WNA Nuclear Century Outlook

 NCO Data Table | pdf of WNA Nuclear Century Outlook

Developed in 2008, the WNA’s Nuclear Century Outlook is:

  • A conceptualization of nuclear power’s potential worldwide growth in the 21st Century; and
  • An evaluation of nuclear energy’s environmental contribution.

The Outlook is unique in nature and scope.  Many nuclear projections extend just to 2030 and assume business-as-usual behaviour.  The Outlook encompasses these scenarios but looks further into the future - with both optimistic and pessimistic assumptions. The focus of the report is to examine the potential for nuclear energy to contribute to emissions reductions. It does not attempt to predict future nuclear capacity. For WNA's biannual review of the nuclear fuel market with scenarios to 2030 please see the Global Nuclear Fuel Market Report .

In gauging nuclear energy’s potential growth and environmental role, the Nuclear Century Outlook also offers perspective on two questions:

  • Will nuclear energy’s contribution depend heavily on introducing nuclear power into new nations?
  • In meeting global clean-energy need, what is the relationship between nuclear power and renewable energy technologies?

The Outlook is built on country-by-country assessments of the growth potential of national nuclear programmes, based on estimates of need and capability, with projected population a key factor.  For each country, the Outlook posits upper and lower growth trajectories, with the low reflecting the minimum nuclear capacity expected and the high assuming a full policy commitment to  nuclear power.  When summed globally, these trajectories yield boundaries within which the future is likely to fall. 


NCO table


The WNA secretariat maintains this analysis through an on-going dialogue with the WNA’s worldwide industry membership and with experts in leading energy organizations, including IEA, WEC, IAEA and OECD-NEA.  The secretariat welcomes advice from all quarters as it continues to update the Outlook analysis.

The latest Outlook tabulation can be seen here.


Energy Need

 Nuclear Share replacement image



These aspects of the Outlook bear emphasis:

  • The low and high global trajectories are not growth “scenarios” as such, but rather the boundaries of a domain of likely nuclear growth.
  • Even the low boundary of about 2,050 GW represents more than a five-fold increase over today’s nuclear capacity of 370 GW.
  • Growth within the Outlook boundaries is postulated on the assumption that fuel availability will pose no constraint in operating a much larger global nuclear fleet.  Most experts support this view on the grounds that a combination of factors – new ore discoveries, advanced mining techniques, use of uranium “tailings”, more reprocessing, introduction of the thorium fuel cycle and, ultimately, employment of breeder reactors – will ensure ample and affordable nuclear fuel supplies into the distant future.
  • The Outlook country projections are implicitly based on the assumption of global environmental stability. This assumption will be vitiated if and as the pace of worldwide conversion to clean-energy technologies proves insufficient to avert catastrophic climate disruption. The essential goal of the Nuclear Century Outlook is to assess and demonstrate the pace of global nuclear growth necessary to prevent that outcome. 

The Central Challenge: Decarbonizing Energy

How do the nuclear capabilities projected in the WNA Nuclear Century Outlook relate to the global environmental challenge?  In short, how essential is the contribution from nuclear energy in the 21st Century?

Today a global population of 6.6 billion is rising toward 9 billion by 2050, as energy demand grows explosively to meet human needs and aspirations worldwide.  The current path is unsustainable.  The UN panel composed of the world’s leading Earth scientists (IPCC) warns that global greenhouse gas (GHG) emissions must, by 2050, be cut by 70% to avert catastrophic change in our planet’s climate system.  Achieving emissions cuts on this scale will require sweeping technological change in the world economy.

Emissions-reduction strategy must be comprehensive, embracing conservation and efficiency, plus pervasive changes in industrial processes, farming and forestry.  But the central task must be a global transformation in energy - because most GHG’s come from the use of fossil fuels.  The crucial challenge in GHG curtailment is to decarbonize an ever-expanding worldwide energy system. 

Components of a Clean-Energy Future

Fundamental questions remain about future clean-energy technologies:

  • Future Transport: What will be the comparative efficacy of advanced batteries vs. hydrogen fuel cells?
  • Clean Fossil Fuel: Will large-scale Carbon Capture and Storage (CCS) prove feasible, affordable and sustainable?
  • Renewables Technology: Can New Renewables (wind, solar, biomass, geothermal, tidal) overcome obstacles of cost and intermittency to contribute on a major scale?

Despite these technological unknowns, the essential components of a global clean-energy economy are already well understood:

1. More and Cleaner Electricity:

  • Full transformation of electricity to emissions-free technologies
  • Greater use of electricity in industrial processes and heating
  • Electrification of transport (trains & battery-powered cars).

2. New Elements (using clean electricity or clean heat):

  • Direct use of heat output of zero-emission plants for industrial process and heating.
  • Desalination of sea water to meet an intensifying world water crisis
  • Hydrogen production for fuel cells.


Future “Global Clean-Energy Need” can be projected as the combined output for clean “EHDH”:

  • Clean Electricity (including battery power)
  • Clean Heating (process and factory/office/home)
  • Clean Desalination
  • Clean Hydrogen production.

Quantifying Clean-Energy Need

As a unit of measure in projecting global EHDH-Need and capability, the Outlook uses “Nuclear Gigawatt” - the energy delivery capacity of a 1,000 MW reactor.  To project global clean-energy need, the Outlook:

  • Takes as a numerical starting point for EHDH-Need the urgent necessity to de-carbonize world electricity consumption (which in 2000 equated to 2,000 Nuclear GW).
  • Accepts energy analysts’ expectation that global energy use will double between 2000 and 2050, while electricity consumption triples or quadruples.
  • On the additional assumption that clean Heating, Desalination and Hydrogen will become substantial, posits a five-fold increase in EHDH-Need by 2050.
  • Assumes that growth in EHDH-Need then slows, growing 40% in 2050-2100, as global population stabilizes at about 9 billion while economic development continues. 

This approach yields an estimate of Clean-Energy Need at mid-century of about 10,000 Nuclear GW, rising by a further 40% in 2100. This means that our world will be chasing a clean-energy target that is receding - in effect, running away as we strive to reach it.


Clean Energy Need

This order-of-magnitude estimate of future Clean-Energy Need gains credence from an alternative calculation. Today the IEA judges that that nuclear power’s 370 GWe (approx 1100 GWth) represent 6.3% of world primary energy consumption. 

If so, world energy consumption corresponds to the output from 5,875 Nuclear GW. If total primary energy consumption doubles by 2050, 85% of energy must be supplied by clean technologies in order to attain a 70% GHG cut from 2000 levels.  

On that basis, Clean-Energy Need in 2050 would be 9,990 Nuclear GW.


Supplying Clean-Energy Need

To place nuclear projections into context, the Outlook makes these assumptions concerning overall clean-energy delivery in the 21st Century:

  • Hydropower growth stops at mid-century.
  • New Renewables grow steadily and robustly, to a capacity by 2100 that is more than double the total of today’s world electricity output.
  • Fossil Carbon Capture and Storage (CCS) makes a substantial contribution during the 21st Century, serving as a bridge technology, but does not grow indefinitely.
  • Nuclear grows within the range defined by the WNA Outlook boundaries.

These assumptions, which are incorporated into the following graph, are highly favourable to the prospects for New Renewables, which today contribute only negligibly, and CCS technologies, which today are still unproven.


Global Clean-Energy Need & Supply


The Nuclear Gigawatt

The Nuclear Century Outlook expresses future clean energy demand in terms of 'Nuclear Gigawatts', whether discussing nuclear electricity, nuclear process heat, energy from renewables or fossil fuels with carbon capture and storage. A Nuclear Gigawatt represents whatever capacity required to generate the same energy delivered as a 1 GWe nuclear reactor operating with a high capacity factor.

A 1 GWe nuclear reactor can generate around 7 TWh of electricity a year. A coal or gas fired power station may generate a similar amount if operated continuously in baseload generation. Because of the intermittent nature of wind, one GWe capacity of wind turbines may only generate 20-40% of the electricity of a1 GWe nuclear plant, the capacity of turbines needed to generate 7TWh in a year would be somewhere in the region of 3-4 GWe.

If the Nuclear Century Outlook only dealt with clean electricity production we could use electrical output (TWh) as a common measure of the performance of different technologies. But the Nuclear Century Outlook includes heat generation, as well as electricity. We use the concept of a Nuclear Gigawatt to give a practical indication of the scale of the task ahead in meeting clean energy needs.

Implications for Global Strategy

The WNA Nuclear Century Outlook, although speculative, is fair-minded in design, draws heavily on respected expert analysis, and serves to underscore the full magnitude and urgency of the global environmental challenge.  The Outlook carries important implications for strategy and action:

  • While new countries can and should introduce nuclear energy, over 80% of nuclear growth – and thus most of nuclear technology’s environmental contribution – will occur in nations already generating nuclear power.
  • Even with expansive growth in nuclear power, renewables will also be needed on a large scale, despite their higher cost. In this sense, nuclear and renewables are not competitors but clean-energy partners.
  • Conversely, even if renewable and clean-fossil technologies meet extremely optimistic assumptions, a global clean-energy revolution adequate to avert catastrophic climate change will require an enormous contribution from nuclear power and extensive realization of its worldwide growth potential.



Published 2008, revised introduction 2012