Safety Studies in Project Life-Cycle

Following the recent post created by Mohammad Maleki , a knowledgeable and exceedingly experienced process engineer, which I had the privilege to work under his supervision for a couple of years in EIED, I decided to write a short article about the required safety studies in different project stages including:

• Concept selection
• FEED
• Detail Design (EPC)
• Normal Operation

This is purely based on my personal experience, and any comments or suggestions are welcomed.

1- Concept Selection Phase.

a) Hazard Identification

• High level hazard identifications studies may be conducted at this stage. It could be in the form of HAZID/ENVID study to identify the main Major Accident Hazards, project risks to nearby communities, high level environmental risks etc.
• It is not expected to conduct a HAZOP study or similar at this stage as there is no P&IDs. Note that some companies do conduct something called CONCEPT HAZOP on PFDs that may be available at this stage.
• Hazards and Effects register could be prepared and further developed in the later phases of the project.

b) Risk Assessment

• Very high-level consequence modelling could be beneficial at this stage of project based on available process data, namely the composition and pressure to identify, Distance between units (Fire Zones), Distance to public (Siting) and/or Distance/Impact onto main buildings.
• It is unlikely to perform QRA at the concept level as it is very difficult to estimate the frequency of release when there is no P&IDs. However, some companies prefer to use methods like package count based on company experience to develop high level land use planning, subject to further assessment in the next Phases of the project.

c) ALARP studies / Safety Cases

• Concept ALARP studies are common to review the options and conduct cost benefit analysis.
• Safety case is not typically required in this stage, as there is not enough input.

d) Active fire protection

A high-level fire water demand calculation may be estimated to identify the primary sources of fire water.

2- FEED.

a) Hazard Identification

• A complete HAZID/ENVID study should be conducted. The major accident hazards should be identified and fed to Bowties.
• A complete HAZOP study should be conducted on Issued for HAZOP P&IDs. The high risk scenarios from HAZOP should further be reviewed in Layers of Protection Analysis (LOPA). It is expected that the LOPA bridges all the gaps by proposing additional safeguards or appropriate SIL rating for SIFs. In any case there is any gap, this needs to be a major deviation and concluded in the ALARP study to review the options. Note that SIL verification and SRS are typically prepared at this stage of project and developed in the next stage.
• A SIMOPS workshop is useful to identify the risks associated with concurrent activities.
• Hazards and Effects register should be completed.

b) Risk Assessment

• A fully fledged QRA to include LSIR, Land Use Planning, IRPA, PLL & Societal Risk to be completed. QRA is used to establish the risk into personnel. This is for on-site, off-site people. For people in open area and buildings etc.
• A risk based fire, gas dispersion and explosion analysis (called FEGDA, FEHA, FRA, ERA etc.), to be completed. The outcomes of FEGDA are quite extensive and could drive different aspects of design including but not limited to passive fire protection (fire proofing), active fire protection requirements, building blast requirements, distance between units, distance to sensitive locations, emergency response requirements, impact on safety critical equipment etc.
• Consequence based or risk based building risk assessment, to identify the fire, blast and toxic/flammable gas impact onto buildings. This needs to be conducted in a systematic manner, for occupied and functionally significant (safety critical) buildings. The risk based is always better method, however, it works in mid-size to large facilities, for a small compressor station or similar size facilities, consequence based should be sufficient. Outcomes of this assessment should identify the level of blast proof for each building, passive fire protection requirements, and the level of protection against toxic/flammable gas ingress which could be a simple HVAC damper interlock with detectors or a sophisticated safe haven building with air bottles to protect people from gas ingress.
• Bowtie should be completed to cover major accident hazards identified in different hazard identification studies. It is expected that safety critical elements and safety critical activities are identified as parts of Bowtie study.
• EERA study. Escape, evacuation and rescue analysis should be conducted at this stage of project to identify the designed EER measures are sufficient.
• ESSA, emergency system survivability analysis should review the adequacy of emergency system in the event of any unwanted event, impacting the process facilities.

c) Safety Critical Elements Performance Standard.

This is a very critical part of FEED. The design performance standards are prepared at this stage to ensure the safety critical elements are designed as specified in the project requirements and so that it give the chance to independent verification body to verify the design.

d) Active fire protection

The active fire protection philosophy should be established at this stage.

The prescriptive aspects of active fire protection are conducted at this stage together with requirements advised by FEGDA study. The designer should identify all the source of fire, the type of fire at each area and the right solution for active fire protection. This includes the building fire protection.

e) Passive fire protection

The passive fire protection philosophy should be established at this stage.

The prescriptive aspects of passive fire protection are conducted at this stage together with requirements advised by FEGDA study. The designer should identify all the source of fire, the type of fire at each area and the right solution for active fire protection. This includes the building fire protection.

f) Fire and gas detection

The fire and gas detection philosophy should be established at this stage. Following the philosophy, fire and gas mapping and cause and effects to be prepared feeding the fire and gas layouts. There is typically a link between fire and gas detection and emergency shutdown, which is in line with emergency shutdown philosophy.

g) Hazardous area classification

The hazardous area classification schedule and layouts are prepared at this stage and the outcomes are shared with electrical engineers to be used in the later stage of project.

h) Escape, evacuation, mustering, emergency response planning

Escape, evacuation and mustering philosophy and layout should be prepared at this stage of project. If there is a requirement for TR, the requirement should be established and a TR impairment study to be conducted. The safety layouts associated to escape routes, mustering and TR to be prepared.

i) EIA, Noise Study

Ensure a comprehensive environmental impact assessment together with noise study is prepared for the scope of work. Environmental permit requirements are analysed and necessary assessments are done and all required permits/consent are in place.

j) HFE Human Factor Engineering (HFE) issues identification and management. This is a whole different discussion and cannot be detailed here.

k) ALARP studies / Safety Cases

This is the main conclusion of the safety studies conducted as part of FEED and should follow the local regulatory requirements. A good safety case should include:

• Introduction to provide the purpose, reference, owner, structure of report etc.
• Facility information, including process description, philosophies, manning, layouts, etc.
• Summary of all safety studies conducted for the project.
• List of all major accident hazards and Bowties, SCEs and link to PS.
• ALARP demonstration and action close out for the project.

Note that aspects like flow assurance, relief and flare, occupational risk, transportation risk etc are not included in this write up.

3- Detail design (EPC)

a) Hazard Identification

• HAZID/ENVID study should be updated.
• HAZOP and LOPA to be updated. Vendor HAZOP/LOPA are to be completed. SIL verification and SRS to be updated with more detail available from vendors.
• SIMOPS workshop to be conducted to update the outcome based on the latest information of project.
• Hazards and Effects register should be completed.

b) Risk Assessment

• QRA update expected in most of cased, in some cases, if there is no change to the process, manning and location, the owner may not have the tenancy to update the QRA.
• FEGDA to be updated.
• BRA to be updated.
• Bowtie should be checked and if there is any update to be reflected.
• EERA to be updated.
• ESSA to be updated.

c) Safety Critical Elements Performance Standard.

The FEED performance standards to be further expanded to EPC and sections for procurement and constructions to be added.

d) Active fire protection

Much more detail available at this stage, the FEED outcomes to be updated.

e) Passive fire protection

Much more detail available at this stage, the FEED outcomes to be updated.

f) Fire and gas detection

Much more detail available at this stage, the FEED outcomes to be updated.

g) Hazardous area classification

Much more detail available at this stage, the FEED outcomes to be updated.

h) Escape, evacuation, mustering, emergency response planning

Much more detail available at this stage, the FEED outcomes to be updated.

i) EIA, Noise Study

Much more detail available at this stage, the FEED outcomes to be updated.

j) HFE Human Factor Engineering (HFE) issues identification and management. This is a whole different discussion and cannot be detailed here.

k) ALARP studies / Safety Cases

This is the main conclusion of the safety studies conducted as part of EPC and should follow the local regulatory requirements. A good safety case should include:

• Introduction to provide the purpose, reference, owner, structure of report etc.
• Facility information, including process description, philosophies, manning, layouts, etc.
• Summary of all safety studies conducted for the project.
• List of all major accident hazards and Bowties, SCEs and link to PS.
• ALARP demonstration and action close out for the project.

Note that many companies prepare the Operate Phase safety case at this stage of project. This is a transient from design to operation and additional sections including the organization chart of operation, safety critical activities and tasks etc could be added to this document at this stage.

Note that aspects like flow assurance, relief and flare, occupational risk, transportation risk etc are not included in this write up.

4- Normal Operation

Companies have standards and reasons to update any of the safety studies conducted as part of earlier stages. For example there is a widely accepted procedure to update the HAZOPs & LOPA every 5 years, or when there is a change in the process. A better way of looking at this is, if there is a written procedure to update safety case every 5 years, or when there is a major change in the process, organisation, methods etc.

The changes during normal operation could be classified as MOC, or a project that requires a full cycle as defined above (concept, FEED, EPC).