NANTeL Human Performance Principles 2 â Questions and Answers
Question 1: Which defense-in-depth layer is considered the LAST line of defense against human error in nuclear operations?
- Administrative controls
- Engineering controls
- Physical barriers
- Emergency response (Correct answer)
Correct answer: Emergency response
Emergency response is the final layer when all other defensesâengineering, administrative, and physicalâhave failed to prevent or mitigate an event.
Question 2: A worker is asked to perform a complex evolution and notices the procedure has not been revised since a plant modification. The BEST action is to:
- Proceed carefully using best judgment
- Stop and report the discrepancy to supervision (Correct answer)
- Cross out the outdated steps and continue
- Perform the task from memory
Correct answer: Stop and report the discrepancy to supervision
Stopping and reporting a procedure discrepancy to supervision ensures the work is authorized only when documentation accurately reflects the current plant configuration.
Question 3: The 'Pre-Job Brief' is most effective when it includes which element?
- A review of past unrelated incidents
- Identification of critical steps and stop points (Correct answer)
- Assignment of blame for previous errors
- A summary of all plant technical specifications
Correct answer: Identification of critical steps and stop points
Identifying critical steps and stop points during a pre-job brief focuses the team's attention on the highest-risk moments in a task.
Question 4: What does the acronym STAR stand for in human performance tool usage?
- Stop, Think, Act, Review (Correct answer)
- Scan, Target, Align, Record
- Stop, Test, Assess, Report
- Simulate, Train, Analyze, Respond
Correct answer: Stop, Think, Act, Review
STARâStop, Think, Act, Reviewâis a self-checking technique that slows down task performance to reduce errors at critical steps.
Question 5: Which condition MOST increases the likelihood of a skill-based error?
- Performing a rarely done task for the first time
- Performing a highly routine task in a distracted state (Correct answer)
- Performing a task under direct supervision
- Performing a task with a detailed procedure in hand
Correct answer: Performing a highly routine task in a distracted state
Skill-based errors occur when automatic, routine actions are performed without conscious attention, especially when distractions interrupt the normal sequence.
Question 6: In nuclear human performance, 'latent organizational weaknesses' are best described as:
- Errors made by individual operators during a shift
- Hidden systemic conditions that make errors more likely (Correct answer)
- Failures caught by automatic safety systems
- Violations intentionally committed by workers
Correct answer: Hidden systemic conditions that make errors more likely
Latent organizational weaknesses are pre-existing, hidden conditions in policies, design, or culture that set the stage for human error before any individual act.
Question 7: A supervisor observes a technician skipping a verification step because they believe the outcome is 'obvious.' The supervisor should FIRST:
- Allow the technician to proceed since they are experienced
- Stop the work and reinforce the importance of the verification step (Correct answer)
- Document the skip and address it at the next performance review
- Ask a second technician to perform the verification later
Correct answer: Stop the work and reinforce the importance of the verification step
Stopping the work immediately and reinforcing the verification step prevents normalization of deviation and upholds the standard that critical checks are never assumed.
NANTeL Human Performance Principles 2
Which defense-in-depth layer is considered the LAST line of defense against human error in nuclear operations?