Small Modular Reactor (Fission) Design Patent Landscape
Korea Hydro & Nuclear Power dominates a moderately concentrated field, holding the largest single position among the top applicants, with the United States as the leading filing jurisdiction. The field is still expanding on a multi-year basis, though annual volume has eased from its 2023 peak and the most recent years are further understated by publication lag.
A Korean-led field with strong U.S. and European challenger presence
Korea Hydro & Nuclear Power Co. Ltd. ranks first among applicants, followed by NuScale Power and BWXT mPower — a Korean incumbent ahead of a U. S.-heavy challenger tier. The top five filers together account for 46% of the combined total among the hundred largest filers, signaling moderate-to-high concentration.
A visible tier gap separates the top three from the remainder of the ranking. Korea Hydro & Nuclear Power’s position is roughly double that of NuScale Power’s, and NuScale Power is nearly double BWXT mPower’s, indicating a steep drop-off after the first two positions before a denser mid-tier cluster.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | KOREA HYDRO & NUCLEAR POWER CO LTD | 37 | |
| 2 | NuScale Power LLC | 19 | |
| 3 | BWXT mPower Inc. | 11 | |
| 4 | Thorizon Holding BV | 9 | |
| 5 | Radiant Industries Inc. | 9 | |
| 6 | French Alternative Energies and Atomic Energy Commission (CEA) | 8 | |
| 7 | SMR Inventec LLC | 7 | |
| 8 | Westinghouse Electric Corporation | 7 | |
| 9 | KEPCO ENG & CONSTR CO INC | 7 | |
| 10 | Sejong University Industry-Academic Cooperation Group | 5 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | General Electric Company | 5 | |
| 12 | Holtec International Inc. | 5 | |
| 13 | BABCOCK & WILCOX MPOWER INC | 4 | |
| 14 | Advanced Reactor Concepts LLC | 4 | |
| 15 | Prodigy Clean Energy Ltd. | 4 | |
| 16 | SHANGHAI NUCLEAR ENGINEERING RESEARCH & DESIGN INS… | 3 | |
| 17 | Nova Chem (Int) SA | 3 | |
| 18 | Xi’an Jiaotong University | 2 | |
| 19 | Amirmokri Homi Nasrollah | 2 | |
| 20 | Southeast University | 2 |
The leader’s scale advantage in reactor design and coolant systems (G21C) implies that challengers seeking differentiation will likely need to focus on distinct sub-classes or application segments rather than competing head-on in core reactor architecture.
The most recent 18–24 months of filings are subject to standard patent publication lag and are likely under-counted; the figures for 2024 and 2025 should be treated as provisional. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
A 2023 filing surge concentrated in nuclear reactor design, with adjacent energy branches emerging
The annual trend and technology composition charts together reveal a field that accelerated sharply in 2023 and remains dominated by core nuclear reactor classes, with a thin but meaningful spread into downstream energy applications.
Annual filing trend
Filings held steady through 2017–2021, dipped in 2022, then surged to a peak in 2023 before easing in 2024. The 2024 and 2025 bars should be read as provisional due to publication lag; the multi-year growth rate of 169% confirms the field’s expansion remains real, not a statistical artifact.
↗ Hover for values · click a bar to ask EurekaTechnology composition
G21C (Nuclear reactors) and G21D (Nuclear power plants) together dominate the branch mix, reflecting that most filings address reactor architecture and plant integration. Smaller clusters in F01K (steam and thermal power plants), C25B (electrolytic production of compounds), and F22B (steam generation and boilers) indicate that a subset of applicants are extending SMR technology toward heat-to-work conversion and hydrogen co-production.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Cooling device and cooling method for small modula…
A small modular reactor cooling device and cooling method are provided. A small modular reactor cooling device includes: a reactor vessel in which a coolant circulates along a flow path structure; and a coolant storage unit provided inside the reactor vessel and charged with the coolant inside based on the circulating flow, wherein the coolant storage unit… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Modular nuclear reactor for a land-based power pla… | 128 |
| 2 | Inadvertent actuation block valve for a small modu… | 25 |
| 3 | Optimized nuclear fuel core design for a small mod… | 25 |
| 4 | SLIMM-Scalable Liquid Metal Cooled Small Modular R… | 24 |
| 5 | Wind-solar reactor system and working method thereof | 21 |
| 6 | Modular nuclear reactor | 18 |
| 7 | 小模块化反应堆安全系统 | 15 |
| 8 | 一种自充压堆芯补水系统 | 15 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the SMR patent structure means for R&D prioritization
The competitive structure, life-cycle stage, and technology distribution each carry distinct implications for teams evaluating where to invest in SMR fission design.
Growth stage — multi-year expansion intact despite post-2023 easing
The field is classified as Growth, with a three-year filing window sitting 169% above the prior three-year window. Annual volume has eased from the 2023 peak, but this likely reflects both natural cyclicality and publication lag rather than saturation. The core design space (G21C, G21D) remains active, and newer application branches are still accumulating filings.
Life-cycle: GrowthModerate-to-high concentration with a pronounced leader gap
The top five filers account for 46% of the combined total among the hundred largest filers. Korea Hydro & Nuclear Power’s position is roughly twice that of NuScale Power, creating a clear first-mover advantage in core reactor IP. Mid-tier applicants — including Thorizon Holding, Radiant Industries, and CEA — hold meaningful but smaller positions, suggesting the field is not yet locked up for challengers with differentiated designs.
Concentration: Moderate-highLimited co-filing activity; NuScale–Curtiss-Wright is the only observed pairing
The only documented co-applicant relationship in the evidence is between NuScale Power and Curtiss-Wright Flow Control, with two joint filings. This sparse collaboration pattern suggests most participants are protecting proprietary designs independently rather than building shared IP platforms. For new entrants, co-development partnerships represent a relatively open ecosystem avenue.
Collaboration: SparseU.S. and South Korea lead filings; PCT and EPO coverage signals export intent
The United States holds the largest share of jurisdictional filings, followed closely by South Korea and WIPO (PCT). Europe (EPO) and Canada also appear prominently, reflecting applicants’ intent to protect SMR designs across prospective deployment markets. China and Japan account for smaller but non-trivial filing counts, indicating awareness of those markets among at least some applicants.
Geography: US + KR coreGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| NuScale Power LLC | Curtiss-Wright Flow Control Corporation | 2 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Korea Hydro & Nuclear Power leads in reactor design; NuScale Power pivots toward power plant integration and hydrogen
The two largest filers occupy distinct technical spaces within the SMR design spectrum, reducing direct overlap and shaping the competitive dynamic for the rest of the field.
Korea Hydro & Nuclear Power Co. Ltd.
The leading applicant holds 37 patent records, concentrated across G21C subclasses covering reactor design, coolant systems, and safety systems. Momentum data shows the position is largely built from recent activity, classified as a new entrant in the evidence window, with 28 filings in the recent period. This suggests an accelerating IP build-out rather than a long-established portfolio.
patent records: 37NuScale Power LLC
NuScale Power holds 19 patent records and shows a distinctive technology emphasis: while it has G21D (nuclear power plant integration) filings, it also holds a cluster in C25B (electrolytic production of compounds), pointing toward hydrogen co-production as a differentiated application layer. Like the leader, NuScale is classified as a new entrant in the evidence window, with 16 recent filings, indicating an ongoing and active filing program.
patent records: 19| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Korea Hydro & Nuclear Power Co. Ltd. | 28 | ▲ new entrant |
| NuScale Power LLC | 16 | ▲ new entrant |
| Radiant Industries Inc. | 2 | ▲ new entrant |
| French Alternative Energies and Atomic Energy Commission (CEA) | 8 | ▲ new entrant |
| Holtec International Inc. | 5 | ▲ new entrant |
Under-served adjacent branches worth monitoring in SMR fission design
Several IPC branches adjacent to the dominant G21C/G21D core have low filing counts relative to the corpus, suggesting areas where intellectual property is sparse. These observations warrant investigation but should not be treated as validated opportunities without further technical and market analysis.
C25B · Electrolytic production of compounds (hydrogen co-production)
With only 7 patent records and a 2% share of the branch mix, C25B is thinly covered relative to the core reactor classes. Technically, SMR heat and electricity are well-suited to drive electrolysis for hydrogen or ammonia production, and NuScale Power’s existing filings here demonstrate a plausible entry path. The sparse IP landscape means differentiated process integration concepts may face limited blocking prior art.
Search this in Eureka →F01K · Steam and thermal power plants (heat-to-work conversion)
F01K holds 9 patent records at a 3% share, the largest of the white-space branches but still sparse for a technology whose core output is thermal energy. SMR-specific steam cycle designs, combined heat and power configurations, and industrial process heat integration represent technically credible applications with limited dedicated IP coverage. Holtec International’s existing F01K activity indicates at least one established player is working this angle.
Search this in Eureka →How leading applicants differ across technology routes
Route coverage across the main technology branches in the current evidence set.
| Player | G21C 1 · Nuclear reactors | G21C 15 · Nuclear reactors | G21C 3 · Nuclear reactors | G21D 1 · Nuclear power plants | G21C 13 · Nuclear reactors |
|---|---|---|---|---|---|
| Korea Hydro & Nuclear Power Co. Ltd. | Strong · 28 | Strong · 25 | Absent | Emerging · 2 | Absent |
| French Alternative Energies and Atomic Energy Commission (CEA) | Strong · 6 | Strong · 5 | Absent | Strong · 4 | Strong · 5 |
| Thorizon Holding BV | Strong · 9 | Absent | Strong · 7 | Absent | Emerging · 1 |
| Babcock & Wilcox mPower Inc. | Strong · 7 | Absent | Strong · 4 | Absent | Strong · 5 |
| General Electric Company | Strong · 5 | Strong · 5 | Absent | Absent | Strong · 5 |
| NuScale Power LLC | Strong · 6 | Moderate · 3 | Absent | Strong · 5 | Absent |
| Westinghouse Electric Corporation | Strong · 4 | Strong · 6 | Absent | Absent | Absent |
Frequently asked questions
The corpus contains 142 patent families in scope. Filing activity peaked in 2023 and has eased since, though the most recent years are subject to publication lag and are likely under-counted.
Korea Hydro & Nuclear Power Co. Ltd. is the top-ranked applicant with 37 patent records, followed by NuScale Power LLC with 19 patent records and BWXT mPower Inc. with 11 patent records.
The United States leads jurisdictional filings, followed by South Korea and WIPO (PCT). Europe (EPO) and Canada also feature prominently, reflecting applicants’ multi-market protection strategies.
The field is classified as Growth. The most recent three-year filing window sits 169% above the prior three-year window on a multi-year basis, though annual volume has eased from the 2023 peak and the latest years are further understated by publication lag.
G21C (Nuclear reactors) and G21D (Nuclear power plants) account for the large majority of patent-record filings. Smaller clusters appear in F01K (steam and thermal power plants), C25B (electrolytic production of compounds), and F22B (steam generation and boilers).
The most notable sparse adjacent branches are F01K (steam and thermal power plants) with 9 patent records and C25B (electrolytic production of compounds) with 7 patent records. Both represent plausible SMR application areas — heat-to-work conversion and hydrogen co-production respectively — with limited dedicated prior art coverage.
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Disclaimer. This page is generated from PatSnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
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