To conduct a system inspection and undertake routine regulatory interactions with Sellafield Limited
- Site: Sellafield - Magnox
- IR number: 14-146
- Date: February 2015
- LC numbers: 10, 23, 24, 27, 28, 34
Purpose of intervention
This intervention was undertaken on 23 – 26 February 2015 at Sellafield Limited’s Sellafield nuclear licensed site in Cumbria.
Inspection of Licence Condition (LC) compliance at nuclear licensed sites forms a significant part of ONR’s activities. ONR’s Sellafield Programme has defined a programme of system inspections and LC compliance inspections to be undertaken on the Sellafield site; this is a key aspect of ONR’s regulatory strategy (for the Sellafield site). Undertaking this intervention is consistent with this strategy, and is identified on ONR’s PP4 inspection plan which covers Sellafield Limited’s Magnox Operating Unit.
Interventions Carried Out by ONR
The intervention comprised:
- undertaking a system inspection of system 1.09b ‘Containment’ within the Medium Active Evaporation and Thermal Denitration (MA evaporation and TDN) plant;
- and attending a number of meetings comprising routine regulatory interactions.
The purpose of the containment system within the MA evaporation and TDN plant is to prevent the leakage and escape of process fluids, and to facilitate the detection and containment of any leakage that does occur. My system inspection sought to determine whether the containment system within the MA evaporation area of the MA evaporation and TDN plant meets the requirements of the safety case and is adequate. The implementation of the Licensee’s arrangements for the following LCs were tested during the system inspection:
- 10 ‘Training’
- 23 ‘Operating Rules’
- 24 ‘Operating Instructions’
- 27 ‘Safety Mechanisms, Devices and Circuits’
- 28 ‘Examination, Inspection, Maintenance and Testing’
- 34 ‘Leakage and Escape of Radioactive Material and Radioactive Waste’
During my inspection I was accompanied by ONR structural integrity and process engineering specialist inspectors. Our inspection included discussions with SL staff, review of plant instructions, records and other documents and an inspection of the plant.
I also attended meetings:
- with the Fuel Handling Plant (FHP) High Hazard Reduction project team to discuss the planned import of legacy fuel to FHP;
- with those responsible for planning the forthcoming Magnox Reprocessing periodic shutdown to discuss ONR’s likely regulatory approach;
- with senior managers from Magnox Reprocessing to discuss their initial response to a letter I had sent on management of safety critical alarms.
Explanation of Judgement if Safety System Not Judged to be Adequate
Based on sampling inspection, the containment system of the MA evaporation area of the MA evaporation and TDN plant was judged to be adequate and consistent with the requirements of the safety case.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
For the containment system of the MA evaporation and TDN plant, I judged the following IIS ratings to be appropriate:
- LC10 – IIS rating 3 (adequate): I confirmed that training material is available to plant operators and engineers that gives them an appreciation of the requirement to keep radioactive materials contained and how leakage and escape of radioactive materials can be prevented and detected. Based on my sample, the training of individuals is up to date and individuals are adequately trained. I judged an IIS rating of 3 (adequate) to be appropriate against LC10 ‘Training’ based on the requirements of ONR’s LC10 guidance.
- LC23 – IIS rating n/a: This LC was not inspected on this occasion as the Operating Rule for this plant is not related to containment.
- LC24 – IIS rating 3 (adequate): I sampled a range of operating instructions, maintenance instructions and alarm response instructions. I judged them to be clear and unambiguous, and related to ensuring compliance with the limits and conditions derived from the safety case. I judged an IIS rating of 3 (adequate) to be appropriate against LC24 ‘Operating Instructions’ based on the requirements of ONR’s guidance.
- LC27 – IIS rating 4 (below standard): I sampled a number of key Safety Mechanisms (SMs) and Safety Related Equipment (SRE). I judged an IIS rating of 4 (below standard) to be appropriate against LC27 ‘Safety Mechanisms, Devices and Circuits’ because, whilst ONR’s guidance requirements were met we did note a number of deficiencies which were sufficient in number to render a rating of 3 (adequate) unjustifiable on this occasion.
- LC28 – IIS rating 4 (below standard): I sampled the maintenance schedule, maintenance instructions and maintenance records for key components of the MA area. At the time of the inspection, I found the MA1 in-cell Examination, Inspection, Maintenance and Testing (EIMT) and periodicity were not included in the Plant Maintenance Schedule (PMS). Subsequently the licensee updated the PMS to include the MA1 in-cell EIMT and the associated periodicity. This prompt action, combined with our evidence demonstrating appropriate EIMT arrangements were in place through means other than the PMS justifies an IIS rating of 4 (below standard) to be appropriate against LC28 ‘Examination, Inspection, Maintenance and Testing’ rather than a lower rating of 5 (significantly below standard).
- LC34 – IIS rating 3 (adequate): I sampled the arrangements in place to detect leakage and escape for the MA1 cell of the MA evaporation and TDN plant. I judged an IIS rating of 3 (adequate) to be appropriate against LC34 ‘Leakage and Escape of Radioactive Material and Radioactive Waste’ because I concluded adequate arrangements are in place to prevent leakage of radioactive materials, and to detect any leakage that does occur.
Based on my sample inspection, I judged that the containment system within the MA area of the MA evaporation and TDN plant is consistent with safety case requirements, the key equipment that verifies this is available and appropriately maintained, those responsible for operations are suitably trained and that appropriate written instructions are available. I conclude the containment system meets the requirements of the safety case.
I also attended a progress meeting to discuss the planned import of legacy fuel to FHP. The focus of the meeting was to clearly communicate my expectations of the prerequisites I would expect to be in place at FHP prior to the import of legacy fuel. The licensee noted my views.
I attended a meeting to outline ONR’s likely approach to the regulation of the forthcoming Magnox Reprocessing periodic shutdown. I confirmed that ONR would work closely with the Sellafield Limited Internal Regulator (SLIR) to gain assurance that the plant was safe to restart after the shutdown. I confirmed ONR’s strategy is to issue a consent to restart the plant after the periodic shutdown provided the outcome of the assurance work undertaken by ONR and SLIR confirms this is safe to do.
I attended a meeting with senior managers from Magnox Reprocessing to discuss safety critical alarms. I was reassured that the issues raised in my recent letter are being addressed and a programme of remedial work has been put in place.
Conclusion of Intervention
The issues raised in my system inspection will be managed to close out as part of normal regulatory interactions with the licensee. Based on the evidence gathered, no significant matters have been identified that are likely to impact on nuclear safety on the Sellafield site at this time.