How Ghana Can Achieve Its Nuclear Energy Goals With SMRs

Ghana Can Lead Africa in SMR Deployment

Fig. 1: Projection of Ghana's electricity demand through 2024, with proposed nuclear supply shown, from the IPSMP. [6] Values for the years 2036-2039 are not in the IPSMP but are interpolated. (Image Source: L. Garcia)

This summer, there were reports that the United States and Ghana agreed to share small modular reactor (SMR) technologies developed by NuScale in order to meet the country's growing demand for alternative energy. [1] An SMR is a nuclear reactor that has a capacity of less than 300 MW, which is less than a third of the capacity of a traditional nuclear power plant. [2] However, companies such as NuScale have designed their SMRs to be deployed in groups, with some plant configurations approaching the energy output of a traditional nuclear plant. [3] These reports indicated Regnum Technology Group, a nuclear developer, committed to deploy a NuScale VOYGR-12 SMR to Ghana. [1] This would lay the groundwork for further use of the technology there. This reported technology-sharing agreement has been decades in the making, and could make Ghana the second African country to deploy a nuclear power plant, with South Africa being the first. It boasts one active nuclear power plant, and plans to build more. [4,5] Adams and Odonkor outline the steps that could lead to Ghana becoming the first country in Africa to deploy a land-based SMR. [4]

Ghana is serious about nuclear energy. In Ghana's Integrated Power Plan, the government outlines five possible strategies for how they will meet rising power demand over the next two decades. [6] Strategy V, which sees twofold reduction in CO₂ emissions per unit of energy produced (measured in kg/kWh), is the only plan that will help Ghana reach its carbon reduction commitment made at the 2015 Paris Climate Accords. [6] This strategy relies heavily on the construction of two nuclear power stations that will provide almost half of the country's electricity by 2040, as shown in Fig. 1. [6] If Ghana incorporates nuclear power into its energy mix as aggressively as Strategy V proposes, it would likely continue to grow throughout the 2050s and 2060s.

Fig. 2: Projected percentage breakdown of Uranium production in the world in 2020. (Images Source: L. Garcia, following Fig. 7 of Hall and Coleman. [13])

Although no land-based SMRs have yet been deployed anywhere in the world, they can be constructed almost anywhere, and on short timescales once the permitting process is complete. [3,7] SMR facilities take up a fraction of the land used by a traditional nuclear power plant, so they can be quickly constructed near areas currently underserved by the grid. [7] Ghana appears to have tapped almost all of its hydropower resources, primarily through constructing dams and generating stations along the Volta River. [6] Climate change will make its existing hydropower generation increasingly unreliable, as Volta river flows become increasingly unpredictable over time. [8] Fig. 1 reflects Ghana's hydroelectric portfolio declining over the next two decades, as other renewable energy sources such as solar see modest growth. The Government of Ghana wishes to meet its carbon reduction commitments, and its largest source of renewable energy, hydroelectricity cannot be significantly expanded; even in Strategy V, which sees the largest increases of other renewable energy sources, these still represent a small fraction of total power generation. Since it appears Ghana now has the support of the U.S. Government, regional regulators, and a strong nuclear talent development program, they can deploy SMRs to provide clean and reliable power to meet growing demand over the following decades. [6,7,9]

Ghana Will Need to Deploy 5 SMR Plants by 2040

The Government of Ghana's enthusiasm for nuclear energy would likely help expedite the permitting process for NuScale, which is one of the largest barriers for the deployment of nuclear power stations in other countries. [10] If Ghana seeks to meet its goals for nuclear power, how many SMR stations would be needed to be deployed by 2040? There have several numbers quoted for the gross output of NuScale VOYGR-12 SMR stations, but I assume the most conservative estimate of 600 MWe in line with the US Nuclear Regulatory Commissions assessment of these stations. [3,11] I also assume that each plant is not running at full tilt for the entire year by multiplying the stated power output by a capacity factor of 95%:

Fig. 3: A standard 20ft shipping container (Source: Wikimedia Commons)

Armed with a conservative estimate of the typical power output of a VOYGR-12 SMR, I compare this to the IPSMP Strategy V estimate for nuclear power in 2040 by converting to GWh / year:

Since Ghana projects nuclear energy will account for 23,000 GWh / year in 2040, this means that if Ghana only uses NuScale VOYGR-12 SMR power stations to meet this goal, they will need to deploy:

This figure rounds up to 5, which means that Ghana will have to build 5 VOYGR-12 SMR power stations in order to achieve the benchmark for nuclear power generating capacity in the governments most ambitious energy strategy.

Ghana Will Need About 25 Metric Tonnes of Fuel Per Year

Ghana will need to find enough Uranium-235 fuel to generate 23,000 GWh / year of nuclear power. Slye gives calculations for the global nuclear fuel budget, which I can adapt to the amount of nuclear fuel that will be needed for this task. [12] First, I take the assumption that 1 GWh is equal to 3.6 × 10¹² J, and convert GWh / year into J / year:

SMRs are powered by a process called fission, which is the breakup of larger atoms (like Uranium) into smaller ones, which releases energy, radiation, and particles. [4,12] Since each fission reaction between a uranium atom releases 200 MeV of energy, I can determine the amount of U-235, which is the radioactive isotope of uranium that helps sustain fission processes needed to fuel these reactors:

NuScale SMR reactors use low-enriched Uranium-Oxide (UO₂) fuel, where less than 4.95% of Uranium mass is radioactive U-235. [3] Despite making up about 4% of the mass of typical uranium fuel, U-235 only accounts for 0.7% of the mass of naturally-occuring Uranium. [12] If 1.01 tonnes of U-235 are needed every year, and I assume that U-235 constitutes exactly 4% of the mass of the reactor fuel, the total mass of reactor fuel that Ghana needs to supply its hypothetical SMR fleet in 2040 is about:

Acquiring this fuel would be fairly straightforward, as the US Geological Survey projected that much of the growth in uranium supply will come from Africa in the next decade. [13] Fig. 2 shows that this growth propels Africa to become the world's second-largest producer of uranium. Since Ghana has friendly trade relationships with every uranium-exporting country on the continent, one could argue that securing this small amount of uranium will likely not come at a significant cost. [14] In practice, this could be complicated by the relationship France and South Africa have with uranium-rich countries in the region. [15,16]

These Reactors Will Create 1.3 m³ of Waste Per Year in 2040

Fig. 4: A diagram of a borehole filled with HLW (Source: Wikimedia Commons)

One of the main concerns governments have about building new nuclear power facilities is the radioactive waste that these create. Finding an effective long-term High Level Waste (HLW) storage site, and storing the waste there has been the largest barrier to constructing new nuclear power stations in the United States. [17] It's incredibly important to know the amount of waste from these new SMRs before Ghana constructs them, so that Ghana can identify an appropriate HLW storage site beforehand. Assuming (as Slye does) that spent nuclear fuel and HLW have the same molecular weight, and 1 cubic meter of nuclear waste weighs 19.05 tonnes: [12]

1.325 m³ is not much yearly nuclear waste. For reference, the standard 20 ft shipping container shown in Fig. 3 has a volume of 33 m³, which means that it would take

to fill up the shipping container if fuel consumption were to continue at the Strategy V 2040 fuel consumption rate projected by this report. Even though this hypothetical future fleet of SMRs doesn't produce much waste, finding a way to store it safely has proved to be difficult for other countries.

Ghana Has Taken Steps to Safely Dispose of This Waste

Ghana has already identified a potential nuclear waste disposal site: the headquarters of the Ghana Atomic Energy Commission (GAEC). The headquarters of the GAEC are situated in Kwabenya, a suburb of Accra, Ghana's capital and largest city. [9] The GAEC has drilled several holes (like the one shown in Fig. 4) over 100 meters deep and scientists performed tests on the areas geology, and concentration of radioactive isotopes of thorium, radium, and potassium. [9] The final boreholes will likely need to be much deeper, on the scale of kilometers as the one shown in Fig. 4. They found there were naturally elevated levels of these isotopes in the soil and groundwater, identified potential interactions between soil and groundwater radionuclides (particularly at the deepest depths of the boreholes) and recommended that robust monitoring systems be implemented in order to safeguard the environment and human health for future generations.

© Léon Garcia. The author warrants that the work is the author's own, and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.

References

[1] T. Gardner, "Ghana Signs Agreement to Build Small NuScale Nuclear Reactor," Reuters, 29 Aug 24.

[2] S. Harber, "Small Nuclear Reactors: Background, Potential Applications, and Challenges," Physics 241, Stanford University, Winter 2017.

[3] F. Reitsma et al., "Small Modular Reactor Technology Developments," International Atomic Energy Agency, September 2020.

[4] S. Adams and S. Odonkor, "Status, Opportunities, and Challenges of Nuclear Power Development in Sub-Saharan Africa: The Case of Ghana," Prog. Nucl. Energy 138, 103816 (2021).

[5] "Integrated Resource Plan (IRP2019)," Department of Energy, Republic of South Africa, October 2019.

[6] "Integrated Power Sector Master Plan for Ghana - Executive Summary (Vol 1)," Ghana Energy Commission, Republic of Ghana, March 2023.

[7] M. A. Nyasapoh et al., "Advancing Africa's Sustainable Energy Development Through Small Modular Reactors (SMRs) as Low-Carbon Power Solution," IEEE 10739595, 12 International Conference on Smart Energy Grid Engineeing (SEGE), 18 Aug 24.

[8] J. K. Mensah et al., "Modeling Current and Future Groundwater Demands in the White Volta River Basin of Ghana Under Climate Change and Socio-Economic Ecenarios." J. Hydrol. Reg. Stud. 41, 101117 (2022).

[9] E. Akortia et al., "Geological Interactions and Radio-Chemical Risks of Primordial Radionuclides ⁴⁰K, ²²⁶Ra, and ²³²Th in Soil and Groundwater From Potential Radioactive Waste Disposal Site in Ghana," J. Radioanal. Nucl. Chem. 328, 57 (2021).

[10] L. W. Davis, "Prospects for Nuclear Power," J. Econ. Perspect. 26, No. 1, 49 (2012).

[11] "Standard Design Approval for the Nuscale Power Plan Based on the Nuscale Standard Plant Design Certification Application," U.S. Nuclear Regulatory Commission, September 2020.

[12] P. Slye, "Small Nuclear Reactor Fuel and Waste Amounts," Physics 240, Stanford University, Fall 2023.

[13] S. Hall and M. Coleman, "Critical Analysis of World Uranium Resources," U.S. Geological Survey, Scientific Investigations Report 2012-5239, 2012.

[14] I. Okyere and J. Liu, "The Impact of Export and Import to Economic Growth of Ghana," Eur. J. Bus. Manage. 12, No. 21, 130 (2020).

[15] G. Hecht, "An Elemental Force: Uranium Production in Africa, and What It Means to Be Nuclear," Bull. Atom. Sci. 76, 431 (2012).

[16] S. el Obeid, "Uranium in Namibia: Yellowcake Fever," Institut Français des Relations Internationales, 2021.

[17] "Reset of America's Nuclear Waste Management: Strategy and Policy," Stanford University Center for International Security and Cooperation, October 2018.