Faulty work blamed for Reactor shutdown

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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Ontario Electricity Pricing Pilot Projects explore alternative rates beyond time-of-use, with LDCs and the Ontario Energy Board testing dynamic pricing, demand management, smart-meter billing, and residential customer choice to enhance service and energy efficiency.

Key Points

Ontario LDC trials testing alternatives to time-of-use rates to improve billing, demand response, and efficiency.

✅ Data shared across LDCs and Ontario Energy Board provincewide

✅ Tests dynamic pricing, peak/off-peak plans, demand management

✅ Insights to enhance customer choice, bills, and energy savings

The results from three electricity pilot projects being offered in southern Ontario will be valuable to utility companies across the province.

Ontario Energy Minister Glenn Thibeault was in Barrie on Tuesday to announce the pilot projects, which will explore alternative pricing plans for electricity customers from three different utility companies, informed by the electricity cost allocation framework guiding rate design.

"Everyone in the industry is watching to see how the pilots deliver.", said Wendy Watson, director of communications for Greater Sudbury Utilities.

"The data will be shared will all the LDCs [local distribution companies] in the province, and probably beyond...because the industry tends to share that kind of information."

Most electricity customers in the province are billed using time-of-use rates, including options like the ultra-low overnight rates that lower costs during off-peak periods, where the cost of electricity varies depending on demand.

The Ontario Energy Board said in a media release that the projects will give residential customers more choice in how much they pay for electricity at different times, reflecting changes for Ontario electricity consumers that expand plan options.

Pilot projects can help improve service

Watson says these kinds of projects give LDCs the chance to experiment and explore new ways of delivering their service, including demand-response initiatives like the Peak Perks program that encourage conservation.

"Any pilot project is a great way to see if in practice if the theory proves out, so I think it's great that the province is supporting these LDCs," she says.

GSU recently completed its own pilot project, the Home Energy Assessment and Retrofit (HEAR) program, which focused on customers who use electric baseboards to heat their homes, amid broader provincial support for electric bills to ease costs."We installed some measures, like programmable thermostats and a few other pieces of equipment into their house," Watson says. "We also made some recommendations about other things that they could do to make their homes more energy efficient."

At the end of the program, GSU provided customers with a report so that they could the see the overall impact on their energy consumption.

Watson says a report on the results of the HEAR program will be released in the near future, for other LDCs interested in new ways to improve their service.

"We think it's incumbent on every LDC...to see what ideas that they can come up with and get approved so they can best serve their customers."

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US SF6 Emissions Decline as NOAA analysis and EPA mitigation show progress, with atmospheric measurements and Greenhouse Gas Reporting verifying reductions from the electric power grid; sulfur hexafluoride's extreme global warming potential underscores inventory improvements.

Key Points

A documented drop in US sulfur hexafluoride emissions, confirmed by NOAA atmospheric data and EPA reporting reforms.

✅ NOAA towers and aircraft show 2007-2018 decline

✅ EPA reporting and utility mitigation narrowed inventory gaps

✅ Winter leaks and servicing signal further reduction options

A new NOAA analysis shows U.S. emissions of the super-potent greenhouse gas sulfur hexafluoride (SF6) have declined between 2007-2018, likely due to successful mitigation efforts by the Environmental Protection Agency (EPA) and the electric power industry, with attention to SF6 in the power industry across global markets. 

At the same time, significant disparities that existed previously between NOAA’s estimates, which are based on atmospheric measurements, and EPA’s estimates, which are based on a combination of reported emissions and industrial activity, have narrowed following the establishment of the EPA's Greenhouse Gas Reporting Program. The findings, published in the journal Atmospheric Chemistry and Physics, also suggest how additional emissions reductions might be achieved. 

SF6 is most commonly used as an electrical insulator in high-voltage equipment that transmits and distributes electricity, and its emissions have been increasing worldwide as electric power systems expand, even as regions hit milestones like California clean energy surpluses in recent years. Smaller amounts of SF6 are used in semiconductor manufacturing and in magnesium production. 

SF6 traps 25,000 times more heat than carbon dioxide over a 100-year time scale for equal amounts of emissions, and while CO2 emissions flatlined in 2019 globally, that comparison underscores the potency of SF6. That means a relatively small amount of the gas can have a significant impact on climate warming. Because of its extremely large global warming potential and long atmospheric lifetime, SF6 emissions will influence Earth’s climate for thousands of years.

In this study, researchers from NOAA’s Global Monitoring Laboratory, as record greenhouse gas concentrations drive demand for better data, working with colleagues at EPA, CIRES, and the University of Maryland, estimated U.S. SF6 emissions for the first time from atmospheric measurements collected at a network of tall towers and aircraft in NOAA’s Global Greenhouse Gas Reference Network. The researchers provided an estimate of SF6 emissions independent from the EPA’s estimate, which is based on reported SF6 emissions for some industrial facilities and on estimated SF6 emissions for others.

“We observed differences between our atmospheric estimates and the EPA’s activity-based estimates,” said study lead author Lei Hu, a Global Monitoring Laboratory researcher who was a CIRES scientist at the time of the study. “But by closely collaborating with the EPA, we were able to identify processes potentially responsible for a significant portion of this difference, highlighting ways to improve emission inventories and suggesting additional emission mitigation opportunities, such as forthcoming EPA carbon capture rules for power plants, in the future.” 

In the 1990s, the EPA launched voluntary partnerships with the electric power, where power-sector carbon emissions are falling as generation shifts, magnesium, and semiconductor industries to reduce SF6 emissions after the United States recognized that its emissions were significant. In 2011, large SF6 -emitting facilities were required to begin tracking and reporting their emissions under the EPA Greenhouse Gas Reporting Program. 

Hu and her colleagues documented a decline of about 60 percent in U.S. SF6 emissions between 2007-2018, amid global declines in coal-fired power in some years—equivalent to a reduction of between 6 and 20 million metric tons of CO2 emissions during that time period—likely due in part to the voluntary emission reduction partnerships and the EPA reporting requirement. A more modest declining trend has also been reported in the EPA’s national inventories submitted annually under the United Nations Framework Convention on Climate Change. 

Examining the differences between the NOAA and EPA independent estimates, the researchers found that the EPA’s past inventory analyses likely underestimated SF6 emissions from electrical power transmission and distribution facilities, and from a single SF6 production plant in Illinois. According to Hu, the research collaboration has likely improved the accuracy of the EPA inventories. The 2023 draft of the EPA’s U.S. Greenhouse Gas Emissions and Sinks: 1990-2021 used the results of this study to support revisions to its estimates of SF6 emissions from electrical transmission and distribution. 

The collaboration may also lead to improvements in the atmosphere-based estimates, helping NOAA identify how to expand or rework its network to better capture emitting industries or areas with significant emissions, according to Steve Montzka, senior scientist at GML and one of the paper’s authors.

Hu and her colleagues also found a seasonal variation in SF6 emissions from the atmosphere-based analysis, with higher emissions in winter than in summer. Industry representatives identified increased servicing of electrical power equipment in the southern states and leakage from aging brittle sealing materials in the equipment in northern states during winter as likely explanations for the enhanced wintertime emissions—findings that suggest opportunities for further emissions reductions.

“This is a great example of the future of greenhouse gas emission tracking, where inventory compilers and atmospheric scientists work together to better understand emissions and shed light on ways to further reduce them,” said Montzka.

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Denmark 2019 electricity CO2 intensity shows record-low emissions as renewable energy surges, wind power dominates, offshore wind expands, and coal phase-out accelerates Denmark's energy transition and grid decarbonization, driven by higher CO2 prices and flexibility.

Key Points

It is 135 g CO2/kWh, a record low enabled by wind power growth, offshore wind, and a sharp coal decline.

✅ Average emissions fell to 135 g CO2/kWh, the lowest on record

✅ Wind and solar supplied 49.9% of national electricity use

✅ Coal consumption dropped 46% as CO2 allowance prices rose

Danish electricity producers set a new green record in 2019, when an average produced kilowatt-hour emitted 135 gr CO2 / kWh.

It is the lowest CO2 emission ever measured in Denmark and about one-seventh of what the electricity producers emitted in 1990.

Never has a kilowatt-hour produced emitted as little CO2 as it did in 2019. And that's according to Energinet's recently published annual Environmental Report on Danish electricity generation and cogeneration, two primary causes.

One reason is that more green power has been produced because the Horns Rev 3 offshore wind farm, which can produce electricity for 425,000 households, was commissioned in 2019. The other is that Danish coal consumption fell by 46 percent from 2018 to 2019, as coal phase-out plans gathered pace across the sector. the dramatic decline in coal consumption is partly due a significant increase in the price of CO2 quotas, and thus also the price of CO2 emissions.

'Historically, 135 gr CO2 / kWh is a really, really low figure, showing the impressive green travel that the Danish electricity system has been on. In 1990, a kilowatt-hour produced emitted over 1000 grams of CO2, ie about seven times as much as today, 'says Hanne Storm Edlefsen, area manager in Energinet Power Systems Responsibility.

Wind energy is the dominant form of electricity generation in Denmark, a pattern the UK wind beat coal in 2016 when shifting away from fossil fuels.

17.1 TWh. Danish wind turbines and solar cells generated so much electricity in 2019, corresponding to 49.9 per cent. of Danish electricity consumption, reflecting broader EU wind and solar growth trends as well. An increase of 15 per cent. The wind turbines alone produced 16 TWh, which is not only a new green record, but also puts a thick line that wind energy is by far the most dominant form of electricity generation in Denmark.

'Thanks to our large wind resources, turbines are by far the largest supplier of renewable energy in Denmark, and this will be for many years to come. The large price drop in new wind energy in recent years - for both onshore and offshore winds - will ensure that wind energy will drive a large part of the growth in renewable energy in the coming years, as new wind generation records are set in markets like the UK, 'says Soren Klinge, electricity market manager at Wind Denmark.

Conversely, total electricity generation from fossil and bio-based fuels decreased by 26 PJ (petajoule ed.), Corresponding to 34 per cent. from 2018 to 2019, mirroring renewables overtaking coal in Germany. Nevertheless, net electricity generation was just under 30 TWh both years.

'It is worth noting that while fossil fuels are being phased out, Denmark maintains its annual net production of electricity. The green, so to speak, replaces the black. It once again underpins that green conversion, high security of supply and an affordable electricity price can go hand in hand, 'says Hanne Storm Edlefsen.

Danish power system is ready for a green future

Including trade in electricity with neighboring countries, 1 kWh in a Danish outlet generates 145 gr CO2 / kWh.

'There has been a very significant development in the Danish electricity system in recent years, where the electricity system can now be operated solely on the renewable energy. It is a remarkable development, also from an international perspective where low-carbon progress stalled in the UK in 2019, that one would not have thought possible for just a few years ago, 'he says.

More than expected have phased out coal

The electricity from the Danish sockets will be greener , predicts Energinet's environmental report , which expects CO2 intensity in the coming years. This is explained by an expectation of increased electrification of energy consumption, together with a continued expansion with wind and solar.

'Wind energy is the cornerstone of the green transition. With the commissioning of the Kriegers Flak offshore wind farm and several major onshore wind turbine projects within the next few years, we can well expect that only the wind's share of electricity consumption will exceed 50 per cent hopefully as early as 2021,' concludes Soren Klinge.

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Barakah Unit 4 Cold Hydrostatic Testing validates reactor coolant system integrity at the Barakah Nuclear Energy Plant in Abu Dhabi, UAE, confirming safety, quality, and commissioning readiness under ENEC and KEPCO oversight.

Key Points

Pressure test of Unit 4's reactor coolant system, confirming integrity and safety for commissioning at Barakah.

✅ 25% above normal operating pressure verified.

✅ Welds, joints, and high-pressure components inspected.

✅ Supports safe, reliable, emissions-free baseload power.

The Emirates Nuclear Energy Corporation (ENEC) has successfully completed Cold Hydrostatic Testing (CHT) at Unit 4 of the Barakah Nuclear Energy Plant, the Arab world’s first nuclear energy plant being built in the Al Dhafra region of Abu Dhabi, UAE. The testing incorporated the lessons learned from the previous three units and is a crucial step towards the completion of Unit 4, the final unit of the Barakah plant.

As a part of CHT, the pressure inside Unit 4’s systems was increased to 25 per cent above what will be the normal operating pressure, demonstrating, as seen across global nuclear projects, the quality and robust nature of the Unit’s construction. Prior to the commencement of CHT, Unit 4’s Nuclear Steam Supply Systems were flushed with demineralised water, and the Reactor Pressure Vessel Head and Reactor Coolant Pump Seals were installed. During the Cold Hydrostatic Testing, the welds, joints, pipes and components of the reactor coolant system and associated high-pressure systems were verified.

Mohammed Al Hammadi, Chief Executive Officer of ENEC said: “I am proud of the continued progress being made at Barakah despite the circumstances we have all faced in relation to COVID-19. The UAE leadership’s decisive and proactive response to the pandemic supported us in taking timely, safety-led actions to protect the health and safety of our workforce and our plant. These actions, alongside the efforts of our talented and dedicated workforce, have enabled the successful completion of CHT at Unit 4, which was completed in adherence to the highest standards of safety, quality, and security.

“With this accomplishment, we move another step closer to achieving our goal of supplying up to a quarter of our nation’s electricity needs through the national grid and powering its future growth with safe, reliable, and emissions-free electricity,” he added.

By the end of 2019, ENEC and Korea Electric Power Corporation (KEPCO), working with Korea Hydro & Nuclear Power (KHNP) on the project, had successfully completed all major construction work including major concrete pouring, installation of the Turbine Generator, and the internal components of the Reactor Pressure Vessel (RPV) of Unit 4, which paved the way for the commencement of testing and commissioning.

The testing at Unit 4 represents a significant achievement in the development of the UAE Peaceful Nuclear Energy Program, following the successful completion of fuel assembly loading into Unit 1 in March 2020, confirming that the UAE has officially become a peaceful nuclear energy operating nation. Preparations are now in the final stages for the safe start-up of Unit 1, which subsequently reached 100% power ahead of commercial operations, in the coming months.

ENEC is currently in the final stages of construction of units 2, 3 and 4 of the Barakah Nuclear Energy Plant, as China’s nuclear program continues its steady development globally. The overall construction of the four units is more than 94% complete. Unit 4 is more than 84 per cent, Unit 3 is more than 92 per cent and Unit 2 is more than 95 per cent. The four units at Barakah will generate up to 25 per cent of the UAE’s electricity demand by producing 5,600 MW of clean baseload electricity, as projects such as new reactors in Georgia take shape, and preventing the release of 21 million tons of carbon emissions each year – the equivalent of removing 3.2 million cars off the roads annually.

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Nova Scotia Power Rate Regulation explains how the privately owned utility is governed by the Utility Review Board, limiting government authority, while COVID-19 relief measures include suspended disconnections, waived fees, payment plans, and emergency assistance.

Key Points

URB oversight where the board, not the province, sets power rates, with COVID-19 relief pausing disconnections and fees.

✅ Province lacks authority to order rate cuts

✅ URB regulates Nova Scotia Power rates

✅ Relief: no disconnections, waived fees, payment plans

The province can't ask Nova Scotia Power to lower its rates to ease the financial pressure on out-of-work residents because it lacks the authority to take that kind of action, even as the Nova Scotia regulator approved a 14% hike in a separate proceeding, the provincial energy minister said Thursday.

Derek Mombourquette said he is in "constant contact" with the privately owned utility.

"The conversations are ongoing with Nova Scotia Power," he said after a cabinet meeting.

When asked if the Liberal government would order the utility to lower electricity rates as households and businesses struggle with the financial fallout from the COVID-19 pandemic, Mombourquette said there was nothing he could do.

"We don't have the regulatory authority as a government to reduce the rates," he told reporters during a conference call.

"They're independent, and they are regulated through the (Nova Scotia Utility Review Board). My conversations with Nova Scotia Power essentially have been to do whatever they can to support Nova Scotians, whether it's residents or businesses in this very difficult time."

Asked if the board would take action, the minister said: "I'm not aware of that," despite the premier's appeals to regulators in separate rate cases.

However, the minister noted that the utility, owned by Emera Inc., has suspended disconnections for bill non-payment for at least 90 days, a step similar to reconnection efforts by Hydro One announced in Ontario.

It has also relaxed payment timelines and waived penalties and fees, while some jurisdictions offered lump-sum credits to help with bills.

Nova Scotia Power CEO Wayne O'Connor has also said the company is making additional donations to a fund available to help low-income individuals and families pay their energy bills.

In late March, Ontario cut electricity rates for residential consumers, farms and small businesses in response to a surge in people forced to work from home as a result of the pandemic, alongside bill support measures for ratepayers.

Premier Doug Ford said there would be a 45-day switch to off-peak rates, later moving to a recovery rate framework, which meant electricity consumers would be paying the lowest rate possible at any time of day.

The change was expected to cost the province about $162 million.

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