Company lists · Data refreshed September 2026
Top 25 Advanced reactor technology companies based in the United States
RevenueBase identified 162 advanced reactor technology companies headquartered in the United States as of September 2026 and tracks 29,562 professional contacts across them, including 1,654 with verified work emails. New York is the largest hub.
This list covers advanced reactor technology companies headquartered in the United States, 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.
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 technology companies based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 10,898 contacts → | ||||
Partial 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. | |||||
| 2 | 4,531 contacts → | ||||
Indirect evidence “The freedom to explore.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 3,832 contacts → | ||||
Partial 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. | |||||
| 4 | 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. | |||||
| 5 | 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. | |||||
| 6 | 494 contacts → | ||||
Indirect 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. | |||||
| 7 | 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. | |||||
| 8 | 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. | |||||
| 9 | 278 contacts → | ||||
Partial 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. | |||||
| 10 | 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. | |||||
| 11 | 226 contacts → | ||||
Partial 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. | |||||
| 12 | 148 contacts → | ||||
Strong evidence “Zap is advancing the next generation of nuclear power technology across fusion, fission and hybrid applications.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 129 contacts → | ||||
Partial evidence “Hi Tech Solutions provides services to the nuclear power generation industry in four main areas: outage services (plant outages and reactor maintenance), nuclear fuel cycle…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 119 contacts → | ||||
Indirect evidence “Aalo Atomics designs and builds factory-manufactured nuclear power plants for data centers, industry, and cities.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 118 contacts → | ||||
Indirect evidence “At Atkins Nuclear Solutions US, we offer client solutions crafted by the best engineers and specialists in the industry, served with truly exceptional customer service.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 116 contacts → | ||||
Indirect evidence “NAC International Inc.(NAC) is an industry-leading provider of engineering, consulting, and nuclear fuel management solutions for nuclear facility operators, fuel cycle companies…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 104 contacts → | ||||
Indirect evidence “HukariAscendent is a technical consulting and engineering company specializing in comprehensive engineering and technical services associated with the nuclear industry and power…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 95 contacts → | ||||
Strong evidence “Terrestrial Energy is a developer of Generation IV nuclear plants that use its proprietary Integral Molten Salt Reactor (IMSR) technology.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 80 contacts → | ||||
Strong evidence “Syzygy Plasmonics is a technology company decarbonizing chemical production with its proprietary light-driven reactor technology.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 70 contacts → | ||||
Indirect evidence “Energy abundance unlocks progress.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 65 contacts → | ||||
Indirect evidence “U.S.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 61 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 54 contacts → | ||||
Indirect evidence “Avalanche is a VC-backed, compact fusion energy start-up based in Seattle, WA.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 50 contacts → | ||||
Strong evidence “NANO Nuclear Energy Inc.(NASDAQ: NNE) NANO Nuclear Energy Inc.(NASDAQ: NNE) is a North American advanced technology-driven nuclear energy company seeking to become a commercially…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 49 contacts → | ||||
Partial evidence “For over 35 years, Crystaphase has provided reactor solutions to hundreds of refining, petrochemical, and chemical plants worldwide.” 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 technology 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 technology companies.
- Partial evidence
- Its own public description names part of advanced reactor technology 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 technology 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 162 advanced reactor technology companies based in the United States
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Advanced reactor technology companies based in the United States at a glance
As of Sep 19, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 162 companies.
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 technology 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.
- What qualifies
- Companies headquartered in the United States whose own description of what they do matches “advanced reactor technology 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 technology 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 technology companies, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
- 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, 1,654 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.
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 technology 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 technology companies are there based in the United States?
RevenueBase identified 162 advanced reactor technology companies headquartered in the United States 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?
Westinghouse Electric Company, headquartered in Cranberry Township, tops this list with the largest team on record.
Which city has the most advanced reactor technology companies?
New York leads with 6 headquartered companies, followed by Washington (6) and Austin (4).
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 1,654 verified decision-maker contacts tracked across these 162 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.
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