Graphene, the extraordinary form of carbon that consists of a single layer of carbon atoms, has produced another in a long list of experimental surprises. In the July 30, 2010 issue of the journal Science, a multi-institutional team of researchers headed by Michael Crommie, a faculty senior scientist in the Materials Sciences Division at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and a professor of physics at the University of California at Berkeley, reports the creation of pseudo-magnetic fields far stronger than the strongest magnetic fields ever sustained in a laboratory - just by putting the right kind of strain onto a patch of graphene

"We have shown experimentally that when graphene is stretched to form nanobubbles on a platinum substrate, electrons behave as if they were subject to magnetic fields in excess of 300 tesla, even though no magnetic field has actually been applied," says Crommie. "This is a completely new physical effect that has no counterpart in any other condensed matter system."

Crommie notes that "for over 100 years people have been sticking materials into magnetic fields to see how the electrons behave, but it's impossible to sustain tremendously strong magnetic fields in a laboratory setting." The current record is 85 tesla for a field that lasts only thousandths of a second. When stronger fields are created, the magnets blow themselves apart.

The ability to make electrons behave as if they were in magnetic fields of 300 tesla or more - just by stretching graphene - offers a new window on a source of important applications and fundamental scientific discoveries going back over a century. This is made possible by graphene's electronic behavior, which is unlike any other material's.

A carbon atom has four valence electrons; in graphene (and in graphite, a stack of graphene layers), three electrons bond in a plane with their neighbors to form a strong hexagonal pattern, like chicken-wire. The fourth electron sticks up out of the plane and is free to hop from one atom to the next. The latter pi-bond electrons act as if they have no mass at all, like photons. They can move at almost one percent of the speed of light.

The idea that a deformation of graphene might lead to the appearance of a pseudo-magnetic field first arose even before graphene sheets had been isolated, in the context of carbon nanotubes (which are simply rolled-up graphene). In early 2010, theorist Francisco Guinea of the Institute of Materials Science of Madrid and his colleagues developed these ideas and predicted that if graphene could be stretched along its three main crystallographic directions, it would effectively act as though it were placed in a uniform magnetic field. This is because strain changes the bond lengths between atoms and affects the way electrons move between them. The pseudo-magnetic field would reveal itself through its effects on electron orbits.

In classical physics, electrons in a magnetic field travel in circles called cyclotron orbits. These were named following Ernest Lawrence's invention of the cyclotron, because cyclotrons continuously accelerate charged particles (protons, in Lawrence's case) in a curving path induced by a strong field.

Viewed quantum mechanically, however, cyclotron orbits become quantized and exhibit discrete energy levels. Called Landau levels, these correspond to energies where constructive interference occurs in an orbiting electron's quantum wave function. The number of electrons occupying each Landau level depends on the strength of the field - the stronger the field, the more energy spacing between Landau levels, and the denser the electron states become at each level - which is a key feature of the predicted pseudo-magnetic fields in graphene.

A serendipitous discovery

Describing their experimental discovery, Crommie says, "We had the benefit of a remarkable stroke of serendipity.

CORVALLIS, Ore. (June 17, 2010) Press Release

http://www.nuscalepower.com/nr-News-NuScale.php

 NuScale Power has designed an NSSS and nuclear power plant that offers the benefits of nuclear power but takes away the issues presented by installing large capacity. 

The NuScale design is for a modular, scalable Light Water Reactor nuclear power plant system. An NPP using NuScale's standardized design produces 540 MWe powered  by 12 NuScale integral PWR modules. Each NuScale module produces 45 MWe and has its own combined containment vessel and reactor system, and its own designated  turbine-generator set. NuScale power plants are scalable - additional modules are added as customer demand for electricity increases. These multi-module plants are highly reliable - one unit can be taken out of service for refueling or maintenance, or a new unit added, without affecting the operation of the others.

Smaller, simpler, safer nuclear plant will cost less, come on line sooner.

Capturing "the economies of small" is pivotal in our nation's effort to re-establish itself as an international leader in the construction of nuclear power plants, NuScale Power's Chief Financial Officer Jay Surina asserted Monday at the Mid-America Regulatory Conference.

"The NuScale power plant takes advantage of simplicity of design, modularity and smaller size to improve the economics of both construction and operation," Surina stated. "This will help overcome the regulatory and financial hurdles impeding the construction of much larger plants."

Surina explained that NuScale's modular design comprising up to 12 small reactors means less up-front risk and cost. Utilities can order plants that can be scaled up to meet their demand requirements over time. And, smaller plants can reach many markets the large, conventional plants can't serve due to small loads and transmission unavailability.

He said the NuScale design has moved into the forefront of efforts to license and build a smaller nuclear power plant. This is largely because the design has been confirmed under operating temperature and pressure at a test facility located at Oregon State University. It is the only small scale modular reactor design to be so tested. This should speed the review and approval process required by the Nuclear Regulatory Commission (NRC), he added.

A naturally cooled, light water reactor that eliminates pumps, pipes, tanks and other components required by its much larger counterparts is both safer and easier to build, Surina said. Our domestic supply chain can provide all of the required components, reducing cost and providing jobs.
NuScale Power, headquartered in Corvallis, Ore., anticipates filing a Design Certification Application with the NRC early in 2012. A plant could be in operation as soon as 2018.

- NuScale Power Chief Executive Officer Paul Lorenzini today announced that Edward G. Wallace has accepted the position of Senior Vice President for Regulatory Affairs with the company.

"We are extremely pleased that Ed has agreed to lead our efforts to license our modular, scalable nuclear technology and power plant design," Lorenzini said. "He brings a wealth of experience in regulatory affairs and in virtually every aspect of the nuclear power industry."

Wallace will direct the submission to the NRC of an application for design certification of NuScale's small, modular, scalable, natural circulation light water reactor. The company expects to submit the application in 2012 with the goal of supporting a plant on line as early as 2018.

Wallace was the founder and president of GNBC, a consulting firm on nuclear power and electric utility issues based in Chattanooga, TN. Since 2004 he filled the role of Senior General Manager - US Programs - PBMR Pty, Ltd. where he was responsible for the development and delivery of PBMR programs in the US including US Nuclear Regulatory Commission design certification. PBMR Pty Ltd, based in South Africa, is the developer of an advanced, small, standardized nuclear power plant for global markets.

Wallace has played key roles in a wide range of activities in the nuclear industry, including work on licensing the pebble bed modular reactor for Exelon and the direction of the merger of PECO Energy and Unicom nuclear organizations. Among his responsibilities at Tennessee Valley Authority, beginning in 1990, was senior manager, licensing and regulatory affairs. From 1996-1999 he was general manager, Service Contracts, where he directed all of TVA's labor and service contracting policies and practices.
A graduate of the U.S, Naval Academy, Wallace served as a nuclear submarine officer. He holds a master of business administration degree from University of Tennessee, Chattanooga.