Company lists · Data refreshed September 2026
Top 25 Advanced reactor design companies worldwide
RevenueBase identified 408 advanced reactor design companies worldwide as of September 2026 and tracks 64,348 professional contacts across them, including 15,084 with verified work emails. The United States is the largest market and New York the largest hub.
This list covers advanced reactor design companies worldwide, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 19, 2026. Country and city lists for advanced reactor design companies follow the table.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest advanced reactor design companies worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 12,439 contacts → | ||||
Indirect evidence “Framatome is an international leader in nuclear energy recognized for its innovative, digital and value added solutions for the global nuclear fleet.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 10,898 contacts → | ||||
Indirect evidence “Westinghouse Electric Company is the world's leading supplier of safe and innovative nuclear technology.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 6,518 contacts → | ||||
Indirect evidence “Assystem, one of the world's leading independent nuclear engineering companies, is committed to accelerating the energy transition.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 4,531 contacts → | ||||
Indirect evidence “The freedom to explore.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 3,832 contacts → | ||||
Indirect evidence “At BWX Technologies, Inc.(NYSE: BWXT), we are People Strong, Innovation Driven.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 2,229 contacts → | ||||
Indirect evidence “Canada's premier nuclear science and technology organization.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 1,315 contacts → | ||||
Indirect evidence “TechnicAtome est spécialisée, depuis plus de 50 ans, dans la conception, la réalisation, la mise en service et le maintien en conditions opérationnelles des réacteurs nucléaires…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 1,055 contacts → | ||||
Indirect evidence “X-energy is delivering the next generation of carbon-free energy by reinventing nuclear power.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 913 contacts → | ||||
Indirect evidence “TerraPower is a leading nuclear innovation company that strives to improve the world through nuclear energy and science.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 640 contacts → | ||||
Indirect evidence “Since launching in 2021 newcleo has quickly established itself as innovator in the field of nuclear energy.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 579 contacts → | ||||
Indirect evidence “KEPCO E&C was founded in 1975 with the objective of obtaining core technology.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 494 contacts → | ||||
Partial evidence “NuScale has designed a new kind of nuclear power plant that is smarter, safer, cleaner, and more cost competitive than the large gigawatt nuclear power plants of the past.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 487 contacts → | ||||
Indirect evidence “TECNATOM was set up in 1957 as a Spanish engineering company specialising in guaranteeing the operation and maintenance of nuclear power plants to the highest levels of safety.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 485 contacts → | ||||
Indirect evidence “Kairos Power has a mission to enable the world’s clean energy transition to improve people’s quality of life while protecting the environment.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 404 contacts → | ||||
Indirect evidence “GSE Solutions supports nuclear power and clean-energy fleets worldwide through integrated engineering services and software that strengthen operational performance.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 395 contacts → | ||||
Indirect evidence “The joint stock company ÚJV Řež is building on the six decades of experience of its predecessor – the Nuclear Research Institute (NRI).” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 345 contacts → | ||||
Indirect evidence “Se ocupa de la primera parte del ciclo de combustible nuclear (diseño, fabricación y abastecimiento de combustible) prestando servicios de ingeniería y combustible a las Centrales…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 297 contacts → | ||||
Indirect evidence “We support our clients by delivering safe, practical and efficient solutions to complex nuclear challenges, with a strong focus on disposability.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 278 contacts → | ||||
Indirect evidence “TAE Technologies (pronounced T-A-E) was founded in 1998 to develop commercial fusion power with the cleanest environmental profile.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 273 contacts → | ||||
Indirect evidence “We are developing the technology to deliver clean, secure and affordable fusion energy in the 2030s.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 254 contacts → | ||||
Indirect evidence “Fabricación de componentes para la industria nuclear.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 234 contacts → | ||||
Strong evidence “Paragon tackles the most difficult challenges of the nuclear industry-those faced by the current operating fleet as well as the next generation of advanced reactors.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 226 contacts → | ||||
Indirect evidence “Oklo's mission is to provide clean, reliable, affordable energy through the deployment of next-generation fast fission technology and recycling nuclear waste.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 211 contacts → | ||||
Indirect evidence “Partner for the nuclear industry Bilfinger has successfully supported and advised customers from the nuclear industry for decades.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 201 contacts → | ||||
Indirect evidence “IRESNE est un institut du CEA implanté sur le centre CEA de Cadarache.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: advanced reactor design companies. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names advanced reactor design companies.
- Partial evidence
- Its own public description names part of advanced reactor design companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name advanced reactor design companies. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 408 advanced reactor design companies worldwide
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Advanced reactor design companies worldwide at a glance
As of Sep 19, 2026Companies by employee count
Email recency is reported on each country list linked below.
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among advanced reactor design companies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
- Coverage
- Every country. Country and city lists for advanced reactor design companies are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “advanced reactor design companies”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names advanced reactor design companies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among advanced reactor design companies, and records with no verified work email.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 15,084 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 19, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Advanced reactor design companies by location
3 lists · largest firstEvery Advanced reactor design companies list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names advanced reactor design companies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many advanced reactor design companies are there worldwide?
RevenueBase identified 408 advanced reactor design companies worldwide as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
Framatome, headquartered in Courbevoie, tops this list with the largest team on record.
Which country has the most advanced reactor design companies?
The United States leads with 125 companies, followed by France (27) and the United Kingdom (25). Every advanced reactor design companies list by country and city is linked on this page.
Which city has the most advanced reactor design companies?
New York leads with 7 headquartered companies, followed by Cambridge (5) and Toronto (5).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 15,084 verified decision-maker contacts tracked across these 408 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 19, 2026.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.