Company lists · Data refreshed September 2026

Top 25 Nuclear maintenance contractors based in the United States

RevenueBase identified 61 nuclear maintenance contractors headquartered in the United States as of September 2026 and tracks 8,978 professional contacts across them, including 1,664 with verified work emails. Charlotte is the largest hub.

This list covers nuclear maintenance contractors 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 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
61Companies
8,978Contacts tracked
1,664Verified emails
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The 25 largest nuclear maintenance contractors based in the United States

Ranked by team size
Top 25 of 61 nuclear maintenance contractors based in the United States, 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
1Indirect 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
2Partial 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
3Partial 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
4Partial 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
5Partial 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
6Partial 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
7Partial 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
8Indirect 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
9Strong 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
10Partial 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
11Partial 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
12Partial 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
13Partial 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
14Indirect 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
15Indirect 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
16Partial evidenceHingham, MA, United StatesHQ checked Sep 17, 202651-20015 contacts →

Partial evidence

“A USA based corp that is a leader in providing condenser and heat exchanger cleaning and specialized services to the nuclear and fossil power, marine, military, government…”

Source: RevenueBase Database · checked Sep 17, 2026
17Partial evidenceOntario, CA, United StatesHQ checked Sep 17, 202651-20012 contacts →

Partial evidence

“Turbine Repair Services, LLC is the quality company for plant maintenance and overhaul needs, a single-source provider of turn-key power plant services.”

Source: RevenueBase Database · checked Sep 17, 2026
18Partial evidenceFramingham, MA, United StatesHQ checked Sep 17, 202651-20012 contacts →

Partial evidence

“EPM is a multi-discipline engineering company that provides cost-effective solutions for safe and reliable operation of nuclear power plants.”

Source: RevenueBase Database · checked Sep 17, 2026
19Indirect evidenceBirmingham, AL, United StatesHQ checked Sep 17, 202651-20010 contacts →

Indirect evidence

“Our Company TriVis Inc.”

Source: RevenueBase Database · checked Sep 17, 2026
20Indirect evidenceHarrisburg, PA, United StatesHQ checked Sep 17, 202651-2009 contacts →

Indirect evidence

“NRG Energy Services provides nationwide services to operate, maintain and repair electric-generation facilities.”

Source: RevenueBase Database · checked Sep 17, 2026
21Indirect evidenceBloomsdale, MO, United StatesHQ checked Sep 17, 202651-2007 contacts →

Indirect evidence

“MidStates Energy Co.”

Source: RevenueBase Database · checked Sep 17, 2026
22Indirect evidenceFlorence, NJ, United StatesHQ checked Sep 17, 202651-2006 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 17, 2026
23Indirect evidenceJoliet, IL, United StatesHQ checked Sep 17, 202611-506 contacts →

Indirect evidence

“ChemStaff is the premier water chemistry consulting firm serving the global power industry.”

Source: RevenueBase Database · checked Sep 17, 2026
24Partial evidenceSpartanburg, SC, United StatesHQ checked Sep 17, 202611-504 contacts →

Partial evidence

“Website: NWS Technologies is a privately owned Nuclear Valve Service Company in the business of off-site testing and repairing safety/relief valves for nuclear power plants.”

Source: RevenueBase Database · checked Sep 17, 2026
25Partial evidenceDowners Grove, United StatesHQ checked Sep 17, 20261-103 contacts →

Partial evidence

“Inservice Engineering is celebrating its 20th year of providing quality engineering services to the nuclear industry!”

Source: RevenueBase Database · checked Sep 17, 2026

Showing 25 of 61 nuclear maintenance contractors based in the United States

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Nuclear maintenance contractors based in the United States at a glance

As of Sep 17, 2026
18.5%Verified-email coverage
147.2Average contacts per company
51-200Median size (employees)
3.3%Largest-city concentration · Charlotte
Sep 17, 2026Page data refreshed

Companies by employee count

1-10
13
11-50
14
51-200
17
201-500
6
501-1,000
2
1,001-5,000
6
5,001-10,000
3

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 61 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 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.
What qualifies
Companies headquartered in the United States 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. 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, 1,664 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 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.

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 based in the United States?

RevenueBase identified 61 nuclear maintenance contractors 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?

NAES, headquartered in Issaquah, tops this list with the largest team on record.

Which city has the most nuclear maintenance contractors?

Charlotte leads with 2 headquartered companies, followed by Framingham (2) and Oak Ridge (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 1,664 verified decision-maker contacts tracked across these 61 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 17, 2026.

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Related lists

Nuclear maintenance contractors 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.