The future of clean energy is hot. Temperatures hit 800 Celsius in parts of solar energy plants and advanced nuclear reactors. Finding materials that can stand that type of heat is tough. So experts look to Mark Messner for answers. A principal mechanical engineer at the U.S. Department of Energy's (DOE) Argonne National Laboratory, Messner is among a group of engineers who are discovering better ways to predict how materials will behave under high temperatures and pressures.
A new take on artificial intelligence may open many doors for 3D printing and designing advanced nuclear reactors. The future of clean energy is hot. Temperatures hit 800 Celsius in parts of solar energy plants and advanced nuclear reactors. Finding materials that can stand that type of heat is tough. So experts look to Mark Messner for answers.
Flexible plant operations are highly desirable in today's power generation industry. Every plant owner desires increased ramp rates and the ability to operate at lower loads so their plants will remain "in the money" longer in today's competitive power markets. This goal, while laudable, remains elusive. The ADEX self-tuning artificial intelligence (AI) system allows plants to continuously optimize plant performance at any operating point rather than being constrained to a static "design point" commonly found in gas- and coal-fired plants. Better yet, no changes to the plant distributed control system (DCS) are required.
On any given day, the electric power industry's operations are complex and its responsibilities vast. As the industry continues to play a critical role in supporting global climate goal challenges, it must simultaneously support demand increases, surges in smart appliance adoption, and decentralized operating system expansions. Behind the scenes, there's the power grid operator, whose role is to monitor the electricity network 24 hours per day, 365 days per year. As a larger number of lower capacity systems (such as renewables) come online and advanced network components are integrated into the grid, generation becomes exponentially more complex, decentralized and variable, stretching control room operators to their limits. More locally, building owners and controllers (Figure 1) are being challenged to deploy grid-interactive intelligent elements that can flexibly participate in grid level operations to economically enhance grid resiliency (while also saving money for the building owner).
Energy communities will play a key role in building the more decentralized, less carbon-intensive, and fairer energy systems of the future. Such communities enable local prosumers (consumers with own generation and storage) to generate, store and trade energy with each other--using locally owned assets, such as wind turbines, rooftop solar panels and batteries. In turn, this enables the community to use more locally generated renewable generation and shifts the market power from large utility companies to individual prosumers. Energy community projects often involve jointly-owned assets such as community-owned wind turbines or shared battery storage. Yet, this raises the question of how these assets should be controlled--often in real-time, and how the energy outputs jointly-owned assets should be shared fairly among community members, given not all members have the same size, energy needs or demand profiles.
The California Public Utilities Commission (CPUC) has issued GM's Cruise the permit needed to be able to give passengers a ride without a driver behind the wheel. It's the first time (PDF) the commission has issued a permit of this kind, and it's a significant milestone for the CPUC's Autonomous Vehicle Passenger Service Pilot Programs. Waymo and Cruise's other rivals already have "drivered" permits from the regulator, but they also have to secure this "driverless" permit to enable fully autonomous rides with passengers onboard. That said, Cruise can't start charging customers just yet. As Prashanthi Raman, Cruise's director of Government Affairs, explained to TechCrunch: "In order to launch a commercial service for passengers here in the state of California, you need both the California DMV and the California PUC to issue deployment permits. Today we are honored to have been the first to receive a driverless autonomous service permit to test transporting passengers from the California PUC."
A multidisciplinary team from the Idaho and Argonne National Laboratories, Kairos Power, and Curtiss-Wright, along with support from academics, have developed digital twin nuclear reactors. By using a US$5.2 million grant from the Department of Energy's Advanced Research Projects Agency-Energy, the scientists and engineers have engaged a physics-based machine learning process to construct and later maintain the digital twin reactors. By grounding the machine learning algorithm in actual physics, the artificial intelligence model generates predictions that are more robust and reliable when compared to more abstract models. The complex nature of this approach provides two layers of problem-solving simultaneously. First, a machine learning-driven predictive maintenance system actively avoids unexpected outages while optimizing maintenance, and predicts mechanical failure before prototypical mechanical stress indicates as much.
Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is managed by Triad, a public service oriented, national security science organization equally owned by its three founding members: Battelle Memorial Institute (Battelle), the Texas A&M University System (TAMUS), and the Regents of the University of California (UC) 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.
Thirty-five years after the Chernobyl Nuclear Power Plant in Ukraine exploded in the world's worst nuclear accident, fission reactions are smoldering again in uranium fuel masses deep inside a mangled reactor hall. “It's like the embers in a barbecue pit,” says Neil Hyatt, a nuclear materials chemist at the University of Sheffield. Now, Ukrainian scientists are scrambling to learn whether the reactions will wink out—or require extraordinary steps to avert another accident. Sensors are tracking a rising number of neutrons, a signal of fission, streaming from one inaccessible room, Anatolii Doroshenko of the Institute for Safety Problems of Nuclear Power Plants (ISPNPP) in Kyiv, Ukraine, reported last month during discussions about dismantling the reactor. “There are many uncertainties,” says ISPNPP's Maxim Saveliev. “But we can't rule out the possibility of [an] accident.” The neutron counts are rising slowly, Saveliev says, suggesting managers still have a few years to figure out how to stifle the threat. Any remedy will be of keen interest to Japan, which is coping with the aftermath of its own nuclear disaster 10 years ago at Fukushima, Hyatt notes. “It's a similar magnitude of hazard.” The specter of self-sustaining fission, or criticality, in the nuclear ruins has long haunted Chernobyl. When part of the Unit Four reactor's core melted down on 26 April 1986, uranium fuel rods and their zirconium cladding, graphite blocks, and sand dumped on the core to try to extinguish the fire melted together into a lava. It flowed into basement rooms and hardened into formations called fuel-containing materials (FCMs), laden with about 170 tons of irradiated uranium—95% of the original fuel. The concrete-and-steel sarcophagus called the Shelter, erected 1 year after the accident to house Unit Four's remains, allowed rainwater to seep in. Because water slows, or moderates, neutrons and thus enhances their odds of striking and splitting uranium nuclei, heavy rains sometimes sent neutron counts soaring. After a downpour in June 1990, a “stalker”—a scientist at Chernobyl who risks radiation exposure to venture into the damaged reactor hall—dashed in and sprayed gadolinium nitrate solution, which absorbs neutrons, on an FCM that scientists feared might go critical. Several years later, the Shelter was equipped with gadolinium nitrate sprinklers. But the spray can't effectively penetrate some basement rooms. Chernobyl officials presumed any criticality risk would fade when the massive New Safe Confinement (NSC) was slid over the Shelter in November 2016. The €1.5 billion structure was meant to seal off the Shelter so it could be stabilized and eventually dismantled. It also keeps out the rain, and since its emplacement, neutron counts in much of the Shelter have been stable or are declining. But they began to edge up in a few spots, nearly doubling over 4 years in room 305/2, which contains tons of FCMs buried under debris. ISPNPP modeling suggests the drying of the fuel is somehow making neutrons ricocheting through it more, rather than less, effective at splitting uranium nuclei. “It's believable and plausible data,” Hyatt says. “It's just not clear what the mechanism might be.” The threat can't be ignored. As water continues to recede, the fear is that “the fission reaction accelerates exponentially,” Hyatt says, leading to “an uncontrolled release of nuclear energy.” There's no chance of a repeat of 1986, when the explosion and fire sent a radioactive cloud over Europe. A runaway fission reaction in an FCM could sputter out after heat from fission boils off the remaining water. Still, Saveliev notes, although any explosive reaction would be contained, it could threaten to bring down unstable parts of the rickety Shelter, filling the NSC with radioactive dust. Addressing the newly unmasked threat is a daunting challenge. Radiation levels in 305/2 preclude installing sensors. And spraying gadolinium nitrate on the nuclear debris there is not an option, as it's entombed under concrete. One idea is to develop a robot that can withstand the intense radiation for long enough to drill holes in the FCMs and insert boron cylinders, which would function like reactor control rods and sop up neutrons. In the meantime, ISPNPP intends to step up monitoring of two other areas where FCMs have the potential to go critical. The resurgent fission reactions are not the only challenge facing Chernobyl's keepers. Besieged by intense radiation and high humidity, the FCMs are disintegrating—spawning even more radioactive dust that complicates plans to dismantle the Shelter. Early on, an FCM formation called the Elephant's Foot was so hard scientists had to use a Kalashnikov rifle to shear off a chunk for analysis. “Now it more or less has the consistency of sand,” Saveliev says. Ukraine has long intended to remove the FCMs and store them in a geological repository. By September, with help from European Bank for Reconstruction and Development, it aims to have a comprehensive plan for doing so. But with life still flickering within the Shelter, it may be harder than ever to bury the reactor's restless remains.
Scientists monitoring the ruins of the Chernobyl nuclear power plant in Ukraine have seen a surge in fission reactions in an inaccessible chamber within the complex. They are now investigating whether the problem will stabilise or require a dangerous and difficult intervention to prevent a runaway nuclear reaction. The explosion at Chernobyl in 1986 brought down walls and sealed off many rooms and corridors. Tonnes of fissile material from the interior of a reactor were strewn throughout the facility and the heat it generated melted sand from the reactor walls with concrete and steel to form lava-like and intensely radioactive substances that oozed into lower floors. One chamber, known as subreactor room 305/2, is thought to contain large amounts of this material, but it is inaccessible and hasn't been seen by human or robotic eyes since the disaster.