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Credit: Eileen De Guire; ACerS

As announced in an earlier post, John Marra, chief research officer at Savannah River National Lab spoke at the conference dinner at the annual meeting of the Glass and Optical Materials Division on May 17. The title of the talk was “Beyond Fukushima: Advanced materials to enable enhanced nuclear power systems.”

Marra set the stage by providing some context for the strategic role of nuclear power in the energy portfolio of the United States and worldwide. At present, about 40% of the energy consumed in the U.S. is in the form of electricity, and, nationally, about 20% of U.S. electricity is produced by nuclear power plants. Globally, there are 436 operational nuclear energy plants, with about 100 located in the U.S.

The worldwide demand for electric power is expected to double by 2050, with much of the increase coming from transitional economies like India and China and emerging economies like sub-Saharan Africa and parts of the Middle East.

In the U.S., one the Obama administration’s energy goals is to reduce CO₂ emissions by 80% by 2050. To reach that goal, Marra says nuclear power will have to continue be part of the nation’s energy portfolio because it is the only CO₂-free power generation technology available that can also meet the demand. However, he noted traditional barriers to nuclear energy will have to be overcome, including the average $5 billion (or more) cost to build a standard size plant, more attention to siting considerations, other safety issues (real and perceived), proliferation risk and sustainable fuel cycles.

These barriers were addressed in a DOE report to Congress, “Nuclear Energy Research and Development Roadmap (PDF),” which identifies four key R&D objectives for the nuclear industry as it looks to expand the use of nuclear power in the nation’s energy portfolio. There are opportunities for the materials community to contribute to each of the Roadmap’s objectives (paraphrasing)

1. Develop technologies that improve the efficiency of the current fleet,
2. Develop technologies that enable better, faster, cheaper building of new plants,
3. Scale-up and deploy lab-proven sustainable fuel cycles (including waste management),
4. Minimize nuclear proliferation risks.

Look for more about ways the materials community can respond to Roadmap objectives in the August issue of the Bulletin, which will include more extensive comments from John Marra about the role specific materials will play

In the second part of his talk, Marra summarized the sequence of events that occurred on March 11 in Japan. When the magnitude 9 earthquake struck, all safety systems in the plant operated as designed and shut down the three reactors, rendering them safe and stable.

But, of course, about 80 minutes after the earthquake, the 14-meter (imagine a 40-foot wall) tsunami, more than twice the size the plant had been designed to withstand, slammed into the shore-side plant, knocking out the grid feed, the diesel generators that were running cooling water pumps, and significantly damaged the building. Even so, a back-up cooling system operated with waste heat and batteries pumped cooling water, but eventually until the batteries drained and crippled the back-up system.

With the loss of cooling, reactor cores were exposed and temperatures rose, eventually exceeding 900 ^oC, above which the Zircalloy fuel cladding begins to lose structural integrity. With failure of the cladding alloy, fission products were released. When the cladding temperature reached 1200 °C, the Zircalloy reacted with steam in the reactor, producing hydrogen gas and leading to the dramatic explosion (broadcast instantly around the world), and releasing the accumulated fission products into the atmosphere. Ultimately, the reactor cores were drowned with seawater, and cooling water was restored to the reactor cores (within seven hours for two of the reactors and in 27 hours for the third).

Marra observed that in the face of a catastrophic, natural event that exceeded all design contingencies (and perhaps even imagination) and caused multiple system failures, the Fukushima plant personnel very quickly returned the plant to a safe and stable condition.

According to Marra, the impact of the Fukushima incident will be “significant and worldwide,” for existing plants and new builds. He expects ceramic materials to adopted to “buy time” in emergency situations. For example, claddings of silicon carbide are able to withstand reactor temperatures well beyond what Zircalloy can tolerate. New glass-to-metal seal materials would need to be developed to seal endcaps to SiC claddings. There are alternative fuel configurations in development that would use silicon carbide to self-encapsulate spent fuel, thus preventing the accidental release of fission products. Materials like pyrolytic carbon or cabon-carbon composites may find applications in the so-called “small modular reactors” (more about those in a future post). Waste containment continues to be a pressing materials problem, and nuclear fuel is expected to be oxide-based for the foreseeable future.

Marra cautioned, however, that it can take the Nuclear Regulatory Commission up to 15 years qualify new materials for reactor components, thus the first new materials likely to be adopted are those about which much is already known like silicon carbide, silicon nitride, carbon-carbon composites, etc.

In light of timelines like these, and the added scrutiny and political pressure that the Fukushima incident will inevitably create, the Obama administration’s goal of 80% CO₂ reduction by 2050 makes the 39-year interval until then look very, very tight.

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Marra

The ACerS Glass and Optical Materials Division is holding its annual meeting May 15-19 in Savannah, Ga., and I just learned that nuclear energy materials expert John Marra has agreed to do a special and timely presentation about Japan’s nuclear power accident at the conference dinner May 17. Marra, the chief research officer of the Savannah River National Lab, has tentatively titled his talk, “Beyond Fukushima: Advanced materials to enable enhanced nuclear power systems.”

I am really looking forward to this because, as far as I know, it will be the first semi-public presentation by a federal lab official in which there is an attempt to sum-up some of the engineering lessons from the Fukushima/TEPCO situation.

The context of this, of course, is that rising fuel prices and increased concerns about greenhouse gas emissions had many scientists and policy makers looking toward nuclear power (and new generations of nuclear reactors) as a way to offset fossil fuels. In reaction to the Fukushima situation, some nations and some members of the science and technology community now want to take a second look at future plans for growing nuclear power systems.

In an abstract on his presentation, Marra says:

On March 11, 2011 an earthquake centered near Japan and the resultant tsunami caused significant damage to several reactors at the Fukushima Daiichi nuclear plant causing many to question the long-term future of nuclear power. As Japan and the international community begin to look at the lessons-learned from the Fukushima accident, advanced materials that eliminate or reduce the consequences of severe accidents will find increased application in advanced nuclear power systems.

Ceramic and glass materials, which have long played a very important role in the commercial nuclear industry, offer some significant advantages under accident conditions. This presentation will review the sequence of events that led to the Fukushima Daiichi accident and discuss the critical role that ceramic and glass materials play throughout the nuclear fuel cycle, and the critical material advancements required to enable the “nuclear renaissance” in light of the recent events.

The conference dinner runs 7-10 p.m. on May 17, and I expect Marra will begin his talk around 8:30 p.m.

I plan on running an interview with Marra, a past president of ACerS, for the August issue of the Bulletin, but I highly recommend that anyone interested in advanced glass science and technology (including optical materials, optical devices, coatings, sensors, solar energy materials, glass–ceramics, and structures and properties) considere coming to the GOMD meeting.

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One the heels of our story on Western Troy Capital Resources’ little nuke announcement, we get word that a Sandia National Lab team has a new small-reactor design. The reactor’s output is projected to be in the range of 100 to 300 megawatts of thermal power, and structurally it would be “about the size of half a fairly large office building,” as the press release puts it. The small-scale economically efficient nuclear reactor could be mass-assembled in factories and supply power for a medium-size city.

The timing of this release is a little odd because it turns out that it was actually announced last December. Regardless, Tom Sanders is leading the SNL research team that has a goal to create an exportable, proliferation-resistant “right-sized reactor” that incorporates intrinsic safeguards, security and safety, and still can produce electricity for less than five cents per kilowatt hour.

The proposal offers a way for possible export sales of the reactor to developing countries that do not have the infrastructure to support large power generation. The smaller reactor design decreases the potential need for a country to develop an advanced nuclear regulatory framework. As noted by WTCR, there is also a possible market for small reactors in developed countries that have remote cities (like Canada). But SNL acknowledges that the first customers might be military bases in the U.S. and in other countries.

The reactor design includes an integrated monitoring system that provides the exporters of such technologies a means of assuring the safe, secure and legitimate use of nuclear technology.

The reactor system is built around a small uranium core submerged in a tank of liquid sodium. The liquid sodium is piped through the core to carry the heat away to a heat exchanger, which is also submerged in the tank of sodium. In the Sandia system, the reactor heat is transferred to a very efficient supercritical CO₂ turbine to produce electricity. This form of heat management is considered “passive” in as much as a meltdown isn’t possible

The Sandia “right-sized” reactors are breeder reactors, meaning they generate their own fuel as they operate. Thus they are designed to have an extended operational life and only need to be refueled once every couple of decades, which also helps alleviate proliferation concerns.

SNL reports that the reactor will include what the lab terms “nuke-star” antiproliferation technology. Given the relative maturity of reactor technology, it is probably safe to assume that nuke-star technology is really at the center of SNL’s belief that manufacturing reactors at this scale can now move forward. But, understandably, the lab is revealing little about how nuke-star works. Sanders, however, says, “[The reactor core is replaced as a unit and] in effect is a cartridge core for which any intrusion attempt is easily monitored and detected.” The reactor system has no need for operator fuel handling.

About 85 percent of the design efforts are completed for the reactor core. The team is seeking an industry partner through a cooperative research and development agreement. The CRADA team will be able to complete the reactor design and enhance the plant side, which is responsible for turning the steam into electricity.

The lure is, “It could also be a more practical means to implement nuclear-based load capacity comparable to natural gas-fired generating stations and with more manageable financial demands than a conventional power plant,” says Sanders. The cost projections suggest the cost could get down to $250 million once they are made in a mass-production mode.

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The DOE says it is going to be shipping off $44 million over the next three years to 31 schools for 71 nuclear energy R&D projects. The funding is coming under the auspices of DOE’s Nuclear Energy University Program. The goal, of course, is to figure out a way to improve the use of nuclear power to mitigate the climatic changes. Actual funding is expected to start flowing in the fourth quarter of 2009.

“The next generation of nuclear power plants – with the highest standards of safety, efficiency and environmental protection – will require the latest advancements in nuclear science and technology. These research and development university awards will ensure that the United States continues to lead the world in the nuclear field for years to come,” said DOE Secretary Steven Chu.

The monies are targeting three specific areas of research:

• Advanced Fuel Cycle Initiative
• Next Generation Nuclear Plant/Generation IV Nuclear Systems
• Light Water Reactor Sustainability
• Investigator-Initiated Research

DOE also announced that is accepting applications for individual nuclear science and engineering scholarships and fellowships under the NEUP.  The agency has set aside a $2.9 million pot, via its Center for Advanced Energy Studies, for these fellowships and scholarships. CAES is now accepting application requests.

Contracts for the R&D projects are expected to be awarded by September 30, 2009 by the Battelle Energy Alliance, LLC, a Management and Operating contractor for DOE at the Idaho National Laboratory.

More information about the 71 research and development awards is available HERE.

¹Advanced Fuel Cycle Initiative projects

¹Advanced Fuel Cycle Initiative   ²Next Generation Nuclear Plant/Generation IV Nuclear Systems ³Investigator-Initiated Research   ⁴Light Water Reactor Sustainability

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For those who still see a “Nuclear Renaissance” in the world’s energy future, the Russian Federation’s and the United State’s respective national academies of sciences have a proposal that is akin to pruning a bush in order to make it flourish: Provide to those nations that want to use it a stable - but tightly controlled – supply of nuclear fuel from a small number of supply centers. When the fuel is spent, it must be returned or exchanged for a fresh supply.

The problem the academies are trying to solve how to accommodate countries desiring to expand or start  nuclear-derived energy plants while not also facilitating the enrichment of uranium for bombs.

The two academies note that, “Any approach for enhancing the nonproliferation features of international fuel cycles must be staged to respond to the nonproliferation needs of the time period. Today, this suggests a focus on convincing countries that they do not need to establish their own enrichment facilities, which has motivated efforts by several countries and international organizations to address the enrichment issue.”

A book has just been published that contains a joint report from the two nations about how this proposal could work. Internationalization of the Nuclear Fuel Cycle summarizes key issues and analyses of the topic, offers some criteria for evaluating options, and makes findings and recommendations to help the U.S., the Russian Federation and the international community.

The authors acknowledge that the idea for a stable but controlled source of nuclear fuels has pitfalls. One, for example, is that nations who might consider a use-and-swap “leasing” system would, understandably, be fearful of the risk of having their supply unilaterally cut off during an international incident. On the other hand, the user nations could avoid the security and environmental hazards of storing or processing spent fuel

Supplier nations could also face internal political problems related to the costs and risks associated with handling another country’s nuclear wastes, not to mention costs associated with keeping the lid on the intellectual capital and preventing intelligence leaks.

The authors believe, however, that it may be possible over time to forge a worldwide system of international centers that are responsible for uranium enrichment, spent fuel management and transportation. They also envision a form of collective ownership of these centers that would allow some joint control and profit sharing. The report also suggests that another incentive to encourage other countries not to develop their own enrichment systems is to have the U.S. and Russia provide “the necessary infrastructure for safe and secure use nuclear energy.”

The authors, lastly note, that the sine qua non in all this is an atmosphere of cooperation between the U.S. and the Russian Federation.

“The joint committees recognize that it is unlikely that the U.S. government will bring the agreement into force in an environment of worsening relations between the United States and Russia. It is the joint committees’ hope that current disagreements that have recently emerged will not interfere with the United States and Russia working together toward their common goal of inhibiting nuclear weapons proliferation as nuclear energy use grows across the world.”

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