Executive summary
Date(s) of inspection:
- January 2023
Aim of inspection
The purpose of this intervention was to provide regulatory confidence regarding the control of major accident hazards on the inactive tank farm (ITF), specifically control of major accident hazards associated with tank overfilling and incompatible mixing during tanker deliveries.
Subject(s) of inspection
- COMAH - Control of Major Accident Hazards Regulations 2015 - rating: Green
Key findings, inspector's opinions and reasons for judgement made
The inspection was focused on verification of technical Process Safety (PS) and Human Factors (HF) improvements, specified to address compliance shortfalls identified during an inspection in January 2021 (Ref: ONR-SDFW-IR-21-059).
The inspection was also an opportunity to confirm completion of additional outstanding actions on the inactive tank farm (ITF). Specifically, addition of fire engulfment vent relief to the kerosene storage tank (safety report action) and a level 4 (lowest level) Regulatory Issue, relating to installation of a nitric acid leak detection system.
The inspection is part of the annual intervention programme agreed with the facility, under the Control of Major Accident Hazards Regulations 2015 (COMAH). In preparation for the site visit, remote engagements were conducted in advance.
During the site inspection, inspectors divided into separate teams of process safety and human factors inspectors. The key regulatory activities undertaken include:
- Reviewing development of a human reliability analysis programme and verification through discussion with front-line / supervisory personnel.
- Exploring alarm displays and response with ITF control room operatives.
- Examining kerosene and nitric acid storage installations.
Regulatory judgement was based on determining compliance with the Control of Major Accident Hazards (COMAH) Regulations 2015 and the Health and Safety at Work etc. Act 1974.
Dutyholder provision of documentation in advance and engagement in remote sessions was welcomed by the Competent Authority (CA). This enabled the regulator to prepare and verify improvement actions in sufficient depth during the site visit. The CA judged that the progression observed across a number of areas has collectively improved major accident control in relation to the specific scenarios sampled.
The visit has enabled closure of extant Human Factors improvement actions related to an extant level 3 Regulatory Issue (RI). Notable progress regarding Process Safety specific actions relating to the same level 3 RI was observed, with the inspection enabling the CA to clarify the final steps required to achieve closure of these actions. Substantial progress against an outstanding level 4 (lowest level) RI was noted. In addition, the CA judged the kerosene storage safety report action to be complete.
An inspection rating of Green, no formal action, has been assigned to this intervention on the basis of progress observed across a number of areas to collectively improve major accident control.
Conclusion
An inspection rating of Green, no formal action, has been assigned to this intervention on the basis of progress observed across a number of areas to collectively improve major accident control.