Company	Ticker	Design	Type	MWe	Market Cap	Target
GE Vernova	GEV	BWRX-300	BWR	300	$244B	End 2029
Rolls-Royce	RR.L	RR SMR	PWR	470	$134B	Mid-2030s
Cameco	CCJ	AP300 / eVinci	PWR / Micro	330	$49B	~2033
Oklo	OKLO	Aurora	Fast reactor	15-100+	$8.4B	2028
NuScale Power	SMR	VOYGR	PWR	77-924	$3.3B	~2030
NANO Nuclear	NNE	KRONOS MMR	HTGR micro	15	$1.15B	~2030
Terrestrial Energy	IMSR	IMSR	Molten salt	390	$500M	Early 2030s
Terra Innovatum	NKLR	SOLO	Gas-cooled micro	1	$321M	2027

Market caps as of April 1, 2026. Target = company-guided first commercial operation or FOAK deployment. All timelines subject to regulatory, financing, and construction risk.

NuScale Power Corp (SMR)

NYSE: SMR | Headquarters: Corvallis, Oregon, United States | Market Cap: ~$3.3 billion USD

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NuScale’s VOYGR power plant can house up to 12 factory-built 77 MWe modules. Source: NuScale Power Investor Presentation, February 2026.

NuScale Power Corp (SMR) is the only company in the world with an NRC-certified SMR design, holding both a Standard Design Approval for its original 50 MWe module (issued 2020) and a Design Certification for that design (issued 2023), as well as a Standard Design Approval for the uprated 77 MWe module (issued May 2025) from the United States Nuclear Regulatory Commission (NRC). Founded in 2007 by researchers from Oregon State University who developed the original reactor concept, the company has spent nearly two decades developing its VOYGR pressurized water reactor.¹

Each NuScale Power Module (NPM) generates 77 MWe and is designed for factory fabrication and truck delivery to site. A single VOYGR plant can house up to 12 modules for a combined output of 924 MWe. The design uses natural circulation cooling and passive safety systems, meaning the reactor can shut down and self-cool indefinitely without operator intervention, AC or DC power, or additional water.¹

NuScale’s commercial pipeline centers on two major programs. RoPower Nuclear, a joint venture between Romania’s Nuclearelectrica and Nova Power & Gas, is planning a six-module VOYGR plant at the Doicesti Power Station site, though the project timeline has slipped to a projected 2033 commercial operation date.² In the United States, ENTRA1 Energy is NuScale’s exclusive global commercialization partner and is in negotiations with the Tennessee Valley Authority (TVA) to deploy up to six 12-module plants totaling approximately 6 GW of capacity, with a first plant targeted for power delivery by 2030.³

NuScale reported a loss from operations of $689.6 million USD for fiscal year 2025, up sharply from $138.7 million in fiscal 2024, driven primarily by a $507.4 million milestone contribution payment under its partnership agreement with ENTRA1 Energy expensed through general and administrative costs. The company has not yet generated revenue from module deliveries. NuScale holds 781 patents granted or pending across 21 countries and has assembled a supply chain including Doosan Enerbility for heavy components, Framatome for fuel, and Paragon Energy Solutions for monitoring and protection systems.

Oklo Inc (OKLO)

NYSE: OKLO | Headquarters: Santa Clara, California, United States | Market Cap: ~$8.4 billion USD

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Oklo’s Aurora powerhouse uses metallic fuel and a fast neutron spectrum. Source: Oklo Investor Day Presentation.

Oklo Inc (OKLO) is developing the Aurora, a compact fast neutron reactor capable of generating 15 to 100+ MWe. Unlike conventional light water reactors, the Aurora uses metallic fuel and can run on high-assay low-enriched uranium (HALEU) or recycled nuclear fuel, giving it a potential cost advantage and reducing waste volume.⁴

The company operates across three business segments: Oklo Power (reactor development and deployment), Oklo Fuel (fuel recycling and supply), and Oklo Isotopes (radioisotope production, following its February 2025 acquisition of Atomic Alchemy). Oklo completed groundbreaking for its first Aurora powerhouse at Idaho National Laboratory and targets initial deployment in 2028.⁵

Oklo’s customer pipeline includes some of the largest names in technology. Meta Platforms has signed a prepayment agreement for a 1.2 GW campus in Ohio, with initial capacity of 150 MW targeted for approximately 2030. Other announced customers include Equinix, Diamondback Energy, Switch (with a 12 GW Master Power Agreement), and Prometheus Hyperscale.

The company’s regulatory pathway involves a combined license application with the NRC. An Operational Testing Authorization (OTA) has been signed with the Department of Energy, and the Nuclear Safety Design Assessment (NSDA) has been approved, with the Preliminary Design Safety Assessment (PDSA) pending. Kiewit serves as lead construction contractor, while Siemens Energy has been contracted for the power conversion system.

Oklo reported total operating expenses of $139.3 million USD in fiscal 2025, up from $52.8 million in fiscal 2024.

Terrestrial Energy Inc (IMSR)

NASDAQ: IMSR | Headquarters: Oakville, Ontario, Canada | Market Cap: ~$500 million USD

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The IMSR uses liquid fluoride salt as a coolant and fuel carrier, operating at 585°C. Source: Terrestrial Energy Investor Presentation.

Terrestrial Energy Inc (IMSR) is developing the Integral Molten Salt Reactor (IMSR), a Generation IV reactor that uses liquid fluoride salt as a coolant and fuel carrier. The company began trading on the NASDAQ following completion of its business combination with HCM II Acquisition Corp.⁶

The IMSR plant consists of two reactor units for a combined output of 390 MWe. It operates at 585°C, which enables thermal efficiency of approximately 44%, significantly higher than the roughly 30% efficiency of conventional light-water reactors. The sealed core unit is designed to be replaced entirely at the end of its seven-year service life. The reactor uses standard assay low-enriched uranium, avoiding the HALEU supply chain constraints faced by some competitors.⁷

In February 2025, the Texas A&M University System selected Terrestrial Energy’s IMSR for siting at its RELLIS campus following a competitive Request for Proposals process.⁸

The Canadian Nuclear Safety Commission (CNSC) completed its Vendor Design Review in April 2023 and declared no fundamental barriers to licensing the IMSR design. Terrestrial Energy’s engagement with the United States NRC commenced in 2016 and includes a joint CNSC-NRC review under a Memorandum of Cooperation. The company targets first commercial IMSR operations in the early 2030s.

Terra Innovatum Global Inc (NKLR)

NASDAQ: NKLR | Headquarters: London, United Kingdom | Market Cap: ~$321 million USD

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The SOLO micro-reactor generates 1 MWe with a footprint under 100 square feet. Source: Terra Innovatum Investor Presentation.

Terra Innovatum Global Inc (NKLR) is developing the SOLO, a helium gas-cooled micro-modular reactor generating 1 MWe (5 MWt). The SOLO’s footprint is under 100 square feet, making it the smallest design on this list by a significant margin. It uses a thermally-moderated, gas-cooled core with standard enrichment uranium (below 5%) and conventional zircaloy-cladded UO2 fuel pellets, with refueling intervals of 15 to 45 years depending on configuration.⁹

In March 2026, the United States NRC formally docketed Terra Innovatum’s SOLO topical reports, initiating the formal review and approval process. The NRC determined that the submissions contained sufficient technical information to begin detailed safety and design evaluation. Earlier in 2026, the company completed the Phenomena Identification and Ranking Table (PIRT), a key pre-licensing milestone, and NRC Safety Evaluations of the topical reports are anticipated by October 2026.¹⁰

The company’s first-of-a-kind (FOAK) deployment is targeted for 2027, accelerated from an earlier 2028 target disclosed in an October 2025 investor presentation. The first commercial customer is Rock City Industrial Park in Valmeyer, Illinois, where Terra Innovatum plans to supply behind-the-meter power with an option to subsequently deploy up to 50 reactors on site for a combined 50 MWe.¹¹

In February 2026, Terra Innovatum announced completion of its full end-to-end supply chain for the SOLO reactor, including nuclear-grade graphite and other critical components. The company also appointed Kathy Williams, former Framatome CEO and CFO, to its leadership team in March 2026.¹²

Rolls-Royce Holdings plc (RR.L)

LSE: RR.L | Headquarters: London, United Kingdom | Market Cap: ~$134 billion USD

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The Rolls-Royce SMR is a 470 MWe PWR designed for a 10-acre footprint. Source: Rolls-Royce SMR.

Rolls-Royce Holdings plc (RR.L) is developing its SMR through Rolls-Royce SMR Ltd, a subsidiary initially backed by Rolls-Royce Group, BNF Resources (the Perrodo family), the Qatar Investment Authority, and Constellation Energy. Czech utility CEZ Group agreed to acquire a 20% stake in October 2024, with the transaction completing in two tranches: approximately 11% in March 2025 and the full 20% by July 2025, diluting the original shareholders’ positions accordingly.¹⁴

The Rolls-Royce SMR is a 470 MWe pressurized water reactor designed for a 10-acre footprint and at least 60 years of operation. The company targets a 500-day on-site construction period within a total four-year build cycle (two years site preparation plus two years construction and commissioning). It received approximately £210 million in United Kingdom government funding and an initial £195 million in private investment from Rolls-Royce Group, BNF Resources, and the Qatar Investment Authority in 2021, with total private investment later growing to approximately £280 million as additional investors participated.

The design is undergoing the United Kingdom’s Generic Design Assessment (GDA), a multi-step regulatory process. Step 1 (Initiation) was completed in April 2023, Step 2 (Fundamental Assessment) in July 2024, and Step 3 (Detailed Assessment) commenced in July 2024 with planned completion by August 2026. Rolls-Royce SMR also received the first regulatory justification approval for an SMR design in the United Kingdom.¹³

In November 2025, the United Kingdom government selected the Wylfa nuclear site on the island of Anglesey, North Wales, to host at least three Rolls-Royce SMRs, with potential capacity for up to eight units. The Welsh Government described the project as an initial investment of £2.5 billion. Great British Energy Nuclear (GBE-N) will begin site activity in 2026, with the government targeting power delivery to the grid from the mid-2030s.¹⁶

GE Vernova Inc (GEV)

NYSE: GEV | Headquarters: Cambridge, Massachusetts, United States | Market Cap: ~$244 billion USD

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The BWRX-300 at Darlington, Ontario, is the most advanced Western SMR construction project. Source: GE Vernova Hitachi Nuclear Energy.

GE Vernova Inc (GEV) is developing the BWRX-300 through GE Vernova Hitachi Nuclear Energy, a joint venture between GE Vernova and Hitachi Ltd. The BWRX-300 is a 300 MWe boiling water reactor (BWR) that simplifies the traditional BWR design by eliminating recirculation pumps, jet pumps, and associated piping, achieving what the company describes as approximately one-tenth the size and complexity of a conventional BWR.¹⁴

The BWRX-300 at Darlington, Ontario, is the most advanced SMR construction project in the Western world. Ontario Power Generation (OPG) has contracted to build four BWRX-300 units at the Darlington New Nuclear Project site. In April 2025, the Canadian Nuclear Safety Commission (CNSC) granted OPG a license to construct the first unit, and OPG received final provincial approval in May 2025. The combined four units will deliver 1.2 GW of baseload power.¹⁵

Early site preparation work has been completed, with key components including the reactor pressure vessel currently in manufacturing. A tunnel boring machine arrived from Germany for assembly in early 2026. OPG is targeting commercial operation of the first unit by the end of 2029, drawing on more than 7,000 lessons learned from the Darlington refurbishment project completed in early 2026.¹⁶

Beyond Canada, GE Vernova Hitachi has signed a Generic Design Agreement with OSGE in Poland in February 2026 and is exploring BWRX-300 deployment in Southeast Asia. For GEV shareholders, the BWRX-300 program represents one component within a diversified power equipment business that generated $38.1 billion in total revenue in fiscal year 2025.¹⁷

Cameco Corp (CCJ)

NYSE: CCJ / TSX: CCO | Headquarters: Saskatoon, Saskatchewan, Canada | Market Cap: ~$49 billion USD

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Westinghouse’s AP300 licensing timeline: design approval by 2027, construction-ready by 2030. Source: Westinghouse AP300 SMR.

Cameco Corp (CCJ) holds a 49% ownership stake in Westinghouse Electric Company, the nuclear technology provider developing two SMR designs: the AP300 (a 300 MWe class pressurized water reactor rated at 330 MWe) and the eVinci (a micro-reactor). Brookfield holds the remaining 51%. Cameco acquired its stake as part of a joint acquisition that closed in 2023, positioning the company across the full nuclear fuel cycle from uranium mining through reactor technology.¹⁸

The AP300 is derived from Westinghouse’s AP1000 technology, of which six units are currently operating (two at Plant Vogtle in the United States, four in China) with four additional AP1000 units under construction in China. According to Cameco’s Q4 2025 investor presentation, the AP300 licensing timeline runs from 2022 to 2027, followed by project preparation from 2027 to 2030 and a 36-month construction period, placing the first unit ready for construction around 2030 and first commercial operation around 2033.¹⁹

Westinghouse has agreements or Memorandums of Understanding in place with Great British Nuclear, Ukraine, and Slovakia for AP300 deployment, with additional sites under consideration in the United States, Canada, and Europe. In the United Kingdom, Community Nuclear Power is planning four AP300 units at Teesside.

On October 27, 2025, Cameco, Brookfield, and the United States Department of Commerce announced a strategic partnership with an $80 billion USD aggregate investment value to facilitate financing and approvals for new Westinghouse AP1000 reactors in the United States. The structure includes a participation interest where the United States Government receives 20% of cash distributions from Westinghouse exceeding $17.5 billion USD.

Westinghouse’s New Build segment (covering AP1000 and AP300) generated approximately $800 million USD in revenue in 2025, representing 16% of total Westinghouse revenue. The core business (outage services, long-term operations, nuclear fuel) generated approximately $4.3 billion USD.

NANO Nuclear Energy Inc (NNE)

NASDAQ: NNE | Headquarters: New York, United States | Market Cap: ~$1.15 billion USD

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The KRONOS MMR is a 15 MWe stationary high-temperature gas-cooled reactor using helium coolant and FCM fuel incorporating TRISO particles in a silicon carbide matrix. Source: NANO Nuclear Energy Q1 FY2026 Presentation.

NANO Nuclear Energy Inc (NNE) is developing the KRONOS MMR™, a 45 MWt (15 MWe) stationary high-temperature gas-cooled reactor (HTGR) using helium coolant and Fully Ceramic Microencapsulated (FCM) fuel, which incorporates TRISO particles in a silicon carbide matrix. The company acquired the KRONOS technology along with the portable LOKI MMR™ from Ultra Safe Nuclear Corporation in early 2025, inheriting a design platform with a high technology readiness level built on decades of prior HTGR operating history spanning programmes including Dragon, Fort St. Vrain, AVR, and China’s HTR-PM.²⁰

On April 2, 2026, NANO Nuclear became the first commercially-ready microreactor developer and the third commercially-ready Generation IV advanced reactor developer to submit a Construction Permit Application (CPA) to the US Nuclear Regulatory Commission (NRC). The CPA was formally submitted by The Grainger College of Engineering at the University of Illinois Urbana-Champaign (U. of I.), NANO Nuclear’s partner for the first KRONOS MMR prototype deployment on campus. The company estimates the NRC formal review period will take approximately 12 months, with construction activities at the U. of I. site targeted to begin by mid-to-late 2027 and the prototype to be operational around 2030.²¹

In Canada, NANO Nuclear is pursuing regulatory approval through the Canadian Nuclear Safety Commission (CNSC), where the KRONOS MMR was the first microreactor to enter the Phase 1 pre-licensing process. The company’s acquisition of Global First Power (rebranded True North Nuclear) provides an existing Canadian licensing application for a KRONOS MMR demonstration project at Chalk River, Ontario. The company also plans a reduced-scale non-nuclear engineering demonstration unit at its Oak Brook, Illinois technical facility to support engineering validation ahead of nuclear construction.

NANO Nuclear frames itself as a vertically integrated advanced nuclear company across five business lines: microreactor development, nuclear fuel fabrication, nuclear fuel transportation, nuclear space applications, and nuclear consulting. Its fuel subsidiaries include HALEU Energy Fuel Inc (developing a domestic HALEU fabrication pipeline) and Advanced Fuel Transportation Inc (AFT), which holds an exclusive licence for a patented high-capacity HALEU fuel transportation basket developed with US national laboratories. Strategic affiliate LIS Technologies, which uses laser isotope separation for uranium enrichment, received a Key Radioactive Material License in early 2026 and announced plans to invest USD 1.38 billion in a commercial enrichment facility in Oak Ridge, Tennessee.²²

Commercially, the company has signed a feasibility study agreement with BaRupOn to evaluate deploying KRONOS MMR reactors to provide up to 1 GW of power to a data centre and manufacturing campus, and MOUs with DS Dansuk (South Korea), Ameresco, and others covering deployment, manufacturing localization, and EPC integration. As of December 31, 2025, NANO Nuclear held cash and cash equivalents of USD 577.5 million following an oversubscribed private placement in October 2025 that raised approximately USD 400 million gross (approximately USD 379 million net of fees). Operating cash burn for Q1 FY2026 (quarter ended December 31, 2025) was USD 4.0 million, with a net loss from operations of USD 11.6 million for the quarter.²³

Risks

Regulatory timelines remain unpredictable. Nuclear licensing processes are lengthy and subject to revision. NuScale’s experience illustrates this clearly: the company holds the only NRC-certified SMR design, yet its commercial deployments have repeatedly shifted further out. Regulatory agencies in the United States, Canada, and the United Kingdom are processing multiple SMR applications simultaneously, and there is no guarantee that review timelines will hold.

None of these companies have generated meaningful revenue from SMR or MMR deployments. NuScale, Oklo, Terrestrial Energy, Terra Innovatum, and NANO Nuclear are pre-revenue on their reactor programs and continue to report significant operating losses. GE Vernova and Rolls-Royce have diversified revenue bases, but their SMR programs are net consumers of capital. Cameco’s Westinghouse investment generates revenue from its existing reactor servicing business, but the AP300 remains a development-stage program.

Construction cost overruns have historically plagued nuclear projects. Westinghouse’s AP1000 units at Plant Vogtle in Georgia experienced years of delays and billions of dollars in cost overruns, ultimately contributing to Westinghouse’s 2017 bankruptcy. While SMR proponents argue that factory fabrication and modular construction will reduce this risk, the hypothesis remains unproven at commercial scale.

HALEU fuel supply is constrained. Oklo’s Aurora reactor and NANO Nuclear’s KRONOS MMR both require high-assay low-enriched uranium (HALEU), which is currently produced commercially only in Russia. Domestic supply efforts are underway, including Oklo’s joint venture with Centrus Energy and NANO Nuclear’s own HALEU Energy Fuel subsidiary, but scaling production to meet demand from multiple advanced reactor programs presents a significant supply chain risk. NANO Nuclear is also developing its own fuel transportation subsidiary to address logistics constraints.

Competing technologies and public perception pose additional challenges. Natural gas, renewables paired with battery storage, and conventional large-scale nuclear all compete for utility capital budgets. Public opposition to nuclear siting remains a factor in some jurisdictions, and any operational incident at a nuclear facility worldwide could affect regulatory and public sentiment toward SMR deployment.

Conclusion

These eight companies represent the listed universe of SMR and MMR developers as of early 2026, spanning reactor types from proven pressurized water technology to experimental molten salt, fast reactor, and high-temperature gas-cooled designs. They range from pre-revenue startups like Oklo, Terra Innovatum, and NANO Nuclear to diversified industrial conglomerates like GE Vernova and Rolls-Royce, offering varying degrees of reactor-specific exposure.

The GE Vernova/OPG BWRX-300 at Darlington stands out as the closest to commercial operation among Western SMR projects, with a licensed construction site and a 2029 target. Terra Innovatum’s 2027 FOAK target is the most aggressive, though its 1 MWe SOLO occupies a fundamentally different market segment than grid-scale designs. NANO Nuclear’s KRONOS MMR CPA submission in April 2026 marks a meaningful regulatory step, though its 15 MWe output positions it squarely in the microreactor segment alongside Terra Innovatum rather than as a grid-scale power source. NuScale’s NRC certification is a meaningful regulatory moat, but the company has yet to translate that advantage into a contracted construction timeline in the United States.

For all eight companies, the period between 2026 and 2030 will be decisive. The first Western SMR or MMR to achieve commercial operation will set an important precedent for cost, construction schedule, and operational performance that will shape capital allocation decisions across the nuclear sector for decades to come.