David Kirkpatrick

August 9, 2010

Is solar power cheaper than nuclear?

Filed under: Business, Science, Technology — Tags: , , , , — David Kirkpatrick @ 9:04 pm

Surprisingly, maybe so.

From the link:

One of the issues associated with shifting from using fossil fuels to alternative energy sources is the cost. While adherents of alternative energy tout its benefits, many are skeptical, pointing out that such alternatives are just too expensive. Advocates of nuclear power point out that it is less polluting (if you don’t count storage of spent fuel) than fossil fuels, and that it costs less than alternatives like solar power.

A new study out of Duke University, though, casts doubt on the idea that  is cheaper than . Using information from North Carolina, the study shows that solar power may be more cost efficient than nuclear power. With costs dropping on the production of photovoltaic cells, and with solar cells becoming increasingly efficient, it appears that — in North Carolina at least — solar installations offer a viable alternative to nuclear power, which is the source for about 20% of the electricity in the U.S.

March 26, 2010

Nanotech and safer nuclear power

A very interesting release:

Safer nuclear reactors could result from Los Alamos research

‘Loading-unloading’ effect of grain boundaries key to repair of irradiated metal

Self-repairing materials within nuclear reactors may one day become a reality as a result of research by Los Alamos National Laboratory scientists.

In a paper appearing today in the journal Science, Los Alamos researchers report a surprising mechanism that allows nanocrystalline materials to heal themselves after suffering radiation-induced damage. Nanocrystalline materials are those created from nanosized particles, in this case copper particles. A single nanosized particle—called a grain—is the size of a virus or even smaller. Nanocrystalline materials consist of a mixture of grains and the interface between those grains, called grain boundaries.

When designing nuclear reactors or the materials that go into them, one of the key challenges is finding materials that can withstand an outrageously extreme environment. In addition to constant bombardment by radiation, reactor materials may be subjected to extremes in temperature, physical stress, and corrosive conditions. Exposure to high radiation alone produces significant damage at the nanoscale.

Radiation can cause individual atoms or groups of atoms to be jarred out of place. Each vagrant atom becomes known as an interstitial. The empty space left behind by the displaced atom is known as a vacancy. Consequently, every interstitial created also creates one vacancy. As these defects—the interstitials and vacancies—build up over time in a material, effects such as swelling, hardening or embrittlement can manifest in the material and lead to catastrophic failure.

Therefore, designing materials that can withstand radiation-induced damage is very important for improving the reliability, safety and lifespan of nuclear energy systems.

Because nanocrystalline materials contain a large fraction of grain boundaries—which are thought to act as sinks that absorb and remove defects—scientists have expected that these materials should be more radiation tolerant than their larger-grain counterparts. Nevertheless, the ability to predict the performance of nanocrystalline materials in extreme environments has been severely lacking because specific details of what occurs within solids are very complex and difficult to visualize.

Recent computer simulations by the Los Alamos researchers help explain some of those details.

In the Science paper, the researchers describe the never-before-observed phenomenon of a “loading-unloading” effect at grain boundaries in nanocrystalline materials. This loading-unloading effect allows for effective self-healing of radiation-induced defects. Using three different computer simulation methods, the researchers looked at the interaction between defects and grain boundaries on time scales ranging from picoseconds to microseconds (one-trillionth of a second to one-millionth of a second).

On the shorter timescales, radiation-damaged materials underwent a “loading” process at the grain boundaries, in which interstitial atoms became trapped—or loaded—into the grain boundary. Under these conditions, the subsequent number of accumulated vacancies in the bulk material occurred in amounts much greater than would have occurred in bulk materials in which a boundary didn’t exist. After trapping interstitials, the grain boundary later “unloaded” interstitials back into vacancies near the grain boundary. In so doing, the process annihilates both types of defects—healing the material.

This unloading process was totally unexpected because grain boundaries traditionally have been regarded as places that accumulate interstitials, but not as places that release them. Although researchers found that some energy is required for this newly-discovered recombination method to operate, the amount of energy was much lower than the energies required to operate conventional mechanisms—providing an explanation and mechanism for enhanced self-healing of radiation-induced damage.

Modeling of the “loading-unloading” role of grain boundaries helps explain previously observed counterintuitive behavior of irradiated nanocrystalline materials compared to their larger-grained counterparts. The insight provided by this work provides new avenues for further examination of the role of grain boundaries and engineered material interfaces in self-healing of radiation-induced defects. Such efforts could eventually assist or accelerate the design of highly radiation-tolerant materials for the next generation of nuclear energy applications.

###

The Los Alamos National Laboratory research team includes: Xian-Ming Bai, Richard G. Hoagland and Blas P. Uberuaga of the Materials Science and Technology Division; Arthur F. Voter, of the Theoretical Division; and Michael Nastasi of the Materials Physics and Applications Division.

The work was primarily sponsored by the Los Alamos Laboratory-Directed Research and Development (LDRD) program, which, at the discretion of the Laboratory Director, invests a small percentage of the Laboratory’s budget in high-risk, potentially high-payoff projects to help position the Laboratory to anticipate and prepare for emerging national security challenges. The research also received specific funding through the Center for Materials under Irradiation and Mechanical Extremes, an Energy Frontier Research Center funded by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences.

About Los Alamos National Laboratory (www.lanl.gov)

Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, The Babcock & Wilcox Company, and URS for the Department of Energy’s National Nuclear Security Administration.

Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.

February 3, 2010

White House promotes nuclear plants

A very necessary — and belated for the Obama administration — move to start to wean the U.S. off foreign petroleum-based energy.

From the link:

President Obama’s proposed 2011 budget could provide a significant boost to the U.S. nuclear power industry, which has been stalled for decades. If approved by Congress, the budget would provide $36 billion in loan guarantees for nuclear power plants, opening the way for around seven new nuclear power plants, depending on the final cost of each. The new guarantees are in addition to $18.5 billion in guarantees provided for in a 2005 energy bill.

The increased support for nuclear power marks a change for the Obama administration, which has opposed similar increases in the past. Some policy experts say it is part of a strategy to win Republican votes for a comprehensive climate and energy bill.

November 17, 2009

Nuclear power may not be the answer

Filed under: Business, Politics, Science — Tags: , , , , — David Kirkpatrick @ 1:11 pm

And the reason might really surprise you — we’re running out of uranium. There’s a lot of talk about building new nuke plants — an idea I like — to help wean the west off of OPEC, et. al. What may come as a shock to many is uranium, the power source for nuclear plants, is going to offer just as many headaches in terms of shortages and being beholden parts of the world with reserves as petroleum provides right now.

Looks like it’s time to redouble the alternative power efforts if we want energy relatively free of the whims of geopolitics.

From the link:

Perhaps the most worrying problem is the misconception that uranium is plentiful. The world’s nuclear plants today eat through some 65,000 tons of uranium each year. Of this, the mining industry supplies about 40,000 tons. The rest comes from secondary sources such as civilian and military stockpiles, reprocessed fuel and re-enriched uranium. “But without access to the military stocks, the civilian western uranium stocks will be exhausted by 2013, concludes Dittmar.

It’s not clear how the shortfall can be made up since nobody seems to know where the mining industry can look for more.

December 20, 2008

Nuclear energy — pro and con

Filed under: Business, Politics, Science, Technology — Tags: , , , — David Kirkpatrick @ 4:58 pm
Nevada Division of Environmental Protection

The Stokes atmospheric nuclear test was conducted at the Nevada Test Site on August 7, 1957. The tests was conducted as part the operation "Plumbbob" testing events. Stokes produced 9 kilotons and was exploded from a balloon. Credit: Nevada Division of Environmental Protection

Here’s debate on nuclear power at LiveScience. Check it out for a quick pro/con breakdown on the energy source. For the record I have no problem with nuclear energy. It’s controversial and there are strong pros and strong cons to the issue, but to me the pros win this one.

From the link:

While the nucleus of an atom is tiny, an extraordinary amount of energy helps hold it together. Nuclear power seeks to harness that energy to safely provide electricity.

Roughly 100 nuclear power plants are now operating in the United States, supplying about one-fifth of the nation’s electricity. These will start to be retired in 2029, and nearly all will be retired by 2050, according to the Union of Concerned Scientists, a science advocacy group.

No new nuclear power plants are currently under construction in the United States. However, about 30 are now in various stages of planning, said Alan Nogee, director of the clean energy program at the Union of Concerned Scientists.