Human Performance Tools in Maintenance: Procedure Use, Pre-Job Briefing, and Self-Checking

Why Human Performance Tools Matter in Nuclear Maintenance

Nuclear power plants operate under strict regulatory oversight because errors in maintenance can have consequences far beyond a single system failure. The U.S. Nuclear Regulatory Commission (NRC) and the Institute of Nuclear Power Operations (INPO) have documented that the majority of significant plant events trace back to human error — not equipment failure alone. Human performance tools are the structured habits and techniques that reduce the chance of those errors reaching the plant. Using them correctly is not optional; it is a condition of employment and, for licensed activities, a condition of your license.

Procedure Use and Place-Keeping

Maintenance procedures in a nuclear plant are controlled documents. They are written, reviewed, and approved through a formal process precisely because every step matters. Your job as a technician or operator is to follow the procedure as written, in sequence, without improvising — even when a step seems obvious or you have done the task many times.

Place-keeping is the physical technique that proves you are following the procedure step by step. You use a place-keeping marker — a physical pointer, highlighter card, or movable flag — to mark the last completed step. You do not move the marker until the step is fully finished and verified. This prevents skipped steps, repeated steps, and loss of position, especially during interruptions. If you are called away from a task, you note the exact step number, secure the marker, and brief your relief before walking away.

Procedures must be used continuously at the work location, not read in the break room and then carried out from memory. If a procedure contains a note or caution before a step, you stop and read it before performing the action. Cautions warn of equipment damage; notes provide important information. Both are there for a reason.

STAR: Stop, Think, Act, Review

STAR is the core self-checking technique used across the nuclear industry. It applies to any critical action — turning a valve, pressing a pushbutton, entering a setpoint, or signing a document.

• Stop: Pause before acting. Break the automatic pattern. Give your brain a moment to engage.
• Think: Identify exactly what you are about to do, what the expected result is, and what the procedure step requires. Ask yourself: Is this the right component? The right action? The right time?
• Act: Perform the single action the procedure step directs. Do not combine steps.
• Review: Immediately check the result. Did the system respond as expected? Does the indication match what the procedure says it should? If not, stop and report — do not proceed.

STAR takes only a few seconds per step, but it interrupts the complacency that causes most maintenance errors.

Peer Check and Two-Person Verification

Some steps carry enough risk that self-checking alone is insufficient. Peer check means a qualified co-worker independently verifies the component, position, and action before or after you perform a step. The peer uses the same procedure and independently reaches the same conclusion — they do not simply agree with you.

Two-person verification (2PV) is a more formal requirement, often procedure-specified, where two qualified individuals both observe the action and both sign the procedure. Two-person verification is commonly required for steps involving radioactive material handling, safety-related valve lineups, and electrical switching on energized equipment. Never shortcut 2PV; the procedure will specify when it is required.

Pre-Job Briefing

Before any significant maintenance task begins, the work team conducts a pre-job briefing. This is a structured conversation — not a casual chat — that ensures everyone on the team understands the job before tools are touched. A compliant briefing covers:

1. Scope: What work is being done, on which system and components, with which procedure and revision.

2. Hazards: Radiological, electrical, thermal, mechanical, or chemical hazards present. Required PPE and dosimetry.

3. Roles and responsibilities: Who is the lead? Who performs which steps? Who is the independent verifier?

4. Stop-work authority: Every team member has the right and the responsibility to stop work if something does not look right. No one needs permission to call a stop. Reinforce this explicitly.

5. Contingencies: What do we do if the valve will not seat, if a torque value cannot be reached, if an unexpected condition is found?

The briefing checklist is your tool. Work through it completely. Shortcuts in the briefing room become problems at the work site.

Condition Reports and Error Trapping

When you find an error in a procedure — a wrong tag number, a missing value, a reversed sequence — you do not cross it out and proceed on your best guess. You stop work, notify your supervisor, and initiate a condition report (CR). The CR documents the discrepancy so the corrective action program can address it. Procedure errors are significant findings; they may indicate the procedure has never been used correctly, or that a similar error exists elsewhere. Identifying and reporting errors is a professional obligation, not a sign of weakness.

Safety Reminders

Lockout/tagout (LOTO) must be verified before any maintenance on energized or pressurized systems — verify isolation yourself; never assume someone else completed it. Confirm your dosimetry is calibrated and worn before entering radiological areas. If PPE requirements change mid-task, stop and re-equip before continuing. Stop-work authority is absolute: if it does not feel right, stop.