Executive summary
Date(s) of inspection:
September 2025
Aim of inspection
This ageing information technology (IT) systems and resilience themed inspection at Heysham 1 (HY1) power station was performed to gain assurance that ageing IT systems relevant to safety and security are being managed with resilience.
Subject(s) of inspection
- FSyP 7 - Cyber Security and Information Assurance - Rating: Amber
- LC10 - Training - Rating: Green
- LC14 - Safety documentation - Rating: Amber
- 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
This themed inspection on ageing information technology (IT) systems resilience was carried out by a team of Office for Nuclear Regulation (ONR) specialist nuclear safety and security inspectors, including the ONR nominated site inspector for Heysham 1 (HY1).
The following technical support computer systems (TSCS) were sampled in relation to Licence Conditions (LC) 10 (Training), 27 (Safety mechanisms, devices and circuits) and 28 (Examination, inspection, maintenance and testing):
- Boiler closure unit (BCU) corrosion probes.
- Chemistry dionex ion chromatograph system (CDICS).
- Chemistry gas chromatograph system (CGCS).
- Traka key presses.
- Dragos cybersecurity system (DCS).
- PI historian.
During the inspection we did not identify any significant shortfalls in relation to the adequacy and application of the LC10, LC27 and LC28 arrangements we sampled. We did provide several pieces of regulatory advice and raised a level 4 regulatory issue (RI); however, we did not consider that any of the associated issues posed a significant or immediate threat to nuclear safety. As a result we assigned an inspection rating of GREEN (no formal action) to each of these LCs.
However, it became evident that formal and systematic safety assessments had not been undertaken for the TSCS we sampled. As a result, we were unable to gain assurance that the nuclear safety consequences associated with all credible failure modes were understood and, furthermore, whether all necessary risk mitigations had been implemented. We considered this to be a significant shortfall in relation to LC14 (Safety documentation) and FSyP 7 (Cyber Security and Information Assurance).
Conclusion
During the inspection we did not identify any significant shortfalls in relation the adequacy and application of the LC10, LC27 and LC28 arrangements we sampled. We did provide several pieces of regulatory advice and raised a L4 RI; however, however, we did not consider that any of the associated issues posed a significant or immediate threat to nuclear safety. As a result we assigned an inspection rating of GREEN (no formal action) to each of these LCs.
However, it became evident that formal and systematic safety assessments had not been undertaken for the TSCS we sampled. As a result, we were unable to gain assurance that the nuclear safety consequences associated with all credible failure modes were understood and, furthermore, whether all necessary risk mitigations had been implemented. In relation to this we sampled BEG/SPEC/IM/001 (Computer system management control) and noted that it states that a computer system plan should be produced for all TSCS, which includes the production of a risk assessment. We, therefore, considered this to be a significant shortfall in relation to LC14 (safety documentation) and FSyP 7 (Cyber Security and Information Assurance). As a result, we assigned an inspection rating of AMBER (seek improvement) in relation to LC14 and will seek ONR Operating Reactors management endorsement for a corporate level 3 RI to ensure that this shortfall is addressed in a timely manner. It is important to note that we did not consider this shortfall posed a significant or immediate threat to nuclear safety.