Company lists · Data refreshed September 2026

Top 25 Nuclear consulting services worldwide

RevenueBase identified 1,050 nuclear consulting services worldwide as of September 2026 and tracks 94,283 professional contacts across them, including 33,825 with verified work emails. The United States is the largest market and London the largest hub.

This list covers nuclear consulting services worldwide, 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 21, 2026. Country and city lists for nuclear consulting services follow the table.

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 21, 2026 86% judged on-target in blind review
1,050Companies
94,283Contacts tracked
33,825Verified emails
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The 25 largest nuclear consulting services worldwide

Ranked by team size
Top 25 of 1,050 nuclear consulting services worldwide, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to nuclear consulting services: 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 evidenceMontreal, QC, CanadaHQ checked Sep 21, 202610001+22,733 contacts →

Partial evidence

“We are a world-class engineering services and nuclear organization.”

Source: RevenueBase Database · checked Sep 21, 2026
2Partial evidenceCourbevoie, FranceHQ checked Sep 21, 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 21, 2026
3Partial evidenceCranberry Township, PA, United StatesHQ checked Sep 21, 20265,001-10,00010,898 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
4Indirect evidenceEpsom, United KingdomHQ checked Sep 21, 202610001+9,297 contacts →

Indirect evidence

“Atkins is now AtkinsRéalis.”

Source: RevenueBase Database · checked Sep 21, 2026
5Partial evidenceCourbevoie, FranceHQ checked Sep 21, 20265,001-10,0006,518 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
6Indirect evidenceMassy, FranceHQ checked Sep 21, 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 21, 2026
7Partial evidenceMarseille, FranceHQ checked Sep 21, 20261,001-5,0001,664 contacts →

Partial 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 21, 2026
8Partial evidenceBirchwood, United KingdomHQ checked Sep 21, 20265,001-10,0001,592 contacts →

Partial evidence

“Cavendish Nuclear is a core part of Babcock International Group’s Nuclear Sector.”

Source: RevenueBase Database · checked Sep 21, 2026
9Indirect evidenceRueil Malmaison, FranceHQ checked Sep 21, 20261,001-5,0001,537 contacts →

Indirect evidence

“Subsidiary of the world-leading VINCI group, NUVIA is an international company that has been operating on highly regulated and sensitive industrial sites for over 60 years.”

Source: RevenueBase Database · checked Sep 21, 2026
10Indirect evidenceVilliers-le-bâcle, FranceHQ checked Sep 21, 20261,001-5,0001,315 contacts →

Indirect evidence

“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…”

Source: RevenueBase Database · checked Sep 21, 2026
11Partial evidenceSalt Lake City, UT, United StatesHQ checked Sep 21, 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 21, 2026
12Indirect evidenceCergy-pontoise Cedex, FranceHQ checked Sep 21, 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 21, 2026
13Indirect evidencePort Elgin, CanadaHQ checked Sep 21, 20261,001-5,000579 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
14Partial evidenceSan Sebastian De Los Reyes, SpainHQ checked Sep 21, 2026501-1,000487 contacts →

Partial evidence

“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.”

Source: RevenueBase Database · checked Sep 21, 2026
15Indirect evidenceCourbevoie, FranceHQ checked Sep 21, 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 21, 2026
16Partial evidenceColumbia, MD, United StatesHQ checked Sep 21, 2026201-500404 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 21, 2026
17Indirect evidenceChester, United KingdomHQ checked Sep 21, 2026501-1,000352 contacts →

Indirect evidence

“Urenco Capenhurst is the Cheshire base for three Urenco companies.”

Source: RevenueBase Database · checked Sep 21, 2026
18Partial evidenceMadrid, SpainHQ checked Sep 21, 2026501-1,000345 contacts →

Partial evidence

“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…”

Source: RevenueBase Database · checked Sep 21, 2026
19Partial evidenceChorley, United KingdomHQ checked Sep 21, 2026501-1,000297 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
20Partial evidenceOcteville, FranceHQ checked Sep 21, 2026501-1,000296 contacts →

Partial evidence

“Expert in risk prevention in the nuclear environment, the CERAP Group brings together through its various entities a range of expertise contributing to the protection of people…”

Source: RevenueBase Database · checked Sep 21, 2026
21Partial evidenceAbingdon, United KingdomHQ checked Sep 21, 2026501-1,000284 contacts →

Partial evidence

“Veolia’s Nuclear Expertise: As part of the global Veolia Group, we deliver integrated nuclear solutions that combine cutting-edge technology, engineering excellence, and decades…”

Source: RevenueBase Database · checked Sep 21, 2026
22Partial evidenceUnited StatesHQ checked Sep 21, 20261,001-5,000254 contacts →

Partial evidence

“CANBERRA, now a part of Mirion Technologies, is a leading provider of innovative and cost-effective nuclear measurement solutions used to maintain safety of personnel, assess the…”

Source: RevenueBase Database · checked Sep 21, 2026
23Strong evidenceWilmington, NC, United StatesHQ checked Sep 21, 2026501-1,000245 contacts →

Strong 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 21, 2026
24Partial evidenceFort Worth, TX, United StatesHQ checked Sep 21, 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 21, 2026
25Indirect evidenceOak Ridge, TN, United StatesHQ checked Sep 21, 2026201-500233 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 21, 2026

Showing 25 of 1,050 nuclear consulting services worldwide

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Nuclear consulting services worldwide at a glance

As of Sep 21, 2026
35.9%Verified-email coverage
89.8Average contacts per company
1-10Median size (employees)
1.1%Largest-city concentration · London
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
559
11-50
253
51-200
126
201-500
45
501-1,000
21
1,001-5,000
26
5,001-10,000
9
10001+
7

Email recency is reported on each country list linked below.

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 consulting services, 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
Every country. Country and city lists for nuclear consulting services are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “nuclear consulting services”. 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 consulting services), 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 consulting services, 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, 33,825 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 21, 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 consulting services by location

5 lists · largest first

Every Nuclear consulting services 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 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 consulting services, 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 consulting services are there worldwide?

RevenueBase identified 1,050 nuclear consulting services worldwide 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?

Atkinsréalis, headquartered in Montreal, tops this list with the largest team on record.

Which country has the most nuclear consulting services?

The United States leads with 287 companies, followed by France (108) and the United Kingdom (105). Every nuclear consulting services list by country and city is linked on this page.

Which city has the most nuclear consulting services?

London leads with 12 headquartered companies, followed by Oak Ridge (9) and Paris (9).

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 33,825 verified decision-maker contacts tracked across these 1,050 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 21, 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.