SITING OF HAZARDOUS INDUSTRIES – ROLE OF RISK ANALYSIS

Dr. A. Koshy

23 Oct 2010, Bengaluru, Karnataka23 Oct 2010, Bengaluru, Karnataka

Capacity Building Programme on “New Techniques and Strategies in Prevention and Management of Industrial Disasters”

to the Karnataka Factory Inspectorate23-24 Oct 2010

Disaster Management Institute

ORGANIZERSORGANIZERSKarnataka State Safety InstituteKarnataka State Safety Institute®®

Department of Factories, Boilers, Industrial Safety & Health, BengaluruDepartment of Factories, Boilers, Industrial Safety & Health, BengaluruSPONSORSSPONSORS

ORGANIZERSORGANIZERSKarnataka State Safety InstituteKarnataka State Safety Institute®®

Department of Factories, Boilers, Industrial Safety & Health, BengaluruDepartment of Factories, Boilers, Industrial Safety & Health, BengaluruSPONSORSSPONSORS

Concerns and issues in Siting/ Layout

Strategic Principles in the determination of safe location and layout for a new or a expansion project

Key information to be considered before selecting a site location

How are siting issues managed when limited space is available?

How are security concerns in a new site addressed ?

An Ideal Situation

A site location and layout that will minimize risk to the surrounding and community/ personnel and property while maximizing the ease of safe operation and maintenance.

Appropriate siting and layout establishes a foundation for a safe and secure operation.

Hazard Management in Life Cycle of an Engineering Project

PRODUCTION

DETAIL ENGINEERING

CONSTRUCTIONFRONT-END

ENGINEERING

INSTALLATION

COMMISSIONING

CONCEPT

Site Lay-out of installation

Hazard Techniques for Site evaluation Techniques of Fire Explosion Index and

Toxicity Index

Dow’s Index Mond’s Index Codes ( OISD)

Allowing objective spacing distances to be taken into account at all stages

Major Accident Hazard Group

“Major accident” means an incident involving loss of life inside or outside the site or 10 or more injuries inside and / or one or more injuries outside or release of toxic chemical or explosion or fire or spillage of hazardous chemicals resulting in ‘on-site’ or ‘off-site’ emergencies or damage to equipment leading to stoppage of process or adverse effects to the environment. THE MAJOR ACCIDENT HAZARD CONTROL RULES, 1997

Features of Well Laid out Site

The potential for toxic impacts, fire escalation, and explosion damage will be low.

The risk to personnel and the surrounding community will be reduced.

Maintenance will be easier and safer to perform.

However, these benefits do not come without associated costs. Separation distances translate to real estate that

costs money.

• Flixborough (6/74) 28 fatalities - $167MM

• Seveso (7/76) Contaminated countryside

• Mex. City (11/84) 550+ fatalities - $26MM

• Bhopal (12/84) 3M+ fatalities - 200M affected

• Chernob. Nuc. Plt. (4/86) 31 fatalities - 300 mi2 evacuated

• Piper Alpha Plat. (7/88) 165 fatalities

• Pasadena, Tx. (11/89) 23 fatalities - $797MM

• Channelview, Tx. (7/90) 17 fatalities - $14MM

• Pemex, Mexico (7/96) Multiple fatalities - $253MM, $8MMM loss to economy • Petrobras, Brasil (6/2001) 10 fatalities - $300MM

• Toulouse, France (9/01) 29 fatalities, 20,000 homes damaged

* Large property damage losses (17th edition); M&M Protection Consultants; 1166 Avenue of the Americas, NY, NY 10036

Some key industrial accidents

Explosion at Chemical facility Flixborough, England, 1974

Explosion at Chemical facility Flixborough, England, 1974

• A large quantity of cyclohexane vapor was released when a 20” “makeshift” bypass pipe ruptured

• The cyclohexane formed a flammable mixture and subsequently found a source of ignition.

• The resulting massive vapor cloud explosion killed 28 workers, injured 36. (Minimized as the office block was unoccupied)

Damages ( Onsite and Offsite)

18 fatalities occurred in the control room as a result of the windows shattering and the collapse of the roof. No one escaped from the

control room. Fires burned for several days

and after ten days those that still raged were hampering the rescue work.

Offsite consequences -- 53 reported injuries.

Property in the surrounding area was damaged to a varying degree.

Contributing Factors Not following codes & operating

procedures while introducing modifications design codes, management of

change procedures, maintenance procedures during recommissioning

Plant layout - position of occupied buildings Control Room not designed

for withstanding major hazards

Emergency plan not updated following modifications

UK COMAH regulation was introduced

Explosion at Refinery, Pasadena, Texas 23 Oct 1989

Explosion at Refinery, Pasadena, Texas 23 Oct 1989

• During maintenance work on a reactor settling leg, a large release of flammable vapor occurred at the Phillips 66 chemical complex.

• The result -- a massive vapor cloud explosion, followed by a series of further explosions and fires.

• 23 fatalities and 300 people injured. Extensive damage to the plant facilities

• Metal & Debris as far as 4 Km

Contributing Factors Site and industry

standards for maintenance not followed

Training and competence

Work permit system - contractors

Positioning of occupied buildings

Risk Factors in Site Selection

Risk to Population density around the site ( from choice hazardous

material, equipment , activites)

Risk from Natural disaster occurrence (earthquake, flood, etc.)

Risk of non-availability of power, steam and water

Plant Siting Safety Considerations Buffer zone Location of other

hazardous installations in vicinity

Inventory of toxic and hazardous materials

Adequacy of firefighting water supply

Access to Emergency equipment

Availability of emergency response support from adjacent industries and the community

Weather extremes and prevailing winds

Location of highways, waterways, railroad and airplane corridors

Environmental and waste disposal restrictions during emergencies

Draining and grade slope Maintenance and

inspection

Layers of Safety in Industrial Project

Critical Radiation Levels

Damage Criteria for ExplosionOver pressure

(bar)Type of damage

0.30 Heavy0.20 to 0.27 Rupture of Oil storage tanks

Possibility of damage to eardrums (Human)

0.20 Steel frame constructions distorted and pulled away from foundations

0.10 Repairable damage0.03 Large & small windows usually

shattered0.02 10% window glass broken0.01 Crack of windows

Damage Contours from Pool fire at manifold

Effect Zone @ 12.5 kW/m2

Ellipse @ 12.5 kW/m2

Effect Zone @ 4 kW/m2

Ellipse @ 4 kW/m2

Radiation Level

Damage Contours from Jetfire at tank farm

Damage Contours from VCE

Toxic Dispersion & Effects

Vapor clouds may give rise to large fires, explosions or toxic effects.

Other things being equal, toxic gas clouds are likely to be dangerous at much greater distances from the point of release than their flammable counterparts.

Dispersion is the process through which gases can travel long distances.

Two types of dispersion occur in industrial situations.

Types of Dispersion

A distinction between different types of dispersion is made for the use of suitable models.

It is based on the type of material

Dispersions

Dense Neutral

Consequences from Toxic Gas Dispersion A large toxic release may give rise to the

following effects on human beings: lethal injury non-lethal injury Irritation

Toxic gas releases may cause domino effects by rendering adjacent plants inoperable and injuring operators. Prevention/mitigation by provision of automatic

control systems using inherently safer principles and a suitable control room

Large Toxic Release

The main mode of exposure is inhalation The effects of a toxic release are estimated

knowing the relationship between the concentration-time profile and the degree of injury

The product C of concentration and the time of exposure t, is called dosage and is directly calculated from the dispersion equation

Exposure Limits

Three agencies provide information regarding exposure limits, specifying safe levels of air borne contaminants OSHA The National Institute of Occupational Safety

(NIOSH) and The American Conference of Governmental

Industrial Hygienists (ACGIH) These 3 agencies have established

guidelines and specific exposure levels of various contaminants

Protection from Domino/ Cascade Effects Arranging separation distances such that damage

to adjacent plants will not occur even in the worst case;

Provision of barriers e.g. blast walls, location in strong buildings;

Protecting plant against damage; e.g. provision of thicker walls on vessels;

Directing explosion relief vents away from vulnerable areas; e.g. other plants or buildings, roadways near site boundaries.

However, these measures may not provide practical solutions against missiles, and risk analysis may be required to prove adequate safety.

LPG TerminalMexico City, Mexico 1984

• A major fire and a series of catastrophic explosions occurred at the PEMEX LPG Terminal.

• After the intial release, the first BLEVE occurred.

• For the next 90 minutes, a series of BLEVEs followed as other LPG vessels violently exploded.

• Approximetly 500 people were killed and the facility was destroyed.

Contributing Factors

Plant layout - the positioning of vessels

Emergency isolation

Survivability of critical systems

Emergency plan and site access

Guidance values for safe separation distances

For prevention of Domino Effects Thermal radiation from fire (Jet/ Flash/ Pool/

Fireball) 12.5 kW/m2 1% Fatality level 4.5 kW/m2 Safe for firefighters

Overpressure from Explosion (UVCE/ VCE/ BLEVE) 0.1 bar 1% Fatality level

Site Factors to be considered where Risks of release of flammable/ toxic materials exists

Plants/Flammable storages should be sited in the open air

Locating all high-volume storage of flammable / toxic material well outside process areas;

Hazardous area classification (HAC) to designate areas for elimination of ignition sources .

Locating hazardous plant away from main roadways through the site;

Fitting remote-actuated isolation valves where high inventories of hazardous materials may be released into vulnerable areas;

Provision of ditches, dykes, embankments, sloping terrain to contain and control releases & limit safety & environmental effects;

Incident at POL Depot, Jaipur, 29th Oct 2009, 6:10 pm • Liquid Motor Spirit had gushed out,

when the tank was being lined up (made ready for pumping to BPCL) because MOV connecting to the tank was also open when the Hammer Blind was in the changeover position

• Product leaked for 75 minutes- 1000 tons of MS= 20 tons TNT before explosion took

• After explosion, fire occurred in 9 of the 11 tanks and the fire continued till the fuel contents were totally burnt.

• 60000KL product burned out in 11 day• 11 fatalities, many injured and 280 cr

loss

LOSS OF SECONDARY CONTAINMENT

Open condition of dyke valve in tank dyke

drainage system is connected to storm water drain also which is open to atmosphere, Hydrocarbon entering this allows vapor to spread throughout installation.

INADEQUATE MITIGATION MEASURES

MOV closure from control room was malfunction

Non availability of SCBA No emergency plan for the scenario No emergency responder

Critical factors to be considered in plant layout

Location of control room /Protection

Fire water tank and fire water pump house

Congestion in the plant site because of buildings, structures, pipelines, trees etc.

The emergency exit gate shall be away from the main gate and always be available for use for personnel evacuation during emergency.

Evacuation routes should not be blocked by poor plant layout

Extract from IOC Fire Accident Report 10.5 Plant Layout

Positioning of occupied buildings

The distance between occupied buildings and plant buildings( w.r.t dangers of explosion, fire and toxicity).

Locate buildings and structures in the upwind direction

Congestion in the plant site because of buildings, structures, pipelines, trees etc.

All buildings which are not related to terminal operation shall be located outside the plant area. (eg. canteen, ignition sources)

Personnel with more general site responsibilities should usually be housed in buildings sited in a non-hazard area near the main entrance.

In all cases occupied buildings should not be sited downwind of hazardous plant areas.

HPCL-Vizag refinery explosion 14th September 1997 Fire broke out at 6:15 am, following a

suspected leak in the LPG pipeline from the Vizag port to the storage farm.

It caused a series of explosions, and soon spread to at least six other naphtha and petrol tanks.

Damages ( HPCL Refinery Fire )

Affected the entire product terminal area, including 11 storage tanks containing naptha, petrol, diesel, kerosene and furnace oil, besides the six ''Horton spheres'' containing LPG.

The refinery's administrative building, its canteen and some other buildings came crashing down like a pack of cards

Even an earthquake measuring eight on the Richter scale would not have caused so much damage.

What to do in case of Restricted Space-Case study of Fire at IOC filling station (petrol bunk)

Gas tanker filling underground tanks of the LPG outlet suddenly caught fire, Caused by leakage of LPG from a nozzle of a gas tanker

3 persons were killed and a dozen others injured

The fire engulfed a gas tanker, an electricity transformer and three cars and spread to a nearby multi-storey apartment building.

Ignition followed by Fire - spread to nearby houses and burnt trees and damaged electricity poles and wires.

Estimate about 12 to 15 tonnes of fuel went up in flames with the fire raging for six hours

IOC LPG Explosion Jaipur - Oct 12 ,2008

Entire gas station was engulfed in flames

Explosion took place in the tanker itself, destroying it completely. , the impact of which was felt in the entire Shastri Nagar residential area up to a distance of three kilometres

After 15 minutes of the gas that had leaked , the tanker blew off.

The rear shell of the tanker had been thrown 250 feet and made a big hole into an building

tanker exploded at that time and huge flames that were thrown out of it 350 feet away

Risk Analysis Need to Be Applied

Helps in Forecasting any

unwanted situation Estimating damage

potential of such situation

Decision making to assess the suitability of sites

Evaluating effectiveness of control measures

IOC LPG Explosion Jaipur - Oct 12 ,2008

Risk

The probability of suffering a harm or loss.

A combination of hazard and Probability Risk = Probability of occurrence of

hazard X magnitude of hazard Measurement of Risk

Individual Risk Societal Risk

Risk Representation

Individual Risk Contour

1.0E-04

2.0E-05

5.0E-06

ALARP – As Low As Reasonable Practicable

1.0E-09

1.0E-07

1.0E-05

1.0E-03

1.0E-01

Ind

ivid

ual

ris

k (

IR)

Unacceptable region

The ALARP

Negligible risk

Broadly acceptable region

The lower the risk less proportionately, it is necessary to spend to reduce it. This concept of diminishing proportion is shown by the triangle

Tolerable only if risk reduction Is impracticable or cost is grossly disproportionate to the improvement gained

Summary & Conclusion

Poorly laid out site increases risk of an accident especially in MAH group of Industries Site layout factors should be considered during Plant

Layout design phase Risk and Damage contours (based on

consequence Analysis) helps to demarcate hazardous areas

Risk analysis may be required to decide the project when there is restriction of space. Risk levels criteria as stipulated in IS 15646 2006

should be employed to decide the case