Nuclear Fission & Fusion Energy Patents: Top Companies & Trends 2026
- Filing is concentrated but not locked up. the top 5 assignees hold 25.6% of all 2,496 records in scope, and the top 10 hold 37.3% — leaving most of the field to a long tail of single- and few-filing entrants.
- Growth resumed after a mid-decade dip. filings ran from 101 in 2021 to 137 in 2024, a 36% rise over that span, even though the peak year on record so far is 2020 at 187.
- Reactor and shielding classes dominate the mix. G21C (nuclear reactors) covers 50.7% of records and G21F (radiation protection) 13.6%, while fusion reactors (G21B) sit at just 6.2% — a much smaller, less contested pool.
Filing growth compares 2021 (101 records) with 2024 (137) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 2,496 records in scope (CR5), not by the ranked leaders only.
What the filing record shows
The dataset spans 2,496 published records filed against nuclear fission and fusion energy topics between 2015 and mid-2026, drawing on search terms that span light water and small modular reactors, the fuel cycle, waste management, safety, decommissioning, fusion materials and isotope production. Filing activity is not new or accelerating in a straight line: it rose to a peak of 187 records in 2020, eased back, then climbed again from 101 in 2021 to 137 in 2024 — a 36% increase over that three-year window. Because publication typically lags filing by around eighteen months, the 2025 and 2026 figures in the trend understate real activity and should not be read as a slowdown.
Reactor design work (G21C) is by far the largest single class, but radiation protection, nuclear power plant systems, fuel-cycle-adjacent drilling technology, and fusion reactors each carry a distinct filing signature. The receiving-office split — led by the United States, followed by the EPO and WIPO's PCT route — points to a field still filed nationally first and internationalized selectively, rather than one where PCT filing is the default entry point.
Filing trends and technology composition
Two views of the same 2,496-record dataset: filing volume over time, and how records distribute across IPC subclasses relevant to fission and fusion technology.
A dip, then a resumed climb
Annual filings ran from 134 in 2017 to a peak of 187 in 2020, before falling and then recovering to 137 by 2024 — the last year the trend can be treated as complete given publication lag. The partial 2025–2026 counts will fill in as later publications are indexed.
Reactor design leads a broad mix
G21C (nuclear reactors) appears in 50.7% of the 2,496 records, well ahead of G21F radiation protection (13.6%) and G21D nuclear power plants (9.3%). Fusion reactors (G21B, 6.2%) and nucleus conversion/isotope work (G21G, 5.9%) form smaller, more specialised pools. Because records can carry multiple IPC classes, these shares sum to more than 100%.
Shares are the percentage of the 2,496 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Nuclear Fission & Fusion Energy Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about nuclear fission & fusion energy patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaA representative filing and the most-cited records
Nuclear powered internal engine, nuclear fuel cycle and housing design improvement
The filing (Global Energy Research Associates, 2018) describes a nanofuel engine that receives a fissile-fuel, passive-agent and moderator mixture internally in an internal combustion engine to release nuclear energy, together with a method for recovering transuranic elements from spent nuclear fuel and converting them into nanofuel.Abstract condensed from the published filing for readability.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20150143806A1 | Quintuple-Effect Generation Multi-Cycle Hybrid Renewable Energy System with Integrated Energy Provisioning, S… | 268 |
| 2 | US20080128134A1 | Producing drive fluid in situ in tar sands formations | 261 |
| 3 | US20090189617A1 | Continuous subsurface heater temperature measurement | 258 |
| 4 | US20080174115A1 | Power systems utilizing the heat of produced formation fluid | 258 |
| 5 | US20090071652A1 | In SITU heat treatment from multiple layers of a tar sands formation | 245 |
| 6 | US7635023B2 | Time sequenced heating of multiple layers in a hydrocarbon containing formation | 231 |
| 7 | US7562707B2 | Heating hydrocarbon containing formations in a line drive staged process | 224 |
| 8 | US7533719B2 | Wellhead with non-ferromagnetic materials | 219 |
| 9 | US20090014180A1 | Moving hydrocarbons through portions of tar sands formations with a fluid | 213 |
| 10 | US20090014181A1 | Creating and maintaining a gas cap in tar sands formations | 212 |
Citation counts favour older filings in a searched corpus; treat them as a signal of influence rather than of current commercial relevance.
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Three read-throughs from the concentration, class and momentum data above.
The top of the ranking is real but not a lock
With the top 5 assignees holding just over a quarter of all records and the top 10 barely over a third, no single entrant controls the field the way a leader can in more mature energy sectors. That leaves substantial room for a well-drafted claim outside the leaders' core filings.
Reactor design is the densest single claim space
Half of all records touch nuclear reactor design (G21C), meaning most incremental reactor-configuration claims face heavy prior art. The smaller pools — fusion reactors at 6.2%, nucleus conversion at 5.9% — carry lighter prior-art density even though they sit in the same broad field.
Activity is building again, not fading
After the 2020 peak of 187 and a subsequent pullback, filings climbed from 101 in 2021 to 137 in 2024. Because publication lag means 2025–2026 figures are still incomplete, the honest read is renewed growth into a data window that has not yet fully reported.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to nuclear fission & fusion energy patent landscape, with the prior art for and against each one.
Who is filing, and where momentum sits
The assignee ranking covers 100 companies across the 2,496 records in scope. A handful of firms plus national labs and universities account for the top of the table; the rest of the ranking thins out quickly into single- and few-filing entrants.
One clear leader, then a steep drop-off
The top-ranked assignee holds 175 records against a fifth-place figure of 86 and a tenth-place figure of 45 — a steep early drop that flattens into a long tail across the rest of the ranked list.
University-industry pairs anchor collaborative filing
The strongest co-assignee links run through a university and its partner research bodies, with the top pairing appearing together on 22 records. This suggests fuel-cycle and materials work in this dataset often moves through sponsored academic research rather than solo corporate R&D.
Even active filers are pulling back in the newest year
Several of the more active assignees show sharp year-on-year declines in the latest year of data, and two established filers show zero records in that year. Given the roughly 18-month publication lag, this looks more like an indexing gap than an actual retreat from the field.
| Assignee | Recent year | YoY |
|---|---|---|
| Abilene Christian University | 2 | -71% |
| TerraPower LLC | 1 | -75% |
| Board of Regents of the University of Texas System | 1 | 0% |
| General Atomics | 1 | — |
| Shell Oil Company | 0 | — |
| Westinghouse Electric Corporation | 0 | — |
| Holtec International Inc. | 0 | — |
| Lawrence Livermore National Security, LLC | 0 | — |
Where to take this from here
The dataset points to open claim space in specific sub-branches and to a filing base that is still consolidating around a handful of leaders.
Map a freedom-to-operate position
Before drafting in reactor design (G21C), run a focused search against the densest prior art in that class rather than the field as a whole — half of all records touch it.
Explore FTO workflows in EurekaTrack the under-claimed branches
Fusion reactor materials and isotope production sub-areas carry lighter filing density; a monitoring watch on these classes can surface new entrants early.
Set up a watch in EurekaFollow the co-filing network
The strongest co-assignee pairs point to sponsored research partnerships; tracing these can reveal which labs and universities are steering fuel-cycle innovation.
Trace assignee networks in EurekaCommon questions about nuclear energy patents
Within this dataset of 2,496 records, one assignee leads with 175 records, well ahead of the fifth-ranked filer at 86 and the tenth at 45. The top 5 assignees combined hold 25.6% of all records and the top 10 hold 37.3%, which means that even the leading filers do not dominate the field outright. The remainder of the 100-company ranking thins into a long tail of firms, national labs and universities with far fewer filings each.
Filings ran from 101 in 2021 to 137 in 2024, a 36% increase over that span, following an earlier peak of 187 records in 2020. The 2025 and 2026 counts in the raw trend look lower, but that reflects the roughly 18-month lag between filing and publication rather than an actual drop in activity. The most reliable read is that filing activity was rebuilding through 2024, with later years still incomplete.
Nuclear reactor design, classified under IPC subclass G21C, appears in 50.7% of the 2,496 records in scope, making it by far the densest claim space in the dataset. Radiation protection and shielding (G21F, 13.6%) and nuclear power plant systems (G21D, 9.3%) follow at a distance. Fusion reactors (G21B, 6.2%) and nucleus conversion or isotope work (G21G, 5.9%) are comparatively small and less crowded pools within the same broad field.
The classes with the lowest filing density relative to the core reactor-design cluster include fusion reactor structural materials, isotope production for medical applications, and specific fuel-cycle steps such as transuranic separation from spent fuel. These are not zero-activity areas, but they carry noticeably less prior art than G21C reactor design, which covers over half of all records. A first claim in these branches has more room to be drafted broadly than an equivalent claim in mainstream reactor configuration work.
Both. The assignee ranking includes corporate filers alongside universities and national security laboratories, and the strongest co-assignee pairs in the dataset run through university-and-partner-research combinations, with the top pairing appearing together on 22 records. This pattern suggests that fuel-cycle, materials and fusion-adjacent research in this field often moves through sponsored academic partnerships rather than purely internal corporate R&D.
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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.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.