10 CFR Part 55: Operator Licensing Requirements — Nuclear Power Plant Technician / Operator Prep

Objective. Students will describe the NRC operator licensing process under 10 CFR Part 55, including the requirements for initial licensing, requalification, medical fitness, and conditions under which a license may be suspended or revoked.

What Is 10 CFR Part 55?

Title 10 of the Code of Federal Regulations, Part 55 (10 CFR Part 55) is the federal regulation that governs the licensing of nuclear reactor operators in the United States. The U.S. Nuclear Regulatory Commission (NRC) enforces Part 55. No person may operate the controls of a nuclear reactor at a licensed facility without holding the appropriate NRC license. Operating without a license is a federal violation. Part 55 applies to two operator categories: Reactor Operator (RO) and Senior Reactor Operator (SRO). This lesson focuses on the requirements that every aspiring operator must meet and maintain.

Initial License Requirements

Before you can sit for an NRC operator licensing examination, you and your utility must satisfy several prerequisites spelled out in Part 55.

Age and education. An applicant must be at least 18 years old. There is no specific college-degree requirement in the regulation itself, but applicants must demonstrate sufficient education, training, and experience to safely operate the reactor controls.

Training program. The utility — not the individual — applies to the NRC on the operator's behalf. The applicant must have completed a structured training program that meets the requirements of 10 CFR Part 55 and the NRC-approved systematic approach to training (SAT). This is why operator licensing is described as "utility-sponsored."

Experience. Applicants must accumulate hands-on experience at the facility, including significant time performing the duties of the position under the supervision of a licensed operator.

Medical fitness. A physician must certify that the applicant meets the medical standards in Part 55 Subpart C. These standards cover vision, hearing, neurological status, cardiovascular health, and the absence of conditions or substance use that could impair judgment or motor control. A licensed physician approved for this purpose performs the examination. Medical fitness is not a one-time gate — it is a continuing requirement throughout the life of the license.

Written examination and operating test. The NRC administers — or authorizes the utility to administer — a written knowledge examination and a hands-on operating test. The operating test is conducted on a plant-referenced simulator or on the actual facility. Both components must be passed to receive the license.

License Conditions

When the NRC issues an operator license, it may attach conditions that restrict or define how the licensee may act. Common conditions include limits on the type of reactor the individual may operate and requirements that certain actions be taken only under the direct supervision of an SRO. Violating a license condition is a violation of federal regulations and can lead to enforcement action.

Requalification: Keeping the License Active

A license does not remain valid simply because it was issued. Part 55 establishes a continuing requalification program that each licensed operator must complete through the utility.

Annual requirements. Licensed operators must complete certain requalification activities on an annual basis, including participation in evaluated examinations and demonstrations of operating proficiency.

Biennial (two-year) requirements. A comprehensive requalification examination — both written and operating — must be completed within each two-year requalification cycle. The NRC or the utility's NRC-approved program administers this examination. Failure to complete biennial requalification causes the license to lapse.

Facility walkdowns and simulator evaluations. Requalification programs include periodic simulator sessions designed to maintain proficiency on abnormal and emergency operating procedures. These sessions are safety-critical: a lapse in emergency-response skills can cost lives.

Absence from licensed duties. If a licensed operator has not actively performed licensed duties for a defined period specified in Part 55, additional requalification activities are required before returning to duty. The regulation sets specific time thresholds; operators and supervisors must track these carefully.

Medical Fitness as a Continuing Obligation

Medical fitness must be maintained throughout the license term. Licensed operators are required to report to the utility any changes in health status that could affect their ability to safely perform licensed duties. The utility is responsible for ensuring that each operator undergoes periodic medical examinations at intervals defined in Part 55. If a medical condition develops that impairs fitness for duty, the operator must be removed from licensed duties until the condition is resolved or a determination is made by qualified medical personnel.

Fitness for duty also includes freedom from impairment due to alcohol, drugs, fatigue, or any other condition affecting performance. The NRC's fitness-for-duty rule works alongside Part 55 to enforce this requirement.

Suspension, Revocation, and Modification

The NRC has authority to suspend, revoke, or modify an operator license for cause. Grounds include:

Falsification of application information or records
Failure to maintain requalification requirements
Medical unfitness to safely perform duties
Violation of license conditions or NRC regulations
Integrity concerns, such as cheating on examinations or deliberate procedural violations

The NRC enforcement process typically begins with a Notice of Violation (NOV). Depending on severity, enforcement actions range from a written reprimand to civil penalties and license revocation. Operators have due-process rights and may request a hearing before adverse action becomes final.

Safety Culture Connection

Part 55 exists because the consequences of an unqualified or impaired person operating a nuclear reactor can be catastrophic. The regulation supports a strong safety culture by ensuring that every licensed operator is trained, examined, medically fit, and continuously requalified. From a worker-safety standpoint, licensed operators are also the last human barrier before hazards such as uncontrolled criticality, loss of cooling, and radiation release reach the public. Understanding Part 55 is not just a licensing formality — it is the foundation of nuclear safety.

Key terms9

10 CFR Part 55The section of the Code of Federal Regulations that establishes NRC requirements for licensing nuclear reactor operators and senior reactor operators at licensed facilities.

Reactor Operator (RO)An individual licensed by the NRC to manipulate the controls of a nuclear reactor, typically under the supervision of a Senior Reactor Operator.

Senior Reactor Operator (SRO)An individual holding a higher-level NRC license that authorizes supervision of licensed ROs and additional control responsibilities at a nuclear facility.

Requalification programThe NRC-required ongoing training and examination program that licensed operators must complete — including annual and biennial components — to keep their license active and demonstrate continued proficiency.

Medical fitnessThe physical and mental health standard that an operator must meet both to obtain and to retain an NRC operator license, verified by a qualified physician at intervals required by Part 55.

License conditionA restriction or requirement attached by the NRC to an individual operator license that defines the scope or limits of authorized activity; violating a condition constitutes a regulatory violation.

Notice of Violation (NOV)A formal NRC enforcement document that officially cites a licensee or individual for failing to comply with NRC regulations or license conditions.

Systematic Approach to Training (SAT)A structured, job-task-analysis-based method for developing nuclear operator training programs, required by the NRC and used by utilities to ensure training content directly supports safe plant operation.

Biennial requalification examinationThe comprehensive written and operating examination that Part 55 requires each licensed operator to pass within every two-year requalification cycle to maintain licensure.

In class: Trace the lifecycle of an NRC Reactor Operator license from initial application through requalification using a process-flow diagram activity; annotate each step with the applicable Part 55 section. · Review sample NRC operator license conditions and a simulated requalification-cycle record; determine whether the licensee is in compliance with annual and biennial requirements. · Case study discussion: review a publicly available NRC enforcement case involving an operator license condition; identify which Part 55 requirements were violated, what enforcement action was taken, and what corrective actions were ordered.
Materials: 10 CFR Part 55, sample operator license (NRC public document), requalification-record worksheet, NRC enforcement-case summary (public), process-flow diagram template
Check: Oral Q&A with instructor: student must correctly answer 4 of 5 questions on the Part 55 lifecycle, medical requirements, and requalification obligations.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.