Planned inspection at Devonport Royal Dockyard Limited (DRDL) licensed site
- Site: Devonport Royal Dockyard
- IR number: 16-012
- Date: May 2016
- LC numbers: 10, 23, 24, 27, 28, 34
Purpose of intervention
This was a planned inspection on the Devonport Royal Dockyard Ltd (DRDL) licensed site, undertaken as part of the planned inspection programme for 2016/17.
Interventions Carried Out by ONR
The site inspector for the Submarine Refit Complex (SRC) and I (Specialist Electrical Inspector) carried out a System Based Inspection (SBI) of the Electrical Supplies and 60Hz Diesel Generators. We were accompanied and assisted by a second ONR Electrical Specialist. DNSR was made aware of the SBI but did not participate in the inspection.
Explanation of Judgement if Safety System Not Judged to be Adequate
The Electrical Supplies and 60Hz Diesel Generators were judged to meet the requirements of the safety case and were adequate.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
The ONR team carried out a system based inspection of the Electrical Supplies and 60Hz Diesel Generators and concluded that:
- LC10 (Training). Operators and maintainers' training records were sampled and demonstrate that the personnel checked are adequately trained in the operation and maintenance of the DRDL electrical system and 60Hz diesels. Good practice was demonstrated in training. Specific opportunities for improvement have been identified regarding training and practice for abnormal, but foreseeable events on the 60Hz system.
- LC23 (Operating rules). While the fundamental objectives of LC23 have been met in practice, there are shortfalls in the provenance and clarity of the safety functional requirements affecting the 60Hz system and diesels.
- LC24 (Operating instructions). We considered there to be shortfalls in the operating instructions sampled which reduce the confidence that operations that may affect safety will always be implemented appropriately, without undue dependency on the knowledge of individuals.
- LC27 (Safety mechanisms, devices and circuits). Based on the areas checked, we conclude that DRDL has in place a system to ensure that SMDCs are properly connected and in a good working order, but there were shortfalls concerning the equipment used to synchronise 60 Hz diesel generators to the system.
- LC28 (Examination, inspection, maintenance and testing). Although there were a number of shortfalls identified in the maintenance arrangements related to the Electrical Supplies and 60Hz Diesel Generators, there was no concern over their capability to fulfil the requirements of the safety case.
- LC34 (Leakage and escape of radioactive material and radioactive waste) - Not rated, since this LC is not applicable to this SBI.
Conclusion of Intervention
Based upon evidence examined during this inspection, we consider that the requirements of the safety case with regard to Electrical Supplies and 60Hz Diesel Generators have been adequately implemented.
There are no findings identified from this inspection that could significantly undermine nuclear safety. However, areas for improvement were identified related to the clarity and provenance of safety functional requirements, equipment labelling, training, control of documentation, particularly that associated with Examination, Inspection, Maintenance and Testing. These were conveyed to licensee staff at the inspection debriefing meeting.
Several ONR Issues have been identified as a result of this inspection and these will be formally communicated to the licensee in a letter and will be followed up by ONR as part of routine regulatory business.