Office for Nuclear Regulation

Sizewell A – Inspection ID: 51980

Executive summary

Date(s) of inspection:

  • October 2022

Aim of inspection

This is a routine inspection of the implementation of the licensee’s LC11 arrangement via the witnessing of a Level 1 Emergency Exercise (on site only). The aim is to assess the licensee’s performance against the ONR Inspection Rating Guide.

Subject(s) of inspection

  • LC11 – Emergency arrangements – Rating – Green

Key findings, inspector’s opinions and reasons for judgement made

This inspection, one of a series of planned inspections for 2022 at the Sizewell A nuclear site, was undertaken to judge the adequacy of compliance with licence condition (LC) 11 – Emergency arrangements.

During this inspection ONR assessed the Level 1 Emergency Exercise “Phoenix”.  This inspection consisted of observing Magnox Limited staff at Sizewell A nuclear licensed site deploying its emergency arrangements to control a simulated emergency incident.

In my opinion the planning for the exercise was comprehensive, and the scenario was sufficiently challenging for Sizewell A site to adequately demonstrate its arrangements for dealing with an accident arising on the site.  I identified a number of points of good practice but also made a small number of observations, which were conveyed to the licensee in the post-exercise de-briefing meeting.

Taking into account the exercise planning/scenario and the observations made by the ONR team during the exercise, I consider the emergency exercise to be an adequate demonstration of the site’s emergency arrangements made under Licence Condition 11.


Based on the evidence above I am of the view that the licensee adequately demonstrated its LC11 arrangements. As such an inspection rating of green is merited.