Ensure You're Relying on the Right Things: Effective Analysis of Controls and Safeguards in PHA and HAZOP

The typical design life expectancy for an operating facility can range between twenty to thirty years while the actual operating life may be longer or even shorter due to factors such as operation and maintenance practices, and aging equipment. Aging is an effect where a component incurs material deterioration and damage with an increasing likelihood of failure over its lifetime. Aging equipment refers to equipment where there is evidence or likelihood of significant deterioration and damage taking place since new, or for which there is insufficient information available to know the extent to which this possibility exists. The deterioration and damage have the potential to render equipment unfit for purpose and can impact the equipment’s functionality, availability, reliability, safety and overall asset integrity (Health and Safety Executive: Plant Ageing Study, 2010).

Figure 1 (excerpt of Figure 5.4-1: Basin Curve for Failure Rate of Equipment from CCPS: Dealing with aging process facilities and infrastructure, 2018) illustrates how equipment failure rates vary as equipment ages or matures. During the early years, the failure rate may decline or plateau, however, as equipment nears its end of life, the failure rate increases. This is mainly due to degradation of equipment and age-related failure mechanisms such as corrosion, erosion and fatigue which pose a significant risk.

Recent research shows that 50% of major ‘loss of containment’ events in Europe stemming from technical plant failures were primarily due to aging plant mechanisms such as erosion, corrosion, and fatigue. These events had overall significant impacts which included the loss of eleven (11) lives, one hundred and eighty-three (183) injuries and economic losses exceeding 170Million € (euros), reinforcing the impact plant related failures can have on asset integrity, safety and business performance (Health and Safety Executive: Plant Ageing Study, 2010).

Aging and degradation of assets poses new safety and environmental risks. It is only by investigating and understanding the nature of these defects and failures that one can identify and implement suitable risk treatment plans to address underlying concerns. The asset integrity strategies developed and implemented for greenfield facilities will differ from those for a brownfield facility, particularly mature ones. As a facility matures through its lifecycle, the process safety and asset integrity management systems, as well as the workforce should evolve to reflect the needs of the operation and organization. The risk profile for a mature facility considers several factors, including:

• Inherent hazards and risks of the installation
• The propensity of the installation to aging-related deterioration or damage
• Likely types of aging mechanisms and where and how these could present themselves
• The extent to which aging is being effectively managed

Figure 2 (excerpt of Figure 1.4-1: Suggested Spectrum for the Aging of a Facility from CCPS: Dealing with aging process facilities and infrastructure, 2018) shows how inspection and maintenance plans gradually shift to address potential defects or concerns that could arise as the facility ages. In the early stages of a facility’s lifecycle, asset and mechanical integrity programs may reveal minor surface defects with occasional visible wear and tear. During this stage, monitoring is recommended to ensure conditions do not deteriorate further. As time progresses, other physical failure mechanisms may begin to manifest as moderate to significant defects or deterioration of equipment progresses. A facility's asset integrity management strategy must therefore evolve to include plans for intrusive inspections, repairs, refurbishment/upgrade projects and replacement of aging assets, where such conditions, if not addressed, can accelerate to full functional failure, and pose major process safety risks. As part of that evolution, leaders must proactively plan and budget for the necessary initiatives and activities that will help ensure continued safe operation of the asset.

According to the “Plant Ageing Study - Phase 1 Report” from the Health and Safety Executive, development of a well-defined, robust Process Safety and Asset Integrity Management System is key to ensuring equipment is designed, constructed, maintained, and managed in a systematic way. This reduces the potential for conditions to develop which could lead to major incidents, and helps ensure the effects of change, and the lifecycle of the operation is monitored. This reduces the likelihood for the development and effects of aging and potential for incidents to be realized. The report also recommends that key elements of management systems be designed to recognize and manage aging plant issues. These include:

1. Policy, strategy, and objectives
2. Standards, organization, responsibilities, resources
3. Hazards and effects (risk) management
4. Asset Integrity planning and procedures
5. Implementation and monitoring
6. Audit and self-verification
7. Management review

With more than twenty years of operation and mature assets, new trends and defects not previously observed are being identified at the Atlantic LNG facility. Process Safety Management concepts applied during the initial years consisted primarily of core elements such as HAZOP-LOPA studies, Management of change (MOC) and baseline inspections. A decade later, the Asset Integrity management standard comprising of ten elements was developed to encompass all of the core PSM elements in addition to safety critical equipment (SCE) management, corrosion management, facility siting studies, incident investigation and learning to manage inherent risks and capture the emergence of new risks identified in the industry. Additionally, a formal performance management system was also introduced to monitor progress and drive improvements. Twenty years later, the management system has evolved even further to a 3-petal model where all of these key elements are managed under the umbrellas of design, operating and technical integrity. The tenets under each of these are held together by robust Process Safety leadership and culture. New initiatives have also been included e.g., use of a live barrier model to provide risk oversight, fabric maintenance campaigns, life extension projects, digitalization of processes and KPIs, and an increased focus on operating discipline and self-verification activities to strengthen Process safety culture.

Asset integrity programs implemented during earlier years must evolve in alignment with the strategic objectives of a business and reflect the needs of an aging facility and emerging risks. An example of this was a noted increase in the frequency and extent of corrosion under insulation and on equipment such as heat exchangers and other structures as the oldest operating asset approached the end of its design life. While routine preventative maintenance tasks were performed, a more systematic and focused approach was required to address the newly emerging defects observed toward the end of life of the assets. Long-term asset management strategies were therefore developed in alignment with overall business strategic objectives and implemented to counteract the risk e.g., intensive corrosion management strategies and fabric maintenance campaigns. Technical experts and equipment manufacturers were also consulted for technical support on various anomalies, obsolescence issues and key lessons learned in the industry e.g., cryogenic heat exchangers, vessels and piping, flares.

For effective asset integrity management for the lifetime of an operating asset, risks and priorities will evolve over time, and as such, management systems and processes must be designed to adequately manage operational risk for the entirety of a facility’s lifecycle. The management systems must be underpinned by a robust process safety culture where employees and contractors are trained and empowered to identify, understand, and act upon hazards and risks in a timely manner. This requires functional leaders to identify, direct and allocate resources to fill safety critical roles and support safety critical activities.

This paper seeks to demonstrate the importance of a dynamic and fit for purpose process safety management system that evolves over time to reflect the age of an operating asset by using the example of Atlantic's process safety and integrity management journey over the past two decades as a case study. It also provides examples of key lessons learned and suggestions for other organizations to help develop more robust process safety and asset integrity management systems that adapt as a facility evolves from a greenfield to a mature brownfield one.