Unusual events: no impact on population or environment

In 2023, there were 13 unusual events at nuclear facilities. These are deviations from normal procedures, which facilities must report to the Authority. In our assessment, these events had no impact on the population or the environment in 2023.

Assessing investigations and solutions

Our 2023 Unusual Events Report (in Dutch) lists all anomalies reported by facilities. Following a report, facilities must launch an investigation. They must look for the cause of the incident, determine how to prevent its recurrence and record their findings. We then assess these and review the facility’s investigation. We also evaluate whether the solutions proposed by the facility are going to be effective.

Determining severity

Finally, we determine how severe the incident was (using the INES-scale) (in Dutch). In 2023, there were:

  • five incidents that are still being investigated;
  • one incident that we classified as an anomaly (INES level 1);
  • seven incidents that we view as minor anomalies with no safety repercussions (INES level 0).

You can read more about these incidents on our unusual events page (in Dutch).

INES level 1 due to incomplete process descriptions

We classified one incident as an anomaly (INES level 1). On 11 April 2023, two employees of EPZ (the owner of the Borssele nuclear power plant) were exposed to slightly elevated radiation levels during their work. The radiation exposure was limited, however: comparable to a hospital X-ray or a return flight from Amsterdam to Los Angeles.

EPZ’s process descriptions, which could have prevented the radiation exposure, were found to be incomplete. This led us to label this incident as an anomaly. You can read more about the incident on the Borssele nuclear power plant’s unusual events page (in Dutch).

Creating clarity

In reviewing the reports we received, we noticed room for improvement in terms of follow-up. It is not always clear what happens after an investigation, and facilities do not always specify when they intend to implement their proposed solutions. The facilities have taken this criticism seriously and made the necessary improvements. 

Process descriptions could be further optimised, however. They could be made clearer to ensure that employees are always able to understand operational processes. Our inspectors will therefore continue to look closely at how each nuclear facility manages its process descriptions.