- Site: Sellafield
- IR number: 21-177
- Date: March 2022
- LC numbers: 22, 28
Executive summary
Purpose of Intervention
In accordance with the Office for Nuclear Regulation (ONR) Strategy, each year ONR performs a series of planned Licence Condition Inspections. In line with the Sellafield, Decommissioning Fuel and Waste (SDFW) strategy, an inspection of Utilities Site Water System against LC 22 and LC 28 was planned and conducted on the 1st and 2nd of March 2022. The purpose of this inspection was for ONR to determine the adequacy of Sellafield Limited’s implementation of its arrangements for plant modification (LC 22) and the adequacy of implementation of its arrangements for the examination, inspection, maintenance and testing (EIM&T) (LC 28), including an assessment of plant condition.
The Sellafield Site Water System supplies all of the water used within the licensed site, including safety related use for pond purging and steam supply. There is a continuous requirement for domestic and demineralised water during normal operations and provision for fire safety. There are four grades of water supply as follows:
- R1 – Wast Water, drawn directly from the lake via the Wast Water Pump House, this is the highest quality raw water available to Sellafield and is used for the production of domestic and demineralised water;
- R2 – Raw Water, from a range of alternative water supplies including boreholes in the vicinity of Brow Top and diverted water from the rivers Calder and Ehen. It is not as clean as Wast Water and requires a higher degree of treatment when used for the purposes above, but it is the primary source of water for fire hydrants and can also be used as backup in the event of loss of the Wast Water supply;
- Domestic Water – Produced on site at the Brow Top reservoir and water treatment plant, used for drinking water and site domestic purposes. Primarily produced from R1 water, but may be produced from R2 if necessary;
- Demineralised Water – Produced in the Sellafield Water Treatment Plant, it is used for pond purging and steam production.
Although the Sellafield Site Water System is low consequence in terms of radiological hazards, the continued availability of ample quantities of appropriate quality water is important in supporting Sellafield Limited’s downstream plant operations and hence supports overall hazard and risk reduction activities across the Sellafield site.
The focus of this inspection was limited to the Wast Water Pump House and Brow Top facilities.
Interventions Carried Out by ONR
On the 1st and 2nd of March 2022 the ONR Site Infrastructure Inspector and I carried out a LC 22 and LC 28 compliance inspection of the Sellafield Site Water System. The inspection sampled plant modifications and EIMT of the Wast Water Pump House and Brow Top facilities. During the visits to plant we were also accompanied by the incoming and outgoing ONR Human and Organisational Capability inspectors, for familiarisation. The purpose of this inspection was to gain assurance of whether the Sellafield Site Water System is being managed in compliance with Sellafield Limited’s arrangements for LC 22 and LC 28.
Explanation of Judgement if Safety System Not Judged to be Adequate
Not applicable as this was not a System Based Inspection.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
From the inspection sample, I found that Sellafield Limited had prepared sound cases for the modifications made to the Site Water System. I sampled in detail two projects and found that these had been appropriately implemented under the licensee’s Plant Modification Proposal (PMP) process. This gave assurance of compliance with LC 22 and I therefore assign a rating of Green.
During plant walkdowns I observed a range of plant in the Brow Top and Wast Water Pump House facilities. All appeared to be in acceptable condition. Maintenance documentation was also sampled and found to be appropriate. Instructions were of a good standard and records indicated that staff carrying out the maintenance were appropriately trained and suitably experienced for the task. This gave assurance of compliance with LC 28 and I therefore assign a rating of Green.
No significant shortfalls were identified during this intervention.
Conclusion of Intervention
From the evidence sampled during this inspection, principally visits to plant, inspection of documentation and interactions with relevant licensee personnel, I am of the opinion that Sellafield Limited is compliant with its arrangements for LC 22 and LC 28. Accordingly, I assess both licence conditions as Green, with no further regulatory action required. No regulatory issues were raised during this intervention.