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IAEA Report on Nuclear Energy for a Net Zero World

Dan Yurman's picture
Editor & Publisher NeutronBytes, a blog about nuclear energy

Publisher of NeutronBytes, a blog about nuclear energy online since 2007.  Consultant and project manager for technology innovation processes and new product / program development for commercial...

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  • Oct 15, 2021

The report is released ahead of the COP26 Climate Summit

iaea logoAhead of the COP26 climate summit, the IAEA has released Nuclear Energy for a Net Zero World. The special report  (Full Text 73 page PDF) highlights nuclear power’s critical role in achieving the goals of the Paris Agreement and Agenda 2030 for Sustainable Development by the following actions.

  • displacing coal and other fossil fuels,
  • enabling the further deployment of renewable energy and
  • becoming an economical source for large amounts of clean hydrogen.

As government, business and societal leaders from around the world prepare to gather at the UN Climate Change Conference in Glasgow on 31 October-12 November, the IAEA report lays out the reasons why nuclear must have a seat at the table whenever energy and climate policies are discussed.

In addition, nine countries—Canada, China, Finland, France, Japan, Poland, Russia, the United States and the United Kingdom—provided statements in the report in support of its findings on nuclear power’s contributions to climate action.

Marking the launch of the report, IAEA Director General Rafael Mariano Grossi said “Over the past five decades, nuclear power has cumulatively avoided the emission of about 70 gigatonnes (Gt) of carbon dioxide (CO2) and continues to avoid more than 1 Gt CO2 annually,”

“As we head toward (COP26), it is time to make evidence-based decisions and ramp up the investment in nuclear. The cost of not doing so is far too high to bear.”

The report demonstrates how nuclear power is vital for achieving the goal of net zero greenhouse gas emissions by ensuring 24/7 energy supply, which provides stability and resilience to electrical grids and facilitates the wider integration of variable renewables such as wind and solar needed to drive the clean energy transition.

Replace Coal / Make “Green Hydrogen”

In addition, nuclear power as a firm source of low carbon electricity is well suited to replace coal and other fossil fuels while also providing heat and hydrogen to decarbonize hard-to-abate sectors such as industry and transportation. As such, nuclear power represents one of the most effective investments for the post-pandemic global economic recovery, contributing directly to UN Sustainable Development goals on energy, economic expansion and climate action.

nuclear and hydrogen

A key topic at COP26 will be accelerating the transition from coal. According to the report, replacing 20% of coal generation with 250 GW of nuclear generation would reduce emissions by 2 Gt CO2, or around 15% of electricity sector emissions per year. Nuclear power can also substitute coal-fired boilers for district heating and industry.

Abundant CO2 Emission Free Energy Drives Economic Growth

The report also outlines how nuclear power can be a significant driver of economic growth, generating jobs in many sectors and enabling a just transition to clean energy. Nuclear power, with a 10% share of global electricity generation, already provides over 800 000 jobs.

process heat rs

International Monetary Fund estimates show that investments in nuclear power generate a larger economic impact than those in other forms of energy, making it among the most effective actions for a sustainable economic recovery as well as the transition to a resilient net zero energy system.

Partnership with Renewables

Nuclear power’s partnership with renewables will be key to driving emissions to net zero, according to the report. Because it is dispatchable, low emission, flexible and reliable, nuclear power can underpin net zero energy mixes based on electricity, while also helping to lower the costs of the overall electricity generating system. Baseload power from nuclear plants stabilize the grid for use by intermittent sources like solar and wind.

Process Heat for Industry

Non-power sectors including steel, cement and chemical production, shipping and air transport—which together account for around 60% of energy-related global emissions—will require the deployment of heat or energy carriers such as hydrogen which must be produced with a low carbon footprint. Nuclear energy can provide low carbon heat and be used to produce hydrogen, particularly with high-temperature reactors currently under development.

Resilience Grids Based on Distributed Small Modular Reactors

The report underscores how resilient energy systems will rely on the robustness of individual generation technologies, grid infrastructure and demand side measures. A distributed fleet of small modular reactors (SMRs) is ideal for this reasons for some nations that are not positioned to develop large reactor power stations, e.g., 1000  MWe/unit.

Reliability in the Face of Extreme Weather

The nuclear sector is well prepared to face the challenges posed by climate change including the risks of more frequent and more extreme weather events and has developed specific adaptation measures to mitigate these risks.

While the frequency of weather-related outages at nuclear power plants has increased over the last 30 years, total production losses were minor, with reduced losses over the past decade, according to data from the IAEA’s Power Reactor Information System.

Action Item List for COP26

The publication recommends a series of actions aimed at accelerating the wider deployment of nuclear power, including:

  • Introduce carbon pricing and measures to value low-carbon energy
  • Adopt objective and technology neutral frameworks for low carbon investments
  • Ensure markets, regulations and policies value and remunerate nuclear energy’s contribution to reliable and resilience low-carbon energy systems
  • Boost public investment and support for private investment in nuclear power, including reactor lifetime extensions, as part of “green deal” and recovery packages
  • Promote diversified electricity systems to mitigate climate risks to energy infrastructure, ensuring the continuity and quality of electricity services

“The task ahead of us — limiting global average temperature rise to 1.5°C and achieving net zero emissions by 2050 — is a formidable challenge and an immense economic opportunity,” John Kerry, Special Presidential Envoy for Climate for the United States of America, said in his statement for the IAEA report.

“The global clean energy transition will require deploying, at massive scale, the full range of clean energy technologies, including nuclear energy, over the next decade and beyond.”

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Bob Meinetz's picture
Bob Meinetz on Oct 15, 2021

Dan, assuming we can consider hydrogen a "fuel", its energy density is the lowest (by volume) of any production fuel in the world. It must be compressed (to ~10,000 psi) or refrigerated (to -423°F) to turn it into liquid fuel that can be shipped or transported. Either process eats up at least one-third of the potential energy in H2 itself. Pipelines leak gaseous hydrogen, with the smallest, lightest atom of all, like sieves.

Hydrogen has only become a fuel as a result of marketing from oil & gas companies. In the 1990s they saw the writing on the wall - the days of gasoline were numbered - and began considering ways oil or gas could be marketed as a clean fuel. If they stripped hydrogen from natural gas then dumped the leftover carbon into the air at a refinery, the thinking was, the only exhaust customers would see emanating from the tailpipes of their fuel-cell vehicles was water. Hence hydrogen, as a fuel. Hence fuel-cell vehicles, as automobiles.

I have to wonder when I see natural gas and coal being used as feedstocks for hydrogen production in a diagram from...the National Renewable Energy Laboratory (above)?. Again: the only reason hydrogen can be considered a viable fuel is that $billions have been invested by oil majors to invent a revenue stream for natural gas.

Nuclear energy can provide an abundant source of electricity for making green hydrogen from water (especially HTGRs, which have proven remarkably efficient at it). But why enable a revenue stream for natural gas? From an environmental standpoint, we'd be far better off combining green hydrogen with captured carbon, using Fisher-Tropsch powered by nuclear electricity, to make carbon-neutral, synthetic gasoline that can be used in cars already on U.S. highways.

Such a proposal was investigated by MIT's Center for Advanced Nuclear Energy Systems (CANES) in 2007. A study estimated 650 GW of nuclear capacity could generate enough liquid fuel to replace all liquid hydrocarbon fuels in the U.S. Granted, that's ~seven times more capacity than currently exists. But any all-hands-on-deck effort at addressing climate change should at least have that option on the table.

Michael Keller's picture
Michael Keller on Oct 25, 2021

From a practicality standpoint, combustion turbines can relatively easily operate with about 30% hydrogen. That translates to CO2 emissions roughly around 25% those associated with a combined cycle plant using natural gas.

Nuclear power plants are not efficient at producing hydrogen, particularly when considering the plants low efficiency (little over 30 %) and low steam temperatures. By contrast, the combined cycle plants are significantly better in terms of both efficiency and steam temperatures.

in general, conventional nuclear power plants are better suited for base-load power production. Also, while High Temperature Gas Reactors (HTGR’s) run at much higher temperatures than conventional water reactors, using those high temperatures is technically very challenging.

A practical and economic approach is to use partially hydrogen fired combustion turbines for hydrogen production. The CO2 emissions are quite low (potentially approaching zero). The combined-cycle machines are much better suited for hydrogen production than conventional nuclear plants. The combined-cycle plants are also routinely located near and in urban areas, simplifying hydrogen distribution.  Nuclear plants are remotely located.

Bob Meinetz's picture
Bob Meinetz on Oct 25, 2021

"A practical and economic approach is to use partially hydrogen fired combustion turbines for hydrogen production."

"Burn hydrogen to make hydrogen"? Now I've heard it all.

Thermodynamics 101: Energy cannot be created nor destroyed (translation: you can't pull energy out of thin air). Your process is a prescription for wasting energy.

If we needed hydrogen as a fuel, it would be more efficient to burn 100% gas to make it. But we don't.

Michael Keller's picture
Michael Keller on Oct 27, 2021

The surplus/I’ll-timed green energy provides a lot of the energy for hydrogen production that is stored for use during evening grid peaks. Does it make sense from a thermodynamic standpoint? Nope,  which is a statement also applicable for most hydrogen production and green energy.

Steam methane production is vastly more economic for chemical production processes that requires hydrogen.

The idea is to make money from the semi-dopey drive to create green hydrogen. Never said it made much sense from an economic standpoint

Dan Yurman's picture
Dan Yurman on Oct 26, 2021

Most hydrogen produced today in the United States is made via steam-methane reforming, a mature production process in which high-temperature steam (700°C–1,000°C) is used to produce hydrogen from a methane source, such as natural gas.   The temperature of steam (light water reactor) from the steam generator (secondary loop) runs at about 500F / 275C which is too low for steam reforming.  For this reason, electrolysis is the preferred method for light water reactors (LWRs) to make hydrogen.  Ref:  US DOE

New advanced reactors may have outlet temperatures, especially TRISO fueled HTGRs, in the required range.  See my report and table for examples on process heat outlet temperatures for advanced reactors in Canada now involved in CNSC's vendor design reviews.

Michael Keller's picture
Michael Keller on Oct 27, 2021

The gas reactors can produce steam at around 1000 F. Combined cycle plants with duct burners can reach boiler temperatures approaching 1400F.

while gas reactor temperatures can also reach around 1400 F. However, hard to use those temperatures directly for steam production at corresponding high temperatures. The steam turbine is the limiting item with temperature limits around of 1000 F.

Bob Meinetz's picture
Bob Meinetz on Oct 28, 2021

"Steam methane production is vastly more economic for chemical production processes that requires hydrogen."

Agree Michael, but there's no reason to make hydrogen to store energy -  unless you're trying to waste fuel, and charge your fuel costs to semi-dopey electricity ratepayers who are willing to pay more for anything "green" - then, it's a cash cow. Cha-ching. Moo.

Michael Keller's picture
Michael Keller on Oct 29, 2021

Bob, actually agree with you. My point is there is money to be made my taking advantage of the situation. True, that is not all together altruistic.

Dan Yurman's picture
Dan Yurman on Oct 29, 2021

The outlet temperature for some HTGR is within the range suitable for steam reforming and can be used assuming the reactor has multiple secondary loops. The first, for steam, can step down the very high temperature of the helium from the RPV by using a molten salt loop and then connecting it to a steam generator to feed a turbine. The second can take the high temperature helium directly to make very high temperature steam for production of hydrogen. One pipe does not fit all. :-)

Michael Keller's picture
Michael Keller on Oct 29, 2021

Multiple loops can create vexing thermal gradient problems in reactor cores. However, the large thermal capacity and slow reaction time of graphite cores may be able to tolerate the transients associated with multiple loops.

Not a big fan of using salt in reactor applications because the stuff more or less turns into rock when it cools off. Am aware of multiple instances where the affected piping had to be cutout and replaced. Not real helpful from a reliability standpoint.

Dan Yurman's picture
Dan Yurman on Nov 3, 2021

HTGRs with TRISO fuel are essentially "graphite cores." The problem for some designs is that they "over achieve" in terms of outlet temperatures of the helium coming off the RPV which creates challenges for materials used in fabrication of the heat transfer loop(s). 

Agreed on the "liability" of molten salt in the secondary loop is an issue. First generation HTGRs in UK wrapped a series of thermal blankets in panels around the RPV to make steam to drive the turbine. 

With helium as the heat transfer medium from the RPV, the use of supercritical CO2 for the secondary loop could be an answer to the problems associated with molten salt. 


Dan Yurman's picture
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