WANO introduces a system for continuous monitoring of nuclear power plant performance

The World Association of Nuclear Operators (WANO) has launched its Enhanced Performance Monitoring (EPM) system for more than 400 nuclear power units worldwide. Its aim is to monitor performance continuously and identify trends early that may precede a decline. With this step, the organization aims to support a consistently high level of nuclear safety over the long term.

From four-year peer reviews to quarterly data

WANO has traditionally based its assessments of nuclear power plant performance on peer reviews, which take place at each operating plant approximately once every four years. The organization will now collect key data from each unit quarterly, enabling ongoing feedback between visits.

WANO Director General Naoki Chigusa said that EPM monitors around 60 different performance indicators. These are mainly predictive indicators—for example, a growing backlog of deferred maintenance or an unplanned reduction in a unit’s output, which may point to a technical problem.

Drawing on peer review experience and advanced data analysis

WANO has 35 years of peer review experience. Over that period, more than 1,000 peer review assessments have been conducted. According to Chigusa, the organization used AI and machine learning methods to analyze this extensive body of experience and define indicators that, in light of past events and performance analyses, are considered possible early warnings of more significant problems.

Quarterly reports and ongoing feedback for plants

A regular flow of data will enable WANO to issue quarterly reports and provide individual plants with ongoing feedback—both on areas where they are meeting expectations and on those where undesirable trends requiring intervention are emerging. EPM information can be combined with WANO’s standard visits to plants.

According to WANO, this can help members identify an emerging decline in performance early and take action, while enabling the organization itself to better identify units that need targeted assistance and allocate its own resources more effectively. The stated aim is to support members in achieving the highest level of nuclear safety.

WANO’s mission and the principle of confidentiality

WANO aims to connect every company and country that operates a nuclear power plant or has a new unit under construction, thereby helping to achieve “the highest possible standards of nuclear safety.” The organization was founded after the 1986 Chernobyl accident, which showed that an event at one plant can affect the entire industry and that nuclear safety is a shared responsibility.

WANO also operates under strict confidentiality: experts from operating units conduct peer reviews at other members’ facilities and provide support and recommendations based on their experience. Enhanced Performance Monitoring is intended to complement this framework with continuous, data-driven monitoring of performance trends.