MSR Passive Safety Patent Landscape 2026
The molten salt reactor passive safety field is in active growth, with a 160% expansion in the recent filing window and annual volume reaching its highest recorded level in 2024. The patent corpus is moderately concentrated, with a university-led alliance anchoring the top positions alongside a cluster of dedicated advanced-fission startups.
Abilene Christian University leads a concentrated but startup-rich field
Abilene Christian University holds the top position in the applicant ranking, followed by Terrestrial Energy Inc, TerraPower LLC, Alpha Tech Research Corp, and Saltfoss Energy ApS. The top five filers collectively account for 59% of the hundred largest filers’ combined patent records, signaling meaningful concentration at the front of the pack.
A clear two-tier structure is visible: the top four applicants each hold substantially more patent records than any entity in the second tier, where Texas. A&M University, Natura Resources LLC, and Georgia Tech Research Corporation occupy the mid-range. Beyond those, a long tail of smaller academic and startup entities each holds fewer than ten records.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Abilene Christian University | 40 | |
| 2 | Terrestrial Energy Inc | 34 | |
| 3 | TerraPower LLC | 29 | |
| 4 | Alpha Tech Research Corp | 24 | |
| 5 | Saltfoss Energy ApS | 13 | |
| 6 | TEXAS A&M UNIVERSITY | 12 | |
| 7 | Natura Resources LLC | 12 | |
| 8 | Board of Regents, The University of Texas System | 9 | |
| 9 | Georgia Tech Research Corporation | 9 | |
| 10 | Westinghouse Electric Corporation | 6 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Transatomic Power Corp | 5 | |
| 12 | Copenhagen Atomics AS | 5 | |
| 13 | Elysium Industries Ltd | 5 | |
| 14 | Korea Atomic Energy Research Institute | 4 | |
| 15 | Brown Rudnick LLC | 3 | |
| 16 | Curio Solutions LLC | 3 | |
| 17 | U.S. Department of Energy | 2 | |
| 18 | Thorium Tech Solution | 2 | |
| 19 | Aikon Techno Inc | 2 | |
| 20 | CEA (Commissariat à l’Energie Atomique et aux Energies Alternatives) | 2 |
The university-led top position—Abilene Christian University with 40 patent records—reflects the foundational, research-oriented nature of the technology at this stage. Commercial developers such as Terrestrial Energy and TerraPower cluster immediately behind, suggesting that IP is transitioning from academic proof-of-concept toward commercial-grade system design.
Filings from approximately the last 18–24 months are subject to publication lag and are likely under-counted; the 2025 and 2026 figures in particular 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.
Filing activity surged in 2023–2024; reactor design dominates the technology mix
Two charts together reveal a field that accelerated sharply after a mid-period trough and remains overwhelmingly focused on core reactor physics, with only a thin dispersal into adjacent technical branches.
Annual filing trend
Annual filings troughed at three records in 2021, then recovered strongly to 24 in 2023 and reached 48 in 2024—the highest single-year total on record. The 2025 figure of 13 and the zero count for 2026 reflect publication lag, not a reversal; treat those years as provisional undercounts. The 160% growth across the recent window confirms that the field is in active expansion.
↗ Hover for values · click a bar to ask EurekaTechnology composition
G21C (Nuclear reactors) dominates the technology composition by a wide margin, with 233 patent records, while G21F (Radiation protection and shielding) and G21G (Conversion of nuclei) are the next most populated branches at 19 and 13 records respectively. All remaining IPC classes hold single-digit or very low counts, indicating that most filers are focused on reactor system design rather than on adjacent disciplines such as materials science, corrosion engineering, or heat exchange.
↗ 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.
SCHMELZSALZREAKTORSYSTEM
The present invention relates to a molten salt reactor system comprising a reactor vessel comprising a reactor core in an upper compartment, and one or more drain tanks situated in a lower compartment below the upper compartment, and a molten fuel salt pump, and a heat exchanger, wherein a molten fuel salt flow direction is provided in a fuel salt loop… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Molten nuclear fuel salts and related systems and … | 81 |
| 2 | Heat pipe molten salt fast reactor with stagnant l… | 77 |
| 3 | Fission reaction control in a molten salt reactor | 66 |
| 4 | Molten Salt Reactor | 62 |
| 5 | Integral molten salt reactor | 57 |
| 6 | Small-fluid molten salt reactor | 51 |
| 7 | Fission reaction control in a molten salt reactor | 48 |
| 8 | Molten Salt Reactor | 48 |
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 IP structure means for R&D investment decisions
The combination of accelerating filings, high concentration among a small set of university–startup pairs, and a shallow technology mix beyond the core reactor class shapes both the risk and opportunity profile for new entrants.
Growth stage: annual filings still rising
The lifecycle evidence places MSR passive safety firmly in the Growth stage. Annual filing volume is still rising, with 2024 marking the highest recorded year, and the multi-year window shows 160% expansion. This signals that foundational IP positions are still being established, making early-mover filing advantageous but also meaning that dominant claims are not yet locked in across all subsystems.
Growth stageTop five hold 59% of the hundred largest filers’ records
The top five applicants—Abilene Christian University, Terrestrial Energy Inc, TerraPower LLC, Alpha Tech Research Corp, and Saltfoss Energy ApS—together hold 59% of the combined patent records among the top 100 filers. This concentration is high enough that new entrants face an established core, yet the long tail of active smaller filers indicates the field has not yet closed off to challengers, particularly in adjacent technical branches.
Moderate-high concentrationAbilene Christian University anchors a multi-institution alliance
The most active co-filing relationships in evidence are: Abilene Christian University with Texas A&M University (11 joint records), Abilene Christian University with Georgia Tech Research Corporation (6), Texas A&M University with Georgia Tech Research Corporation (6), Abilene Christian University with the Board of Regents of the University of Texas System (5), and Texas A&M University with the same UT System board (5). A separate pairing exists between Seaborg Technologies and Saltfoss Energy ApS (2). The dominant collaboration cluster is a US academic consortium centered on Abilene Christian University.
University-led consortiumUS-primary filing with meaningful PCT and European coverage
The United States leads jurisdictional filings at 54 patent records, followed by Europe (EPO) at 39, WIPO (PCT) at 37, and Canada at 32. Australia, India, and South Korea each have a presence, while China and Japan hold only 5 records each—notably low given those nations’ stated interest in advanced fission. This geographic gap in Asia suggests that current IP holders have limited enforcement coverage in two major potential deployment markets.
US-EPO-PCT primaryGo 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 |
|---|---|---|
| Abilene Christian University | Texas A&M University | 11 |
| Abilene Christian University | Georgia Tech Research Corporation | 6 |
| Texas A&M University | Georgia Tech Research Corporation | 6 |
| Abilene Christian University | Board of Regents, The University of Texas System | 5 |
| Texas A&M University | Board of Regents, The University of Texas System | 5 |
| Seaborg Technologies | Saltfoss Energy ApS | 2 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Abilene Christian University and Terrestrial Energy lead distinct strategic postures
The top two applicants differ meaningfully in technology emphasis and institutional character: the leader is a university with a broad reactor-design and fuel-cycle focus, while the first commercial challenger concentrates on reactor system integration and monitoring.
Abilene Christian University
Abilene Christian University holds 40 patent records, the highest count in the corpus, and its momentum is classified as a new entrant—reflecting a rapid recent build-up with 37 of those records filed in the recent window. Its technology focus spans G21C 19 (reactor operation and fuel handling, 26 records), G21C 3 (reactor fuel elements, 20 records), and G21C 1 (reactor types, 13 records), indicating a broad foundational position across passive safety, fuel management, and reactor architecture. Its collaborative network with Texas A&M University, Georgia Tech Research Corporation, and the UT System further reinforces its role as the hub of the dominant US academic consortium.
patent records: 40Terrestrial Energy Inc
Terrestrial Energy Inc holds 34 patent records and anchors the commercial challenger tier. Its technology emphasis is concentrated in G21C 1 (reactor types, 33 records), G21C 17 (reactor instrumentation and control, 20 records), and G21C 5 (reactor moderator and reflector, 15 records)—a profile that reflects integrated system design and operational safety rather than fuel-cycle fundamentals. No momentum data places it in the recent entrant category in the evidence; its position reflects a mature, deep filing posture in commercial-grade molten salt reactor IP.
patent records: 34| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Abilene Christian University | 37 | ▲ new entrant |
| Alpha Tech Research Corp | 3 | ▼ -86% |
| Texas A&M University | 10 | ▲ new entrant |
| Natura Resources LLC | 9 | ▲ new entrant |
| Saltfoss Energy ApS | 8 | ▲ new entrant |
| Board of Regents, The University of Texas System | 5 | ▲ new entrant |
| Georgia Tech Research Corporation | 6 | ▲ new entrant |
Under-served technical branches adjacent to the reactor core
Beyond the dominant G21C class, several IPC branches have low patent-record counts relative to the activity level in the field; these represent areas where coverage is thin and where targeted filings could establish differentiated positions.
G21F · Radiation protection and shielding
With only 19 patent records and a 6% share of the branch distribution, radiation protection and shielding is the most populated of the sparse adjacent branches but remains thinly covered relative to the core reactor class. For MSR passive safety, shielding design is directly relevant to decay-heat management and freeze-plug containment; an applicant with materials or structural expertise could file targeted claims here with limited incumbent overlap.
Search this in Eureka →G21D · Nuclear power plants (balance-of-plant integration)
G21D holds only 10 patent records, representing approximately 3% of the branch distribution. Balance-of-plant integration—covering power conversion, thermal coupling, and grid interface—is technically necessary for any deployed MSR but is almost absent from current filings. Entrants with thermal engineering or turbomachinery expertise face very low incumbent density here, though the realistic entry path requires coupling MSR-specific passive safety claims to conventional power-plant system architecture.
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 3 · Nuclear reactors | G21C 19 · Nuclear reactors | G21C 15 · Nuclear reactors | G21C 17 · Nuclear reactors |
|---|---|---|---|---|---|
| TerraPower LLC | Strong · 29 | Strong · 23 | Strong · 18 | Moderate · 7 | Moderate · 13 |
| Terrestrial Energy Inc | Strong · 33 | Moderate · 11 | Emerging · 4 | Moderate · 9 | Strong · 20 |
| Abilene Christian University | Moderate · 13 | Strong · 20 | Strong · 26 | Moderate · 9 | Absent |
| Alpha Tech Research Corp | Strong · 12 | Strong · 15 | Strong · 16 | Emerging · 3 | Absent |
| Saltfoss Energy ApS | Strong · 11 | Strong · 9 | Absent | Moderate · 3 | Absent |
| Texas A&M University | Moderate · 4 | Strong · 9 | Absent | Strong · 7 | Absent |
Frequently asked questions
The evidence covers 161 patent families in scope. The United States is the leading filing jurisdiction at 54 patent records, followed by Europe (EPO) at 39 and WIPO (PCT) at 37.
Abilene Christian University holds the top position with 40 patent records, ahead of Terrestrial Energy Inc (34), TerraPower LLC (29), Alpha Tech Research Corp (24), and Saltfoss Energy ApS (13). The top five together account for 59% of the combined total among the hundred largest filers.
The field is in the Growth stage. Annual filings reached their highest recorded level in 2024 at 48 records, up from a trough of 3 in 2021, and the recent multi-year window shows 160% growth. The 2025 and 2026 counts are likely understated due to publication lag and should not be read as a reversal.
G21C (Nuclear reactors) accounts for the large majority of patent records at 233, reflecting that most IP is focused on reactor system design. Adjacent branches—G21F (Radiation protection and shielding, 19 records), G21G (Conversion of nuclei, 13 records), and G21D (Nuclear power plants, 10 records)—are each significantly smaller.
Both are active. Abilene Christian University leads the overall ranking, and a US academic consortium involving Texas A&M University, Georgia Tech Research Corporation, and the UT System Board of Regents is the most active collaboration cluster. Commercial developers—Terrestrial Energy Inc, TerraPower LLC, and Saltfoss Energy ApS—occupy the next tier, indicating the field is transitioning from academic IP toward commercial system patents.
The clearest under-served adjacent branches are G21F (Radiation protection and shielding, 19 records), G21G (Conversion of nuclei, 13 records), G21D (Nuclear power plant balance-of-plant integration, 10 records), G01N (Material analysis and testing, 6 records), and C01G (Compounds of other metals, 5 records). These branches have low filing density relative to the core G21C class and may offer differentiated filing opportunities for entrants with relevant technical expertise.
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