- Site: Sellafield
- IR number: 21-059
- Date: July 2021
- LC numbers: N/A
Executive summary
Purpose of Intervention
The purpose of this intervention was to provide regulatory confidence regarding the control of major accident hazards on the inactive tank farm (ITF), specifically tank overfilling and incompatible mixing during tanker deliveries. Verification of control measure implementation and follow up of issues raised during a previous ITF site visit were also undertaken.
The inspection is part of the annual intervention programme agreed with the facility, under the Control of Major Accident Hazards Regulations 2015 (COMAH).
The intervention involving both management system and site inspection, was organised by ONR as part of the COMAH Competent Authority (CA). Conducted together with HSE process safety (PS), electrical control and cyber security (ECCS) and human factors (HF) technical specialists, supported by ONR process safety and electrical control and instrumentation (ECI) specialists.
Interventions Carried Out by ONR
Remote inspections were conducted on 1 and 6 July 2021, followed by a site inspection on 7 July 2021 and inspection feedback meeting on 8 July 2021. Due to Covid 19 the four-part intervention structure was applied to reduce personal contact time.
During the site inspection, inspectors divided into two teams. Team A consisted of process safety and regulatory inspectors, whilst electrical and human factors inspectors formed Team B. The key regulatory activities undertaken during the inspection to provide regulatory confidence in the application of COMAH included:
- Review of road tanker offloading processes.
- Verification of control measure installation and follow up of issues raised in June 2021.
- Examination of instrument functional safety management .
- Assessment of operator performance, safety critical task identification and human reliability assessment.
Explanation of Judgement if Safety System Not Judged to be Adequate
Significant compliance shortfalls were identified, spanning both engineering and administrative controls. It is my judgement that SL is unable to demonstrate under COMAH Regulation 5(2) that the requirements of COMAH Regulation 5(1) have been satisfied. Specifically, that all measures necessary have been taken to prevent the specific ITF major accident scenarios and limit their consequences for human health and the environment.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
Team A were able to successfully sample the installation of a safety measures, as specified within the safety report. However, inspection revealed significant compliance shortfalls regarding alarm response and documentation, coupled with inconsistency in relation to high level alarm systems.
The inspection conducted by Team B revealed similar themes regarding procedures and operational response. The significance the safety functions associated with instrumented systems was not clear and SL were not able to demonstrate that existing systems were sufficient. The inspection identified the need to focus on identification of COMAH critical tasks specific to the areas sampled.
The CA identified a number of improvement actions regarding alarm systems and response, instrument functional safety management, COMAH-critical task identification and human reliability analysis. Actions will be tracked to completion through Level 3 regulatory issue (RI 8882). Minor shortfalls in relation to accumulated waste and incompatible material were also identified, with corrective action to be tracked through Level 4 regulatory issues (RI 8875 and RI 8876).
Conclusion of Intervention
A summary of inspection findings, observations and an outline of the corrective actions were shared with the SL team through a remote intervention on 8 June. Both the CA and SL viewed the discussion as beneficial. Feedback from the regulator was received by SL in an open and constructive manner.
At the close of this session I specified a provisional rating of Amber, seek improvement. Consequently, subject to ONR governance an enforcement letter will be issued in line with the ONR enforcement policy statement (EPS) and associated guidance (ONR-ENF-GD-006).