Executive summary
Date(s) of inspection
- November 2025
Aim of inspection
Low Active Effluent Management Group (LAEMG) has a number of areas in the large area of facilities which rely on electrical backup power in the safety case. A full blackout can lead to offsite release and local contamination in the facility. Recently there have been a number of sitewide power outages which have resulted in damage and failure of the electrical systems at LAEMG, including the backup electrical system. This inspection will seek assurance that the electrical system operation and maintenance regime is meeting the expectations of the safety case and that the facility is in compliance with Sellafield Internal Arrangements for LCs 24, 27 and 28.
Subject(s) of inspection
- LC10 - Training - Rating: GREEN
- LC23 - Operating rules - Rating: GREEN
- LC24 - Operating instructions - Rating: GREEN
- LC27 - Safety mechanisms, devices and circuits - Rating: GREEN
- LC28 - Examination, inspection, maintenance and testing - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
I, the Site Inspector for Low Active Effluent Management Group (LAEMG) at the Sellafield Site in Cumbria undertook a system based inspection (SBI) covering the electrical system at LAEMG.
For Licence Condition 10, I targeted the training of the Senior Authorised Person (Electrical), an Electrical Maintainer who is responsible for carrying out maintenance on the electrical systems and a B800 Operator that the Inspection team talked to during the walk round. Overall, I judged that the required standard was met and an inspection rating of Green (no formal action) is appropriate against LC10.
For Licence Condition 23 and 24, the safety case makes no direct safety claims for the provision of electrical power to the plant but the LAEMG recognises that the loss of electrical power is an initiating event for several faults. Although there is no safety designation, the LEAMG electrical systems have been identified as requiring an electrical SAP, safety controls, back-up, and emergency arrangements. I targeted my inspection on a sample of the electrical boards, diesel generator connection points, Uninterrupted Power Supply (UPS) batteries associated with the electrical supply to the safety function of the vessel ventilation system including the relevant emergency instructions for the loss of power and the maintenance instructions associated with the electrical boards. I was satisfied that the instructions followed a detailed step wise format containing the relevant steps to meet the safety requirements. Based on the evidence sampled I judge that an inspection rating of Green (no formal action required) is appropriate against Licence Conditions 23 and 24.
For Licence Condition 27 and 28, I targeted my inspection on a sample of the electrical boards, diesel generator connection points and UPS batteries associated with the electrical supply and undertook a review of the maintenance records and system health reports. I found a few shortfalls against Sellafield arrangements and have raised two RIs (RI-12827 and RI-12855) to track the dutyholder's response to these shortfalls. Overall, I judge that the required standard is met and an inspection rating of Green (no formal action) is appropriate against Licence Condition 27 and 28.
For Licence Condition 34, I reviewed the potential for leakage and escape of radioactive material in connection with the electrical and back up system and judged that the electrical systems within LAEMG are not sufficiently relevant to the licence condition under consideration. I have therefore not assigned any rating for Licence Condition 34 as a result of this inspection.
From the areas sampled, I provided some minor regulatory advice and identified a few shortfalls. I have raised two Level 4 RIs (RI-12827 and RI-12855) to track the facility response to identified shortfalls.
Conclusion
From the evidence sampled during the inspection, I judge that Sellafield Ltd has adequately implemented the safety function of the electrical and back-up system (which support the relevant claims in the safety case) and that the formal arrangements for LCs 10, 23, 24, 27 and 28 are being adequately implemented. For LCs 10, 23, 24, 27 and 28 an inspection rating of Green (no formal action) is appropriate. I have raised two Level 4 regulatory issues to track several shortfalls (RI-12827 and RI-12855) and to ensure that the dutyholder addresses these shortfalls.
I have not assigned any rating for LC34 as a result of this inspection, since I judged this licence condition was not sufficiently relevant to the system under consideration.