Operating Experience (OpEx)

01

Internal vs external operating experience

Internal operating experience originates within the organisation: equipment failures, procedural errors, near-misses, condition reports, audit findings, and corrective action program entries. This is the most directly applicable category because it reflects the specific equipment, procedures, culture, and operating environment of the facility. A well-functioning corrective action program is the primary feed for internal OE capture — organisations with high reporting rates generate more internal OE data, which in turn supports better trend analysis and earlier identification of systemic issues.

External operating experience comes from outside the organisation: NRC event notifications, IAEA incident reporting system (IRS) entries, WANO performance indicator data, industry alert bulletins, and operating experience publications from utilities, owner groups, and research organisations. External OE is valuable precisely because it represents events that occurred elsewhere, providing an opportunity to assess whether the same preconditions exist at your facility and to act before a similar event occurs.

02

The operating experience cycle

Identification and capture: Events, observations, and external notices are entered into the OE system. The entry threshold should be low — it is better to evaluate something that turns out to be insignificant than to miss something significant because it did not appear worth reporting. For external OE, a designated function should be responsible for monitoring industry sources and routing relevant items for evaluation.

Screening and significance determination: Not all OE entries warrant the same level of evaluation. A screening step assesses each entry for safety significance, applicability to the facility, and whether immediate action is required. High-significance items are escalated; routine items are batched for periodic review. The screening criteria must be documented and applied consistently to prevent important items from being downgraded inappropriately.

Evaluation: Applicable OE is evaluated to determine whether the preconditions for a similar event exist at the facility. For internal events, this typically involves root cause analysis. For external OE, it involves a gap assessment: does our facility have the same equipment, procedures, or organisational conditions that contributed to the external event? The evaluation must be documented, not simply summarised.

Action assignment and tracking: Where the evaluation identifies a gap or vulnerability, corrective actions are assigned and tracked to completion. Actions must have owners, due dates, and completion criteria. OE actions that are entered into the corrective action program but never closed, or closed without verifying effectiveness, are a common finding during regulatory assessments.

Effectiveness review: After corrective actions are completed, a verification step assesses whether the actions actually addressed the root cause. An action that satisfies the paperwork requirement but does not eliminate the underlying condition provides false assurance. Effectiveness reviews are the quality control step on the OE process itself.

Lessons learned dissemination: Significant OE findings — particularly those with broad applicability — should be communicated across the organisation. Lessons learned bulletins, toolbox talks, and procedure revisions are all vehicles for dissemination. The measure of an effective dissemination step is whether the people who could have encountered the original event know about it and understand what changed.

03

Common weaknesses in OpEx programs

The most prevalent weakness is a high threshold for internal reporting. When workers perceive that raising minor issues creates administrative burden without visible benefit, or when past experience suggests that reports are not taken seriously, reporting rates fall and the OE program loses its early-warning function. Leadership behaviour is the primary driver of reporting culture.

OE evaluations that describe what happened without analysing why it happened produce actions that address symptoms rather than causes. An evaluation that concludes "the technician made an error" without asking why the procedure permitted the error, why the training did not prevent it, and why the supervision did not catch it, will generate actions that do not prevent recurrence.

External OE is frequently reviewed, screened as "not applicable," and closed without documented basis. When regulators review OE records, they look for the applicability determination: why was this external event not applicable to this facility? Closing an external OE entry as not applicable without documented rationale is treated as a program weakness, not a clean record.