The U.S. Occupational Safety and Health

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1 Engineering Inherently Safer Plants Ravishankar Krishnaswamy, Srinivas Dendukuri An inherently safe plant design is generally a design that avoids hazards, instead of controlling them, often by removing or reducing the inventory of hazardous material in the plant, and by reducing or removing the number of hazardous operations in the plant. For this approach to be effective, early identification of hazards is critical. However, the inherent safety of a plant is addressed only in part by these traditional methods. These do not adequately address potential safety hazards originating from risks associated with inappropriate engineering design. To minimise these risks, safety risk review, mitigation mechanisms and Process Management (PSM) systems need to be embedded in all the engineering phases starting from concept to commissioning. This paper explains the various steps towards achieving inherent safety in chemical plants. Introduction The U.S. Occupational and Health Administration (OSHA) 1 website www. osha.gov states: Unexpected releases of toxic, reactive or flammable liquids and gases in processes, involving highly hazardous chemicals, have been reported for many years in various industries that use chemicals with such properties. Regardless of the industry that uses these highly hazardous chemicals, there is a potential for an accidental release any time they are not properly controlled, creating the possibility of disaster. To help ensure safe and healthy workplaces, OSHA has issued the Process Management of Highly Hazardous Chemicals Standard (29 CFR ), which contains requirements for the management of hazards associated with processes using highly hazardous chemicals. The Standard seeks to establish a Ravishankar Krishnaswamy is Manager, Design Assurance and Commissioning, Foster Wheeler India Private Ltd. He has over 25 years of experience in the oil and gas industry in the areas of design, execution, commissioning and advanced process control. AUTHORS Srinivas Dendukuri is Chief Engineer - Design Assurance, Foster Wheeler India Private Ltd. He has over 17 years of experience in the hydrocarbons industry. He has conducted project feasibility studies, licensor/technology selection studies, and has led process teams in front-end engineering design activities and engineering, procurement and construction projects. 72

2 comprehensive management programme that integrates technologies, procedures, and management practices. In line with the above thinking, there is a growing recognition across the process and hydrocarbons industries that there is a need to manage health, safety and the environment (HSE) in an increasingly organised and responsible manner. This approach has been amply demonstrated by operators who have embraced safety management systems like Process Management (PSM), Responsible Care, etc. Of these safety management systems, PSM occupies a very important position in the hierarchy of plant safety. AIChE s Centre for Chemical Process (CCPS) 2 defines Process Management as, a management system that is focussed on prevention of, preparedness for, mitigation of, response to and restoration from catastrophic releases of hazardous chemicals or energy from a process associated with a facility. PSM provides a wider coverage of the plant operations and processes at a fundamental level and makes allowances for modifications by organisations to suit their requirements. Operating plants, by virtue of being the last bastion before a catastrophic release of chemicals or energy occurs, have developed a number of systems and programmes to educate their operating and maintenance personnel on the merits of implementing effective PSM. In selecting a process technology for a new plant or for a plant modification/upgrade, a number of criteria may be applied, including: Economic viability Ease of operation The technology and equipment required are reliable It is safe to operate and maintain It will comply with applicable environmental and other legislation It is difficult to rank the criteria in any set order of importance this will change on a case-by-case basis. The human and economic implications and the potential loss of reputation due to an accident caused by either operational error or poor engineering weigh heavily on decision-makers. For a long time, the operators were left to handle the safety responsibility. Thus were born approaches such as PSM. As stated above, an inherently safe plant design is generally a design that avoids hazards, instead of controlling them, often by removing or reducing the inventory of hazardous material in the plant, and by reducing or removing the number of hazardous operations in the plant. However, the inherent safety of of plant operation should be a consideration from the earliest point in the design of a plant, and care should be taken to ensure that all the potential hazards in plant operations are adequately identified and addressed. One of the most effective means of achieving this objective is to engineer an inherently safer plant. a plant is addressed only in part by these traditional methods. These do not adequately address potential safety hazards originating from risks associated with inappropriate engineering design, nor can a robust safety management system in an operating plant fully offset these risks. To minimise these risks, safety risk reviews, mitigation mechanisms and PSM systems need to be embedded in all the engineering phases of process plant development, starting from concept, right through to commissioning. Inherent in Engineering of plant operation should be a consideration from the earliest point in the design of a plant, and care should be taken to ensure that all the potential hazards in plant operations are adequately identified and addressed. One of the most effective means of achieving this objective is to engineer an inherently safer plant. The safety of a chemical process can be achieved through built-in (inherent) and external (added-on) means. The inherent safety is related to the inherent properties of the process; e.g. the use of less hazardous designs that result in safer operations. This may involve the application of fundamental principles, including intensification, attenuation, substitution and/or simplification. These techniques help to achieve the goal of developing a process design with inherent safety by avoiding and removing hazards rather than by controlling them by added-on protective systems. The above-mentioned approach is very effective in arriving at an inherently safer engineering design, with the hazardous materials in question being reduced to a level that is as low as reasonably possible. But this approach does not adequately address potential safety hazards originating from risks associated with inappropriate engineering design. To provide a few examples, hazards can arise from wrong selection of materials, inadequate engineering design methods and incomplete data used for design. Recognising this, engineering contractors have invested their commitment and resources in the 73

3 development of quality management systems, in particular, quality assurance. Quality assurance is part of quality management which focuses on providing confidence that internal and client quality requirements are fulfilled by means of audits, reviews and traceable documentation. It also provides a mechanism to identify recurring events, against which trends can be measured regarding the effectiveness of the resulting continuous improvement initiatives in addressing quality improvements in engineering deliverables. Some engineering organisations have developed management systems to help provide higher levels of design quality performance. These management systems comprise a hierarchy of management and discipline quality reviews tailored around the schedule of engineering design development. The aim of these reviews is twofold; technical quality governance and discipline technical quality assurance. inadequate These quality management systems essentially depend on the prevailing work processes/ procedures that govern the engineering development and therefore can be effective only if the applicable processes/procedures are robust. Nonetheless, these quality management systems do not exclusively or explicitly address a future hazardous eventuality and the ability of the resulting process plant and the asset operator to handle such an eventuality. Design Assurance The desirable situation in engineering design is one where health, safety and environmental (HSE) considerations underpin every facet of the project. To accomplish this goal, a management system called Design Assurance was developed and implemented within Foster Wheeler. This system was developed by the company with the aim of designing, engineering, procuring, constructing and commissioning plants that can be operated safely by strengthening existing technical quality assurance management systems. The means to achieve this aim was to systematically identify and strengthen the existing management systems to identify and mitigate the potential for HSE incidents by bringing elements of HSE into the reviews. The company also invested heavily in reinvigorating the lessons learned culture and making it selfsustaining. This Design Assurance programme draws heavily Hazards can arise from wrong selection of materials, design methods and incomplete data used for design. on PSM. The PSM structure was adapted to suit an engineering organisation. The Design Assurance system, thus developed, rests on four foundation stones, namely: Commitment to - Criticality and commitment at all levels, be it corporate or project, to the concept of Engineering Design and its management Hazard Identification - Work processes that will aid in the identification and elimination /mitigation of hazards and risks Managing Risks - A management system that will verify that work processes are followed Learning from Experience - A feedback / reporting mechanism comprising a knowledge database for collection and dissemination of lessons learned and indicators to gauge where an engineering organisation stands with respect to assuring safety in design engineering At the heart of this strategy is acknowledgement of the importance of understanding and valuing the contribution of all disciplines to achieve the desired Design Assurance objectives. Implicit in this is the coordination and commitment required from each link in the chain that delivers a project. Development of Design Assurance (DA) The foundation stones can be explained as follows: Foundation Stone #1: Commitment to Raising awareness, through advertisement and training, of the concept of Design Assurance at all levels in the organisation is the key to this foundation stone. The vision of delivering safe designs through a sustained campaign begins with this foundation. These requirements are realised by: Development of the terms of reference of the Design Assurance system Education and buy-in of all the stakeholders Preparation of immediate and sustained campaign material for transmission across the company Regular publication of design HSE statistics along with other materials, such as newsletters and safety beacons Foundation Stone #2: Hazard Identification Fundamental to preventing safety incidents caused 74

4 by inappropriate engineering, is the ability of an engineering organisation to foresee and mitigate, early in the design phase, any possible occurrence of hazardous situations, through a structured review process. These reviews are attended by engineers of various disciplines who have the necessary engineering experience, safety awareness and adequate technical competence. To meet the above requirement, the following is executed for Hazard Identification in engineering design: Development of discipline design safety risk matrix for all design activities Ranking of design safety risks to differentiate high risks from low risks Reviewing and tightening of current control measures - Writing rules for Risk Mitigation. Design safety risk mitigation measures are written by considering the following: Design reviews/validation Timing and placement of current internal design reviews Additional internal design reviews Design validation exercises Entry criteria for design activity Design procedure coverage of the activity Personnel experience for conducting, reviewing and approving Clear definition of input data Exit criteria for design activity Personnel competence and procedure requirements are met Output quality is consistent and to the required level After compiling the database of design risks and their associated mitigation plans, this knowledge is utilised to update existing quality management systems and technical governance systems that control the conduct of engineering design work. Further, it is mandated that, at the beginning of a new project, a project-specific design safety risk analysis exercise should be conducted with the aim of developing project-specific risk mitigation measures. Project-specific risk-mitigation plans are derived by: Reviewing and confirming time lines within projects when reviews should be conducted Fundamental to preventing safety incidents caused by inappropriate engineering, is the ability of an engineering organisation to foresee and mitigate, early in the design phase, any possible occurrence of hazardous situations, through a structured review process. Introducing methods within existing reviews (or introduce new reviews) that brought out safety- related issues based on the specific project, undertaken with the client s buy in Updating and issuing a project-specific Design Assurance plan by incorporating the project-specific risks and their associated risk-mitigation plans Furthermore, the following additional measures are taken to ensure that the personnel s technical competence is appropriate for conduct of design activities by: Developing Design Assurance skills / competence requirements for discipline engineers, and updating job descriptions / technical skill requirements Developing a system to revise current and appropriate engineering work procedures Foundation Stone #3: Management of Risks The template of management systems / work processes that need to be followed on projects have been developed as part of the hazard identification process as a joint effort between disciplines and project teams coordinated by the company s management. The responsibility of monitoring adherence to procedures and developing monitoring mechanisms lies within the corporate management structure. The foundation stone Manage Risks therefore comprises developing and applying monitoring mechanisms, monitoring of performance using those systems, and maintenance of competency levels. Key elements include: Ensuring compliance with the Design Assurance plan during the entire duration of the project, monitoring conduct of reviews, and introducing a stop log/gate system so that design does not proceed to the next step without the required review being satisfactorily completed Assessing technical capability of the project team against requirement and putting training plans in place as required Ensuring that the technical audit reporting system also addresses emerging trends and developing a method by which audit findings are categorised for easy tracking, trending and follow up 75

5 Having plans for exposing discipline engineers to latest developments in their sphere of activity Developing a tracker tool to ensure lessons learnt, key audit points and all the HSE-related actions generated within a project are all closed and ultimately result in modification of procedures where required Updating the skills matrix covering technical skills, project execution skills and competencies and linking this skill matrix to training requirements Foundation Stone #4: Learning from Experience Engineering organisations should certainly learn from their experience; a smarter way to do it is also to learn from others. This requires developing an infrastru-cture to identify, capture and disseminate learning. Further, it is established 3 that for every lagging indicator (indicators which are more outcome / results orientated) of a safety incident, there would be an increasing number of leading indicators (indicators which are predictive and are used to identify a weakness that can be corrected before a higher consequence event occurs) occurring in a fixed relationship with lagging indicators. Therefore, by recording, tracking and controlling the leading indicators, we can control the occurrence of a lagging indicator. This is accomplished by establishing leading metrics or key performance indicators (KPIs) for safety, which look at performance of key work processes, and thorough incident investigation involving tracking and analysing incidents to establish their causes and implementing corrective action so that similar incidents do not recur. Pillars resting on this foundation stone are: o Design Assurance incident database Development of Design Assurance database, where Design Assurance action items collected internally and from external databases are collated Incident investigation for root cause analysis of incidents o Establishing high-level control measures o Modifying appropriate engineering work procedures Identifying KPIs o Measuring leading and lagging Indicators Summary At the beginning of a new project, a project-specific design safety risk analysis exercise should be conducted with the aim of developing projectspecific risk mitigation measures. International engineering organisations offer a spectrum of services ranging from feasibility studies and front-end engineering design, through to detailed engineering, procurement, construction and commissioning. Throughout all phases of a project, safety should be paramount. Traditional design methods typically concentrate on the hazardous nature of operations involving materials with inherent risk and attempt to remove these hazards only. However, Foster Wheeler, along with clients and other engineering contractors, advanced their approach, incorporating the concept of designing, engineering and building inherently safer plants. To meet this requirement, a Design Assurance system implemented by Foster Wheeler is described. Design Assurance helps engineering organisations strengthen their existing engineering management systems through systematic risk identification, review and mitigation in their engineering work. Another key element of engineering inherently safer plants is the ongoing review of existing work procedures based on learning from experience. This approach, supported by corporate and project management, and backed by a sustained awareness campaign, drives a culture across the engineering organisations where safety considerations are inherent in every one of the design / engineering activities Foster Wheeler References 1. Process Management (PSM), OSHA, United States Department of Labour 2. Understanding Process Management, Adrian L Sepeda, Aug 2010, CEP (AIChE) 3. Process Performance Indicators for the Refining and Petrochemical Industries, ANSI/API Recommended Practice 754 First Edition, April 2010 Acknowledgements Assurance Process for Complex Electronics, NASA 76