This is precisely why the concept is steadily transitioning from beautiful slideshows into the domain of engineering economics. It is being analyzed not only by reactor developers, who naturally want to build their designs wherever possible, but also by US national laboratories and institutions, including the US Department of Energy (DOE), Idaho National Laboratory, Argonne National Laboratory, Oak Ridge National Laboratory, Pacific Northwest National Laboratory, MIT, NASEO, and NARUC. For these entities, the core question is not "how to sell a reactor," but rather "can such a transition actually work as an infrastructural, economic, and social strategy." The DOE specifically advances the coal-to-nuclear track through GAIN, maintaining technical and informational resources for communities, states, and regulators considering the repurposing of coal sites for nuclear generation.
A New Nuclear Plant on a Legacy Energy Site, Not a "Reactor in Place of a Boiler"
The greatest misconception regarding coal-to-nuclear is viewing it as a simple technological upgrade of a TPP. In reality, coal-fired plants and nuclear power plants operate under completely different operational logic, safety frameworks, regulatory philosophies, and life cycles. A coal plant centers on fuel combustion: the boiler, coal handling, fuel delivery systems, ash disposal areas, smokestacks, flue gas cleaning, emissions, and continuous fuel and waste logistics. A nuclear plant centers on the reactor unit, nuclear fuel, safety systems, containment, physical security, radiation control, emergency planning, safety culture, and a fundamentally different level of regulatory oversight.
Therefore, no one literally drops a reactor into an old boiler. Most of the nuclear island must be built from the ground up. However, the true value lies elsewhere: a nuclear facility can occupy a site that already possesses some of the most capital-intensive energy infrastructure. This drastically alters project economics.
In modern power generation, the power plant itself represents only a fraction of the cost. Land acquisition, grid access, regulatory permitting, industrial logistics, transmission capacity, community engagement, environmental remediation, water access, transport links, a qualified workforce, and the historical reality of the site serving as an energy hub for decades are all exceptionally expensive assets. In a 2024 brief, PNNL explicitly noted that retired or retiring coal plants offer a turnkey opportunity for clean energy infrastructure, specifically new nuclear generation. This transition allows for the reuse of land, specific facilities, and electrical interconnection infrastructure.
Why Coal Sites Matter
A coal-fired TPP is not merely a collection of aging buildings and smokestacks; it is a critical node in the power grid. Its original location was chosen deliberately, offering access to the grid, water sources, railways, or other logistics, alongside an industrial zone, land, personnel, and an established dispatch and balancing role. When such a station closes, the power system loses more than just megawatts. It loses a point of dispatchable generation, jobs, a local tax base, industrial expertise, and frequently, the social anchor of a city or region.
Consequently, coal-to-nuclear is about preserving energy geography just as much as it is about decarbonization. Simply shutting down a TPP and leaving the site to decay creates a classic post-industrial crisis: stranded infrastructure, unemployment, declining local budgets, environmental liabilities from legacy generation, and the necessity of building new capacity from scratch elsewhere. Repurposing the site gives it a second lease on life—shifting from coal to dispatchable, carbon-free generation.
This logic is thoroughly detailed in the NASEO/NARUC report, which identifies the reuse of existing infrastructure, economic development, power supply reliability, decarbonization, and potential time and cost savings compared to greenfield construction as key benefits of coal-to-nuclear. The report also highlights grid interconnection, water infrastructure, roads, administrative offices, and auxiliary facilities as highly valuable retained assets.
The Economics: Why the Site Assets Carry More Weight Than Assumed
Conventional debates surrounding nuclear energy typically focus narrowly on reactor costs. What is the cost per megawatt? What are the construction costs? What is the levelized cost of electricity (LCOE)? For a real-world investor or a state, the scope is far broader. The critical factors include not just reactor costs, but where it stands, how it connects to the grid, land costs, required transmission lines, permitting timelines, water availability, road access, workforce availability, local support, and whether the facility will spend years waiting in a grid interconnection queue.
This is where a coal site provides a distinct competitive edge. A 2022 DOE/INL study estimated that locating a nuclear plant on a legacy coal site could reduce overnight capital costs by 15% to 35% compared to greenfield construction, driven by the reuse of existing infrastructure. This does not automatically make nuclear energy inexpensive; rather, it demonstrates that selecting the right site can fundamentally reshape a project's financial model.
The same DOE/INL study highlights another vital insight: a nuclear facility replacing a coal plant can have a lower installed capacity while generating a comparable volume of electricity, due to a significantly higher capacity factor. In a case study involving the replacement of a large 1200 MW coal plant, researchers analyzed a transition to 924 MW of nuclear capacity, projecting a positive net impact on the regional economy, including sustained local employment and increased economic activity.
Thus, the formula of "one megawatt of coal equals one megawatt of nuclear" is fundamentally flawed. A coal plant may operate with a lower actual capacity factor, experience generation volatility, and face exposure to fluctuating fuel prices, environmental constraints, and market dynamics. A nuclear unit, particularly as baseline or dispatchable carbon-free generation, delivers higher annual generation per unit of installed capacity. Evaluations must focus on megawatt-hours, systemic value, reliability, fuel risks, emissions, operational lifespan, and load-following capabilities rather than simple megawatt parity.
The Centralia Case Study: When the Concept Faces Rigorous Modeling
One of the most compelling real-world examples is the Centralia site in Washington State, which was evaluated as a prospective location for small modular reactors (SMRs). A 2021 PNNL/MIT study analyzed several deployment scenarios for Generation III+ reactors in the US Pacific Northwest, including NuScale and GE Hitachi's BWRX-300, utilizing Centralia as a primary evaluation site. The authors explicitly stated that PNNL and MIT conducted this research to evaluate the specific value proposition of SMR deployment within the region.
The scenario featuring the BWRX-300 at the Centralia site is particularly illuminating. The PNNL/MIT study calculated an LCOE for the BWRX-300 ranging from 44 to 51 dollars per megawatt-hour, utilizing GE Hitachi's design-to-cost framework and target pricing assumptions. For the Centralia site specifically, under a scenario modeling the replacement of one or two coal units, the estimated LCOE fell between 50.52 and 50.70 dollars per megawatt-hour, depending on the configuration. Crucially, the authors transparently noted that these projections remain highly dependent on assumptions regarding capital costs, construction timelines, electricity market conditions, and the maturity of project cost estimates.
This does not imply that nuclear power costs 50 dollars everywhere and unconditionally. It represents a highly specific model built on precise assumptions within a distinct region, tailored to a specific technology and aligned with the decarbonization policies of Washington State. Nevertheless, such modeling underscores that under the right conditions, nuclear generation on a prepared energy site is a commercially viable option for a future carbon-free power grid rather than an abstract ideal.
Furthermore, the BWRX-300 has advanced far beyond promotional presentations. In Canada, the CNSC issued a license for construction to Ontario Power Generation in April 2025 for a single BWRX-300 reactor at the Darlington New Nuclear Project site; by March 2026, the project successfully cleared its first regulatory milestone for pouring the reactor building foundation.
What Can Be Reused and What Must Be Scrapped
The coal-to-nuclear concept involves a critical practical caveat: not all infrastructure at a legacy TPP can or should be reused. Certain assets possess immense value, others offer limited utility, and some introduce unacceptable risks. The most viable assets for retention include land, grid interconnections, switchyards, substations, roads, rail links, administrative facilities, water infrastructure, specific auxiliary systems, the industrial zone itself, and an experienced power sector workforce.
Conversely, reusing the steam turbine cycle presents a much steeper challenge. The DOE/INL explicitly state that repurposing steam cycle components from a coal plant represents both the greatest opportunity and the most significant hurdle to reducing a nuclear project's capital costs. The underlying reason is simple: steam parameters, temperatures, pressures, turbine configurations, condensers, heat exchangers, and regulatory licensing requirements differ drastically between coal and nuclear technologies. For light-water reactors, reusing turbine components is often unfeasible due to divergent steam parameters. While high-temperature or fast reactors utilizing intermediate loops or thermal energy storage may offer greater compatibility, feasibility ultimately depends entirely on the specific technology and site conditions.
This explains why coal-to-nuclear cannot be marketed as a simplistic "remove the boiler, install a reactor" scheme. It invariably requires exhaustive technical and economic feasibility studies to determine what can be retained, what must be dismantled, what requires environmental remediation, what can be redesigned, what meets nuclear licensing standards, and what must be discarded due to age, degradation, technical incompatibility, or safety mandates.
Grid Interconnection: The Hidden Currency of the Energy Transition
One of the most potent advantages of a legacy TPP is its existing point of grid interconnection. In an era where new energy projects frequently languish in interconnection queues for years, an established grid connection becomes an invaluable asset class in its own right. PNNL explicitly noted in 2024 that a coal plant's transmission injection point can be repurposed for new nuclear generation, delivering substantial time and capital savings, particularly since extensive interconnection queues represent a primary bottleneck for clean energy deployment.
This is exceptionally vital for nuclear generation because nuclear facilities cannot simply be deployed in isolated locations. They require robust grid infrastructure, a stable power injection node, seamless integration into dispatch logic, redundancy, operational regime planning, and a long-term role in grid balancing. If a coal site has historically functioned as a hub for dispatchable generation, its value to a nuclear project extends far beyond the nominal cost of the land.
This marks a fundamental difference from certain renewable energy projects. While solar or wind generation may offer lower costs during peak production hours, they cannot automatically replicate the systemic functions of a thermal power plant. If a legacy TPP historically provided dispatchable capacity, grid inertia, spinning reserves, voltage support, and critical load-center stability, replacing it solely with intermittent generation leaves a dangerous structural void in the grid. A nuclear unit, or a deployment of small modular reactors, aligns closely with the systemic profile of a TPP: it delivers dispatchable capacity capable of sustained, stable operation with a high capacity factor.
Social Logic: Preserving Cities Built Around Power Generation
Thermal power generation features a human dimension that technical discussions often overlook: the host communities. A TPP is rarely just an industrial facility; it functions as the economic heartbeat of its locality. It secures employment, drives tax revenues, sustains local contractors and maintenance services, fosters an engineering culture, feeds technical vocational schools, supports local businesses, maintains infrastructure, and defines community identity. When such a plant closes, the community frequently experiences economic devastation rather than a "green transition."
The DOE emphasized in its 2024 brief that transitioning from a coal plant to a nuclear facility can expand local employment opportunities, generate additional high-paying positions, and accelerate regional economic activity. Furthermore, with proactive planning and workforce retraining, the vast majority of personnel at an operating coal plant can successfully transition to roles at the replacement nuclear facility.
This does not suggest that a boiler operator can seamlessly step into a reactor operator role overnight. The nuclear industry enforces a vastly different safety culture, stringent training mandates, rigid procedural compliance, and specialized certification frameworks. However, it does mean that a coal site possesses a workforce that fundamentally understands power generation, shift schedules, heavy machinery, maintenance protocols, dispatch discipline, industrial risks, electrical engineering, turbines, generators, water chemistry, and occupational safety. This is a robust foundational asset, not a blank slate.
PNNL similarly concludes that nuclear energy is uniquely positioned to preserve the regional economic footprint and employment base of legacy coal plants. Citing a case study conducted for the Four Corners region, the laboratory demonstrated that coal-to-nuclear projects can yield a positive net employment impact, given that a significant portion of the existing workforce's skills are directly transferable.
Regulation and Safety: A Legacy Industrial Zone Does Not Automatically Qualify as a Nuclear Site
Despite its advantages, coal-to-nuclear faces profound constraints. Not every TPP site is legally or technically suitable for a nuclear project. Thorough assessments must evaluate seismology, hydrology, flooding risks, water supply security, local population density, proximity to external hazards, industrial co-location risks, legacy chemical contamination, ash pond stability, soil mechanics, emergency evacuation logistics, grid resilience, physical security infrastructure, and the transportation logistics required for heavy, oversized components.
In their research, the DOE/INL utilized a structured site-screening methodology built on OR-SAGE parameters, mapping population density, seismic hazards, surface faulting, protected lands, terrain slopes, landslide risks, wetlands, open water proximity, floodplains, and nearby hazardous facilities. While small and advanced reactors offer potential for deployment closer to load centers, final siting approvals remain strictly dependent on technology-specific parameters, dose calculations, emergency planning zones, and definitive regulatory determinations.
This reality is of paramount importance for Ukraine. It is impossible to simply take a map of aging TPPs and label each one as an SMR site. Such an approach is not a strategy; it is merely an exercise in making slides with arrows. Ukraine requires a comprehensive national site screening program to rigorously determine which TPPs possess genuine potential for nuclear repurposing, which are ideally suited for energy storage systems, which should host gas-fired peaking capacity, which should be converted into industrial parks, which are suited for hydrogen production or district heating, and which must first undergo environmental remediation and remain untouched for several years.
Complementarity, Not Competition: A Distinct Systemic Function
Coal-to-nuclear should never be framed as a conflict between nuclear power and renewable energy sources like solar or wind. That is an incorrect framework. Solar and wind generation play a critical role, particularly when the grid has the flexibility to absorb low-cost, variable electricity. However, coal plants historically fulfilled an entirely different function: providing dispatchable capacity, grid stabilization, serving as power hubs, performing during peak demand hours, and maintaining systemic equilibrium. If a nation phases out coal, it must answer a fundamental question: what asset will assume this systemic responsibility?
Nuclear energy does not compete on the basis of matching the lowest cost of a solar megawatt-hour at noon. Nuclear excels where the grid demands dispatchable, carbon-free, long-term capacity operating with an exceptionally high capacity factor. When that capacity can be integrated into a site that already features a grid connection, water access, an industrial foundation, an experienced workforce, and an established role in the grid architecture, the underlying economics transform completely.
This represents the core thesis of "coal-to-nuclear": it is not a mere substitution of fuel, but a complete transformation of the site's industrial paradigm. It eliminates coal combustion while safeguarding dispatchable generation. It preserves energy-dependent communities by providing a new high-tech specialization. It avoids building entirely from scratch by capitalizing on existing assets of proven systemic value.
What This Means for Ukraine
For Ukraine, this concept could emerge as one of the most powerful pillars of post-war energy reconstruction. Ukraine possesses extensive experience in operating nuclear infrastructure, a world-class engineering tradition, legacy thermal power sites, damaged or destroyed energy infrastructure requiring modernization, a critical need for dispatchable generation, a clear path toward decarbonization, and a strategic imperative to eliminate reliance on fossil fuels. However, this reality demands an exceptionally disciplined and sober approach.
In the post-war era, it will not be enough to simply sketch new reactors onto a map. Ukraine must establish a rigorous state or public-private audit of its legacy energy sites. For every potential location, definitive answers must be provided for a series of concrete questions: Is the available land acreage sufficient? What is the technical condition of the grid connection? Is there adequate cooling water available? What are the specific seismic and hydrological risks? What is the status of soil contamination and legacy ash deposits? What is the precise distance to populated centers? Can robust physical security be guaranteed? Is the logistics network capable of handling heavy reactor components? What role will this node play in the future configuration of the integrated power system? Is the local workforce available? Does the host community support the project? What is the financing model? Who will act as the licensed operator? What is the regulatory roadmap, and which specific technology fits this exact site?
Under this scrutiny, coal-to-nuclear can evolve from a popular industry buzzword into a highly effective national asset management program. Aging TPPs should not be automatically written off as obsolete relics of the Soviet or coal eras. A portion of them may prove to be invaluable energy sites for next-generation power deployment, while others will not. This differentiation must be driven by rigorous technical and economic analysis, not by political slogans.
Ukraine must shift its focus from merely deciding "which reactor design to buy" to determining "where a reactor creates the maximum systemic value for the grid." The optimal answer may not lie in a greenfield site, but on a legacy energy asset that already holds a grid connection, deep industrial memory, and a workforce that truly understands the reality of power generation.
Conclusion
Coal-to-nuclear is not a romantic narrative where nuclear energy seamlessly replaces coal and delivers immediate harmony. It represents a highly complex engineering, economic, regulatory, and social transformation. It demands meticulous site screening, environmental remediation, careful technology selection, systemic value modeling, deep community engagement, structured financial architecture, targeted workforce retraining, and a highly mature regulatory body.
Yet, this complexity is precisely where its strength lies. The future of energy generation does not always have to begin in an empty field. Quite often, it begins with a precisely targeted question: What assets do we already own that can be repurposed to build the future?
In some cases, a legacy TPP truly marks the absolute end of a coal story. In others, however, it can mark the beginning of a nuclear one. Before swapping a coal-fired "kettle" for a uranium core, we must stop drawing arrows on presentation slides and honestly calculate the engineering reality, grid physics, land mechanics, water security, human capital, safety margins, and capital costs. In the energy architecture of the future, the victory will go not to the party with the most impressive digital rendering, but to the one that is first to accurately recalculate a legacy asset as a future powerhouse.
