In accordance with the Office for Nuclear Regulation (ONR) Strategy, each year ONR performs a series of planned System Based Inspections (SBIs). In line with the Sellafield, Decommissioning Fuel and Waste (SDFW) strategy, an SBI of Utilities Site Water System was planned and conducted between 22-23th January 2019. The purpose of this inspection was for ONR to determine the adequacy of implementation of the safety case claims in respect of this system.
The Site Water System supplies different equipment in process plants and service buildings at Sellafield 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 water supplies as follows:
Although the Site Water System is low consequence in terms of radiological hazards the continued operation is important in supporting SL’s down steam plant operations and hence supports SL’s overall hazard and risk reduction activities across the SL site.
This SBI was conducted as a joint inspection with the Environment Agency (EA) given the common areas of interest with the Site Water System. However, this Intervention Record only captures ONR’s key regulatory observations. The regulatory observations from the EA are recorded within their own inspection report.
In order to determine the adequacy of implementation of the Licensee’s safety case claims in respect of this system, ONR examined evidence to determine compliance against six key Licence Conditions (LCs). These LCs (listed below) have been selected in view of their importance to nuclear safety and in providing a structured approach to determining whether the safety case has been implemented adequately.
ONR assessed compliance in Utilities Site Water System against the following LCs using applicable inspection guidance:
The inspection was conducted over the course of two days looking at compliance with the above LCs. It involved reviewing the applicable safety case claims and sampling, through a combination of document reviews, discussions with plant operators and plant inspections to determine compliance against the selected LCs. SL’s Internal Regulator also supported this inspection.
Based on the sampling undertaken, I judged the safety case supporting the Site Water System to be adequately implemented.
From the areas I targeted and the evidence examined during the inspection, I consider SL has adequately implemented those safety case claims that relate to the Site Water System.
I identified an area of good practice as follows:
Areas for concern were identified as:
Whilst some minor deficiencies and anomalies against SL’s compliance were identified, I consider that SL has provided adequate assurance that shortfalls will be addressed with the implementation of the new safety case.
Consequently, it is my opinion that an overall rating of Green for the Utilities Site Water System as a whole, is appropriate.
I consider that the licensee has a good knowledge of the physical condition of the Structures, Systems and Components reviewed during this inspection and has in place appropriate management controls to ensure on-going safety.
I also identified several minor improvements that could be made for improving the Site Water System. I have therefore raised a ONR Regulatory Issue at Level 4 to track SL’s progress of these matters.
Overall, on balance, I consider the safety case supporting this system to be adequately implemented.