Human Performance Tools & Pre-Job Briefs

What Human Performance Tools Are and Why They Matter

Nuclear power plants operate with very low tolerance for error. A single misidentified valve, a skipped step, or a miscommunication can initiate an unplanned transient, cause equipment damage, or expose workers to radiation. Human Performance (HuP) tools are structured behaviors and techniques that workers apply deliberately to catch errors before they cause harm. The Institute of Nuclear Power Operations (INPO) has developed and refined these tools through decades of operating experience, and they are embedded in the industry's Uniform Curriculum and in the safety culture standards that the NRC expects every licensee to maintain.

HuP tools do not replace procedures — they complement them. The goal is to place multiple defenses between a potential error and its consequences.

Core Human Performance Tools

Self-checking (STAR): Stop, Think, Act, Review. Before touching any component, the worker pauses, thinks about what is about to happen, performs the action deliberately, and then reviews the result against the expected condition. STAR is applied at every critical step.

Procedure use and adherence: Procedures are used in hand, not from memory. Workers place a finger or marker on the active step and do not advance until that step is verified complete. Departing from a procedure without authorization is a significant safety violation.

Peer checking: A second qualified person independently verifies a component identification or action before or immediately after it is performed. This is distinct from a supervisor reviewing paperwork — it is real-time verification at the work location.

Two-minute drill (task preview): Immediately before beginning a task, the worker mentally walks through the steps to identify hold points, potential hazards, and stop conditions. This is not the full pre-job brief; it is an individual mental rehearsal.

Phonetic alphabet and repeat-back: When communicating critical information (component numbers, switch positions, readings), workers use standardized repeat-back to confirm understanding. The receiver repeats the message; the sender confirms accuracy.

Flagging: Physical tags, colored labels, or temporary caution signs placed on components that are out of service, in a special configuration, or involved in an active work order. Flagging reduces the chance of inadvertent operation.

Conservative decision-making: When in doubt, stop. Workers are empowered — and expected — to stop a task if conditions differ from what the pre-job brief described, if a step outcome is unexpected, or if uncertainty exists about plant status. Stopping is never penalized in a healthy safety culture.

The Pre-Job Brief

A pre-job brief is a structured team meeting held immediately before work begins. It is not optional and is not a formality. INPO guidance (reflected in ACAD documents) describes the minimum content of an effective brief:

1. Task objective: What are we trying to accomplish, and what will success look like?

2. Scope and procedure: Which procedure(s) govern this task? What revision is in use? Are there any open condition reports or temporary modifications that affect the job?

3. Hazards: What are the radiological, industrial, and equipment-damage hazards? This includes dose rate fields, contamination boundaries, electrical hazards, stored energy, and fall hazards. Required PPE is identified here.

4. Stop conditions: Under what circumstances will the crew stop work and not proceed? Examples: unexpected alarm, component found in wrong position, dose rate higher than briefed, communication loss with the control room.

5. Roles and responsibilities: Who is the task lead? Who performs? Who verifies? Who maintains communication with the control room?

6. Human performance tools selected: Which specific HuP tools will be used at which steps? The team does not use all tools on every step — they identify the critical steps where peer checking or STAR will be applied.

7. Questions and clarifications: Every team member must have the opportunity to ask questions before work starts.

A brief that omits safety-significant hazards or stop conditions is incomplete, regardless of how smooth the discussion sounded.

The Post-Job Review

A post-job review is conducted after task completion — or after an unexpected condition stops the task — while details are fresh. The team addresses three questions:

• What went differently than planned? This includes any variance from the procedure, any unexpected equipment condition, any change in radiological status, or any communication difficulty.
• Which human performance defenses worked? Identifying effective tool use reinforces good behavior and documents it for future crews.
• What should be entered into the Corrective Action Program (CAP)? Any condition adverse to quality, near-miss, or procedural inadequacy must be entered into the CAP. Failing to enter a known issue is itself a safety culture deficiency.

The post-job review is not a blame session. Its purpose is organizational learning.

Safety Culture Connection

The NRC expects a strong nuclear safety culture at every licensed facility. A worker who uses HuP tools consistently, speaks up when something does not look right, and enters findings into the CAP is demonstrating that culture in practice. A worker who skips briefs, works from memory, or withholds a concern to avoid delay is a culture risk — regardless of experience level.

Lockout/tagout (LOTO) and equipment clearances are always verified at the work location before touching any isolated equipment. PPE requirements identified during the pre-job brief are donned before entering the work area, not after arriving at the component.