Executive summary
Date(s) of inspection:
May 2025
Aim of inspection
The Sellafield Ltd arrangements for Site Licence Condition 11 require a Regulator Evaluated Demonstration Exercise (REDE) on an annual basis for nuclear safety and security.
The aim of the inspection was for the Office for Nuclear Regulation (ONR) to evaluate the emergency exercise and judge the adequacy and ability of Sellafield Ltd to put its' emergency response arrangements into effect at any time.
Subject(s) of inspection
- LC11 - Emergency arrangements - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
Sellafield Ltd demonstrated its emergency arrangements with a severe accident at the High Level Waste Plant. The scenario provided a challenge to the responders with a steam leak, casualties, radiological release and planning for the partial evacuation of site. The scenario also separated the site-wide command and control function between the Main Site Command Facility and Off Site Command Facility. The scenario represented a challenging exercise and ONR welcomes this as such exercises generally provide greater learning opportunities.
There were a number of areas of good practice with effective command and control and the implementation of timely and considered actions to protect the workers and public. The exercise objectives were achieved, there were several learning opportunities captured by Sellafield Limited which will be followed-up with an ONR Level 4 Regulatory Issue.
Conclusion
In our opinion, this was a challenging demonstration and Sellafield Limited adequately demonstrated the application of their emergency arrangements warranting an intervention rating of GREEN (no formal action) for LC11.