Competitive nuclear energy in a world of new paradigms

Nuclear power currently faces a global energy landscape experiencing a pace of change unmatched since cities began to electrify in the 1800s. For much of the history of electricity generation, load variation was driven purely by consumer demand. Yet the global mindset has changed, motivated by concern about what impact electricity production is having on the planet. To facilitate the transition away from resources emitting carbon dioxide (CO2) and other particulate matter, governments are incentivizing the development and installation of low-carbon and carbon-free energy resources, where wind and solar play an important part.

This transition has had the most significant impact for generation types like nuclear, which traditionally operated as baseload. In this changing landscape, nuclear generation has won a competitive edge thanks to experience garnered over the years, as well as efficient research and innovation.

Results are already visible in many fields, be it digital transition, flexible operation, asset management, fuel, system engineering and, above all, in excellence of execution across the entire balance of the plant. New reactors are benefiting from digital solutions such as virtual reality, digital instrumentation and control, and system engineering. Existing fleets are also taking advantage of efficient methods and operating procedures, new manufacturing and repair solutions, and new fuels to continue to operate safely and efficiently, now and well into the future.

The following three technical examples illustrate areas where innovation, delivery and execution have allowed nuclear energy to meet the rapid pace of change facing the energy sector.

FLEX operations: how nuclear power can complement renewable growth

Increasing levels of solar and wind adoption present unique challenges to the grid because these renewables are variable and depend on how much sun or wind is available. Renewables are also “must take” in many markets, meaning that other generating assets must follow the net-load demand curve. To do so, generating assets must be started or stopped, maneuvered up and down, or, if operating at baseload, they must pay to produce power through negative pricing. 

The nuclear energy industry worldwide recognizes the need to improve maneuvering capabilities to avoid negative pricing associated with baseload operation and high renewable penetration by evolving. Framatome has significant expertise, products and services that can improve the maneuvering capabilities of nuclear plants derived from more than 30 years of successful flexible operations of nuclear fleets worldwide. The company has delivered flexible operations products and services to countries including France, Germany, the United States, Finland, South Korea, England, Belgium, China, the Netherlands, South Africa and Switzerland.

For a plant that is looking to improve maneuvering capabilities, the first step in determining the right technical solutions is to perform a feasibility study. This study identifies ways to optimize maneuvering transients to best match the customer’s local grid challenges. The study scope includes all plant systems, structures, components and programs from the reactor core to the grid. It identifies high impact areas, like lifetime issues (e.g., fatigue) and fuel issues (e.g., power maneuvering guidelines), and offers tailored solutions like fatigue/vibration monitoring instrumentation, fast fatigue evaluation software and operational changes, among others, to mitigate possible impacts.

For existing reactors that demand the highest levels of flexibility and maneuverability, we have developed state-of-the-art solutions like the Advanced Load Following Control (ALFC) system. ALFC is a fully automated control system that can accommodate the full range of grid operator demands for daily load maneuvers, primary and secondary frequency control, unexpected grid upsets and extended low power operation. ALFC minimizes reactivity transients by automatically adjusting control rod position and reactor control system (RCS) boration/dilution based on real-time power demand. ALFC enhances safety by reducing operator burden, improving operator reactivity awareness through visualization and increasing operating margins. With seven Framatome ALFC systems operating in Germany, Switzerland and the Netherlands, customers are reaping the benefits of flexible power load maneuverability.

Instrumentation and Control: innovative digitization offers key benefits

Utilities are increasingly turning to digital instrumentation and control systems (I&C) for the host of benefits they offer. New functions improve operator actions, reduce surveillances, cut the number of unscheduled outages and enhance diagnostics, allowing reactors to operate more safely, efficiently and economically.

Additional operational benefits come from the ability to harness a wealth of data – data that continues to drive improved performance. Process data offers insight into how to manage reactor performance in an increasingly flexible grid. This data offers better prediction for maintenance and operating conditions. Digital equipment allows for automatic, remote diagnostic, analytical and self-testing capabilities, which means that utilities can gain time during outages and operations while having a better understanding of the state of their control equipment.

Further, digital systems bring more flexibility to operators. Equipment that would previously have been a single monolithic item can comprise smaller distributed packages in multiple rooms. This offers greater safety because of physical ergonomic separation considerations.

Upgrading to a digital I&C system also helps overcome costly and challenging obsolescence issues. Legacy analogue I&C systems are becoming more and more expensive to maintain, particularly as some Original Equipment Manufacturers (OEMs) no longer support these systems or have even gone out of business.

Generation III+ reactors, such as Framatome’s EPR design, have adopted digital I&C into their foundational design. Simultaneously, legacy reactors built with analogue systems are modernizing to digital systems to take advantage of the many benefits of digitization.

Operators learning to run both new and modernized systems have benefitted from simulators and are now able to mock up a wide range of plant scenarios. Framatome and its subsidiary, CORYS, offer training on a full-scale, fully configurable digital control room simulator and deployed operator training in a simulator in Taishan, China for Framatome’s EPR start up.

Enhanced Accident Tolerant Fuel: Improving Safety and Operational Efficiency

Nuclear fuel encompasses a wide range of cost and safety factors for nuclear operators. Enhanced Accident Tolerant Fuel (EATF) technologies under development make positive contributions to both categories – creating more efficient and economical fuel that offers better margins in the unlikely event of an accident, while helping reactors operate in today’s energy mix.

Framatome, along with its global partners, is currently developing near-term and long-term solutions under its PROtect program. The near-term solution uses chromium – through both chromia-enhanced pellets and chromium-coated fuel rods – and features important safety benefits, like decreasing fission gas release in high-power/high-burnup conditions, increasing resistance to wear from potential foreign materials that could enter the core, and improving margins during conditions where temperatures or pressures fluctuate within the reactor. The long-term solution includes even more advanced technology, such as chromia-enhanced pellets with a ceramic silicon carbide-based cladding.

While both of these technologies certainly improve safety, they also directly respond to operational imperatives facing nuclear energy today and into the future. Both designs in Framatome’s PROtect program offer enhanced load following capabilities and more power variability. This is a benefit of the enhanced mechanical resistance of the chromium-coated M5Framatome cladding and the high visco-plasticity of the chromia-enhanced fuel, together reducing pellet cladding interactions.

The PROtect program has an aggressive schedule to bring advanced fuel technologies to all light water reactors of the current fleet and for the next generation of advanced reactors. Since 2016, segments of the near- and long-term solution have been under irradiation in a Swiss pressurized water reactor (PWR), and teams of experts are confirming the positive results from out-of-pile tests. Since 2019, lead assemblies with the near-term solution have been under irradiation in a commercial PWR in the U.S. (GAIA design) and in Switzerland (HTP design). Currently available results confirm expectations with all positive indications. After successful in-pile irradiation, industrialisation and licensing, the first reloads with PROtect near-term solution are expected.

Meeting future demand  

Framatome’s advanced reactor designs are well-matched for the future of energy. The company’s Generation III+ EPR design has met many recent milestones. This summer, the second unit at Taishan  was connected to the electrical grid following closely in the footsteps of Unit 1, which was declared as in commercial operation in December 2018. These reactors are providing critical clean energy to China as it rapidly expands its grid and overall generating capacity.

Framatome is also playing a key role in innovating solutions that utilize nuclear power reactors in a way never seen before. Framatome joined forces with Bruce Power and Kinectrics to develop and deliver a medical isotope that allows for the therapeutic treatment of small tumors like prostate cancer, potentially helping to save thousands of lives.

While many uncertainties persist about the future of the energy mix and the composition of the grid, innovation in nuclear energy not only bolsters the industry’s capability to meet the world’s clean air and energy needs into the future, but also enables it to move beyond energy into new sectors that can benefit from its expertise. Furthermore, creativity and innovation are important components of Framatome’s commitment to help our customers continue to operate reactors around the world well into the future. 

Author information: Bernard Fontana, chief executive officer of Framatome