Office for Nuclear Regulation

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SIXEP LC28 & LC32 Inspections and Routine Interactions

Executive summary

Purpose of intervention

This intervention was undertaken on 16 – 19 March 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 2014-15 PP4 inspection plan which covers Sellafield Limited’s Magnox Operating Unit.

Interventions Carried Out by ONR

LC28 ‘Examination, Inspection, Maintenance and Testing’ requires the licensee to make and implement adequate arrangements to ensure that all plant that may affect safety, as identified in the safety case, receives regular and systematic examination, inspection, maintenance and testing (EIMT).  The EIMT must be carried out by and under the control of suitably qualified and experienced persons (SQEPs) and in accordance with arrangements made and implemented by the licensee.  The purpose of this maintenance is to ensure the plant remains capable of performing the functions required by the safety case at the required levels of reliability.

LC32 ‘Accumulation of Radioactive Waste’ requires the licensee to make and implement adequate arrangements to ensure that both the rate of production of, and the amount of radioactive waste on nuclear licenced sites are minimised and at all times adequately controlled. The licensee is also required to keep records of the amount and location of any radioactive material (including fuel and waste). 

I completed compliance inspections (comprising a number of office-based discussions and a plant walk down) against these LCs in accordance with the following ONR guidance:

I also attended a number of planned meetings as part of my routine interactions, and made initial enquiries about an event that took place earlier this month.

Explanation of Judgement if Safety System Not Judged to be Adequate

N/A.  This was not a safety system inspection.

Key Findings, Inspector's Opinions and Reasons for Judgements Made

I undertook a LC28 compliance inspection within the Site Ion-EXchange Plant (SIXEP) jointly with Environment Agency and the Sellafield Limited Internal Regulator (SLIR).  The inspection forms part of an ongoing intervention to gain assurance that SIXEP is sufficiently resilient and will continue to safely perform its functions if and when fuel is imported to Fuel Handling Plant (FHP) from the legacy ponds on the Sellafield site for long term storage.  I identified key instruments and a number of process vessels within SIXEP for inspection and sampled the EIMT arrangements for these. 

For key instruments, the arrangements for EIMT met my expectations (as informed by ONR’s guidance requirements).  However, for certain process vessels (and process cells) the arrangements for EIMT are not consistently prompted by the SIXEP Plant Maintenance Schedule (PMS).  Specifically, the scopes to which the inspections are undertaken are not always those on the PMS, and there were a number of outstanding inspections.  The requirement to update the PMS was recognised by the licensee in advance of my inspection.  Nevertheless, deficiencies with the PMS across the Magnox Operating Unit (within which SIXEP resides) were previously identified by ONR following a LC28 inspection in 2010; these deficiencies were of a similar nature to those I noted in this inspection. 

In view of the deficiencies noted in my sampling inspection, I do not consider the SIXEP EIMT arrangements (specifically the PMS) meet the requirements of ONR’s guidance on LC28.  I therefore judge an IIS rating of 5 (significantly below standard) to be appropriate.  I have therefore placed an action for the licensee to remedy its conduct of operations in regard to the SIXEP PMS and a second, similar action to remedy similar deficiencies in the FHP PMS (which I also noted during my inspection).  I emphasised the importance of SL’s working to an up-to-date and properly managed PMS ahead of any bulk transfers of legacy fuel into the FHP pond.

My LC32 compliance inspection, undertaken jointly with Environment Agency and SLIR, is part of a wider intervention to gain assurance in radioactive waste management at SIXEP, e.g. in regard to minimising waste generation and the adequacy of  storage capacity both now and following any future legacy fuel imports to FHP.   I am satisfied the operational regime at SIXEP seeks to minimise, so far as is reasonably practicable, the generation of radioactive wastes. 

Radioactive wastes arising as a result of the operation of SIXEP are stored in Bulk Storage Tanks (BSTs).  I noted the licensee has not yet made substantial progress on preparation for eventual retrieval, processing and disposal of the contents of the BSTs.  I nevertheless consider this position to be acceptable in the context of the ongoing hazard and risk reduction activities on the Sellafield site because there are no immediate safety concerns, e.g. in regard to the remaining capacity of the BSTs or their material condition.  Overall, I consider the licensee meets the requirements of ONR’s guidance on LC32 and therefore judge an IIS rating of 3 (adequate) to be appropriate. 

I also attended a number of meetings for information-gathering purposes and received routine updates on a number of topics.  From a regulatory perspective, the key meeting I attended was to discuss SL’s response to a letter I had sent recently detailing concerns on the conduct of operations and on the functionality of, and response to instructions associated with safety-critical alarms in Magnox Reprocessing.  In response the licensee has put in place a programme of work to make the necessary improvements.  I will take this programme into account when considering whether to recommend further regulatory action in regard to the adequate conduct of operations in Magnox Reprocessing.

On 10th March there was a breach of a required Operating Instruction (rOI) specified in the Magnox Reprocessing Separation plant criticality safety case.  Although advice from an ONR criticality specialist inspector is that there is no immediate safety concern, this incident is the latest in a series of ‘conduct of operations’ related events within Magnox Reprocessing (i.e. where individuals have not consistently undertaken the actions expected of them in situations that may affect safety).  Sellafield Limited will report this event to ONR as an incident following the formal process and is already undertaking an investigation.  The findings from this investigation will be reported to ONR when they are available after which I will consider whether to follow up the incident.  I will also take this matter into account when considering whether to recommend further regulatory action in regard to the adequate conduct of operations in Magnox Reprocessing.

Conclusion of Intervention

Two regulatory issues were raised as a result of this intervention relating to the adequacy of SL’s conduct of operations in regard to the PMS.  I will send a letter to the licensee detailing my LC28 findings and requesting a programme of work to remedy these deficiencies as a matter of priority. 

More generally, I will use SL’s work programme to improve its conduct of operations and the information provided in regard to the recent rOI breach to inform my recommendation as to whether further regulatory action is needed here.