The module coursework requires you to develop a HAZOP study and a Quantitative Risk Assessment (QRA) study on a chemical storage facility. The QRA study has to be completed using Singapore QRA guidelines. For simplification purpose, consider modelling only for catastrophic rupture of all equipment, a single weather condition and wind direction. Any other assumptions made in the QRA study should be clearly stated and justified in the report.
It is recommended for your report to have the following structure:
Chapter 1: Description of the process unit/storage facility.
Describe in detail the process plant and identify the storage facility. Draw and describe the pipeline and instrument diagram and provide the equipment count for the storage facility. The chemical chosen must be acute hazards, either flammable or toxic. Describe about the process unit/storage facility and must include a Process and Instrumentation Diagram (P&ID). Ensure that the chemicals considered are either flammable and/or acutely toxic. This places the emphasis on rare but potentially catastrophic events. Chronic effects such as cancer or other latent health problems should not be considered in the QRA. The careful definition of scope and depth of study in the application of QRA is crucial to success because it is costly and resource intensive. The site location in google map including the site plan and coordinates of this location must be provided.
Chapter 2: Hazard Identification
Perform a HAZOP study on the storage facility using the below guidewords. Use chemical hazard assessment and Hazard and Operability Study (HAZOP) study to identify the major accident hazards and explain how various initiating causes can be realised into loss of containment scenarios.
Chapter 3: Frequency Analysis
Perform frequency estimation (i.e. use of generic failure rates and event tree analysis). Fault tree analysis (FTA) permits the hazardous top event frequency to be estimated from a logic model of the failure mechanisms of a system. The model is based on the combinations of failures of more basic system components, safety systems, and human reliability. Event tree analysis (ETA), which may be used to quantitatively estimate the distribution of scenario outcomes (e.g., frequencies of explosions, pool fires, flash fires, toxic dispersal). Commonly used historical failure data sources include:
• United Kingdom Health and Safety Executive Failure Rate and Event Data (UK HSE FRED)
• TNO Purple Book
• Oil and Gas Producers (OGP)
• Specific equipment failure rate – OREDA
Chapter 4: Consequence Analysis
Consequence modelling (using ALOHA software) for each of the identified loss of containment scenarios.
Use ALOHA and MARPLOT software.
Atmospheric Category 2B daytime weather and Category 1F typical night time software.
The wind speed shall be 3m per second.
Use Emergency Response Planning Guidelines (ERPGs) as prepared by an industry task force and are published by the American Industrial Hygiene Association (AIHA).
Use National Institute for Occupational Safety and Health (NIOSH) as published Immediately Dangerous to Life and Health (IDLH) concentrations to be used as acute toxicity measures for common industrial gases
Harm foot prints
Chapter 5: Risk Assessment
Calculate the individual risk (fatality) value to a hypothetical onsite occupied building and perform ALARP demonstration.
Wind Direction Probability
Steps in calculating individual risks
Chapter 6: ALARP demonstration
Compare IR fatality calculation and evaluate if ALAPR demonstrations are required. Suggest suitable ALARP recommendations where required
Chapter 7: Conclusion & Recommendations
Provide a conclusion and recommendations to conclude the study.
An Example to follow
Pipeline and Instrumentation drawing- Example
Isotable Section and Equipment Count- Example
- All raw data and excel calculations / tabulations must be included
- Harvard referencing to be used for references
- No of words: 7000
- Times New Roman Font , Font size 12
- Spacing 1.5