Company lists · Data refreshed September 2026
Top 25 Nuclear consulting firms based in the United States
RevenueBase identified 223 nuclear consulting firms headquartered in the United States as of September 2026 and tracks 8,207 professional contacts across them, including 1,641 with verified work emails and 3,669 with mobile numbers. Oak Ridge is the largest hub.
This list covers nuclear consulting firms 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 5, 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 consulting firms based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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 5, 2026Thanks. The Data Team will review it. | |||||
| 2 | 468 contacts → | ||||
Indirect 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 5, 2026Thanks. The Data Team will review it. | |||||
| 3 | 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 5, 2026Thanks. The Data Team will review it. | |||||
| 4 | 245 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 5, 2026Thanks. The Data Team will review it. | |||||
| 5 | 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 5, 2026Thanks. The Data Team will review it. | |||||
| 6 | 188 contacts → | ||||
Indirect evidence “SMSI is a small business providing management and technical/engineering services to the DOE/NNSA, national laboratories, and industrial clients.” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 7 | 187 contacts → | ||||
Partial evidence “United Engineers & Constructors is an industry-leading infrastructure engineering, procurement, construction, and consulting company dedicated to improving lives by delivering the…” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 8 | 180 contacts → | ||||
Indirect evidence “Longenecker & Associates: A Geosyntec Company (L&A) has more than 35 years’ experience supporting the national security, environmental remediation, scientific research and energy…” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 9 | 162 contacts → | ||||
Partial evidence “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: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 10 | 129 contacts → | ||||
Partial 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 5, 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 5, 2026Thanks. The Data Team will review it. | |||||
| 12 | 116 contacts → | ||||
Strong 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 5, 2026Thanks. The Data Team will review it. | |||||
| 13 | 104 contacts → | ||||
Strong 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 5, 2026Thanks. The Data Team will review it. | |||||
| 14 | 91 contacts → | ||||
Indirect evidence “Since 1981, BCP Engineers and Consultants (BCP) has provided engineering and project management services to the U.S.” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 15 | 79 contacts → | ||||
Indirect evidence “Founded in 1989, TFE, Inc.” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 16 | 79 contacts → | ||||
Partial evidence “Meridian Services Group (formerly High Bridge Associates and Work Management, Inc.) is a project management consulting and services company.” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 17 | 65 contacts → | ||||
Indirect evidence “TerranearPMC (TPMC) is an experienced and highly qualified business at the forefront of the environmental service solutions industry with a focus on innovative technologies and…” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 18 | 61 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 19 | 60 contacts → | ||||
Partial evidence “Fauske & Associates (FAI) is a world leader in nuclear, industrial and chemical process safety.” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 20 | 54 contacts → | ||||
Partial evidence “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: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 21 | 52 contacts → | ||||
Partial evidence “Empyrean, a Consulting Solutions company, is a premier provider of technical and engineering workforce solutions and consulting services for the energy sector across North America.” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 22 | 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 5, 2026Thanks. The Data Team will review it. | |||||
| 23 | 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 5, 2026Thanks. The Data Team will review it. | |||||
| 24 | 46 contacts → | ||||
Indirect evidence “Sigma Science is now part of the RSI Group.” Source: RevenueBase Database · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 25 | 45 contacts → | ||||
Partial evidence “Managing the transition to 21st century Utilities including Commercial and DOE Nuclear Power, Fossil and Hydro Power, Electrical and Gas Transmissions & Distribution and other…” Source: RevenueBase Database · checked Sep 5, 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 consulting firms. 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 consulting firms.
- Partial evidence
- Its own public description names part of nuclear consulting firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name nuclear consulting firms. 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 223 nuclear consulting firms based in the United States
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Nuclear consulting firms based in the United States at a glance
As of Sep 5, 2026Companies by employee count
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 consulting firms, 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 consulting firms”. 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 firms), 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 firms, 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, 1,641 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 5, 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 consulting firms, 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 firms are there based in the United States?
RevenueBase identified 223 nuclear consulting firms 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?
Energysolutions, headquartered in Salt Lake City, tops this list with the largest team on record.
Which city has the most nuclear consulting firms?
Oak Ridge leads with 7 headquartered companies, followed by Albuquerque (5) and Richland (5).
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 1,641 verified decision-maker contacts tracked across these 223 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 5, 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.
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