Company lists · Data refreshed September 2026

Top 25 Advanced reactor design companies worldwide

RevenueBase identified 408 company matches for 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 company matches for advanced reactor design companies worldwide, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. 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 SmartSearch, 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.

How to read this list RevenueBase SmartSearch · Exact Recorded Sep 19, 2026 How this list was built
408Companies
64,348Contacts tracked
15,084Verified emails
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The 25 largest advanced reactor design companies worldwide

Ranked by team size
Top 25 of 408 company matches for advanced reactor design companies worldwide, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 19, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchCourbevoie, FranceHQ recorded Sep 19, 202610001+12,439 contacts →

Exact match

“Framatome is an international leader in nuclear energy recognized for its innovative, digital and value added solutions for the global nuclear fleet.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
2Exact matchCranberry Township, PA, United StatesHQ recorded Sep 19, 20265,001-10,00010,898 contacts →

Exact match

“Westinghouse Electric Company is the world's leading supplier of safe and innovative nuclear technology.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
3Exact matchCourbevoie, FranceHQ recorded Sep 19, 20265,001-10,0006,518 contacts →

Exact match

“Assystem, one of the world's leading independent nuclear engineering companies, is committed to accelerating the energy transition.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
4Exact matchSan Diego, CA, United StatesHQ recorded Sep 19, 202610001+4,531 contacts →

Exact match

“The freedom to explore.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
5Exact matchLynchburg, VA, United StatesHQ recorded Sep 19, 20265,001-10,0003,832 contacts →

Exact match

“At BWX Technologies, Inc.(NYSE: BWXT), we are People Strong, Innovation Driven.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
6Exact matchChalk River, ON, CanadaHQ recorded Sep 19, 20261,001-5,0002,229 contacts →

Exact match

“Canada's premier nuclear science and technology organization.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
7Exact matchVilliers-le-bâcle, FranceHQ recorded Sep 19, 20261,001-5,0001,315 contacts →

Exact match

“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…”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
8Exact matchRockville, MD, United StatesHQ recorded Sep 19, 2026501-1,0001,055 contacts →

Exact match

“X-energy is delivering the next generation of carbon-free energy by reinventing nuclear power.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
9Exact matchBellevue, WA, United StatesHQ recorded Sep 19, 2026501-1,000913 contacts →

Exact match

“TerraPower is a leading nuclear innovation company that strives to improve the world through nuclear energy and science.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
10Exact matchParis, ItalyHQ recorded Sep 19, 2026501-1,000640 contacts →

Exact match

“Since launching in 2021 newcleo has quickly established itself as innovator in the field of nuclear energy.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
11Exact matchPort Elgin, CanadaHQ recorded Sep 19, 20261,001-5,000579 contacts →

Exact match

“KEPCO E&C was founded in 1975 with the objective of obtaining core technology.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
12Exact matchCorvallis, OR, United StatesHQ recorded Sep 19, 2026201-500494 contacts →

Exact match

“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.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
13Exact matchSan Sebastian De Los Reyes, SpainHQ recorded Sep 19, 2026501-1,000487 contacts →

Exact match

“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.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
14Exact matchAlameda, CA, United StatesHQ recorded Sep 19, 2026501-1,000485 contacts →

Exact match

“Kairos Power has a mission to enable the world’s clean energy transition to improve people’s quality of life while protecting the environment.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
15Exact matchColumbia, MD, United StatesHQ recorded Sep 19, 2026201-500404 contacts →

Exact match

“GSE Solutions supports nuclear power and clean-energy fleets worldwide through integrated engineering services and software that strengthen operational performance.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
16Exact matchHusinec-řež, Czech RepublicHQ recorded Sep 19, 2026501-1,000395 contacts →

Exact match

“The joint stock company ÚJV Řež is building on the six decades of experience of its predecessor – the Nuclear Research Institute (NRI).”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
17Exact matchMadrid, SpainHQ recorded Sep 19, 2026501-1,000345 contacts →

Exact match

“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…”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
18Exact matchChorley, United KingdomHQ recorded Sep 19, 2026501-1,000297 contacts →

Exact match

“We support our clients by delivering safe, practical and efficient solutions to complex nuclear challenges, with a strong focus on disposability.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
19Exact matchFoothill Ranch, CA, United StatesHQ recorded Sep 19, 2026201-500278 contacts →

Exact match

“TAE Technologies (pronounced T-A-E) was founded in 1998 to develop commercial fusion power with the cleanest environmental profile.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
20Exact matchMilton, United KingdomHQ recorded Sep 19, 2026201-500273 contacts →

Exact match

“We are developing the technology to deliver clean, secure and affordable fusion energy in the 2030s.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
21Exact matchMaliaño, SpainHQ recorded Sep 19, 2026201-500254 contacts →

Exact match

“Fabricación de componentes para la industria nuclear.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
22Exact matchFort Worth, TX, United StatesHQ recorded Sep 19, 2026201-500234 contacts →

Exact match

“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.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
23Exact matchSanta Clara, CA, United StatesHQ recorded Sep 19, 202651-200226 contacts →

Exact match

“Oklo's mission is to provide clean, reliable, affordable energy through the deployment of next-generation fast fission technology and recycling nuclear waste.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
24Exact matchMontrouge, FranceHQ recorded Sep 19, 20261,001-5,000211 contacts →

Exact match

“Partner for the nuclear industry Bilfinger has successfully supported and advised customers from the nuclear industry for decades.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
25Exact matchSaint Paul Lez Durance Cedex, FranceHQ recorded Sep 19, 2026501-1,000201 contacts →

Exact match

“IRESNE est un institut du CEA implanté sur le centre CEA de Cadarache.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase

Showing 25 of 408 advanced reactor design companies worldwide

See the full list, filter by size, metro and specialty, and access 15,084 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Advanced reactor design companies worldwide at a glance

As of Sep 19, 2026
23.4%Verified-email coverage
157.7Average contacts per company
11-50Median size (employees)
1.7%Largest-city concentration · New York
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
139
11-50
125
51-200
62
201-500
29
501-1,000
16
1,001-5,000
21
5,001-10,000
8
10001+
8

Email recency is reported on each country list linked below.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, 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
Company records worldwide whose business descriptions match “advanced reactor design companies” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 15,084 professional contacts with verified work emails across the full matched dataset. 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.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Advanced reactor design companies by location

3 lists · largest first

Every 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 SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “advanced reactor design companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many advanced reactor design companies are there worldwide?

RevenueBase identified 408 company matches for advanced reactor design companies worldwide as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Framatome tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

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 company records, 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 limited free results with 500 credits to start. Upgrading provides access to the 15,084 professional contacts with verified work emails tracked across these 408 companies; direct dials are available where recorded.

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 SmartSearch, 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.