Company lists · Data refreshed September 2026

Nuclear maintenance contractors: the worldwide list

RevenueBase identified 100 nuclear maintenance contractors across the 2 countries with a published list, as of September 2026, and tracks 28,234 professional contacts across them, including 10,556 with verified work emails and 0 with mobile numbers. The United States is the largest market and Lyon the largest hub.

This is the worldwide list of nuclear maintenance contractors: the 2 country lists RevenueBase publishes for the category, summed and ranked as one. The company count is that sum, not a census of every company on earth; a country with no published list is not counted. 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 17, 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 17, 2026 86% judged on-target in blind review
100Companies
28,234Contacts tracked
10,556Verified emails
0Mobile numbers
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The 25 largest nuclear maintenance contractors across the 2 countries with a published list

Ranked by team size
Top 25 of 100 nuclear maintenance contractors across the 2 countries with a published list, ranked by team size, largest first. Data refreshed Sep 17, 2026. RevenueBase Smart Search rates how each company's information relates to nuclear maintenance contractors: 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 evidenceCourbevoie, FranceHQ checked Sep 17, 202610001+12,439 contacts →

Partial 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 17, 2026
2Indirect evidenceIssaquah, WA, United StatesHQ checked Sep 17, 20261,001-5,0001,956 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 17, 2026
3Indirect evidenceMassy, FranceHQ checked Sep 17, 20265,001-10,0001,684 contacts →

Indirect evidence

“Orano DS fait partie du Groupe Orano, le fournisseur de référence du cycle du combustible nucléaire.”

Source: RevenueBase Database · checked Sep 17, 2026
4Strong evidenceMarseille, FranceHQ checked Sep 17, 20261,001-5,0001,664 contacts →

Strong evidence

“Onet Technologies has 40 years of experience in the nuclear industry, with a strong expertise in engineering and services for reactor maintenance; dismantling, decommissioning and…”

Source: RevenueBase Database · checked Sep 17, 2026
5Partial evidenceSalt Lake City, UT, United StatesHQ checked Sep 17, 20261,001-5,0001,254 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 17, 2026
6Indirect evidenceCergy-pontoise Cedex, FranceHQ checked Sep 17, 20261,001-5,0001,079 contacts →

Indirect evidence

“À propos de SPIE Nucléaire Filiale de SPIE France, SPIE Nucléaire est le partenaire de référence multi-technique dans la conception, la réalisation, les travaux de modification…”

Source: RevenueBase Database · checked Sep 17, 2026
7Partial evidenceDeer Park, TX, United StatesHQ checked Sep 17, 20265,001-10,000718 contacts →

Partial evidence

“HPC Industrial, a Clean Harbors business, is the leading provider of specialty maintenance services and technology solutions to the critical energy infrastructure in the United…”

Source: RevenueBase Database · checked Sep 17, 2026
8Indirect evidenceCourbevoie, FranceHQ checked Sep 17, 2026501-1,000485 contacts →

Indirect evidence

“Sur les centrales nucléaires du groupe EDF, nous intervenons sur tous les types de bâtiments, à la fois de production et tertiaires.”

Source: RevenueBase Database · checked Sep 17, 2026
9Partial evidenceOak Ridge, TN, United StatesHQ checked Sep 17, 2026201-500468 contacts →

Partial evidence

“Navarro Research & Engineering is an award-winning federal contractor dedicated to partnering with our clients to overcome their most challenging environmental, technical, and…”

Source: RevenueBase Database · checked Sep 17, 2026
10Partial evidenceBaton Rouge, LA, United StatesHQ checked Sep 17, 20265,001-10,000408 contacts →

Partial evidence

“Allied Power is dedicated to delivering best-in-class maintenance, modifications, and project services.”

Source: RevenueBase Database · checked Sep 17, 2026
11Partial evidenceBourg Saint Andéol, FranceHQ checked Sep 17, 2026501-1,000406 contacts →

Partial evidence

“Installation & Maintenance | Études, Ingénierie & Prestations Intellectuelles.”

Source: RevenueBase Database · checked Sep 17, 2026
12Partial evidenceWilmington, NC, United StatesHQ checked Sep 17, 2026501-1,000245 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 17, 2026
13Partial evidenceFort Worth, TX, United StatesHQ checked Sep 17, 2026201-500234 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 17, 2026
14Partial evidenceMontrouge, FranceHQ checked Sep 17, 20261,001-5,000211 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 17, 2026
15Indirect evidenceChesapeake, VA, United StatesHQ checked Sep 17, 2026201-500131 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 17, 2026
16Strong evidenceKennewick, WA, United StatesHQ checked Sep 17, 2026501-1,000129 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 17, 2026
17Partial evidenceCharlotte, NC, United StatesHQ checked Sep 17, 202651-200118 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 17, 2026
18Partial evidenceLyon, FranceHQ checked Sep 17, 202651-20073 contacts →

Partial evidence

“TUNZINI Maintenance Nucléaire intervient lors des opérations d’arrêts de tranche pour la réalisation des travaux mécaniques et de manutention de gros composants en bâtiments…”

Source: RevenueBase Database · checked Sep 17, 2026
19Partial evidenceKnoxville, TN, United StatesHQ checked Sep 17, 202651-20042 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 17, 2026
20Partial evidenceLatrobe, PA, United StatesHQ checked Sep 17, 2026201-50038 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 17, 2026
21Partial evidenceOak Ridge, TN, United StatesHQ checked Sep 17, 202651-20036 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 17, 2026
22Partial evidenceDampierre En Burly, FranceHQ checked Sep 17, 202651-20027 contacts →

Partial evidence

“DB Power est une entreprise spécialisée dans la maintenance mécanique nucléaire et industrielle.”

Source: RevenueBase Database · checked Sep 17, 2026
23Partial evidenceEnnery, FranceHQ checked Sep 17, 202651-20025 contacts →

Partial evidence

“Créée en 2010, la société QUALIS est à ce jour un acteur reconnu du marché de la maintenance mécanique sur le parc nucléaire français.”

Source: RevenueBase Database · checked Sep 17, 2026
24Indirect evidenceSeneca, SC, United StatesHQ checked Sep 17, 202611-5024 contacts →

Indirect evidence

“Global Technical Training Services, Inc.(GTTSi) is a privately held South Carolina corporation and a women/minority owned small business.”

Source: RevenueBase Database · checked Sep 17, 2026
25Indirect evidenceWashington, PA, United StatesHQ checked Sep 17, 202611-5017 contacts →

Indirect evidence

“NDE Technology is a full service Non-Destructive Testing Company.”

Source: RevenueBase Database · checked Sep 17, 2026

Showing 25 of 100 nuclear maintenance contractors across the 2 countries with a published list

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Nuclear maintenance contractors worldwide at a glance

As of Sep 17, 2026
37.4%Verified-email coverage
282.3Average contacts per company
51-200Median size (employees)
4.0%Largest-city concentration · Lyon
Sep 17, 2026Page data refreshed

Companies by employee count

1-10
24
11-50
20
51-200
28
201-500
6
501-1,000
6
1,001-5,000
10
5,001-10,000
4
10001+
2

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 contractors, 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
This worldwide list is the sum of the 2 country lists RevenueBase publishes for nuclear maintenance contractors, largest first: the United States, France. Its company and contact totals add up those lists, so they understate the true worldwide figures: a country with no published list is not counted. The ranked table is exact across the countries covered, the largest companies of every country list ranked together with duplicates removed.
What qualifies
Companies worldwide whose own description of what they do matches “nuclear maintenance contractors”. 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 contractors), 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 contractors, 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, 10,556 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
The country lists behind this page were pulled from the company graph on September 17, 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.

Nuclear maintenance contractors by location

2 lists · largest first

Every Nuclear maintenance contractors list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date; the worldwide figures above are the sum of the 2 country lists.

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 nuclear maintenance contractors, 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 contractors are there worldwide?

RevenueBase identified 100 nuclear maintenance contractors across the 2 countries with a published list, as of September 2026, matched on each company's own description of what it does rather than its industry code. The figure is the sum of those country lists, not a census of every company worldwide.

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 nuclear maintenance contractors?

The United States leads with 61 companies, followed by France (39). Every country with a published nuclear maintenance contractors list is linked on this page.

Which city has the most nuclear maintenance contractors?

Lyon leads with 4 headquartered companies, followed by Pierrelatte (3) and Charlotte (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 10,556 verified decision-maker contacts tracked across these 100 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. The country lists behind this page were pulled from the company graph on September 17, 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.