Introduction
In oil and gas petro-chemical plants, a Temporary Refuge (TR) is an important safe place where personnel can take shelter from fire, explosion, or toxic release until evacuation to permanent safety can be achieved. But when the sanctuary itself is unsafe, the result can be devastating.
We offer a full-scale Temporary Refuge Impact Assessment (TRIA) at iFluids Engineering to ensure that refuge must take effect in case of major accident hazards. We simulate these risks with advanced simulation tools and CFD-dispersion modelling, guaranteeing your refuge performs when you need it to.
Understanding TRIA – What It Means for Safety
The Temporary Refuge Impact Assessment (TRIA) is an in-depth engineering analysis to prove the construction of the refuge will remain robust throughout all realistic accident conditions without losing its life-saving integrity.
The assessment focuses on evaluating:
- Structural strength against blast overpressure
- Ablative and insulative thermal performance complementing resistance to fire and radiant heat
- Protection against H₂S or smoke infiltration with gas-tight integrity
- Emergency Mode: Performance of ventilation and air quality
- Redundancy for HVAC, alarm, and damper systems
With quantitative modelling, the TRIA calculates the length of time that it is safe for personnel to stay in the refuge and subsequently if the refuge meets regulation guidelines (e.g. ISO 13702 and DNV-GL RP-A101).
Objectives and Aims of a TRIA Study
TRIA is simply an assessment process making use of temporary refuges with a proposed beginning, middle, and end time. The aim of Temporary Refuge Impact Assessment (TRIA) is to determine if it’s reasonable that, throughout an event duration, occupants could continue to have access to refuge zones where they can reasonably remain safe.
Key goals include:
- Verification of the smokeproofing, gas tightness, and heat load resistance of the refuge
- Blast load capacity of walls, doors, and joints
- Determining safe dwell time and power-off wait time for shelter and ventilation
- Checking emergency life safety systems (HVAC, detectors, dampers, airlocks)
- Suggesting design changes to accomplish the survival conditions
The scope of the TRIA includes offshore platforms, FPSOs, process control buildings, living quarters buildings, and refinery safe shelters.
TRIA Methodology – Data, Tools, and Evaluation Process
At iFluids Engineering, each TRIA Study we perform follows a regimented and open process:
- Preparation: Shop drawings, HVAC system, and layout drawings; blast analysis; material review.
- Hazard Identification: Establishing realistic fire, explosion, and toxic release scenarios based on the QRA/FERA results.
- Simulation & Modelling: Utilisation of validated software such as FDS, PHAST, or CFD models to predict where smoke will move, where gas will ingress, and how intense thermal effects might be.
- Performance Comparison: Against tenability limits of temperature, overpressure, toxic gases, and visibility.
- Validation: Correlation with industry standards (API RP 752/753, Shell DEP, OISD-180) to ensure compliance.
This methodical process provides confidence that the data performance of your refuges is credible, traceable, and defensible during regulatory inquiries.
Performance Criteria and Design Validation Parameters
Every Temporary Refuge Impact Assessment (TRIA) structurally challenges the refuge to determine if a shelter is safe for occupancy.
By matching developments with Emergency Response Planning Guideline (ERPG), Acute Exposure Guideline Level (AEGL), Immediately Dangerous to Life or Health (IDLH), and Threshold Limit Value – Time Weighted Average (TLV-TWA) limits, the TRIA will enable safety of the refuge for prolonged shelter durations.
Applications Across the Energy Sector
TRA Impact Analysis is important at all upstream, midstream, and downstream facilities:
- Offshore: Accommodation Modules, CCRs, and Lifeboat Stations
- Refineries & Petrochemical Plants: Central control rooms and process shelters
- FPSO/FLNG Assets: Mechanical decks and accommodation areas
- On Land: Common utility buildings, substations, operator enclosures, and MCC rooms
Each TRIA reinforces the facility’s Safety Case, providing proof of regulatory compliance and safeguarding personnel against simultaneous fire, explosion, and toxic hazards.
QRA, FERA, and Emergency Response System Integration
Temporary Refuge Impact Assessment (TRIA) studies complement other safety analyses to help facilitate comprehensive risk management:
- Including Quantitative Risk Assessment (QRA): Estimates the frequency of toxic or explosion hazards that may impact the Temporary Refuge (TR), helping quantify potential risks and define safety design measures.
- With Fire and Explosion Risk Analysis (FERA): Conducts fire and blast-based load simulations to model fire and explosion-induced effects on the TR, ensuring the structural integrity and survivability of the refuge.
- With Emergency Response Planning (ERP): Determines insulation performance, shelter occupation times, and emergency withdrawal timings to ensure personnel safety during critical events.
This alignment keeps risks ALARP and strengthens operational resilience.
Primary Outputs from a TRIA Analysis
An in-depth TRIA report generally consists of:
- Results of smoke and gas entry simulation
- Blast and heat load contour determination
- Refuge tenability and survivability analysis
- Review of system functionality and failure tolerance
- Practical mitigation and upgrade recommendations
These outputs assist operators in making rational decisions, optimizing plant design, and convincing regulators to certify compliance.
Why iFluids Engineering for TRIA Analysis
With expertise in Process Safety, Structural Analysis, and CFD Modelling, our team of engineers uses proven software and industry standards worldwide to ensure accurate, defensible results.
For both new process units and existing plants, our TRIA assessments keep your refuge zones strong, operational, and compliant with all legislative demands reassuring your workforce they’re not on their own.
Request a Tailored TRIA Study
Embolden your refuge areas with an iFluids Engineering-developed Temporary Refuge Impact Assessment (TRIA).
Frequently Asked Questions
A TRIA evaluates how well safe havens like control rooms or living quarters can withstand real accident conditions blast waves, toxic gas ingress, and heat radiation. By identifying weak points in structure, insulation, or ventilation, it helps operators implement preventive design upgrades, ensuring personnel can survive long enough for controlled evacuation.
While TRIA focuses on engineering performance, it also considers how people respond under duress time to reach the refuge, visibility in smoke, and ability to operate emergency systems. These behavioral inputs influence dwell-time calculations and evacuation planning.
Best practice recommends revalidating TRIA findings every 5 years or following major plant modifications, equipment replacements, or layout changes. Regular updates ensure that evolving hazards, new materials, and altered HVAC or alarm configurations don’t compromise refuge safety.
A Temporary Refuge (TR) is specifically engineered to maintain life-supporting conditions during fire, explosion, or toxic gas incidents. Unlike ordinary safe rooms, it integrates blast-resistant construction, gas-tight ventilation, and independent air supply systems designed for extended occupancy under hazardous conditions.
Engineers calculate safe occupancy time using simulations of toxic gas infiltration, oxygen depletion, and heat transfer. The time duration is set such that conditions remain breathable and temperatures survivable until full evacuation is feasible or external rescue support arrives.
Modern TRIA approaches are adopting AI-assisted CFD modeling, digital twins, and real-time sensor data integration. These technologies allow continuous performance monitoring of refuges, enabling predictive maintenance and faster decision-making during live emergencies.