MMI Engineering

Eric Peterson, Ph.D.

Technical Process Safety and Risk Manager

www.mmiengineering.com

Date: 6 November 2013

Incorporating Inherently Safer Designs to

Improve Sustainability of Industrial

Facilities

Abstract

An increasing number of facilities across the globe are reaching a

significant age of maturity. Those facilities were constructed under

different regulations and guidelines than those used today. Renovations,

upgrades and retrofits are abundant in the oil, gas, and petrochemical

facilities and these new constructions must follow the current

regulations. The new guidelines will enhance the facility to become more

sustainable and inherently safer based on newer design and construction

practices. This paper discusses the coming challenges to facilities and the

need to incorporate inherently safer designs in the upgrades,

modifications to the facilities.

Requirements for Facilities

One question is: Are the older facilities grandfathered in under these

new regulations or must they comply. For safety concerns, they should

be required to perform safety assessments.

Being safety conscientious provides the facility a means to have

protocols in place to remove or reduce the cause (or provide mitigation

for the consequence) of an event whether this event is caused by human

error or faulty equipment in origin. Incorporating inherently safe

designs allow the facility to tolerate a consequence event while

maintaining the integrity of the surrounding structures and safety of

personnel to a reasonably practicable level.

Regulations vs. Industry Guidelines

– Recognized and Generally

Accepted Good Engineering

Practice (RAGAGEP) guidelines

• API RP-752/753

• CCPS publications

• ASME, ASCE codes

OSHA, Title 29 Code of Federal

Regulations (CFR) 1910.119

Encompassing Onshore Facilities

API Recommended Practice (RP)

752/753

ASME, ASCE

CCPS Guidelines for Facility Siting

and Layout

4

Past Events at Aging Facilities

VCE which resulted in 28

employees killed and 36

injured with many of the

fatalities were in the

collapsed control room

building.

5

Flixborough, UK on 1 June 1974

1989 Phillips disaster in Texas

A series of massive explosions

destroyed polyethylene facility resulting

in 23 on-site fatalities and another 130

were injured. The control room was

located very near to hazardous

operations. There were also inadequate

in firefighting capabilities.

Facility Siting Methods

Facility siting

– a high level (screening or using look-up tables),

– performing a consequence based, or

– risk based approach

– or a combination of the above

Hazards identification forms the cornerstone for any

facility siting study

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Hazard Identification Methods

Consequence based scenario selection

– desktop review of process safety information

• HMBs, PFDs, P&IDs, Layout, Receptor/Building Data

• Validation with a site visit to determine “select” scenarios in

various locations of the facility.

– The data utilized to perform this task is listed as followings:

The scenarios are based on the process area specific factors

such as equipment failure, process parameters data, and

design of the equipment in the process area, process stream

composition, operating conditions, and proximity to buildings.

7

Hazard Identification Methods

Risk Based Approach, such as, such as quantitative

risk assessments (QRA) or semi-quantitative risk

analysis.

– This method is more rigorous and utilizes relevant company

and industry loss of containment data on similar types of

processes and equipment when selecting scenarios.

– This is in addition to the process safety information identified

in consequence based approach.

– This method requires a company to have or use (i.e.

assumption log) a risk criteria established.

8

Hazard Identification Methods

Checklists can be too generic

– There is potential to not address all relevant issues:

• A hydrocarbon drift scenario to a utility area from truck

loading may not be captured in the utility system PHA or

HAZOP, and utility area may not be considered a higher

concern than proximity of process areas in truck loading

PHA or HAZOP.

– There is potential to be too generic:

• A corrosion leak is considered for loss of containment

and a severity rating applied in a HAZOP setting in a

global node without consideration for release locations is

not helpful for a facility siting.

9

Proposed

Facility Siting Hazard Identification

Combining as basis for a comprehensive facility siting

study

– process hazard analysis checklists,

– process information and

– relevant event failure data

A formal facility study workshop

– Facility Siting HAZID or Facility Siting Risk Assessment (FSRA)

Workshop to review all reasonably sources of hazards

• From process design

• From hazards external to the process design

• From proposed changes to existing operations.

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The Benefits?

– A structured approach to capture specific concerns.

– Managing this process over the lifecycle of the facility.

– Justification of scenario basis for compliance and

– Demonstration for As-Low-As Reasonably-Practicable

(ALARP) principle also added benefits

Similar to upstream capital design industry - Major

Accident Events (MAE) workshop

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Proposed

Facility Siting Hazard Identification

Methodology (before workshop)

High severity loss of containment consequences

identified during a PHA or HAZOP should be given

special consideration

Model a sample applicable consequences analysis

– fire, toxic, asphyxiation, cryogenic, and explosion

– variation of parameters

• type of hydrocarbons available for release, the process

conditions, hole sizes, weather conditions, immediate ignition,

delayed ignition etc.

Modeling these scenarios would be a useful element to

a hazards identification workshop.

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• Inherently Safe Design

• Combination of Inherently Safe Designs and Process Control Systems

• Codes and Standards

• Safety Assessments

• Planning and Implementation of Engineering and Administrative Controls

Safety Management

Technical Safety

Risk Management

Overall Technical

Safety and Risk

Methodology(during workshop)

Defining potential hazard events

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– Toxic gas

– Asbestos

– Noise

– Flammable liquids

– Others

– Hydrocarbon under

pressure

– Elevated objects

– Working at height

– Moving vehicles

– Electricity

Once a hazardous event is defined, mechanisms for causes can

be defined and postulated scenarios can be further developed.

Author: David Sanderson

Date: 01 January 2011

CFD Modeling

Author: David Sanderson

Date: 01 January 2011

Heat transfer on Wall

Author: David Sanderson

Date: 01 January 2011

CFD Modeling of Mitigation Solutions

Methodology (during workshop)

Failure mechanisms identified

– Stress cracking

– Corrosion internal/external

– Fatigue

– Impact (dropped object, collision etc.)

Loss of containment (LOC) hazardous events

consequences should be defined

– Consequence analysis before the workshop would be helpful

to the team

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Methodology (during workshop)

Define prevention and consequence mitigation for

each area or system

Inherently safer design principles such as:

– Engineered controls – e.g. spacing, reduced inventory,

pressure vessel integrity, emergency shutdown valves,

pressure relief valves, etc.

– Procedural controls – e.g. technical operating procedures,

maintenance procedures, emergency response procedures,

etc. (not necessary to detail in the workshop)

– Management controls – e.g. responsibilities, competence

assurance, etc. (not necessary to detail in the workshop)

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Methodology (after workshop)

The structured approach can be represented in a

“bow-tie” format for each of the hazardous events.

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Note that the primary purpose of this discussion is to define hazardous

scenarios for facility siting and not to detail specific of a bow-tie methodology.

EVENT

H

A

Z

A

R

D

Barriers

C

O

N

S

E

Q

U

E

N

C

E

S

RecoveryPreparedness

Measures

Controlling the RiskRecovering from the

Realisation of the Risk

The optimization identifies the critical structural components which need to remain intact

during the identified fire scenarios in order to withstand the structural loads for a required

period of time so that the acceptance criteria are met.

The flow chart shows the assessment procedure for determining the optimum structural

protection scheme.

Assessment Procedure for Determining an Optimum PFP Scheme

PFP Optimization Procedure

CFD - Safety & Economic Benefit

Examples Conceptual: Facility plot layout possibilities (decrease incorrect solutions early

& the “re-”engineering resources)

Front End Engineering Design: New processing facilities (reduce plant footprint or increase efficiency of space available)

Detail Engineering Design: New production facilities (better estimate of required construction material)

Asset Acquisition: Evaluation of feasibility

Reserve Enhancement: Advance oil recovery (Method comparison)

Process Alteration: Change in process conditions (T, p, flowrate)

New Product Line Viability: (HMB’s, reactants, products)

HOW?!?!

Optimal Solutions Result In:

1. Increased Safety

– Deeper understanding of potential consequences

– Detailed knowledge of risk drivers

– Know efforts to optimally improve safety

– Better control of actual risk level

2. Reduced Cost

– Mitigation efforts may more easily be proven to not be required

– Material (steel) type & amount required for an acceptable level

– Reducing weight (both steel walls and passive fire protection)

Safety in Design using CFD (Computational Fluid

Dynamics) in Fire, Blast & Toxicology Assessments

Conclusions

The Facility siting studies have proven to be

invaluable in the quest to ensure safety in the oil, gas

and petrochemicals industry.

– The benefits of facility siting studies are realized through

fewer incidents, specifically those resulting in high

consequences such as multiple fatalities, associated

environmental and social costs, associated downtime and

privilege to operate.

This presentation has proposed developing a facility

siting hazards identification assessment plan as part

of the facility siting process

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Concluding Remarks

Employing CFD is Increasingly Important in Effective

Risk Management for Onshore & Offshore Facilities

Detailed Understanding of Potential Consequences Allow

for Improved Engineering Design, Mitigation Measures &

Procedures, for Enhanced Safety Performance &

Financial Results

Effective Means to Improve Insight of New Hazards &

Potential Consequences Where New Technologies are

Applied

Engineering a Safer World

For more information: Eric Peterson 281-810-5019 epeterson@mmiengineering.com www.mmiengineering.com