Company lists · Data refreshed September 2026
Top 25 Nuclear maintenance service providers based in the United States
RevenueBase identified 110 nuclear maintenance service providers headquartered in the United States as of September 2026 and tracks 18,673 professional contacts across them, including 1,896 with verified work emails. Charlotte is the largest hub.
This list covers nuclear maintenance service providers 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 20, 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 nuclear maintenance service providers 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 20, 2026Thanks. The Data Team will review it. | |||||
| 2 | 1,956 contacts → | ||||
Indirect evidence “NAES is the power generation industry’s largest independent services provider, with more than 40 years of experience managing risk and turning it into profits.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 3 | 1,254 contacts → | ||||
Partial evidence “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: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 4 | 408 contacts → | ||||
Partial evidence “Allied Power is dedicated to delivering best-in-class maintenance, modifications, and project services.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 5 | 404 contacts → | ||||
Partial 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 20, 2026Thanks. The Data Team will review it. | |||||
| 6 | 245 contacts → | ||||
Partial evidence “Founded in 1977 Sonic Systems International (SSI) is a full-service quality-consulting firm serving the nuclear power generation utility industry.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 7 | 234 contacts → | ||||
Partial 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 20, 2026Thanks. The Data Team will review it. | |||||
| 8 | 131 contacts → | ||||
Indirect evidence “Established in 1960, Electric Motor and Contracting remains one of the largest independently owned electric motor and pump repair shops in the U.S.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 9 | 129 contacts → | ||||
Strong 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 20, 2026Thanks. The Data Team will review it. | |||||
| 10 | 123 contacts → | ||||
Partial evidence “With more than a half-century in the nuclear business, is an expert in nuclear material handling and lifting equipment.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 11 | 118 contacts → | ||||
Partial 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 20, 2026Thanks. The Data Team will review it. | |||||
| 12 | 116 contacts → | ||||
Partial 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 20, 2026Thanks. The Data Team will review it. | |||||
| 13 | 104 contacts → | ||||
Partial 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 20, 2026Thanks. The Data Team will review it. | |||||
| 14 | 76 contacts → | ||||
Partial evidence “Turbine Generator Maintenance, Inc.(TGM) is the premier solution provider for steam and combustion turbine and generator inspection, testing, and repair.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 15 | 63 contacts → | ||||
Partial evidence “Dominion Engineering, Inc, a division of Allied Power, has over 40 years of experience delivering innovative field service equipment and technology to support nuclear utilities…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 16 | 61 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 17 | 51 contacts → | ||||
Indirect evidence “United Controls International was established as a division of Reliance Electric in 1971 and was later spun off as an independent company.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 18 | 50 contacts → | ||||
Indirect evidence “At Universal, we understand healthcare has been transformed by a complex set of regulatory and business challenges directly impacting the way hospitals and practices manage…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 19 | 47 contacts → | ||||
Partial evidence “EXCEL has evolved over the last four decades to meet the needs of the nuclear energy industry.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 20 | 46 contacts → | ||||
Indirect evidence “Sigma Science is now part of the RSI Group.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 21 | 45 contacts → | ||||
Indirect evidence “Quality Turbine/Generator Turnkey Services- Featuring first-class power generation component repairs, generator testing and repairs, airfoil/blade and precision component…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 22 | 42 contacts → | ||||
Partial evidence “Analysis and Measurement Services Corporation (AMS) is a nuclear engineering consulting firm and recognized market leader in providing the worldwide nuclear power industry with…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 23 | 38 contacts → | ||||
Partial evidence “Established in 1987, Master-Lee Energy Services was founded to provide the commercial Nuclear Power Industry with engineering, reactor services, decontamination, Reactor Coolant…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 24 | 36 contacts → | ||||
Partial evidence “At Paschal Solutions, we are more than engineers-we are problem solvers, innovators, and trusted partners in providing nuclear safety and specialized nuclear engineering technical…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 25 | 24 contacts → | ||||
Partial evidence “Park Nuclear stands at the forefront of the Nuclear Power Industry, specializing in providing top-tier solutions for obsolescence management, strategic sourcing of hard-to-find…” Source: RevenueBase Database · checked Sep 20, 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: nuclear maintenance service providers. 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 nuclear maintenance service providers.
- Partial evidence
- Its own public description names part of nuclear maintenance service providers, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name nuclear maintenance service providers. 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 110 nuclear maintenance service providers based in the United States
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 1,896 reachable decision-makers.
Free signup · no credit card
Nuclear maintenance service providers based in the United States at a glance
As of Sep 20, 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 110 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 nuclear maintenance service providers, 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 maintenance service providers”. 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 maintenance service providers), 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 maintenance service providers, 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, 1,896 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 20, 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 maintenance service providers, 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 maintenance service providers are there based in the United States?
RevenueBase identified 110 nuclear maintenance service providers 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 maintenance service providers?
Charlotte leads with 4 headquartered companies, followed by Columbia (3) and Alexandria (2).
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 1,896 verified decision-maker contacts tracked across these 110 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 20, 2026.
Ready to reach these companies? Verified emails and direct dials for all 110 nuclear maintenance service providers based in the United States. Start with a free account, no credit card.
Download this list →Related lists
Nuclear maintenance service providers 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.
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Nuclear maintenance service providers based in France
- AI companies based in the United States
- Cybersecurity companies based in the United States
- Manufacturing companies based in the United States
- Media companies based in the United States
- Oil and gas companies based in the United States