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Belgian Regulators Approve Restart of Flawed Reactors

Belgian nuclear authorities have authorized the restart of two reactors whose steel reactor pressure vessels (RPVs)—which contain the reactors' fissioning cores and primary coolant—are riddled with flaws. The flaws were discovered during routine maintenance in 2012. After followup ultrasonic imaging of the RPVs, experimental testing of steel samples, and extensive computational analyses, the regulators accepted the operator’s argument that the RPV flaws are decades old and do not compromise the vessels’ structural integrity.

The flaws in Belgium’s Doel 3 and Tihange 2 reactors idled the two 1,000-megawatt reactors in 2012 and again in 2014, prompting preparations for potential blackouts in Belgium and stymying European grid operators’ efforts to upgrade their system for coordinating cross-border power flows. They also prompted European regulators to call for expanded ultrasonic testing of all RPVs—a move resisted by the U.S. Nuclear Regulatory Commission.  

The Belgian reactors will take about four weeks to restart, according to World Nuclear News. There’s no word yet on whether Brussels-based reactor operator Electrabel will seek to extend the operation of Tihange 2 and Doel 3, which reach their 40-year original design lifespan in 2022 and 2023, respectively. However, regulators approved 10-year extensions for the Doel plant's two older reactors last month.

An independent structural analysis by Oak Ridge National Laboratory (ORNL) in the United States affirmed the structural integrity of the Tihange 2 and Doel 3 reactors, says Richard Bass, a corporate fellow at ORNL and coauthor of the review commissioned by Belgium's Federal Agency for Nuclear Control (FANC). “As far as we’re concerned, the flaw population meets the ASME pressure vessel requirements,” says Bass, referring to the American Society of Mechanical Engineers’ RPV codes.

ORNL, the principal contractor for the U.S. Nuclear Regulatory Commission on RPV integrity issues, applied that expertise to evaluate the safety case for the Belgian reactors put forward by Electrabel. “We had about two months total, so we did everything that we could reasonably do during that period,” says Bass. 

Bass and his colleagues examined the flaws—a total of 16,196 disc-shaped gaps detected in the RPVs' steel plates—and ran simulations meant to indicate whether the faults would initiate cracks under various stress scenarios. Simulations focused on the rapid temperature fluctuations that could happen, for example, in the case of a loss-of-coolant accident such as occurred at Fukushima Daiichi in 2011. They also projected the embrittlement of the RPV as it ages.

Of the thousands of flaws in the two reactors, four faults flunked ORNL’s initial simulations. Bass said that ORNL then accounted for the fact that the loading on the RPV would occur while it was warm, which makes the steel more robust during subsequent cooling—a metallurgical phenomenon that ORNL demonstrated experimentally in the 1970s and 1980s. 

Three of the Belgian reactors' four questionable flaws were deemed compliant with safety regulations under pre-stress warming conditions. The remaining flaw, labeled flaw #1660, was cleared after closer scrutiny of its geometry. 

The initial screenings were performed with a simplification of the shape, in which each was assumed to be a circular disc—an approach that Bass calls “very conservative." When ORNL modeled flaw #1660 and found that it is an elliptical disc (roughly 8.5 millimeters across in one direction and 10 mm across in the other), it passed muster. 

"You change the problem and go back to the original representation that’s much closer to reality,” says Bass. "When we did that we found that the real flaw met the ASME code acceptance criteria.”  

ORNL did not estimate how big the RPVs' margin of safety is, but it is “significant” in Bass’ expert opinion: ”There is significant margin between the driving forces on the flaws and the toughness of the material."

ORNL also concurred with Electrabel’s calculations regarding the risk posed by hydrogen diffusing into the steel and forcing open cracks during temperature swings. "We looked at what they did and it looked reasonable to us,” says Bass.

FANC, meanwhile, concurred with Electrabel’s assertion, based on ultrasonic inspections in 2012 and 2014, that the flaws were created when the RPVs were forged and are not growing over time. Still, it approved the reactors to restart on the condition that Electrabel must reinspect the RPVs when they are next shut down for refuelling.

Several independent experts argued in 2014 that FANC had overlooked the risks posed by ongoing hydrogen diffusion. Among them was Digby Macdonald, a corrosion expert at the University of California at Berkeley. (Spectrum highlighted Macdonald’s concerns in April of this year.) 

FANC addressed their concerns in a special report released this week. The report cites input from several independent experts, including two proposed by Macdonald’s colleague Walter Bogaerts, a Belgian materials science expert. 

The independent experts affirmed that “significant experiment and theoretical results” constrain the pressure caused by hydrogen within the RPV to low levels: about 200 kilopascals at 25 degrees Celsius and 35 kPa at 300 °C. To put that in context, computations by Electrabel suggest that even hydrogen exerting 10 megapascals of pressure within the flaws would have a “small impact” on RPV integrity. 

Macdonald told IEEE Spectrum that he remains concerned about the FANC experts’ failure to “correctly address” the potential production of hydrogen within the reactor via radiolysis—the splitting of water molecules by nuclear radiation. However, he says he has yet to publish his own analysis of radiolysis.


An All Wind, Water, and Solar Grid Will Be Stable Without Batteries

The U.S. electrical grid could rely completely on solar, wind, and water power, and existing low-cost methods of storing energy—rather than than giant battery farms—could help make up for the erratic nature of the sources of that electricity, researchers say.

Previous research suggested that the United States could get 100 percent of its energy from these green sources by 2050 and, more ambitiously, that the world could as well.

However, solar and wind are all intermittent sources of power—sometimes the sun doesn’t shine brightly and the wind doesn’t blow strongly. As such, power plants driven by fossil fuel are often brought in to compensate for the uncertain nature of these green sources of energy and to keep power grids stable.

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U.S. Airlines Could Cut Emissions In Half By 2050 With Minimal Cost

Heads of state will be talking climate in Paris this week. And next year, when the International Civil Aviation Organization meets, national representatives will find themselves under great pressure to sign a deal that reduces greenhouse gas emissions from air travel. Although improved aerodynamics, greater engine efficiency, and higher passenger density have cut per-passenger emissions in half compared with 1990 levels, total aviation emissions still increased by 3.6 percent every year, which means a doubling every 20 years.

But the aviation industry, which accounts for 2.5 percent of global carbon emissions, is already tackling the problem. In a bold open letter published in September, airline industry leaders including Boeing and Airbus vowed to flatten aviation emissions by 2020 and halve them by 2050 compared with a 2005 baseline.

A new study published in Nature Climate Change shows that this goal might just be reachable, at least in the industrialized world. The study shows that U.S. passenger airlines could cut emissions in half by 2050 compared with 2012 levels—a reduction of 2 percent per year for the next 35 years. Doing so would involve a few smart aircraft retrofits, design upgrades, and more efficient air traffic management and flight operations. These changes would have a minimal effect on the airlines’ bottom lines. In fact, a few carriers are already adopting some of these straightforward changes.

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Can Energous Deliver on Wireless Power Promises?

Wireless power sounds like an absolutely fantastic idea, in theory. All of your devices, charging themselves all the time, without you having to plug them in or even think about their batteries. Wearables you never have to take off. Cellphones that work when you need them to. Remote controls that never need the batteries changed. But, beaming power through the air in a safe, effective, and efficient way is hard, and so far, the technology isn’t always living up to the promises that it’s making.

The promises made by a company called Energous include multi-device charging using radio frequency energy out to a range of 4.5 meters, relying on transmitters integrated into home appliances and receivers that can easily fit into portable electronics. Last week, Energous released a report from Underwriters Laboratories (UL) that tested and verified the wireless power delivery provided by Energous’ WattUp transmitters and receivers. It answered some of our questions, but raised a few more, and we spoke with Energous founder and CTO Michael Leabman to get things all figured out.


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Getting Up Close and Personal With High-Voltage Electricity

As director of innovation at KEMA Laboratories in Arnhem, Netherlands, René Smeets is no stranger to power. The lab tests circuit breakers and transformers built for ultrahigh-voltage (UHV) transmission systems, ensuring that these components can control the titanic current flows unleashed during short circuits. KEMA’s strategies to mimic those extreme conditions in the lab, which Smeets describes in an article in the latest issue of Spectrum, give him an intimate understanding of how the components will perform when they’re deployed in vast, nation-spanning transmission networks.

Sometimes, however, this expert likes to get a broader view and see the equipment he tests in its natural habitat. In September, while in Shanghai for a meeting convened by the State Grid Corp. of China, Smeets and other UHV specialists got a tour of State Grid’s nearby Liantang substation (shown in the photo above). The utility says this facility, which receives electricity from coal-fired power plants in the interior province of Anhui, handles more high-voltage power than any other substation in the world. The brand new 1,100-kilovolt transmission system routinely delivers 6,900 megawatts of power to Shanghai. State Grid already has plans to scale it up to an astounding 10,000 MW.

What impressed Smeets most in this superlative substation? “All the components used in the station were Chinese-made,” he says. This fact didn’t surprise him, as KEMA Labs has tested many pieces of Chinese equipment in recent years. But it did demonstrate that China has developed a world-leading UHV industry. It’s an exciting time to be a UHV tourist, Smeets says: India’s Power Grid Corp. is now building a 1,200‑kV network, which will set a new mark for the highest-voltage transmission system. “It will be the pride of India,” Smeets says. He’s looking forward to a tour.


Nuclear Waste Deep Storage Plans Approved

Finland’s government issued a construction license to nuclear disposal consortium Posiva last week, Reuters reported. The license gives the group approval to build a storage facility on Olkiluoto Island, Finland, designed to last 100,000 years.

The facility would be the first of its kind in the world. Since the beginning of the nuclear power age, energy firms have paid to store nuclear waste in temporary holding ponds unlikely to last more than a couple of centuries.  The Posiva facility, decades in the planning, may pioneer a more sustainable era of disposal. (See “Finland’s Nuclear Waste Solution,” IEEE Spectrum, December 2009.)

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Steak and ground beef

The Global Energy Risk of Growing More Protein

The global shortlist of security concerns just became a bit longer: border security, cyber security, economic security, water security and now, protein security.

Access to high quality protein sources, beef or otherwise, is increasingly challenging for companies and nations as more of world’s population adopts Western diets, according to a new study from Lux Research.

With the considerable water and energy requirements to grow beef and many other protein sources, the research is meant to help stakeholders understand how to increase the amount of protein produced without jeopardizing environmental resources. 

The study looked at protein production data from more than 100 publications. The researchers then compared all of the protein sources across their entire life cycle. Each protein source was then benchmarked using the concept called “beef parity”, the total resource requirement and risk involved to produce the equivalent of 1 kilogram of beef protein.

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Shocking Trick To Desalinate Seawater

Getting clean water for drinking and agriculture to a burgeoning population is one of the most pressing challenges of this century. A natural place to turn to is the world’s oceans, but desalinating seawater has so far proven to be costly and energy-intensive.

Engineers at MIT have come up with a new desalination system that uses a shockwave to get the salt out of seawater. It could be a practical and energy-efficient method for desalination; water purification in remote locations and emergencies; and for cleaning brackish wastewater generated from hydraulic fracturing, the researchers say.

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Putting California Wind Power Out to Sea

Wind power developers eyeing California’s renewable energy market are literally floating a novel idea. Seattle-based Trident Winds has filed preliminary environmental documents for a farm of 100 floating wind turbines off California’s central coast, according to reporting this week by the San Jose Mercury News

Trident Winds’ proposal is a longterm bet—startup is probably a decade away according to CEO Alla Weinstein—but it's a vision that sounds less and less like science fiction. Just last week Norwegian oil and gas giant Statoil gave the green light to what is likely to be the world’s first floating wind farm, with construction set to begin next year near Scotland; it is to be generating 30 megawatts (MW) of power by the end of 2017. 

There is no doubt that California will need plenty of renewable energy as the state gears up to meet a new mandate requiring half of its power to be renewable by 2030. Less clear is whether it will be ready to stomach floating wind power's financial and maritime pricetag.

Floating turbines rely on the same types of spar buoys and tension-leg platforms used by offshore oil platforms, enabling them to access wind power in deeper waters well beyond the 40- to 50-meter limits of turbines on fixed foundations. That's an enabler for offshore wind power near coastlines that drop off quickly, such as California's, and it also provides access to the stronger, more consistent airflows that prevail further offshore. 

Trident Winds’ project would float offshore from the California coastal city of Morro Bay, which lies between Santa Cruz and San Luis Obispo. The plan calls for 10-MW floating turbines standing up to 194 meters tall, which the Mercury News notes is even taller than Morro Rock, "the craggy 581-foot-tall monolith that dominates” the local shoreline.

The fleet of 100 turbines would, of course, be 24 kilometers offshore and thus no competition for Morro Bay's iconic structure. That’s in marked contrast to Morro Bay’s old power plant. San Francisco–based PG&E shut down the coal-fired plant in 2013 but, according to the New York Times, the utility has no plans to demolish its three 137-meter smokestacks

Floating wind turbines have been in the pilot/demonstration phase since the first turbines were installed offshore in Europe in 2007 and 2008. They stepped up in power significantly with the 2009 installation of a 2.3-MW, 65-meter-tall machine off the Norwegian coast by Statoil. Berkeley-based floating wind developer Principle Power (previously led by Trident Winds' Weinstein) installed a 2-MW machine in Portuguese waters in 2011. 

Since then even bigger machines have been floated. In August a consortium of Japanese industrial firms anchored a 7-MW, 105-meter-high turbine off the coast of Fukushima. Statoil’s Scottish wind park plans call for six 6-megawatt machines

Larger scale is seen as critical to making deepwater installations cost-effective, which makes Trident Winds’ proposal for 10-MW turbines understandable. The Guardian’s reporting on Statoil’s project suggests that scale could ultimately render floating turbines more cost-effective than today’s fixed offshore turbines. Citing a June 2015 report from the U.K.’s Carbon Trust, it says the current global average for offshore wind is £112 ($169) per megawatt-hour (MWh), whereas “larger concepts” for floating wind such as Statoil’s could produce power at £85–95/MWh.

Design could help too. The innovator behind the very first floating offshore turbine test recently launched a crowd-funding campaign to fund certification of a simplified turbine for offshore use, redesigned from the ground up with floating installation and operation in mind. 

Cost reductions will be critical to selling offshore wind in the U.S. Since at least 2013, Principle Power has been advancing a proposal to install floating turbines off the coast of Oregon. But, as this weekend’s Mercury Star report notes, Principle Power's projected $240/MWh pricetag is “more than the utilities in Oregon want to pay.” 

Another challenge facing technology proponents is demonstrating that their floating leviathans will have limited impacts on the marine environment. European studies have found that offshore wind farms have limited impact on seabirds. But location is everything, and conservation groups will be looking for reassurance that the technology will be benign for the birds frequenting the U.S. Pacific coast.

A more difficult flashpoint could be impacts on fishing resources. Trident Winds’ project would create a 162-square-kilometer no go zone for drag nets, thanks to power cables dangling between the floating turbines.


Paris Climate Talks Facing Growing Carbon Emissions and Credibility Gaps

Three weeks before the start of the Paris climate talks, negotiators working to craft an international agreement that will curb rising global greenhouse gas emissions are staring into a wide gulf between what countries are willing to do and what they need to do. Most countries have stepped up with pledges to meaningfully cut carbon emissions or to at least slow the growth of emission totals between 2020 and 2030. However, national commitments for the Paris talks still fall short of what’s needed to prevent the average global temperature in 2100 from being any more than 2 degrees Celsius warmer than at the start of this century—the international community’s consensus benchmark for climate impact.

Worse still, the national pledges employ a hodgepodge of accounting methods that include some significant loopholes that ignore important emissions such as leaking methane from U.S. oil and gas production and underreported coal emissions from China. How the promised emissions reductions will be verified post-Paris is “a big debate right now and it makes a massive difference in the numbers,” says Jennifer Morgan, global director for the climate program at the World Resources Institute (WRI), a Washington, D.C.-based non-governmental organization. 

The best news out of Paris so far is that, as of last week, climate plans—Intended Nationally Determined Contributions (INDCs) in UN-speak—had been submitted for 156 countries (129 INDCs, including a joint submission for the 28 European Union states). The 156 countries account for about 90 percent of global greenhouse emissions according to the Paris talks’ organizer, the secretariat of the UN Framework Convention on Climate Change. 

Broad involvement marks a dramatic contrast with the 1997 Kyoto Protocol. That deal, which was exclusively for developed countries, was never ratified by the United States. But in the run up to Paris, U.S. President Barack Obama and Chinese President Xi Jinping reached a broad deal a year ago assuring that their countries would ante up; that encouraged the six of the world’s next biggest carbon emitters, including India, Brazil, and Indonesia,to step up. 

The plans, by and large, propose massive shifts to from fossil fuels to renewables. Number crunching by the Washington, D.C.-based World Resources Institute shows that the “Big 8” emitters have pledged to roughly double their use of renewable energy by 2030 compared with 2012 levels. 

The INDC filed by the United States fits the pattern. It largely relies on the U.S. Environmental Protection Agency's Clean Power Plan, which mandates a one-third reduction in carbon emissions from the electric power sector by 2030. The EPA projects that coal-fired power will drop from 39 percent of the nation’s electricity supply in 2013, to 27 percent by 2030—largely thanks to the addition of renewables.

Globally speaking, the promised emissions cuts are both substantial and inadequate. Fully implementing the INDCs submitted so far would hold global temperature rise this century to about 2.7 °C above pre-industrial levels, according to Christiana Figueres, Executive Secretary of the UN Framework Convention on Climate Change. Policy consultancy Climate Interactive, in Washington, D.C., projects a 3.5 °C rise without stronger action post-2030. (These jumps include the 0.85 °C increase already recorded between 1880 and 2012.) 

Those projections represent a substantial step down from the 4.5 °C net rise by 2100 that is projected by the Intergovernmental Panel on Climate Change (IPCC) based on current emissions trends. But a degree-and-a-half hotter than the 2 °C limit that world leaders agree is needed to head off the worst impacts of climate change is still significant. 

And for some parties, 2 degrees Celsius remains unacceptably high. For example, that amount of warming could cause sea levels to rise far enough to devastate some small island nations such as the Maldives, and some continental coastal zones such as the Mekong Delta and the shores of Bangladesh. The Dalai Lama and other authorities representing over half a billion practicing Buddhists worldwide issued a letter calling for political leaders find the will for a more protective 1.5-°C target.

A tighter target for 2030 appears unlikely, considering that the UN climate secretariat stated categorically last month that the INDCs are not be up for discussion at Paris. But there is growing support for a belt-tightening mechanism that would continually raise ambitions post-2030. Last week, Xi Jinping and French president Francois Hollande endorsed the idea of a five-year review mechanism for INDCs. 

Recent developments suggest there is room for greater ambition. California, for example, was on track to comply with the EPA’s Clean Power Plan even before last month when legislators approved new renewable power mandates for the state’s power sector. Renewable energy’s share of California’s power generation mix is to rise from at least 33 percent in 2020 to at least 50 percent by 2030.

Unfortunately, uncounted emissions could push the global warming trajectory in the opposite direction, making the INDC-based temperature projection, predicting an increase between 2.7 °C and 3 °C, look optimistic. 

Consider the underestimated methane leaks in the United States. A molecule of methane released into the atmosphere traps over 80 times as much heat within 20 years as a CO2 molecule does; after a 100-years, it will still be 28 to 34 times as potent as the longer-lived CO2 molecule. Remote sensing suggests that U.S. methane emissions are 25 to 75 percent higher than what the EPA acknowledges in its bottom-up inventory of methane sources such as oil and gas facilities, belching livestock, and landfills. 

The reality of this missing methane was affirmed in July by an intensive bottom-up accounting of methane leaks at oil and gas operations in Texas’ Barnett Shale reported in the journal Environmental Science & Technology. The study predicts that methane leaks from the Barnett are about 50 percent higher than what is reported in the EPA’s inventory

What that means for Paris is that the U.S. INDC understates its carbon footprint and overstates some of the promised carbon reductions that rely on a switch from coal to natural gas-fired power plants. “There has been no adjustment made for this,” says Ramón Alvarez, a coauthor on the Barnett study and a senior scientist with the Environmental Defense Fund. 

Other loopholes are seeing increased scrutiny thanks to intensifying media coverage in the run up to Paris. The New York Times reported last week that China has been undercounting coal emissions for many years.

And a series by online outlet Climate Central in October questioned emissions reductions attributed to European power plants burning U.S.-produced wood pellets instead of coal. According to the report, this accounts for almost half of what European regulators count as carbon-neutral renewable energy. But the source of wood is critical. Scientists say that power plants burning waste biomass can play a key role in reducing emissions. But Climate Central's reporting found that U.S. forests are being harvested to fuel Europe's biomass power; forest regrowth to recover the released carbon could take over a century.

There was an attempt to head off such accounting discrepancies ahead of the Paris talks by setting standardized accounting rules for INDCs, or perhaps even subjecting INDCs to a pre-Paris vetting process, according to Jennifer Morgan at WRI. Speaking at the Society of Environmental Journalists’ conference in Oklahoma last month, Morgan said those attempts failed. Countries were instead merely encouraged to be transparent in their accounting methodologies. “It was voluntary. Some did,” said Morgan.

Morgan is looking for negotiators to create a process by which a robust INDC verification mechanism will be created in the months and years ahead. She predicts that rule-making will take about two years of work post-Paris. 

All of these issues make the Paris treaty look more like the end of the beginning than a final destination. 


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