Office for Nuclear Regulation

Sizewell B – Inspection ID: 51250

Executive summary

Date(s) of inspection:

  • March 2023

Aim of inspection

The aim of this intervention was to undertake a planned licence condition (LC) compliance inspection of LC 8 (warning notices) at Sizewell B.

This inspection was undertaken as part of a series of planned inspections described in the Integrated Intervention Strategy for Sizewell B.

Subject(s) of inspection

  • LC 08 – Warning notices – Rating: Green

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

Containment is usually only accessible during outages, at which time a large number of external contractors unused to the site will work in containment. Further, the plant areas inside containment are somewhat labyrinthine and not easy to access. Therefore, at an early stage during the outage, I considered it prudent to inspect the emergency signage in containment for its legibility and accuracy.

I walked the entirety of accessible areas within containment (except the gantry and polar crane) to confirm the following:
Emergency escape route signage was visible (i.e. not obscured by equipment brought into containment) and legible (i.e. the escape route could be clearly identified).
The escape route indicated was the most expedient one.


As a result of my plant walkdown I am satisfied with both the legibility and accuracy of the signage, and consider an inspection rating of green (no formal action required) to be appropriate for compliance with LC 8. No changes to the proposed IIS plan for the site are necessary.