Executive summary
Date(s) of inspection:
February 2025
Aim of inspection
This inspection will seek assurance that there is adequate inspection and maintenance of the main steam distribution system controlled by Utilities at Sellafield Ltd.
The Utilities steam system has a key role in supporting a significant number of facilities across the entirety of the Sellafield estate, the steam supply has claims for nuclear safety and welfare provision and therefore is strategically significant to the mission at Sellafield.
Regulatory Intelligence indicated that the plant is at the end of it’s envisaged design life and in need of significant material improvement to meet the updated mission timescales, at present the system is required until 2075.
The purpose of my inspection was to seek assurance that the PSSR 2000 and asset management arrangements for the Utilities steam systems are suitable and sufficient to ensure that the plant will be able to safely support the site mission until 2075.
Subject(s) of inspection
MHSWR - Rating: AMBER
Provision and Use of Work Equipment Regulations 1998 (PUWER) - Rating: AMBER
PSSR - Rating: AMBER
Key findings, inspector's opinions and reasons for judgement made
We identified significant risk gaps on the steam distribution system and associated protective devices, the potential safety risk was such we pivoted the inspection to define the risk gaps to the extent that a risk of serious personal injury could be discounted or actions taken to ensure safety. There were two separate risk gaps; the capability of the system to provide pressure relief in normal operation and the availability of protective devices on a live system when the protective devices are undergoing out of service maintenance and inspection.
We undertook assurance work to confirm that a risk of serious personal injury was not present with the system in its normal operational state, this included a walkdown of the Fellside CHP facility and the steam plant of concern on the Sellafield Ltd site.
I was of the opinion that there are suitable and sufficient control measures that are robustly implemented that a risk of serious personal injury did not exist.
However, Sellafield limited have not provided adequate assurance that the design parameters are understood, recorded and subsequently used to inform the safety of plant operations. I will seek improvement utilising ONR's established enforcement arrangements.
There were also significant design induced safety risks identified raised when the protective devices are undergoing out of service maintenance and inspection. I sought further clarity on the arrangements to ensure safety during maintenance of the protective devices, Sellafield Ltd have provided assurance by revising their maintenance philosophy for future maintenance campaigns which I consider to be aligned to relevant good practice and not longer represents a risk of serious personal injury.
Conclusion
Given the reactive actions required, we were not able to complete the original scope. I did however have enough evidence to judge this intervention rating as AMBER (Seek Improvement).