NAICS 221113

Overview

The North American Industry Classification System (NAICS) is the U.S. standard for grouping business establishments so federal statistical agencies can collect, analyze, and publish economic data. Developed under the Office of Management and Budget with Canada and Mexico, NAICS replaced SIC in 1997; the current structure used by Census programs is the 2022 vintage. ¹
221113 — Nuclear Electric Power Generation — covers establishments whose primary activity is operating nuclear electric power plants that produce electricity for delivery to transmission or distribution systems. The definition is activity‑based (operating generation facilities), not ownership‑based, and excludes firms primarily engaged in transmission or distribution activities, which are coded elsewhere. ²

See also on G2X:

• G2X — NAICS 221113 overview
• G2X — NAICS 221121 Electric Bulk Power Transmission and Control
• G2X — NAICS 221122 Electric Power Distribution

What this NAICS covers

• Operation of commercial nuclear power generation facilities (utility service) ²
• Nuclear fission–based electricity production at central‑station plants ²
• Running reactor, turbine‑generator, and balance‑of‑plant systems to produce electric energy ²
• Delivering generated electricity to transmission or distribution networks for sale ²
• Integrated plant operations and control rooms supporting generation activities ²
• On‑site support functions when they are part of operating a nuclear generating facility ²

Related NAICS and PSC codes

Type	Code	Descriptor
NAICS	221121	Electric Bulk Power Transmission and Control
NAICS	221122	Electric Power Distribution
PSC	S112	Utilities – Electric
PSC	9105	Electric Power Supply from a Third Party Generation Entity

NAICS descriptors per Census NAICS. ²
PSC descriptors per the Product and Service Code (PSC) Manual. ³

Key exclusions and cross-references

• Operating bulk transmission systems or controlling transmission is classified under NAICS 221121; distributing electricity to end users is classified under NAICS 221122. ²
• Trash incinerators that also generate electricity are not in 221113; they are classified under solid waste combustors and incinerators. ²
• Activities unrelated to operating electric generation facilities (e.g., standalone engineering services, decommissioning services) are classified by their primary activity. Not specified by official sources ²

SBA small business size standard (current)

• NAICS 221113 small business size standard: 1,150 employees (effective March 17, 2023, per SBA’s Table of Small Business Size Standards). ⁴

Frequently asked questions

• How does NAICS 221113 differ from 221121 and 221122?
  221113 covers operating nuclear plants to produce electricity. 221121 covers transmission system operation and control; 221122 covers distribution to end users. Establishments are classified by their primary activity. ²

• Does 221113 include small modular reactors (SMRs) once operational?
  NAICS defines industries by activity, not technology. If the establishment’s primary activity is operating a nuclear facility to generate electricity, it falls under 221113. NAICS does not distinguish by reactor size or design. Not specified by official sources ²

• Which PSCs commonly align to spending for electric service under this industry?
  Agencies often record utility electricity purchases under PSC S112. For commodity electricity supplied by third‑party generators, PSC 9105 applies. PSC selection describes “what is bought” and is independent of NAICS assignment. ³

• What is the small business size standard for 221113 in federal contracting?
  SBA sets the size standard for NAICS 221113 at 1,150 employees. This threshold governs eligibility for small business programs and is published in SBA’s Table of Size Standards. ⁴

• Does 221113 cover ownership models such as public power or federally owned plants?
  NAICS classification is based on an establishment’s primary activity (operating nuclear electric generation), not ownership. Ownership type does not change the industry code assignment. Not specified by official sources ²

Useful resources

• U.S. Census Bureau — NAICS overview and 2022 implementation (definition, governance, and current vintage). ¹
• U.S. Census Bureau — NAICS Utilities (includes the official definition and cross‑references for 221113). ²
• GSA Acquisition — Product and Service Code (PSC) Manual (PSC S112, 9105, and other utility codes). ³
• U.S. Small Business Administration — Table of Small Business Size Standards (NAICS 221113 = 1,150 employees). ⁴

References

1. U.S. Census Bureau. The Census Bureau’s Implementation of the 2022 North American Industry Classification System (NAICS). https://www.census.gov/naics/
2. U.S. Census Bureau. NAICS 221113 (Nuclear Electric Power Generation), 2022. https://www.census.gov/naics/?input=221113&year=2022
3. U.S. General Services Administration. Product and Service Code (PSC) Manual. https://www.acquisition.gov/psc-manual
4. U.S. Small Business Administration. Table of Small Business Size Standards. https://www.sba.gov/document/support-table-size-standards