Company lists · Data refreshed September 2026

Top 25 Nuclear reactor design companies based in the United States

RevenueBase identified 141 nuclear reactor design companies headquartered in the United States as of September 2026 and tracks 25,918 professional contacts across them, including 1,367 with verified work emails and 9,858 with mobile numbers. New York is the largest hub.

This list covers nuclear reactor design 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 7, 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 7, 2026 86% judged on-target in blind review
141Companies
25,918Contacts tracked
1,367Verified emails
9,858Mobile numbers
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The 25 largest nuclear reactor design companies based in the United States

Ranked by team size
Top 25 of 141 nuclear reactor design companies based in the United States, ranked by team size, largest first. Data refreshed Sep 7, 2026. RevenueBase Smart Search rates how each company's information relates to nuclear reactor design companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceCranberry Township, PA, United StatesHQ checked Sep 7, 20265,001-10,00010,898 contacts →

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

Source: company website · checked Sep 7, 2026
2Indirect evidenceLynchburg, VA, United StatesHQ checked Sep 7, 20265,001-10,0003,832 contacts →

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

Source: company website · checked Sep 7, 2026
3Partial evidenceSalt Lake City, UT, United StatesHQ checked Sep 7, 20261,001-5,0001,254 contacts →

“EnergySolutions is an international nuclear services company headquartered in Salt Lake City, Utah, and Charlotte, North Carolina, with operations across the United States and…”

Source: company website · checked Sep 7, 2026
4Partial evidenceRockville, MD, United StatesHQ checked Sep 7, 2026501-1,0001,055 contacts →

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

Source: company website · checked Sep 7, 2026
5Partial evidenceBellevue, WA, United StatesHQ checked Sep 7, 2026501-1,000913 contacts →

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

Source: company website · checked Sep 7, 2026
6Strong evidenceCorvallis, OR, United StatesHQ checked Sep 7, 2026201-500494 contacts →

“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: company website · checked Sep 7, 2026
7Indirect evidenceAlameda, CA, United StatesHQ checked Sep 7, 2026501-1,000485 contacts →

“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: company website · checked Sep 7, 2026
8Partial evidenceColumbia, MD, United StatesHQ checked Sep 7, 2026201-500404 contacts →

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

Source: company website · checked Sep 7, 2026
9Strong evidenceFort Worth, TX, United StatesHQ checked Sep 7, 2026201-500234 contacts →

“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: company website · checked Sep 7, 2026
10Partial evidenceSanta Clara, CA, United StatesHQ checked Sep 7, 202651-200226 contacts →

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

Source: company website · checked Sep 7, 2026
11Partial evidenceEl Segundo, CA, United StatesHQ checked Sep 7, 202651-200189 contacts →

“Radiant is building the world’s first mass-produced portable nuclear microreactors.”

Source: company website · checked Sep 7, 2026
12Partial evidenceOak Ridge, TN, United StatesHQ checked Sep 7, 2026201-500162 contacts →

“Spectra Tech is an engineering, environmental, and nuclear services company that focuses on providing high quality and cost-effective technical solutions for our Federal…”

Source: company website · checked Sep 7, 2026
13Strong evidenceKennewick, WA, United StatesHQ checked Sep 7, 2026501-1,000129 contacts →

“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: company website · checked Sep 7, 2026
14Strong evidenceAustin, TX, United StatesHQ checked Sep 7, 2026201-500119 contacts →

“Aalo Atomics designs and builds factory-manufactured nuclear power plants for data centers, industry, and cities.”

Source: company website · checked Sep 7, 2026
15Partial evidenceCharlotte, NC, United StatesHQ checked Sep 7, 202651-200118 contacts →

“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: company website · checked Sep 7, 2026
16Partial evidencePeachtree Corners, GA, United StatesHQ checked Sep 7, 202651-200116 contacts →

“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: company website · checked Sep 7, 2026
17Partial evidenceWheat Ridge, CO, United StatesHQ checked Sep 7, 202651-200104 contacts →

“HukariAscendent is a technical consulting and engineering company specializing in comprehensive engineering and technical services associated with the nuclear industry and power…”

Source: company website · checked Sep 7, 2026
18Indirect evidenceGretna, LA, United StatesHQ checked Sep 7, 202651-20091 contacts →

“Since 1981, BCP Engineers and Consultants (BCP) has provided engineering and project management services to the U.S.”

Source: company website · checked Sep 7, 2026
19Indirect evidenceBethesda, MD, United StatesHQ checked Sep 7, 2026501-1,00065 contacts →

“U.S.”

Source: company website · checked Sep 7, 2026
20Indirect evidenceStonington, CT, United StatesHQ checked Sep 7, 202651-20061 contacts →
Source: company website · checked Sep 7, 2026
21Indirect evidenceSeattle, WA, United StatesHQ checked Sep 7, 202651-20054 contacts →

“Avalanche is a VC-backed, compact fusion energy start-up based in Seattle, WA.”

Source: company website · checked Sep 7, 2026
22Partial evidenceNewport News, VA, United StatesHQ checked Sep 7, 2026201-50054 contacts →

“The Nuclear & Environmental Group, part of Huntington Ingalls Industries' Technical Solutions division, manages environmental issues and is an industry leader in providing the DOE…”

Source: company website · checked Sep 7, 2026
23Partial evidenceNew York, NY, United StatesHQ checked Sep 7, 202651-20050 contacts →

“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: company website · checked Sep 7, 2026
24Partial evidenceRockville, MD, United StatesHQ checked Sep 7, 202651-20047 contacts →

“EXCEL has evolved over the last four decades to meet the needs of the nuclear energy industry.”

Source: company website · checked Sep 7, 2026
25Partial evidenceSeattle, WA, United StatesHQ checked Sep 7, 2026201-50045 contacts →

“Our mission is to develop and deploy nuclear-based power generating equipment that is safe, commercially competitive, and simple to use.”

Source: company website · checked Sep 7, 2026

Showing 25 of 141 nuclear reactor design companies based in the United States

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Nuclear reactor design companies based in the United States at a glance

As of Sep 7, 2026
5.3%Verified-email coverage
38.0%Mobile-number coverage
183.8Average contacts per company
11-50Median size (employees)
4.3%Largest-city concentration · New York
Sep 7, 2026Page data refreshed

Companies by employee count

1-10
48
11-50
41
51-200
27
201-500
9
501-1,000
7
1,001-5,000
5
5,001-10,000
4

Freshness & accuracy

How recently the business emails on this list were verified

Email last verified

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 nuclear 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.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “nuclear 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 nuclear 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 nuclear reactor design 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, 1,367 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 7, 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 nuclear 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 nuclear reactor design companies are there based in the United States?

RevenueBase identified 141 nuclear reactor design 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 nuclear reactor design companies?

New York leads with 6 headquartered companies, followed by Charlotte (5) 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 1,367 verified decision-maker contacts tracked across these 141 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 7, 2026.

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Related lists

Nuclear reactor design companies by geography

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.