The Office for Nuclear Regulation (ONR) undertakes all regulatory interaction with the Sellafield site licensee (Sellafield Limited, SL) against a strategy defined by the ONR Sellafield Sub Division. In accordance with that strategy, compliance inspections were undertaken in December 2019 at the Waste Treatment Complex (WTC) and Engineered Drum Stores (EDS) against Licence Conditions 4 (LC4 – restrictions on nuclear matter on the site) and 32 (LC32 – accumulation of radioactive waste).
The purpose of this planned inspection was for ONR to determine the adequacy of implementation of the licensee’s formal arrangements for compliance with LC4 and LC 32. SL’s WTC and EDS were selected as the target for this inspection because of the receipt of nuclear matter in the form of plutonium contaminated material (PCM) waste from off-site consignors, specifically Magnox Limited (Harwell) and the Atomic Weapons Establishment (AWE).
LC 4 requires that the licensee ensures that no nuclear matter is brought onto the site or stored on the site except in accordance with adequate arrangements made by the licensee for this purpose. LC 32 requires the licensee to make and implement adequate arrangements to minimise, so far as is reasonably practicable, the rate of production and volume of radioactive waste, and for the control of such waste, once generated.
On 10 December 2019, I carried out a one day licence condition compliance inspection of the WTC and EDS facilities. The inspection comprised discussions with SL staff, reviews of plant records and other documentation and a plant inspection. I was supported by the incoming Remediation Site Inspector and the outgoing Remediation Site Inspector. A member of SL’s Nuclear Intelligence and Independent Oversight team also participated in the inspection.
As part of my preparation for the delivery of this intervention, the following formal ONR technical inspection guidance documentation was used:
This was not a system based inspection, and therefore no judgement has been made of the adequacy of implementation of any part of the safety case.
Prior to the inspection, I undertook a review of the relevant Sellafield procedures against the ONR guidance document for LC4 and LC32. From the areas sampled, I did not identify any significant shortfalls in the licensee’s formal arrangements for compliance with the licence conditions which would prompt an inspection of these arrangements earlier than currently planned.
During my LC 4 inspection, I sampled documentary evidence that supported bringing nuclear matter onto the SL licenced site and the storage of nuclear matter in the EDS, in a safe and controlled manner. I observed that the licensee has a good understanding of the local arrangements for control of nuclear matter and that the process for receipt of wastes from Harwell is robust. This gives confidence that future consignments of nuclear matter from AWE will be adequately controlled.
During the inspection, the licensee recognised that the database used for tracking PCM on the site is now obsolete, and although there has been an ongoing project to replace the system, this has stalled. The licensee agreed that the project should be reinvigorated and I have raised an ONR Regulatory Issue to oversee progress on the project. I therefore consider that the required standard was met and an inspection rating of Green (No Formal Action) is merited.
During my LC32 inspection, I sampled documentary evidence that supported the long-term management of PCM wastes in WTC and EDS. Additionally, I undertook a plant inspection to confirm the extent of accumulated wastes on plant, and to establish if the licensee is adequately managing the accumulation and safe storage for future disposal of such waste within appropriate site radioactive waste streams.
On the basis of the evidence sampled at the time of this inspection, I judged that the licensee has adequately implemented its arrangements for compliance with LC 32 (accumulation of radioactive waste). I therefore consider that the required standard was met and an inspection rating of Green (No Formal Action) is merited.
From the evidence gathered during this intervention, I do not consider there to be any matters that have the potential to impact significantly on nuclear safety.
At present, no additional regulatory action is needed over and above the planned interventions within the Remediation Value Stream at the Sellafield Nuclear Site as set out in the Integrated Intervention Strategy, which will continue as planned. I have raised a Level 4 Regulatory Issue to monitor progress with the project for replacing the database relating to tracking of PCM on the Sellafield Site.