estimated cost of constructing a nuclear power plant has increased at a rate of 15% per year heading into the current economic downturn. This is based both on the cost of actual builds in Japan and Korea and on the projected cost of new plants planned for in the United States. Capital costs for both coal and natural gas have increased as well, although not by as much. The cost of natural gas and coal that peaked sharply is now receding. Taken together, these escalating costs leave the situation [of relative costs] close to where it was in 2003."

According to MIT's study, the overnight capital cost of constructing a nuclear power plant is $4000 per kilowatt (kW), in 2007 dollars. This compares with a figure of $2000/kW, in 2002 dollars, given in the original 2003 study.

The updated study says that, applying the same cost of capital to nuclear as to coal and gas, nuclear came out at 6.6 c/kWh, coal at 8.3 cents and gas at 7.4 cents, assuming a carbon charge of $25 per tonne of CO2 on the latter.



[The updated study can be downloaded from MIT's website]
Will this development help countries which have difficulties in getting electric power due to the peculiarities of geography?
K.S.Parthasarathy



WNN
New Nuclear
Assembly of Russian floating plant starts
20 May 2009

A ceremony has been held to mark the start of the assembly of the world's first floating nuclear power plant in St Petersburg, Russia. Construction had earlier been transferred from Severodvinsk.


The keel was originally laid for the first floating plant - the Akademik Lomonosov - at the Sevmash shipyard in Severodvinsk in April 2007. However, in 2008, Rosatom said that it was to transfer its construction to the Baltiysky Zavod shipbuilding company in Saint Petersburg because Sevmash was inundated with military contracts.



Click to enlarge
Five floating reactors could go to Gazprom to power oil and
gas extraction in Kola and Yamal, with four more used in
northern Yakutia in connection with mining operations. Seven
or eight units could be produced by 2015. (Click to enlarge)


A contract was signed on 27 February 2009 between Rosatom and the Baltiysky Zavod shipyard for completion of the plant. The contract was valued at almost 10 billion roubles ($315 million). A new keel has now been laid at Saint Petersburg for the first floating plant. As part of the contract, Baltiysky Zavod will receive the incomplete floating plants started by Sevmash.

The first plant will house two 35 MW KLT-40S nuclear reactors, similar to those used in Russia's nuclear powered ice breakers, and two generators, and will be capable of supplying a city of 200,000 people. OKBM will design and supply the reactors, while Kaluga Turbine Plant will supply the turbo-generators.



The Akademik Lomonosov was originally destined for the Archangelsk industrial shipyard, which is near to Severodvinsk in northwestern Russia, but the vessel is now destined for Vilyuchinsk, in the Kamchatka region in Russia's far east.


Baltiysky Zavod is to complete the floating plant in 2011. It should then be ready for transportation by the second quarter of 2012 and is set to be handed over to Energoatom by the end of 2012. Rosatom is planning to construct seven further floating nuclear power plants in addition to the one now under construction, with several remote areas under consideration for their deployment. Gazprom is expected to use a number of the floating units in order to exploit oil and gas fields near the Kola and Yamal Peninsulars.

Speaking at the ceremony, Sergey Obozov, director general of Energoatom, said that construction of a second floating plant may start in the autumn of 2010. He said, "We already have agreement with the authorities of Chukotka to station the plant in Pevek."

Bacteria with a built-in thermometer

Enigmatic features of tiny creatures
Parthasarathy



[ Public release date: 20-May-2009


Contact: Dr. Bastian Dornbach
bastian.dornbach@helmhotz-hzi.de
49-053-161-811-407
Helmholtz Association of German Research Centres
Bacteria with a built-in thermometer
Researchers at the Helmholtz Center demonstrate how bacteria measure temperature and thereby control infection

Researchers in the "Molecular Infection Biology group" at the Helmholtz Centre for Infection Research (HZI) in Braunschweig and the Braunschweig Technical University could now demonstrate for the first time that bacteria of the Yersinia genus possess a unique protein thermometer – the protein RovA - which assists them in the infection process. RovA is a multi-functional sensor: it measures both the temperature of its host as well as the host's metabolic activity and nutrients. If these are suitable for the survival of the bacteria, the RovA protein activates genes for the infection process to begin. These results have now been published in the current online edition of the PLoS Pathogens science magazine.

Yersinia can trigger various different diseases: best well-known is the Yersinia pestis type which caused the Plague in medieval times. This led to the death of around a third of Europe's population. The Yersinia enterocolitica and Yersinia pseudotuberculosis species cause an inflammation of the intestines following food poisoning: the bacteria infect the cells of the intestines, leading to heavy bouts of diarrhoea. The Yersinia bacteria contain invasin as a surface protein to help them penetrate the intestinal cells. The immune cells quickly identify this so-called virulence factor as a danger and launch an immune response. To avoid this, the bacteria quickly lose the invasin soon after entering the body. The germs then adapt their metabolism and feed on the nutrients prepared by the host cells. They also produce substances which kill off the body's defence cells, such as phagocytes. Little was known about how Yersinia is able to regulate these individual stages of infection until now.

Researchers at the HZI, led by Petra Dersch, have now identified how these mechanisms work. The RovA protein plays a key role. The protein reads the temperature for the bacteria. Depending on the environment of the bacteria, this protein either contains the factors required for the infection to begin or else adapts to life within the host. "The functioning of RovA in this way is unique among bacteria," says Petra Dersch.

If inhabiting an environment of around 25°C, the protein RovA ensures that the Yersinia bacteria form invasin as a surface protein. This ensures that the Yersinia can penetrate the intestinal cells immediately upon reaching the 37°C intestine via food. In this warm environment, the RovA alters its form and de-activates the gene for invasin production. Without invasin on their surface, the Yersinia bacteria are invisible to the body's immune system. In its new form, the RovA can now activate other genes in the bacteria to adapt the Yersinia metabolism to that of the host.

Until now, little was known about RovA and the fact that it reacts to temperature. Researchers were presented with a puzzle: "We have long been searching for the mechanisms which regulate RovA activity," says Petra Dersch. "It was therefore all the more surprising to discover that RovA controls various processes by acting as a thermometer and as such is self-regulating". At the end of the process, the RovA is responsible for its own decomposition. If the initial stages of infection prove successful, the Yersinia bacteria no longer need the RovA: in its modified form at 37°C, enzymes in the bacteria can attack and break down the RovA.

###

Original article: Herbst K, Bujara M, Heroven AK, Opitz W, Weichert M, et al. 2009 Intrinsic Thermal Sensing Controls Proteolysis of Yersinia Virulence Regulator RovA. PLoS Pathog 5(5): e1000435. doi:10.1371/journal.ppat.1000435

Sunday, April 26, 2009

Hydrogen protects nuclear fuel in final storage

An interesting development in nuclear waste management technology

Dr K.S.Parthasarathy





Public release date: 24-Apr-2009
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Contact: Sofie Hebrand
sofie.hebrand@chalmers.se
46-317-728-464
Swedish Research Council
Hydrogen protects nuclear fuel in final storage

When Sweden's spent nuclear fuel is to be permanently stored, it will be protected by three different barriers. Even if all three barriers are damaged, the nuclear fuel will not dissolve into the groundwater, according to a new doctoral dissertation from Chalmers University of Technology in Sweden.

By Midsummer it will be announced where Sweden's spent nuclear fuel will be permanently stored. Ahead of the decision a debate is underway regarding how safe the method for final storage is, primarily in terms of the three barriers that are intended to keep radioactive material from leaking into the surrounding groundwater.

But according to the new doctoral dissertation, uranium would not be dissolved by the water even if all three barriers were compromised.

"This is a result of what we call the hydrogen effect," says Patrik Fors, who will defend his thesis in nuclear chemistry at Chalmers on Friday. "The hydrogen effect was discovered in 2000. It's a powerful effect that was not factored in when plans for permanent storage began to be forged, and now I have shown that it's even more powerful than was previously thought."

The hydrogen effect is predicated on the existence of large amounts of iron in connection with the nuclear fuel. In the Swedish method for final storage, the first barrier consists of a copper capsule that is reinforced with iron. The second barrier is a buffer of bentonite clay, and the third is 500 meters of granite bedrock. Some other countries have chosen to make the first barrier entirely of iron.

It is known that microorganisms and fissure minerals in the rock will consume all the oxygen in the groundwater. If all three barriers were to be damaged, the iron in the capsule would therefore be anaerobically corroded by the water, producing large amounts of hydrogen. In final storage at a depth of 500 meters, a pressure of at least 5 megapascals of hydrogen would be created.

Patrik Fors has now created these conditions in the laboratory and examined three different types of spent nuclear fuel. All of the trials showed that the hydrogen protects the fuel from being dissolved in the water, even though the highly radioactive fuels create a corrosive environment in the water as a result of their radiation. The reason for the protective effect is that the hydrogen prevents the uranium from oxidizing and converting to liquid form.

Furthermore, the hydrogen makes the oxidized uranium that already exists as a liquid in the water shift to a solid state. The outcome was that the amount of uranium found dissolved in the water, after experiments lasting several years, was lower than the natural levels in Swedish groundwater.

"The hydrogen effect will prevent the dissolution of nuclear fuel until the fuel's radioactivity is so low that it need no longer be considered a hazard," says Patrik Fors. The amount of iron in the capsules is so great that it would produce sufficient hydrogen to protect the fuel for tens of thousands of years.

###

Patrik Fors carried out his experiments at the Institute for Transuranium Elements in Karlsruhe, Germany, in a joint project with Chalmers. The institute is operated by the European Commission. The research was also funded by SKB, the Swedish Nuclear Fuel and Waste Management Company.

The dissertation "The effect of dissolved hydrogen on spent nuclear fuel corrosion" will be publicly defended on April 24 at 10 a.m. Place: Hall KE, Chemistry Building, Kemigården 4, Chalmers University of Technology, Gothenburg, Sweden.

For more information, please contact: Patrik Fors, Nuclear Chemistry, Department of Chemical and Biological Engineering, Chalmers University of Technology, Sweden

Tel: +46707-696 334 patrik.fors@chalmers.se

Supervisor: Kastriot Spahiu, Adjunct Professor, Department of Chemical and Biological Engineering, Chalmers University of Technology, Sweden

+468-459 8561 Kastriot.spahiu@skb.se

Tuesday, March 10, 2009

Inserting catheters without X-rays

X-ray imaging to locate catheter can be avoided by using MRI but the guide wire must be plastic. The technique to prepare such wire is available now and may be available shortly for use.

K.S.Parthasarathy


Public release date: 9-Mar-2009
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Contact: Adrian Schütte
adrian.schuette@ipt.fraunhofer.de
49-241-890-4251
Fraunhofer-Gesellschaft
Inserting catheters without X-rays

This release is available in German.



Have the patient's coronary vessels, heart valves or myocardial muscle changed abnormally? Doctors can verify this and administer the necessary therapy with the help of a catheter, which is inserted into the body through a small incision in the groin area and pushed to the heart through the vascular system. A metal guide wire inside the catheter serves as a navigational aid. It is pulled and turned by the physician to steer and guide the catheter. At the same time the catheter's position in the vascular system has to be monitored. This task is performed by X-rays, which penetrate the patient and show exactly where the catheter is. The problem with this computer tomography method is that it exposes the patient to quite a high dose of radiation. In addition, a contrast medium has to be injected into the patient's body in order to make the vascular system and the soft tissue visible on the X-ray images.

Researchers at the Fraunhofer Institute for Production Technology IPT in Aachen have now found a way of avoiding both the radiation and the contrast medium. In collaboration with colleagues at Philips and University Hospital Aachen, they have developed a guide wire made of glass-fiber-reinforced plastic. "Because the guide wire is made of plastic the imaging can be performed by magnetic resonance tomography instead of computer tomography," says IPT scientist Adrian Schütte. "This is not possible with metal guide wires as the metal wire acts as an antenna and heats up too much – this would damage the vessels, and could cause proteins to clot." Magnetic resonance tomography has many advantages for doctors and patients. It does not produce ionizing radiation like computer tomography, and soft tissue is clearly visible, so there is no need for a contrast medium.

For the manufacture of the two-meter guide wires the researchers use the pultrusion method, which is the standard procedure for making continuous profiles from glass-fiber-reinforced plastic. "Diameters of half a millimeter or less are required for the guide wires – that's the absolute minimum," explains Schütte. The new guide wires will be presented at the JEC trade fair in Paris (Hall 1, Stand T18) from March 24 to 26 and will be used in hospitals for the first time in the next few months.

###Public release date: 9-Mar-2009
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Sunday, November 23, 2008

'Fish technology' draws renewable energy from slow water currents

A very interesting concept illustrating a new method of generating power from slow-moving ocean and river currents. The estimated cost of this power source is 5.5 cents per kwh. Wind energy costs 6.9 cents a kilowatt hour. Nuclear costs 4.6, and solar power costs between 16 and 48 cents per kilowatt hour depending on the location.

"If we could harness 0.1 percent of the energy in the ocean, we could support the energy needs of 15 billion people.", Michael Bernitsas, a professor in the University of Michigan, Department of Naval Architecture and Marine Engineering, who developed the concept claimed.

K.S.Parthasarathy



Public release date: 21-Nov-2008

Contact: Nicole Casal Moore
ncmoore@umich.edu
734-647-1838
University of Michigan
'Fish technology' draws renewable energy from slow water currents

IMAGE: An artist's illustration of an array of VIVACE converters on the ocean floor.
Click here for more information.

ANN ARBOR, Mich.---Slow-moving ocean and river currents could be a new, reliable and affordable alternative energy source. A University of Michigan engineer has made a machine that works like a fish to turn potentially destructive vibrations in fluid flows into clean, renewable power.

The machine is called VIVACE. A paper on it is published in the current issue of the quarterly Journal of Offshore Mechanics and Arctic Engineering.

VIVACE is the first known device that could harness energy from most of the water currents around the globe because it works in flows moving slower than 2 knots (about 2 miles per hour.) Most of the Earth's currents are slower than 3 knots. Turbines and water mills need an average of 5 or 6 knots to operate efficiently.

VIVACE stands for Vortex Induced Vibrations for Aquatic Clean Energy. It doesn't depend on waves, tides, turbines or dams. It's a unique hydrokinetic energy system that relies on "vortex induced vibrations."

Vortex induced vibrations are undulations that a rounded or cylinder-shaped object makes in a flow of fluid, which can be air or water. The presence of the object puts kinks in the current's speed as it skims by. This causes eddies, or vortices, to form in a pattern on opposite sides of the object. The vortices push and pull the object up and down or left and right, perpendicular to the current.

These vibrations in wind toppled the Tacoma Narrows bridge in Washington in 1940 and the Ferrybridge power station cooling towers in England in 1965. In water, the vibrations regularly damage docks, oil rigs and coastal buildings.

"For the past 25 years, engineers---myself included---have been trying to suppress vortex induced vibrations. But now at Michigan we're doing the opposite. We enhance the vibrations and harness this powerful and destructive force in nature," said VIVACE developer Michael Bernitsas, a professor in the U-M Department of Naval Architecture and Marine Engineering.

Fish have long known how to put the vortices that cause these vibrations to good use. "VIVACE copies aspects of fish technology," Bernitsas said. "Fish curve their bodies to glide between the vortices shed by the bodies of the fish in front of them. Their muscle power alone could not propel them through the water at the speed they go, so they ride in each other's wake."

This generation of Bernitsas' machine looks nothing like a fish, though he says future versions will have the equivalent of a tail and surface roughness a kin to scales. The working prototype in his lab is just one sleek cylinder attached to springs. The cylinder hangs horizontally across the flow of water in a tractor-trailer-sized tank in his marine renewable energy laboratory. The water in the tank flows at 1.5 knots.

Here's how VIVACE works: The very presence of the cylinder in the current causes alternating vortices to form above and below the cylinder. The vortices push and pull the passive cylinder up and down on its springs, creating mechanical energy. Then, the machine converts the mechanical energy into electricity.

Just a few cylinders might be enough to power an anchored ship, or a lighthouse, Bernitsas says. These cylinders could be stacked in a short ladder. The professor estimates that array of VIVACE converters the size of a running track and about two stories high could power about 100,000 houses. Such an array could rest on a river bed or it could dangle, suspended in the water. But it would all be under the surface.

Because the oscillations of VIVACE would be slow, it is theorized that the system would not harm marine life like dams and water turbines can.

Bernitsas says VIVACE energy would cost about 5.5 cents per kilowatt hour. Wind energy costs 6.9 cents a kilowatt hour. Nuclear costs 4.6, and solar power costs between 16 and 48 cents per kilowatt hour depending on the location.

"There won't be one solution for the world's energy needs," Bernitsas said. "But if we could harness 0.1 percent of the energy in the ocean, we could support the energy needs of 15 billion people."

The researchers recently completed a feasibility study that found the device could draw power from the Detroit River. They are working to deploy one for a pilot project there within the 18 months.

###

This work has been supported by the U.S. Department of Energy, the Office of Naval Research, the National Science Foundation, the Detroit/Wayne County Port Autrhority, the DTE Energy Foundation, Michigan Universities Commercialization Initiative, and the Link Foundation. The technology is being commercialized through Bernitsas' company, Vortex Hydro Energy.

The paper is called "VIVACE (Vortex Induced Vibration for Aquatic Clean Energy): A New Concept in Generation of Clean and Renewable Energy from Fluid Flow." Other authors are Naval Architecture and Marine Engineering graduate students Kamaldev Raghavan, Yaron Ben-Simon and Elizabeth M.H. Garcia.

For more information:
Michael Bernitsas: http://www.engin.umich.edu/dept/name/faculty_staff/bernitsas/Main.htm
Vortex Hydro Energy: http://www.vortexhydroenergy.com/

Michigan Engineering: The University of Michigan College of Engineering is ranked among the top engineering schools in the country. At more than $130 million annually, its engineering research budget is one of largest of any public university. Michigan Engineering is home to 11 academic departments and a National Science Foundation Engineering Research Center. The college plays a leading role in the Michigan Memorial Phoenix Energy Institute and hosts the world class Lurie Nanofabrication Facility. Find out more at http://www.engin.umich.edu/.

EDITORS: Watch and link to a video at: http://www.ns.umich.edu/podcast/video.php?id=499
Photos are available at http://www.ns.umich.edu/htdocs/releases/story.php?id=6841

Friday, October 24, 2008

Magic solar milestone reached

Solar voltaic cell has achieved the highest efficiency of 25 %. Credit for this goes to the researchers at the University of South Wales (UNSW)'s ARC Photovoltaic Centre of Excellence.


K.S.Parthasarathy


Contact: Peter Trute
p.trute@unsw.edu.au
61-293-851-933
University of New South Wales
Magic solar milestone reached
UNSW claims 25 percent solar cell efficiency title

UNSW's ARC Photovoltaic Centre of Excellence has again asserted its leadership in solar cell technology by reporting the first silicon solar cell to achieve the milestone of 25 per cent effiency.

The UNSW ARC Photovoltaic Centre of Excellence already held the world record of 24.7 per cent for silicon solar cell efficiency. Now a revision of the international standard by which solar cells are measured, has delivered the significant 25 per cent record to the team led by Professors Martin Green and Stuart Wenham and widened their lead on the rest of the world.

Centre Executive Research Director, Scientia Professor Martin Green, said the new world mark in converting incident sunlight into electricity was one of six new world records claimed by UNSW for its silicon solar technologies.

Professor Green said the jump in performance leading to the milestone resulted from new knowledge about the composition of sunlight.

"Since the weights of the colours in sunlight change during the day, solar cells are measured under a standard colour spectrum defined under typical operational meteorological conditions," he said.

"Improvements in understanding atmospheric effects upon the colour content of sunlight led to a revision of the standard spectrum in April. The new spectrum has a higher energy content both down the blue end of the spectrum and at the opposite red end with, dare I say it, relatively less green."

The recalibration of the international standard, done by the International Electrochemical Commission in April, gave the biggest boost to UNSW technology while the measured efficiency of others made lesser gains. UNSW's world-leading silicon cell is now six per cent more efficient than the next-best technology, Professor Green said. The new record also inches the UNSW team closer to the 29 per cent theoretical maximum efficiency possible for first-generation silicon photovoltaic cells.

Dr Anita Ho-Baillie, who heads the Centre's high efficiency cell research effort, said the UNSW technology benefited greatly from the new spectrum "because our cells push the boundaries of response into the extremities of the spectrum".

"Blue light is absorbed strongly, very close to the cell surface where we go to great pains to make sure it is not wasted. Just the opposite, the red light is only weakly absorbed and we have to use special design features to trap it into the cell," she said.

Professor Green said: "These light-trapping features make our cells act as if they were much thicker than they are. This already has had an important spin-off in allowing us to work with CSG Solar to develop commercial 'thin-film' silicon-on-glass solar cells that are over 100 times thinner than conventional silicon cells."

ARC Centre Director, Professor Stuart Wenham said the focus of the Centre is now improving mainstream production. "Our main efforts now are focussed on getting these efficiency improvements into commercial production," he said. "Production compatible versions of our high efficiency technology are being introduced into production as we speak."

The world-record holding cell was fabricated by former Centre researchers, Dr Jianhua Zhao and Dr Aihua Wang, who have since left the Centre to establish China Sunergy, one of the world's largest photovoltaic manufacturers. "China was the largest manufacturer of solar cells internationally in 2007 with 70 per cent of the output from companies with our former UNSW students either Chief Executive Officers or Chief Technical Officers", said Professor Green.

###

Media Contact: Professor Martin Green | 9385 4018 | 0411 492 416 | m.green@unsw.edu.au

UNSW Media Office: Peter Trute | 02 9385 1933 | 0410 271 826 | p.trute@unsw.edu.au