Torness - SBI 11 - Fire Protection Systems
- Site: Torness
- IR number: 16-252
- Date: March 2017
- LC numbers: 10, 23, 24, 27, 28
Purpose of intervention
The purpose of this intervention was to carry out a system based inspection of compliance with Licence Conditions (LC) in line with the ONR planned inspection programme contained in the Torness Integrated Intervention Strategy (IIS) for 2016/17.
Interventions Carried Out by ONR
This intervention: consisted of a System Based Inspection, SBI-11 - Fire Detection, Suppression, Barriers, Doors and Dampers, which included compliance inspections against the following Licence Conditions (LCs):
- LC10 – Training
- LC23 – Operating Rules
- LC24 – Operating Instructions
- LC27 – Safety Mechanisms
- LC28 – Examination, inspection, maintenance, and testing
The intervention included:
- reviewing safety documentation relevant to the fire protection systems,
- a plant walkdown which was a sample inspection of some of the relevant systems,
- meetings with various station system engineers to understand the stewardship of the systems relevant to fire protection including their maintenance, their OPEX, and any identified challenges such as obsolescence,
- meetings with operations personnel, both decision making (control room) operators, and operational staff carrying out duties around the plant, such as walkdowns and fire system plant isolations, and
- reviewing a sample of controlling documents such as the maintenance records, and records of training history.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
From the areas sampled during this inspection, I judged that overall the fire protection systems met the requirements of the safety case and are adequate.
At the close-out meeting from the inspection, ONR identified some learning or points of challenge for the station to consider. These covered some minor concerns over the clarity of some of the maintenance records, and also some reflections over whether the company could gain more useful insights from data gathered in work carried out by contract partners. The most important challenge was related to a safety case modification which had the effect of increasing the safety categorisation of a fire suppression system in the gas circulator houses. Despite this change, the plant condition which we saw in our plant inspection suggested that this change did not lead to improved maintenance of the system or to improved control of the plant configuration. The system engineer agreed to look further at this.
My final point of challenge was the importance to guard against complacency in fire safety – there has been a long period without a fire, and a risk that standards may slowly drop. Fire avoidance and the effectiveness of fire protection depends upon shared commitment from all staff, with high levels of hazard awareness and a willingness to report degraded conditions. There were some areas of good behaviours, including awareness campaigns and a fire awareness newsletter. Nevertheless there were some small indications of the need for continuing pressure from all levels of station staff and management to further improvement.
With respect to the SBI against ONR’s approach I was able to make the following judgements;
- LC 10 (Training) – We examined records for several individuals covering a variety of roles associated with areas of the fire protection systems. The records showed all training up to date. I judge that in the areas sampled my understanding of ONR’s expectations have been met and therefore have assigned an inspection rating of green to LC10.
- LC 23 (Operating Rules) – we had reviewed the relationship between the technical specifications, how these were complied with in plant operation and also covered surveillance. Based on the evidence sampled, I judged that there are no significant shortfalls when compared with appropriate benchmarks for LC23 compliances and therefore assigned an inspection rating of green.
- LC 24 (Operating Instructions) – the inspection looked at a number of supporting procedures associated with the fire protection systems including procedures for some plant maintenance and for surveillance. The evidence sampled showed the operating instructions provided to station staff were appropriate to ensure that operations that could affect safety are adequately controlled and that relevant operating rules are implemented. I judged that this met my understanding of ONR’s expectations and therefore assigned an inspection rating of green for LC24 compliance.
- LC 27 (Safety Mechanisms, Devices and Circuits) – With respect to the fire protection system, I have interpreted this as the application of configuration control via the yellow padlocks. We viewed these on several systems during the plant walkdown. In the plant areas visited, we saw no sign of a failure to comply with this approach for configuration control of the water supply to fire suppression systems. We had a query about whether this also needs to apply to the air side valves on a particular deluge system, and EDF NGL will consider this further. Notwithstanding this caveat, I judge that the LC27 element of this inspection meets ONR’s expectations and I have assigned an inspection rating of green to LC27.
- LC 28 (Examination, Inspection, Maintenance and Testing) – during the plant walkdowns, we viewed several plant areas where plant was out for maintenance or overhaul. We also sampled maintenance requirements both for passive and active fire systems (detection and suppression) in our discussions with the relevant system engineers. We drew down maintenance records for some activities. From these activities, I judge that overall compliance with LC28 in the areas sampled meet my understanding of ONR’s expectations and therefore have assigned an inspection rating of green to LC28.
- LC 34 (Leak and Escape of Radioactive Material and Radioactive Waste) – the inspection did not cover any area where fire protection systems could lead to leak and escape of radioactive material and radioactive waste either directly or indirectly so I have not assigned an inspection rating to LC34 compliance.
Conclusion of Intervention
As a result of the system based inspection of fire detection, suppression, barriers, doors, I judged that compliance with LC10, 23, 24, 27 and LC28 met the expected standards in the area covered by the inspection, and were rated as green. Overall I concluded that the systems met the requirements of the safety case.
There are no findings from this inspection that could significantly undermine nuclear safety. At present, no additional regulatory action is needed over and above the planned interventions of Torness nuclear power station as set out in the Integrated Intervention Strategy, which will continue as planned.