The Last Time I Saw

The Last Time I Saw – Concrete

Not much thought about by energy types, but exceptionally important in the construction of a nuclear power plant, concrete would seem an unchangeable item. After all, it’s been in use since Roman times. But that, as MIT demonstrates, is remarkably unimaginative thinking – the creation of cement, a component of concrete, accounts for 5 to 10 percent of the carbon emissions in the world (though that range is so broad, we think they should say, “If we had to guess.”) So how to make it more energy efficient?

In the January issue of the Journal of the Mechanics and Physics of Solids, the team reports that the source of concrete's strength and durability lies in the organization of its nanoparticles. The discovery could one day lead to a major reduction in carbon dioxide emissions during manufacturing.

It’s all about the nanoparticles.

He [Franz-Josef Ulm] and Georgios Constantinides, a postdoctoral researcher in materials science and engineering, studied the behavior of the nanostructure of cement. They found that at the nano level, cement particles organize naturally into the most densely packed structure possible for spherical objects, which is similar to a pyramid-shaped pile of oranges.

The guys poked various cements with nanoparticle needles to create a kind of taxonomy.

The C-S-H [calcium-silicate-hydrate] particles (each about five nanometers, or billionths of a meter, in diameter) have only two packing densities, one for particles placed randomly, say in a box, and another for those stacked symmetrically in a pyramid shape (like a grocer's pile of fruit). These correspond exactly to the mathematically proved highest packing densities allowed by nature for spherical objects: 63 and 74 percent, respectively. In other words, the MIT research shows that materials pack similarly even at the nano scale.

And?

If the researchers can find--or nanoengineer--a different mineral to use in cement paste, one that has the same packing density but does not require the high temperatures during production, they could conceivably cut world carbon dioxide emissions by up to 10 percent.

Yes, it’s pretty deep-dish. And creating that new mineral – ah, there’s the rub – may well prove as carbon intensive as creating cement. Nobody knows. But it’s fascinating that someone (Ulm and Constantinides being the someones) decided to do the deep-dish look at concrete and begin to ideate a replacement for it. Obviously, very early days, but enormous potential. Do read the whole thing.

Architect Aron Losonczi has developed a new type of concrete [this story is from 2006] that transmits light by adding "optical fibers" into the mix. The fibers are used to shift light at each end, producing a "see-through" effect. Called LiTraCon, "the blocks are a combination of 'optical fibers' and concrete, mixed so that the fibers create a fine glass aggregate within the concrete." The glass fibers then transfer light from one side of the block to the other, creating the effect of light transmission.

Perhaps Ulm and Constantinides need to have a chat with Mr. Losonczi.

Activists' Claims Distort Facts about Advanced Reactor Design

Below is from our rapid response team . Yesterday, regional anti-nuclear organizations asked federal nuclear energy regulators to launch an investigation into what it claims are “newly identified flaws” in Westinghouse’s advanced reactor design, the AP1000. During a teleconference releasing a report on the subject, participants urged the Nuclear Regulatory Commission to suspend license reviews of proposed AP1000 reactors. In its news release, even the groups making these allegations provide conflicting information on its findings. In one instance, the groups cite “dozens of corrosion holes” at reactor vessels and in another says that eight holes have been documented. In all cases, there is another containment mechanism that would provide a barrier to radiation release. Below, we examine why these claims are unwarranted and why the AP1000 design certification process should continue as designated by the NRC. Myth: In the AP1000 reactor design, the gap between the shield bu...

Wednesday Update

From NEI’s Japan micro-site: NRC, Industry Concur on Many Post-Fukushima Actions Industry/Regulatory/Political Issues • There is a “great deal of alignment” between the U.S. Nuclear Regulatory Commission and the industry on initial steps to take at America’s nuclear energy facilities in response to the nuclear accident in Japan, Charles Pardee, the chief operating officer of Exelon Generation Co., said at an agency briefing today. The briefing gave stakeholders an opportunity to discuss staff recommendations for near-term actions the agency may take at U.S. facilities. PowerPoint slides from the meeting are on the NRC website. • The International Atomic Energy Agency board has approved a plan that calls for inspectors to evaluate reactor safety at nuclear energy facilities every three years. Governments may opt out of having their country’s facilities inspected. Also approved were plans to maintain a rapid response team of experts ready to assist facility operators recoverin...

Nuclear Utility Moves Up in Credit Ratings, Bank is "Comfortable with Nuclear Strategy"

Some positive signs that nuclear utilities can continue to receive positive ratings even while they finance new nuclear plants for the first time in decades: Wells Fargo upgrades SCANA to Outperform from Market Perform Wells analyst says, "YTD, SCG shares have underperformed the Regulated Electrics (total return +2% vs. +9%). Shares trade at 11.3X our 10E EPS, a modest discount to the peer group median of 11.8X. We view the valuation as attractive given a comparatively constructive regulatory environment and potential for above-average long-term EPS growth prospects ... Comfortable with Nuclear Strategy. SCG plans to participate in the development of two regulated nuclear units at a cost of $6.3B, raising legitimate concerns regarding financing and construction. We have carefully considered the risks and are comfortable with SCG’s strategy based on a highly constructive political & regulatory environment, manageable financing needs stretched out over 10 years, strong partners...

NEI Nuclear Notes

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