Vietnam to build two nuclear power plants

Natrium small modular reactor pairs a sodium-cooled fast reactor with molten salt storage to deliver load-following, dispatchable nuclear power, enhancing grid flexibility and peaking capacity as TerraPower and GE Hitachi pursue factory-built, affordable deployment.

Key Points

A TerraPower-GE Hitachi SMR joining a sodium-cooled reactor with molten salt storage for flexible, dispatchable power.

✅ 345 MW base; 500 MW for 5.5 hours via thermal storage

✅ Sodium-cooled coolant and molten salt storage enable load-following

✅ Backed by major utilities; factory-built modules aim lower costs

Nuclear power is the Immovable Object of generation sources. It can take days just to bring a nuclear plant completely online, rendering it useless as a tool to manage the fluctuations in the supply and demand on a modern energy grid.  

Now a firm launched by Bill Gates in 2006, TerraPower, in partnership with GE Hitachi Nuclear Energy, believes it has found a way to make the infamously unwieldy energy source a great deal nimbler, drawing on next-gen nuclear ideas — and for an affordable price. 

The new design, announced by TerraPower on August 27th, is a combination of a "sodium-cooled fast reactor" — a type of small reactor in which liquid sodium is used as a coolant — and an energy storage system. While the reactor could pump out 345 megawatts of electrical power indefinitely, the attached storage system would retain heat in the form of molten salt and could discharge the heat when needed, increasing the plant’s overall power output to 500 megawatts for more than 5.5 hours. 

“This allows for a nuclear design that follows daily electric load changes and helps customers capitalize on peaking opportunities driven by renewable energy fluctuations,” TerraPower said. 

Dubbed Natrium after the Latin name for sodium ('natrium'), the new design will be available in the late 2020s, said Chris Levesque, TerraPower's president and CEO.

TerraPower said it has the support of a handful of top U.S. utilities, including Berkshire Hathaway Energy subsidiary Pacificorp, Energy Northwest, and Duke Energy. 

The reactor's molten salt storage add-on would essentially reprise the role currently played by coal- or gas-fired power stations or grid-scale batteries: each is a dispatchable form of power generation that can quickly ratchet up or down in response to changes in grid demand or supply. As the power demands of modern grids become ever more variable with additions of wind and solar power — which only provide energy when the wind is blowing or the sun shining — low-carbon sources of dispatchable power are needed more and more, and Europe is losing nuclear power at a difficult moment for energy security. California’s rolling blackouts are one example of what can happen when not enough power is available to be dispatched to meet peak demand. 

The use of molten salt, which retains heat at extremely high temperatures, as a storage technology is not new. Concentrated solar power plants also collect energy in the form of molten salt, although such plants have largely been abandoned in the U.S. The technology could enjoy new life alongside nuclear plants: TerraPower and GE Hitachi Nuclear are only two of several private firms working to develop reactor designs that incorporate molten salt storage units, including U.K.- and Canada-based developer Moltex Energy.

The Gates-backed venture and its partner touted the "significant cost savings" that would be achieved by building major portions of their Natrium plants through not a custom but an industrial process — a defining feature of the newest generation of advanced reactors is that their parts can be made in factories and assembled on-site — although more details on cost weren't available. Reuters reported earlier that each plant would cost around $1 billion.

NuScale Power

A day after TerraPower and GE Hitachi's unveiled their new design, another nuclear firm — Portland, Oregon-based NuScale Power — announced that the U.S. Nuclear Regulatory Commission (NRC) had completed its final safety evaluation of NuScale’s new small modular reactor design.

It was the first small modular reactor design ever to receive design approval from the NRC, NuScale said. 

The approval means customers can now pursue plans to develop its reactor design confident that the NRC has signed off on its safety aspects. NuScale said it has signed agreements with interested parties in the U.S., Canada, Romania, the Czech Republic, and Jordan, and is in the process of negotiating more. 

NuScale previously said that construction on one of its plants could begin in Utah in 2023, with the aim of completing the first Power Module in 2026 and the remaining 11 modules in 2027.

NuScale
An artist’s rendering of NuScale Power’s small modular nuclear reactor plant. NUSCALE POWER
NuScale’s reactor is smaller than TerraPower’s. Entirely factory-built, each of its Power Modules would generate 60 megawatts of power. The design, typical of advanced reactors, uses pressurized water reactor technology, with one power plant able to house up to 12 individual Power Modules. 

In a sign of the huge amounts of time and resources it takes to get new nuclear technology to the market’s doorstep, NuScale said it first completed its Design Certification Application in December 2016. NRC officials then spent as many as 115,000 hours reviewing it, NuScale said, in what was only the first of several phases in the review process. 

In January 2019, President Donald Trump signed into law the Nuclear Energy Innovation and Modernization Act (NEIMA), designed to speed the licensing process for advanced nuclear reactors, and the DOE under Secretary Rick Perry moved to advance nuclear development through parallel initiatives. The law had widespread bipartisan support, underscoring Democrats' recent tentative embrace of nuclear power.

An industry eager to turn the page

After a boom in the construction of massive nuclear power plants in the 1960s and 70s, the world's aging fleet of nuclear plants suffers from rising costs and flagging public support. Nuclear advocates have for years heralded so-called small modular reactors or SMRs as the cheaper and more agile successors to the first generation of plants, and policy moves such as the UK's green industrial revolution lay out pathways for successive waves of reactors. But so far a breakthrough on cost has proved elusive, and delays in development timelines have been abundant. 

Edwin Lyman, the director of nuclear power safety at the Union of Concerned Scientists, suggested on Twitter that the nuclear designs used by TerraPower and GE Hitachi had fallen short of a major innovation. “Oh brother. The last thing the world needs is a fleet of sodium-cooled fast reactors,” he wrote.  

Still, climate scientists view nuclear energy as a crucial source of zero-carbon energy, with analyses arguing that net-zero emissions may be impossible without nuclear in many scenarios, if the world stands a chance at limiting global temperature increases to well below 2 degrees Celsius above pre-industrial levels. Nearly all mainstream projections of the world’s path to keeping the temperature increase below those levels feature nuclear energy in a prominent role, including those by the United Nations and the International Energy Agency (IEA). 

According to the IEA: “Achieving the clean energy transition with less nuclear power is possible but would require an extraordinary effort.”

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Toronto Flood Cleanup details the citywide response to storm damage after heavy rain, stressing drainage system upgrades, emergency services, transit disruptions, infrastructure repair, financial aid, insurance claims, and climate resilience planning for future weather.

Key Points

Toronto Flood Cleanup is the city's flood response, restoring infrastructure, aiding residents, and upgrading drainage.

✅ Emergency services and public works lead debris removal.

✅ Repairs to roads, bridges, transit, and utilities underway.

✅ Aid, insurance claims, and drainage upgrades prioritized.

Toronto is grappling with significant cleanup efforts following severe storms that unleashed heavy rains and caused widespread flooding across the city. The storms, which hit the area over the past week, have left a trail of damage and disruption, prompting both immediate response measures and longer-term recovery plans.

The intense rainfall began with a powerful storm system that moved through southern Ontario, with Sudbury Hydro crews working to reconnect service as the system pressed toward the GTA, delivering an unprecedented volume of water in a short period. The resulting downpours overwhelmed the city's drainage systems, leading to severe flooding in multiple neighborhoods. Streets, basements, and parks were inundated, with many areas experiencing water levels not seen in recent memory.

Emergency services were quickly mobilized to address the immediate impact of the floods. Toronto’s Fire Services, along with other first responders and skilled utility teams, as Ontario recently sent 200 workers to Florida to help restore power, were deployed to assist residents affected by the rising waters. Rescue operations were carried out to help people trapped in their homes or vehicles, and temporary shelters were set up for those displaced by the flooding.

The storm's impact was felt across various sectors of the city. Public transportation services were disrupted, as strong gusts led to significant power outages in parts of the region, with numerous subway stations and bus routes affected by the high water levels. Major roads were closed due to flooding, causing significant traffic delays and affecting daily commutes for many residents. Local businesses also faced challenges, with some forced to close their doors as a result of the water damage.

The city's infrastructure bore the brunt of the storm's fury. Several key infrastructure components, including roads, bridges, and utilities, suffered damage. The city's water treatment plants and sewage systems were stressed by the volume of water, raising concerns about potential contamination and the need for extensive maintenance and repair work.

In the wake of the flooding, the Toronto Municipal Government has launched a comprehensive cleanup and recovery effort. The city's Public Works Department is spearheading the operation, focusing on clearing debris, repairing damaged infrastructure, and restoring essential services, as Hydro One crews restore power to hundreds of thousands across Ontario. Teams of workers are diligently addressing the damage to roads and bridges, ensuring that they are safe for use and functioning properly.

Efforts are also underway to assist residents and businesses affected by the flooding. Financial aid and support programs are being implemented to help those who have suffered property damage or loss, including customers affected by Toronto power outages as repairs continue. The city is working closely with insurance companies to facilitate claims and provide relief to those in need.

In addition to the immediate cleanup, there is a heightened focus on evaluating and improving the city's flood management systems. The recent storms have highlighted vulnerabilities in Toronto’s infrastructure, prompting calls for enhanced flood prevention measures. City officials and urban planners are assessing the current drainage systems and exploring ways to bolster their capacity to handle future extreme weather events.

The storms have also sparked discussions about the broader implications of climate change and its impact on urban areas. Experts suggest that increasingly severe weather events, including heavy rainfall and flooding, may become more common, as seen with Houston's extended power outage after severe storms, as global temperatures rise. This has led to a call for more resilient and adaptable infrastructure to better withstand such events.

Community organizations and volunteers have played a vital role in the recovery process. Local groups have come together to support their neighbors, providing assistance with cleanup efforts, distributing supplies, and offering emotional support to those affected by the disaster. Their contributions underscore the importance of community solidarity in times of crisis.

As Toronto works towards recovery, there is a clear recognition of the need for a comprehensive strategy to address both the immediate and long-term challenges posed by severe weather events. The city’s response will involve not only repairing the damage caused by this storm but also investing in infrastructure improvements, drawing lessons from London power outage disruption cases to harden critical systems, and adopting measures to mitigate the impact of future floods.

In summary, the severe storms that recently struck Toronto have led to widespread flooding and significant disruption across the city. The immediate response has involved extensive cleanup efforts, damage assessment, and support for affected residents and businesses. Looking ahead, Toronto faces the challenge of enhancing its flood management systems and preparing for the potential impacts of climate change. The collective efforts of emergency services, city officials, and community members will be crucial in ensuring a swift recovery and building resilience against future storms.

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NRC Special Inspection at River Bend reviews failures of portable emergency diesel generators, nuclear safety measures, and Entergy Operations actions after Fukushima; off-site power loss readiness, remote COVID-19 oversight, and corrective action plans are assessed.

Key Points

An NRC review of generator test failures at River Bend, assessing nuclear safety, root causes, and corrective actions.

✅ Evaluates failures of portable emergency diesel generators

✅ Reviews causal analyses and adequacy of corrective actions

✅ Remote COVID-19 oversight; public report expected within 45 days

The Nuclear Regulatory Commission has begun a special inspection at the River Bend nuclear power plant, part of broader oversight that includes the Turkey Point renewal application, to review circumstances related to the failure of five portable emergency diesel generators during testing. The plant, operated by Entergy Operations, is located in St. Francisville, La., as nations like France outage risks continue to highlight broader reliability concerns.

The generators are used to supply power to plant systems in the event of a prolonged loss of off-site electrical power coupled with a failure of the permanently installed emergency generators, a concern underscored by incidents such as the SC nuclear plant leak that shut down production for weeks. These portable generators were acquired as part of the facility's safety enhancements mandated by the NRC following the 2011 accident at the Fukushima Dai-ichi facility in Japan, and amid constraints like France limiting output from warm rivers, the emphasis on resilience remains.

The three-member NRC team will develop a chronology of the test failures and evaluate the licensee's causal analyses and the adequacy of corrective actions, informed by lessons from cases like Davis-Besse closure stakes that underscore risk management.

Due to the COVID-19 pandemic, they will complete most of their work remotely, while other regions address constraints such as high river temperatures limiting output for nuclear stations. An inspection report documenting the team's findings, released as global nuclear project milestones continue across the sector, will be publicly available within 45 days of the end of the inspection.
 

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London Underground Power Outage 2025 disrupted Tube lines citywide, with a National Grid voltage dip causing service suspensions, delays, and station closures; TfL recovery efforts spotlight infrastructure resilience, contingency planning, and commuter safety communications.

Key Points

A citywide Tube disruption on May 12, 2025, triggered by a National Grid voltage dip, exposing resilience gaps.

✅ Bakerloo, Waterloo & City, Northern suspended; Jubilee disrupted.

✅ Cause: brief National Grid fault leading to a voltage dip.

✅ TfL focuses on recovery, communication, and resilience upgrades.

On May 12, 2025, a significant power outage disrupted the London Underground during the afternoon rush hour, affecting thousands of commuters across the city. The incident highlighted vulnerabilities in the city's transport infrastructure, echoing a morning outage in London reported earlier, and raised concerns about the resilience of urban utilities.

The Outage and Its Immediate Impact

The power failure occurred around 2:30 PM, leading to widespread service suspensions and delays on several key Tube lines. The Bakerloo and Waterloo & City lines were completely halted, while the Jubilee line experienced disruptions between London Bridge and Finchley Road. The Northern line was also suspended between Euston and Kennington, as well as south of Stockwell. Additionally, Elizabeth Line services between Abbey Wood and Paddington were suspended. Some stations were closed for safety reasons due to the lack of power.

Commuters faced severe delays, with many stranded in tunnels or on platforms. The lack of information and communication added to the confusion, as passengers were left uncertain about the cause and duration of the disruptions.

Cause of the Power Failure

Transport for London (TfL) attributed the outage to a brief fault in the National Grid's transmission network. Although the fault was resolved within seconds, it caused a voltage dip that affected local distribution networks, leading to the power loss in the Underground system.

The incident underscored the fragility of the city's transport infrastructure, particularly the aging electrical and signaling systems that are vulnerable to such faults, as well as weather-driven events like a major windstorm outage that can trigger cascading failures. While backup systems exist, their capacity to handle sudden disruptions remains a concern.

Broader Implications for Urban Infrastructure

This power outage is part of a broader pattern of infrastructure challenges facing London. In March 2025, a fire at an electrical substation in Hayes led to the closure of Heathrow Airport, affecting over 200,000 passengers, while similar disruptions at BWI Airport have underscored aviation vulnerabilities. These incidents have prompted discussions about the resilience of the UK's energy and transport networks.

Experts argue that aging infrastructure, coupled with increasing demand and climate-related stresses, poses significant risks to urban operations, as seen in a North Seattle outage and in Toronto storm-related outages that tested local grids. There is a growing call for investment in modernization and diversification of energy sources to ensure reliability and sustainability.

TfL's Response and Recovery Efforts

Following the outage, TfL worked swiftly to restore services. By 11 PM, all but one line had resumed operations, with only the Elizabeth Line continuing to experience severe delays. TfL officials acknowledged the inconvenience caused to passengers and pledged to investigate the incident thoroughly, similar to the Atlanta airport blackout inquiry conducted after a major outage, to prevent future occurrences.

In the aftermath, TfL emphasized the importance of clear communication with passengers during disruptions and committed to enhancing its contingency planning and infrastructure resilience.

Public Reaction and Ongoing Concerns

The power outage sparked frustration among commuters, many of whom took to social media to express their dissatisfaction, echoing sentiments during Houston's extended outage about communication gaps and delays. Some passengers reported being trapped in tunnels for extended periods without clear guidance from staff.

The incident has reignited debates about the adequacy of London's transport infrastructure and the need for comprehensive upgrades. While TfL has initiated reviews and improvement plans, the public remains concerned about the potential for future disruptions and the city's preparedness to handle them.

The May 12 power outage serves as a stark reminder of the vulnerabilities inherent in urban infrastructure. As London continues to grow and modernize, ensuring the resilience of its transport and energy networks will be crucial. This includes investing in modern technologies, enhancing communication systems, and developing robust contingency plans to mitigate the impact of future disruptions. For now, Londoners are left reflecting on the lessons learned from this incident and hoping for a more reliable and resilient transport system in the future.

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California Battery Storage is transforming grid reliability as distributed energy, solar-plus-storage, and demand response mitigate rolling blackouts, replace peaker plants, and supply flexible capacity during heat waves and evening peaks across utilities and homes.

Key Points

California Battery Storage uses distributed and utility batteries to stabilize power, shift solar, and curb blackouts.

✅ Supplies flexible capacity during peak demand and heat waves

✅ Enables demand response and replaces gas peaker plants

✅ Aggregated assets form virtual power plants for grid support

Last month as a heat wave slammed California, state regulators sent an email to a group of energy executives pleading for help to keep the lights on statewide. “Please consider this an urgent inquiry on behalf of the state,” the message said.

The manager of the state’s grid was struggling to increase the supply of electricity because power plants had unexpectedly shut down and demand was surging. The imbalance was forcing officials to order rolling blackouts across the state for the first time in nearly two decades.

What was unusual about the emails was whom they were sent to: people who managed thousands of batteries installed at utilities, businesses, government facilities and even homes. California officials were seeking the energy stored in those machines to help bail out a poorly managed grid and reduce the need for blackouts.

Many energy experts have predicted that batteries could turn homes and businesses into mini-power plants that are able to play a critical role in the electricity system. They could soak up excess power from solar panels and wind turbines and provide electricity in the evenings when the sun went down or after wildfires and hurricanes, which have grown more devastating because of climate change in recent years. Over the next decade, the argument went, large rows of batteries owned by utilities could start replacing power plants fueled by natural gas.

But that day appears to be closer than earlier thought, at least in California, which leads the country in energy storage. During the state’s recent electricity crisis, more than 30,000 batteries supplied as much power as a midsize natural gas plant. And experts say the machines, which range in size from large wall-mounted televisions to shipping containers, will become even more important because utilities, businesses and homeowners are investing billions of dollars in such devices.

“People are starting to realize energy storage isn’t just a project or two here or there, it’s a whole new approach to managing power,” said John Zahurancik, chief operating officer at Fluence, which makes large energy storage systems bought by utilities and large businesses. That’s a big difference from a few years ago, he said, when electricity storage was seen as a holy grail — “perfect, but unattainable.”

On Friday, Aug. 14, the first day California ordered rolling blackouts, Stem, an energy company based in the San Francisco Bay Area, delivered 50 megawatts — enough to power 20,000 homes — from batteries it had installed at businesses, local governments and other customers. Some of those devices were at the Orange County Sanitation District, which installed the batteries to reduce emissions by making it less reliant on natural gas when energy use peaks.

John Carrington, Stem’s chief executive, said his company would have provided even more electricity to the grid had it not been for state regulations that, among other things, prevent businesses from selling power from their batteries directly to other companies.

“We could have done two or three times more,” he said.

The California Independent System Operator, which manages about 80 percent of the state’s grid, has blamed the rolling blackouts on a confluence of unfortunate events, including extreme weather impacts on the grid that limited supply: A gas plant abruptly went offline, a lack of wind stilled thousands of turbines, and power plants in other states couldn’t export enough electricity. (On Thursday, the grid manager urged Californians to reduce electricity use over Labor Day weekend because temperatures are expected to be 10 to 20 degrees above normal.)

But in recent weeks it has become clear that California’s grid managers also made mistakes last month, highlighting the challenge of fixing California’s electric grid in real time, that were reminiscent of an energy crisis in 2000 and 2001 when millions of homes went dark and wholesale electricity prices soared.

Grid managers did not contact Gov. Gavin Newsom’s office until moments before it ordered a blackout on Aug. 14. Had it acted sooner, the governor could have called on homeowners and businesses to reduce electricity use, something he did two days later. He could have also called on the State Department of Water Resources to provide electricity from its hydroelectric plants.

Weather forecasters had warned about the heat wave for days. The agency could have developed a plan to harness the electricity in numerous batteries across the state that largely sat idle while grid managers and large utilities such as Pacific Gas & Electric scrounged around for more electricity.

That search culminated in frantic last-minute pleas from the California Public Utilities Commission to the California Solar and Storage Association. The commission asked the group to get its members to discharge batteries they managed for customers like the sanitation department into the grid. (Businesses and homeowners typically buy batteries with solar panels from companies like Stem and Sunrun, which manage the systems for their customers.)

“They were texting and emailing and calling us: ‘We need all of your battery customers giving us power,’” said Bernadette Del Chiaro, executive director of the solar and storage association. “It was in a very last-minute, herky-jerky way.”

At the time of blackouts on Aug. 14, battery power to the electric grid climbed to a peak of about 147 megawatts, illustrating how virtual power plants can rapidly scale, according to data from California I.S.O. After officials asked for more power the next day, that supply shot up to as much as 310 megawatts.

Had grid managers and regulators done a better job coordinating with battery managers, the devices could have supplied as much as 530 megawatts, Ms. Del Chiaro said. That supply would have exceeded the amount of electricity the grid lost when the natural gas plant, which grid managers have refused to identify, went offline.

Officials at California I.S.O. and the public utilities commission said they were working to determine the “root causes” of the crisis after the governor requested an investigation.

Grid managers and state officials have previously endorsed the use of batteries, using AI to adapt as they integrate them at scale. The utilities commission last week approved a proposal by Southern California Edison, which serves five million customers, to add 770 megawatts of energy storage in the second half of 2021, more than doubling its battery capacity.

And Mr. Zahurancik’s company, Fluence, is building a 400 megawatt-hour battery system at the site of an older natural gas power plant at the Alamitos Energy Center in Long Beach. Regulators this week also approved a plan to extend the life of the power plant, which was scheduled to close at the end of the year, to support the grid.

But regulations have been slow to catch up with the rapidly developing battery technology.

Regulators and utilities have not answered many of the legal and logistical questions that have limited how batteries owned by homeowners and businesses are used. How should battery owners be compensated for the electricity they provide to the grid? Can grid managers or utilities force batteries to discharge even if homeowners or businesses want to keep them charged up for their own use during blackouts?

During the recent blackouts, Ms. Del Chiaro said, commercial and industrial battery owners like Stem’s customers were compensated at the rates similar to those that are paid to businesses to not use power during periods of high electricity demand. But residential customers were not paid and acted “altruistically,” she said.

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Florida Hurricane Irma Power Outages strain the grid as utilities plan rebuilds; FPL and Duke Energy deploy crews to restore transmission lines, substations, and service amid flooding, storm surge, and widespread disruptions statewide.

Key Points

Large-scale post-storm power losses in Florida requiring grid rebuilds, thousands of crews, and phased restoration.

✅ Utilities prioritize plants, transmission, substations, then critical facilities

✅ 50,000-60,000 workers mobilized; bucket trucks wait for safe winds

✅ Remote rerouting and hardening aid faster restoration amid flooding

Parts of Florida could be without electricity for more than a week, as damage from Hurricane Irma will require a complete rebuild of portions of the electricity grid, utility executives said on Monday.

Irma has knocked out power to 6.5 million Florida electricity customers, or nearly two-thirds of the state, since making landfall this weekend. In major areas such as Miami-Dade, 74 percent of the county was without power, according to Florida's division of emergency management.

Getting that power back online may require the help of 50,000 to 60,000 workers from all over the United States and Canadian power crews as well, according to Southern Company CEO and Chairman Thomas Fanning. He is also co-chair of the Electricity Subsector Coordinating Council, which coordinates the utility industry and government response to disasters and cyberthreats.

While it is not uncommon for severe storms to down power lines and damage utility poles, Irma's heavy winds and rain batted some of the state's infrastructure to the ground, Fanning said.

"'Restore' may not capture the full sense of where we are. For the very hard impacted areas, I think you're in a 'rebuild' area," he told CNBC's "Squawk Box."

"That's a big deal. People need to understand this is going to take perhaps weeks, not days, in some areas," Fanning said.

Parts of northern Florida, including Jacksonville, experienced heavy flooding, which will temporarily prevent crews from accessing some areas.

Duke Energy, which serves 1.8 million customers in parts of central and northwestern Florida, is trying to restore service to 1.2 million residences and businesses.

Florida Power & Light Company, which provides power to an estimated 4.9 million accounts across the state, had about 3.5 million customers without electricity as of Monday afternoon, said Rob Gould, vice president and chief communications officer at FPL.

The initial damage assessments suggest power can be restored to parts of the state's east coast in just days, but some of the west coast will require rebuilding that could stretch out for weeks, Gould told CNBC's "Power Lunch."

"This is not a typical restoration that you're going to see. We actually for the first time in our company history have our entire 27,000-square-mile, 35-county territory under assault by Irma," he said.

FPL said it would first repair any damage to power plants, transmission lines and substations as part of its massive response to Irma, then prioritize critical facilities such as hospitals and water treatment plants. The electricity company would then turn its attention to areas that are home to supermarkets, gas stations and other community services.

Florida utilities invested billions into their systems after devastating hurricane seasons in 2004 and 2005 in order to make them more resilient and easier to restore after a storm. Irma, which ranked among the most powerful storms in the Atlantic, has nevertheless tested those systems.

The upgrades have allowed FPL to automatically reroute power and address about 1.5 million outages, Gould said. The company strategically placed 19,500 restoration workers before the storm hit, but it cannot use bucket trucks to fix power lines until winds die down, he said.

Some parts of Florida's distribution system — the lines that deliver electricity from power plants to businesses and residences — run underground. However, the state's long coastline and the associated danger of storm surge and seawater incursion make it impractical to run lines beneath the surface in some areas.

Duke Energy has equipped 28 percent of its system with smart grid technology to reroute power remotely, according to Harry Sideris, Duke's state president for Florida. He said the company would continue to build out that capability in the future.

Duke deployed more than 9,000 linesmen and support crew members to Irma-struck areas, but cannot yet say how long some customers will be without power.

Separately, Gulf Power crews reported restoring service to more than 32,000 customers.

"At this time we do not know the exact restoration times. However, we're looking at a week or longer from the first look at the widespread damage that we had," Sideris told CNBC's "Closing Bell."

FPL said on Monday it was doing final checks before bringing back nuclear reactors that were powered down as Hurricane Irma hit Florida.

"We are in the process now of doing final checks on a few of them; we will be bringing those up," FPL President and CEO Eric Silagy told reporters.

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