chapter 4 modeling scenarios and computation of...

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CHAPTER 4

MODELING SCENARIOS AND COMPUTATION OF

RESULTS

4.1 OVERVIEW

This chapter deals with calculation of modeling scenarios with

respect to all the thirty-five industries studied by the researcher and the

computational results of the scenarios are tabulated. However, for the purpose

of easy understanding, thermal radiation and shock wave pressure for five

selected industries among the 35 sample industries, located in different

regions in the State, with different capacities are discussed in detail. The data

for the remaining industries were also calculated for scenarios in the same

way and the computational results of all the 35 industries are given in Table

4.4. The damage Contour details are incorporated in the layouts. Damage

contours including thermal radiation distances with various intensities, graph

showing thermal radiation versus damage distances and damage due to

explosion with various shock wave pressure levels are incorporated in the

exact location map. This has been done to identify the areas of domestic

population, houses, industrial properties, roads, public utilities, possibilities of

domino effects and other environmental aspects, which may likely be affected

in and around the location of the industry.

Data collected during physical inspection of the industries and

computational results of consequence scenario of all the elements are fed into

the questionnaire. The consolidated results of positive and negative impacts,

thus arrived at, are shown in percentages in tabular form.

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4.2 PLAN OF ACTION FOR THE STUDY

The study details of the different modeling strategies and statistical

interpretations of LPG release scenarios with consequences based on the

information arrived from the questionnaire are administered to different

industries. The action plan for carrying out the study comprised of the

following steps:

Step 1: Preparation of Questionnaire and collection of data.

Step 2: Selection of software for analysis of the data collected.

Step 3: Method of calculation of Consequence modeling scenarios

for fire and explosion.

Step 4: Detailed discussion of scenarios calculated for five sample

industries and its results.

Step 5: Computational results of scenario of all thirty-five industries.

4.2.1 Preparation of Questionnaire and Collection of Data

A research questionnaire was prepared for carrying out the research

study. Research questionnaire contains details of statutory requirements such

as safety, health and environmental aspects. The researcher adopted two

strategies while carrying out the study. The first strategy involved physical

visit to the plant facility of all the sample industries. The second strategy

involved scrutiny of records in all the industries to acquire the first hand

information about the compliance of statutory provision by each and every

company with regard to onsite and offsite emergency requirements, besides

other information. Copy of the questionnaire is given in Table 4.1.

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Table 4.1 Research Questionnaire (For Academic Purpose only)

INDUSTRY DETAILS SL DESCRIPTION DETAILS 1 Name of the Company and Address Serial No. 2 Contact Person and Details 3 Name of Manufacturing Process 4 Description on use of LPG in the industry

QUESTIONNAIRE S.NO. DETAILS YES NO I. LPG BULLETS

1. Whether the factory has valid PESO License? 2. Whether all the safety equipments are functional? 3. Whether Fire Hydrant System is available? 4. Whether the vessel is maintained well? 5. Whether support columns are intact? 6. Whether the vessel and other fittings are intact? 7. Whether the level gauges are functioning? 8. Whether the dyke wall is intact? 9. Whether the dyke is adequate?

10. Whether Earthing and bonding provided and periodically checked?

II. SAFETY MANAGEMENT SYSTEM 1. Whether MSDS of LPG is displayed? 2. Whether unloading procedures are displayed in English

and Tamil?

3. Whether adequate supervision is provided during unloading?

4. Whether effective access control is provided? 5. Whether Static Charge discharging facility is provided 6. Whether sparking tools are allowed inside the LPG area? 7. Whether wooden wheel stoppers are provided? 8. Whether hazardous area classification system has been

implemented?

9. Whether FLP Electrical fittings are available? 10. Whether Hazard Communication Warning is exhibited?

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III. EMERGENCY PREPAREDNESS 1. Whether Onsite Emergency Plan has been prepared? 2. Whether the Emergency Plan covers all the details of

LPG Hazard?

3. Whether the Chief Inspector of Factories has approved the Onsite Emergency Plan?

4. Whether onsite Mock Drills are conducted once in six months?

5. Whether the recommendations of the mock drill are implemented?

6. Whether windsocks are installed? 7. Whether sensor /detectors are functional? 8. Whether the hydrant lines are always maintained with

water under adequate pressure?

9. Whether the LPG detectors are available? 10. Whether Emergency Siren System is available? 11. Whether Mutual Aid facilities are available?

IV. RISK ANALYSIS AND CONSEQUENCE MODELING 1. Whether any Risk Analysis Study has been conducted? 2. Whether DNV PHAST Software has been used in Risk

Analysis and Consequence Modeling?

3. Whether this Risk Analysis Report is approved? 4. Whether the Damage Zone has been identified? 5. Whether the Damage Zone has been superimposed on the

site plan?

6. Whether the Thermal Radiation Concept has been taken into account?

7. Whether Over-pressure Concept has been taken into account?

8. Whether confinement is not available during LPG Release?

9. Whether any Public Road is running near the LPG Storage?

10. Whether the vehicles are fitted with Spark Arrestors including internal vehicle?

V. ENVIRONMENT IMPACT ASSESSMENT 1. Whether the Factory is covered within the purview of

EIA System?

2. Whether Consent Deals with the LPG Storage available?

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3. Whether the Ambient Air Monitoring is in conformance with the requirement?

4. Whether there is any LPG Emergency effect on the atmospheric air?

5. Whether any water facility within the damage zone is likely to be affected?

6. Whether there is any Historical Monument near the damage zone?

7. Will there be any effect on Flora and Fauna? 8. Will there be any effect on Cattle Field? 9. Will there be impact effect on cultivation and

agriculture?

10. Will there be any effect on Forest zone? 11. Will there be any effect on endangered species?

VI. IMPACT RESULT AND DAMAGE CONTOUR 1. Whether the Damage Zone goes outside the compound? 2. Whether there is any possibility of Offsite Emergency? 3. Whether any Public houses are located within the

Damage Zone?

4. Whether any Schools are located within the Damage Zone?

5. Whether any open and naked flames are available within the Damage Zone?

6. Whether any hospitals are located within the Damage Zone?

7. Whether any Public Utilities are available within the Damage Zone?

8. Whether any Offsite Consequences are going to have Domino Cascading Effect?

9. Whether any Adjacent factory workers are affected? 10. Whether any Public Roads are falling within the Damage

Zone?

Name &Designation:

Sign with Date:

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After the completion of the questionnaire, the out come of the

results were discussed with the management and their signatures obtained to

confirm their acceptance.

4.2.2 Selection of Modeling Software

Around 80 software models are utilized globally for conducting

Risk Analysis studies. On detailed analysis and field experience, the DNV

Phast model was found to be the suitable software for carrying out

quantitative risk assessment studies.55 Since Environmental Protection

Agency (EPA) has approved this software, various Regulatory bodies and

research organizations are also using this software for conducting Risk

Analysis and Consequence Modeling for various chemicals including LPG. In

view of the above and taking into consideration the various technical inputs

and ground conditions for effective analysis with less errors and deviations,

this software was procured from DNV for the purpose of this research study.

The software was utilized to analyse the following;

- Discharge and dispersion models.

- Flammable models resulting in radiation effects for jet fires, pool fires and fire balls.

- Flame shape can be displayed in a radiation contour map.

- Explosion models to calculate overpressure and impulse effects.

- Models for toxic hazards of a release including indoor toxic dose calculations.

- Continuous validation of modeling capabilities against experimental data.

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- Use of geographical information system (GIS) for display of consequence results on maps and plot plans.

- 3 D modeling results for fire balls etc.

DNV software is licensed for the researcher and screen shot of the

opening page of the model is given in Figure 4.1.

Figure 4.1 Snapshot showing Analytical Aspects of DNV Software Model

Screen shot showing separate folder of each company in the

software and the selection of chemical i.e. LPG is given in Figure 4.2.

Figure 4.2 DNV Screen Shot showing Selection of Chemical LPG

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4.2.2.1 Set of Rules and Assumptions for Consequence Analysis

Consequence analysis is part of a Quantitative Risk Analysis. Here, as part of the risk modeling, the researcher adopted the following set of rules and assumptions inline with statutory obligations, prior to the execution of the risk calculations. Changes to the assumptions in this document may have an impact on the calculated risk levels. The QRA is intended to assess the total individual, societal risk to personnel and impact on environment, which includes the risk from fire and explosion events.

1. Catastrophic Rupture of LPG Bullet.

2. Release inventory is 80 % of total volume stored.

3. BLEVE is considered for calculation. Because this will give maximum impact than pipeline leak, rupture etc.

4. Release time of LPG is taken into consideration of 600 Seconds (10 Minutes) for all events.

Table 4.2 summarises the possible ignition sources applicable to the

accidental events.

Table 4.2 Possible Ignition Sources

Sl. Onsite Ignition sources

A Electrical lines within or outside the boundary

B Possible occurrence of Static electricity in storage and operation area.

C Canteen area

D Plant area

E Truck movement

F LPG yard

G Cigarette smoking and use of match box inside the premises.

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Table 4.2 (Continued)

Sl. Offsite Ignition sources

A Electrical Wires

B Domestic/Commercial Cooking activity

C Crackers

D Grass Fire

E Industrial fire outside

F Commercial Vehicle movement (Car /Trucks)

5. Wind Speed and Pasquill stability classes are taken for calculation, i.e. 5D (neutral) and 5 m/s wind speed.

6. Operating Temperature is 35oC. Bullet pressure is variable for each bullet based on the process requirements, which is given by the management concerned.

4.2.3 Method of Calculation of Consequence modeling scenarios

The purpose of conducting environmental risk assessment is to

complete the research tool questionnaire pertaining to Emergency

preparedness, Risk analysis, Environmental Impact Assessment, onsite and

offsite Impacts and damage contour. In consequence analysis, mainly the

worst - case scenarios of BLEVE, fireball, jet fire and vapour cloud

explosions are considered for calculations.

Consequence descriptions may be qualitative or quantitative

estimates of the effects of an accident in terms of factors such as health

impacts, economic loss and environmental damage. Consequence analysis

quantifies the extent of damages on onsite as well as offsite. Release

modeling is called discharge or source modeling mainly used to identify

possible worst-case scenarios such as thermal radiation effects due to fireball,

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jet fire, pool fire and shock wave pressure due to confined or unconfined

vapour cloud explosion.

Thermal radiation results are obtained in terms of heat flux in three

variables as per DNV, 37.5 kW/m2, 12.5 kW/m2 and 4.0 kW/m2. The results

would quantify exact damage areas in and around the LPG using automobile

industries, which includes domestic population in the vicinity, schools,

colleges, public roads and agricultural lands including flora and fauna.

The flow chart for consequence modeling scenarios is given below:

Figure 4.3 Flow Chart Scenarios

The various terms indicated in the flowchart scenario are explained

as follows:

Liquid Petroleum Gas (LPG) is a naturally occurring by-product of

natural gas extraction. It is a combination of propane and butane molecules,

along with trace amounts of other compounds. At a normal temperature, LPG

is a gas. Under pressurized condition, it transforms into a liquid.

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The LPG releases can be gases or two-phase substances. Gaseous

releases may result in fireball or jet fire depending on the availability of the

conditions and the effects of such combustion is thermal radiation having its

own damage distances that may either result in onsite or offsite consequences.

Thermal radiation is the emission of electromagnetic waves from

all matter that has a temperature greater than absolute zero. The heat flux

depends on the release volume of LPG. This may occur due to catastrophic

failure of LPG bullet, pipeline rupture, safety valve rupture resulting in

thermal radiation such as BLEVE, Jet fire, Pool fire etc.

The word BLEVE is an acronym for ‘‘Boiling Liquid Expanding

Vapour Explosion’’. A BLEVE is the consequence of the rupture of a

pressure vessel containing a liquefied gas. In other words, it can be explained

that a BLEVE is an explosion resulting from the failure of a vessel containing

a liquid at a temperature above its boiling point at normal atmospheric

pressure when released vapour cloud reaches ignition source, it results in the

formation of a fireball.

A flash fire is a sudden, intense fire caused by ignition of a mixture

of air and a dispersed flammable substance.

A jet fire is an intense, highly directional fire resulting from

ignition of a vapour or two phase release with significant momentum.

Radiation level depends on release quantity and wind direction.

A pool fire is from an ignited liquid pool of flammable liquid.63

A Vapour Cloud Explosion (VCE) is an explosion occurring

outdoors and producing a damaging overpressure. They occur by a sequence

of steps, which are:

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1) sudden release of a large quantity of flammable vapour, which occurs when a vessel containing a superheated and pressurized liquid ruptures,

2) dispersion of the vapour throughout the plant site while mixing with air, and

3) ignition of the resulting vapour cloud.

An explosion occurring within a vessel or confined area is called

confined vapour cloud explosion. These are most common and usually result

in injury to the inhabitants and extensive damage to the buildings.

An unconfined explosion occurs in the atmosphere. This type of

explosion is usually the result of a flammable gas spill and leakage due to

rupture and holes. The gas is dispersed and mixed with air until it comes in

contact with an ignition source. These explosions are very destructive, since

large quantities of gas and large areas are often involved.

A shock wave pressure or overpressure is the pressure caused by

a shock wave, over and above normal atmospheric pressure. The shock wave

may be caused by sonic boom or by explosion and the resulting overpressure.

A major emergency can be defined as an accident/incident that has

potential to cause serious injuries or loss of life. It may cause extensive

damage to property, serious disruption both in production and working of

factory and may adversely affect the environment. The factors which cause

major emergency are (i) Plant failure (ii) Human error (iii) Vehicle crash

(iv) Sabotage (v) Earthquake (vi) Natural Calamities and (vii) Fire.

‘Onsite Emergency’ is an accident/incident, which takes place in a

factory, and its effects are confined to the factory premises, involving only the

persons working in the factory and the property inside the factory.

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‘Offsite Emergency’ is an accident/incident, which takes place in a

factory and its effects are uncontrollable and spreads even outside the factory

premises, affecting the general public and property in the nearby vicinity

outside the factory.

For the purpose of Research study, two major scenarios were

considered for calculations. They are:

1. Fire due to thermal radiation and

2. Shock wave due to explosion.

4.2.3.1 Fire due to thermal radiation

In order to carry out calculation of consequence modeling, the input

parameters used for obtaining thermal radiation results due to Catastrophic

Rupture/Pipe Line Rupture are as follows:

- LPG bullet type

- LPG release capacity

- Bullet Storage Pressure

- Temperature

- Wind speed

- Stability class

- Atmospheric condition

- Humidity

- Elevation

- Release phase

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- Rupture area such as Safety relief valve, Unloading tanker and lines

- Pipe line Diameter, Length

- Pipe line pressure

The study report contains, three levels of thermal radiation damage

results, which are reflected in terms of heat flux in kW/M2. The three levels

are:

37.5 kW/m2 - Sufficient to cause major damage and 100 %

fatality

12.5 kW/m2 - Minimum energy required for melting plastic

and1% fatality

4.0 kW/m2 - Cause pain for prolonged exposure.

The following results containing thermal radiation damage

distances are accounted and incorporated in layouts for each sample

companies.

1. Snapshot showing Radiation effect - Fire Ball.

2. Snapshot showing Intensity versus radiation distances Fireball.

3. Snapshot showing Thermal radiation results incorporated in the layout.

Thermal radiation distances are dependant on mass and storage

pressure. As the mass increases, there will be repeated explosion / fire since

the availability of certain quantity of combustive LPG within the

flammable/explosive range will be restricted and hence the damage zone will

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be less even though the quantity is more and the relationship between quantity

/mass and damage distance is neither linear nor proportional.

Further, storage pressure is directly proportional to thermal radiation

distance. For e.g., In the case of 95 MT, storage pressure is 16 Bar and the

radiation distance are 193 M. However for 1350 MT the storage pressure is

very less, 4 Bar only and hence the damage distance is also less and restricted

to 303 M.

The source of heat generation is at the centre of LPG bullet. Due to

the subsequent explosion at the same place and since the storage pressure is

very less proportionately the damage distance is also very less.

4.2.3.2 Vapour Cloud Explosion

Shock wave pressure occurs due to confined or unconfined Vapour

Cloud Explosions. An explosion occurring outdoors beginning with the

unplanned release of a large quantity of flammable gas or vapourising liquid

which ignites following the formation of a cloud or plume of pre-mixed fuel

and air. The speed of flame travelling through the cloud may approach

detonation velocity with a massive pressure rise63.

The following three levels of shock wave pressure are only

calculated for research study purpose and the same are as under:

0.20 bar - Heavy damage

0.13 bar - Moderate damage

0.02 bar - Significant or minor damage.

The following results containing thermal radiation damage

distances are accounted and incorporated in layouts for each sample

companies.

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1. Snapshot of shock wave pressures (Catastrophic Rupture).

2. Snapshot of shockwave pressure versus distances.

3. Snapshot of shock wave pressure results incorporated in the layout.

The result clearly reveals exact damage areas in and around the

LPG using automobile industries, by which impact on domestic population in

the vicinity, schools, colleges, public roads and agricultural lands including

flora and fauna are quantified.

4.3 DETAILED DISCUSSION OF SCENARIOS CALCULATED

FOR FIVE INDUSTRIES

For the purpose of detailed discussion of scenarios, the researcher

selected five samples among 35 industries having LPG storage in the

premises, one each from five different locations in the State of Tamilnadu.

The scenarios calculated for five industries are discussed in Table 4.3 given

below:

Table 4.3 Selected Five Industries Detail

SL Industry List Sl.

No.

LPG Bullet Capacity

Pressure Details

Quantity Discharged

(80%)

Location of the Plant

1 1 95 MT 16.00 Bar 76 MT Sriperumpudur

2 7 20 MT 14.50 Bar 16 MT Kancheepuram

3 15 5 MT 6.00 Bar 4 MT Mahindra World City

4 23 30 MT 14.50 Bar 24 MT Tiruvallur

5 30 10 MT 5.00 Bar 5.0 MT Hosur

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The name of the chemical, mass inventory in kg. storage conditions

such as pressure and temperature are fed into the software through the drop

boxes. The LPG chemical and its storage and inventory information are fed

for all the selected LPG storages and accordingly, modeling was done.

The toxic and explosion parameters, fire ball, jet fire, pool fire are

arrived for different scenarios, materials, discharge parameters for short pipe,

dispersion and bund, building and terrain conditions.

Scenario type includes line rupture, leak and catastrophic failure of

LPG storage and piping system. Piping dimension, which includes internal

diameter of the pipe and pipe length are fed to the software for each sample of

the study. For hole leak, the orifice diameter, which is a primary factor that

decides release velocity and length is fed to the software for such modeling.

The software also accommodates release location i.e. height of release from

the ground level which again will impact the liquid column above the point of

release from the ground level.

4.3.1 Modeling Results of Thermal Radiation of Industry No.1

(95MT Bullet - BLEVE)

The results of thermal radiation of 95 MT bullet leads to 37.5

kW/m2 (100% Fatal Zone) and extends to 193 m, 12.5 kW/m2 extends to

459 m and 4 kW/m2 extends to 846 m. Snapshot showing radiation effect of

Industry No.1 are given in Figure 4.4.

In figure 4.5, the snapshot showing thermal radiation versus

distances for fireball are calculated and shown. At a required distance, the

radiation effects are calculated and accordingly, the location of machinery and

workstation can be decided.

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Figure 4.4 Snapshot showing Radiation Effect of Industry No.1- Fire Ball (5D Stability Class)

Figure 4.5 Snapshot Graph showing Radiation versus Distance for Industry No.1 - Fire Ball (5D Stability Class)

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Figure 4.6 shows the snapshot of thermal radiation results

incorporated in the layout for Industry No.1 and its damage effect, which

extends to onsite as well as offsite to a radius of 846 m. The damage zone

covers three factories, National Highway NH-4 and adjacent road (100 Ft),

temple and office structure. In case of any other chemicals stored and handled

by the any other factories located within the damage zone, this may further

lead to domino effect.

The result calls for the urgent need of preparation of onsite and

offsite plan by the management concerned and obtaining approvals from the

statutory authority.

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Figure 4.6 Snapshot showing Thermal Radiation Result Incorporated in the Layout of Industry No.1

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4.3.2 Modeling Results of Vapour Cloud Explosion of Industry No.1

(95MT Bullet - VCE)

The results of shock wave pressure of 95 MT bullet leads to 0.20

kg/cm2 extends to 383 m, 0.13 kg/cm2 extends to 428 m and 0.02 kg/cm2

extends to 1734 m. Figure 4.7 shows snapshot of shock wave pressure for

Industry No.1.

Figure 4.7 Snapshot showing Shock Wave Pressure Results for Industry No.1 (5D Stability Class)

The shock wave pressure versus distances are calculated and given

in Figure 4.8.

At a required distance, overpressure effects can be calculated and

accordingly, the location of machinery and workstation can be decided.

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Figure 4.8 Snapshot Graph showing Worst Case Late Explosive Overpressure versus Distance for Industry No.1 (5D Stability Class)

Figure 4.9 shows the shock wave pressure results for Industry No.1

incorporated in the layout and its damage effect, which extends onsite and

offsite to the radius of 1745 m. The damage zone covers five factories, pond,

trees, shops, National Highway NH-4 and adjacent road (100 Ft), temple and

office structure.

The result calls for the urgent need of preparation of an onsite and



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Figure 4.9 Snapshot showing Shock Wave Pressure Results Incorporated in the Layout for Industry No.1 (5D Stability Class)

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4.3.3 Modeling Results of Thermal Radiation of Industry No.7(20MT

Bullet - BLEVE)

The results of thermal radiation effect of Industry No.7 of 20 MT

bullet leads to 37.5 kW/m2 (100% Fatal Zone) and extends to 56 m,

12.5 kW/m2 extends to 220 m and 4 kW/m2 extends to 427 m. Figure 4.10

shows the thermal radiation results for Industry No.7.

Figure 4.10 Snapshot showing Thermal Radiation Effect for Industry No.7- Fire Ball (5D Stability Class)

The thermal radiation versus distances for Industry No.7 are

calculated and given in Figure 4.11.

At a required distance, the radiation effects can be calculated and


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Figure 4.11 Snapshot Graph showing Radiation versus Distance for Industry No.7 - Fire Ball (5D Stability Class)

Figure 4.12 shows the results of thermal radiation for Industry No.7

incorporated in the layout and its damage effect, which extends onsite as well

as offsite to a radius of 427 m. The damage zone covers agricultural lands,

cattle field and proposed construction of supplier park industries. In case of

any other chemicals stored and handled by the factories located within the

damage zone, this may lead to domino effect.

The result calls for urgent need of preparation of onsite and offsite

plan by the management concerned and obtaining approvals from the


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Figure 4.12 Snapshot showing Thermal Radiation Result Incorporated in the layout for Industry No.7

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(20MT Bullet - VCE)


kg/cm2, which extends to 196 m, 0.13 kg/cm2 extends to 242 m and 0.02

kg/cm2 extends to 999 m. Figure 4.13 shows the snapshot of shock wave

pressure results for Industry No.7.


The shock wave pressures versus distances are calculated for

Industry No.7 are given in Figure 4.14.


accordingly, the location of machinery and workstation are decided.

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Figure 4.15 shows the shock wave pressure result in respect of

Industry No.7 and damage effect, which extends to onsite and offsite for a

radius of 999 m. The damage zone covers agricultural lands, cattle field and

proposed construction of supplier park industries.




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Figure 4.15 Snapshot of Shock Wave Pressure Result Incorporated in the Layout of Industry No.7 (5D Stability Class)

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(5MT Bullet – BLEVE)

The results of thermal radiation of 5 MT bullet leads to 37.5 kg/cm2

(100% Fatal Zone) and extends to 129 m, for 12.5 kg/cm2 extends to 459 m

and 4 kg/cm2 extends to 256 m. Figure 4.16 shows the snapshot of radiation

effect for Industry No.15.

Figure 4.16 Snapshot showing Radiation Effect for Industry No.15 - Fire Ball (5D Stability Class)


calculated and given in Figure 4.17. At a required distance, the radiation

effects can be calculated and accordingly, the location of machinery and

workstation can be decided.

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Figure 4.17 Snapshot Graph showing Radiation versus Distance for Industry No.15.Fire Ball (5D Stability Class)

Figure 4.18 shows the snapshot of thermal radiation result for

Industry No.15 incorporated in the layout and the damage effect, which

extends onsite as well as offsite to a radius of 256 m. The damage zone covers

the nearest village and agricultural lands including cattle field.

In case of any other chemicals stored and handled by the factories

located within the damage zone, this may lead to domino effect. The result

calls for the urgent need of preparation of onsite and offsite plan by the

management concerned and obtaining approvals from the statutory authority.

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Figure 4.18 Snapshot showing Thermal Radiation Result Incorporated in the Layout of Industry No.15.

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4.3.6 Modeling Results of Vapour cloud Explosion of Industry No.15

(5MT Bullet - VCE)



extends to 611 m. Figure 4.19 shows the snapshot of shock wave pressure

results for Industry No.15.


The shock wave pressure versus distances are calculated and given

in Figure 4.20.



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Figure 4.21 shows the shock wave pressure result for Industry

No.15 incorporated in the layout and the damage effect, which extends onsite

and offsite to the radius of 611 m. The damage zone covers the nearest

automobile factory having LPG installation, village, houses and agricultural

lands including cattle field.




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Figure 4.21 Snapshot showing Shock Wave Pressure Results Incorporated in the Layout for Industry No.15 (5D Stability Class)

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kW/m2 (100% Fatal Zone) and extends to 87 m, 12.5 kW/m2 extends to 269 m

and 4 kW/m2 extends to 512 m. Figure 4.22 shows the thermal radiation effect

for Industry No.23.

Figure 4.22 Snapshot showing Thermal Radiation Effect for Industry No.23- Fire Ball (5D Stability Class)


calculated and given in Figure 4.23. At a required distance, radiation effects

can be calculated and accordingly, the location of machinery and workstation

are decided.

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Figure 4.23 Snapshot Graph showing Radiation versus Distance for Industry No.23- Fire Ball (5D Stability Class)

Figure 4.24 shows the thermal radiation result of Industry No.23


as offsite to a radius of 512 m. The damage zone covers one factory having

LPG bullets, storm water canal in longitudinal direction of length covering

approximately one kilometer with small area of cattle fields. In case of any

other chemicals stored and handled by the factories located within the damage

zone, this may lead to domino effect.




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Figure 4.24 Snapshot showing Thermal Radiation Result Incorporated in the Layout for Industry No.23.

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(30MT Bullet – VCE)



extends to 1149 m. Figure 4.25 shows the snapshot for shock wave pressure

result of Industry No.23.


The shock wave pressure versus distance was calculated and given

in Figure 4.26.

At a required distance, the overpressure effects can be calculated

and accordingly, the location of machinery and workstation can be decided.

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Figure 4.27 shows the shock wave pressure result of Industry No.23

and the damage effect, which extends onsite and offsite to a radius of 1149 m.

The damage zone covers three factories, between this two factories having

LPG bullets, warehouse, school and storm water canal, state highway and

adjacent road (40 ft) and symmetry.




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Figure 4.27 Snapshot of Shock Wave Pressure Results Incorporated in the Layout for Industry No.23 (5D Stability Class)

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4.3.9 Modeling Results of Thermal Radiation of Industry No. 30



kW/m2 (100% Fatal Zone) and extends to 22 m, 12.5 kW/m2 extends to 155 m

and 4 kW/m2 extends to 307 m. Figure 4.28 shows the snapshot of thermal

radiation effect for Industry No.30.

Figure 4.28 Snapshot showing Thermal Radiation Effect of Industry No 30- Fire Ball (5D Stability Class)

The thermal radiation versus distances was calculated and given in

Figure 4.29. At a required distance, the radiation effects can be calculated and


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Figure 4.29 Snapshot Graph showing Radiation versus Distance for Industry No.30- Fire Ball (5D Stability Class)

Figure 4.30 shows the thermal radiation result of Industry No.30


as offsite to a radius of 307 m. The damage zone covers five small shops,

state highway, eight numbers of houses and agricultural lands with cattle

fields. In case of any other chemicals stored and handled by the factories

located within the damage zone, this may lead to domino effect.




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Figure 4.30 Snapshot showing Thermal Radiation Result Incorporated in the Layout for Industry No.30

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4.3.10 Modeling Results of Vapour Cloud Explosion of Industry No.

30 (10MT Bullet – VCE)



extends to 755 m. Figure 4.31 shows the snapshot of shock wave pressure

results for Industry No.30.


The shock wave pressure versus distance was calculated and given

in Figure 4.32. At a required distance, the overpressure effects can be

calculated and accordingly, the location of machinery and workstation can be

decided.

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Figure 4.33 shows the snapshot of shock wave pressure results

incorporated in the layout for Industry No.30 and its damage effect, which

extends onsite and offsite to the radius of 755 m. The damage zone covers a

village with domestic population and their houses, state highway and village

road (30 Ft), agricultural land with cattle fields.




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Figure 4.33 Snapshot of Shock Wave Pressure Results Incorporated in the Layout for Industry No.30 (5D Stability Class)

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4.4 COMPUTATION OF MODELING SCENARIO RESULTS

OF ALL THIRTY-FIVE INDUSTRIES.

Consequence Modeling scenarios such as thermal radiation and

vapour cloud explosion results of all thirty-five industries were consolidated

and the results are discussed as given below in Table 4.4.

Table 4.4Modeling Scenario Results of all thirty-five Industries

SL

Cap

acity

of B

ulle

ts

in M

T

Dis

char

ge Q

ty in

(8

0%) M

T

Pres

sure

in B

ar

Thermal Radiation Vapour cloud

explosion

37.5 12.5 4.0 0.20 0.13 0.02

kW/m2 Bar

Radius in Meter

1 95.0 76.0 16.0 193 459 846 383 428 1734

2 4.7 3.76 6.0 21 130 257 119 146 603

3 9.35 7.48 6.0 36 167 327 151 185 775

4 5.0 4.0 6.0 9 129 256 123 150 611

5 9.35 7.48 7.0 43 172 335 150 184 777

6 4.7 3.76 6.0 21 130 257 119 146 603

7 20.0 16.0 14.5 56 220 427 196 242 999

8 4.6 3.68 6.0 21 129 255 118 144 601

9 100 80.0 16.0 196 467 860 390 435 1765

10 9.35 7.48 5.00 25 162 319 152 186 772

11 30.0 24.0 14.5 87 269 512 224 275 1149

12 7.49 5.99 6.0 31 154 303 140 174 730

13 9.1 7.28 6.0 35 166 324 150 183 771

14 15.0 12.0 8.0 63 210 402 177 219 921

15 5.0 4.0 6.0 9 129 256 123 150 611

115

Table 4.4 (Continued) SL

Cap

acity

of B

ulle

ts

in M

T

Dis

char

ge Q

ty in

(8

0%) M

T

Pres

sure

in B

ar

Thermal Radiation Vapour cloud

explosion

37.5 12.5 4.0 0.20 0.13 0.02

kW/m2 Bar

Radius in Meter

16 50.0 40 14.5 144 359 668 306 343 1399

17 33.0 26.4 14.5 123 310 578 262 298 1224

18 9.36 7.48 7.0 43 172 335 150 184 777

19 10.0 8.0 6.0 37 171 335 155 190 785

20 17.0 13.6 18.5 103 256 477 209 237 973

21 25.0 20.0 14.5 110 281 525 238 271 1104

22 7.5 6.0 6.0 31 154 303 140 174 730

23 30.0 24.0 14.5 87 269 512 224 275 1149

24 15.0 12.0 7.0 56 204 395 176 219 921

25 4.6 3.68 5.0 7 125 249 119 146 598

26 4.7 3.76 6.0 21 130 257 119 146 603

27 10.0 8.0 6.0 37 171 335 155 190 785

28 9.35 7.48 5.5 31 165 323 151 185 774

29 25.0 20.0 18.5 120 294 545 241 271 1104

30 10.0 8.0 5.0 22 155 307 146 179 755

31 5.0 4.0 6.0 9 129 256 123 150 611

32 10.0 8.0 2.5 NR 146 298 160 196 801

33 9.35 7.48 7.0 43 172 335 150 184 777

34 9.4 7.52 14.5 73 198 374 169 194 792

35 1350 1080 4.0 303 911 1715 845 1019 4162

116

4.4.1 Analysis of Onsite and Offsite Results for 35 industries

The results reveal the damage distances from the source. Based on

the damage distance levels, onsite emergency and offsite emergency were

identified. If the damage distance is restricted within the premises and within

the boundary, it is called as onsite damage only. If the damage distance goes

beyond the boundary, it is called as offsite damage.

During the field visit, it was observed that in most of the industries

fire hydrant system, LPG vessel maintenance, adequacy and intactness of the

dyke, LPG sensor/detector, access control, static discharge facilities,

provision of wheel stoppers, emergency siren system and mutual aid

arrangement system were missing.

During the verification of records pertaining to safety management

system, emergency preparedness, consequence modeling and impact study

details carried out in the company, it was found that components of safety

management system such as safe operating procedures, implementation of

hazardous area classification system and other communicational warning

procedures were not given due importance by the companies. Most of the

industries did not have the mandatory document of Onsite Emergency Plan

(OSEP), offsite emergency plan and risk assessment report. The probability of

onsite and offsite emergency plan to protect the surrounding facilities, general

public and environmental aspects were not properly addressed and ensured.

In view of the above lacuna, the researcher prepared a detailed

onsite emergency plan and risk assessment report for the industries

concerned. As committed by the researcher, the results were shared with each

industry and a report was prepared on the possible consequences in case of

accidental release of LPG stored. Accordingly, the report of OSEP was

prepared as per Manufacture, Storage and Import of Hazardous Chemicals

117

Rules 1989 (MSIHC Rules 1989) and submitted to all the 35 industries by the

researcher with suitable suggestions/recommendations for implementation.

This document could be used by the industries concerned for obtaining

approvals by the statutory authority like Director Industrial Safety and Health,

Government of Tamilnadu and Tamilnadu Pollution Control Board.

The offsite emergency plan preparation would be taken care by the

district administration for all the hazardous installation in other factories

located in the district level. Hence, the management concerned should take

efforts towards the preparation of offsite emergency plan with the help of the

district administration.

All the managements shall cover the Public liability insurance to

the equal value of affected victims in terms of human population and

environmental facility in the vicinity, in case of emergency.

4.5 CONSOLIDATION OF QUESTIONAIRE RESULTS

The primary data for all the 35 industries were personally collected.

Secondary data were prepared based on the collected primary data and both

the data was fed into the questionnaire in order to calculate the actual impacts

on environment. The completed data with respect to risk, consequences

modeling of various scenarios, emergency preparedness, environment impact

assessment and damage zones were systematically analyzed and the results

were tabulated.

4.5.1 Completion of Research Questionnaire

The results were organized based on the total number of companies

satisfying partially or fully with the statutory requirements and the same are

tabulated as shown in Table 4.5. Green colour coding indicates a positive

118

impact on environment and the red coding shows a negative impact to the

environment in percentages.

Table 4.5 Consolidated Questionnaire Results

Description

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

List of Factories 1 2 3 4 LPG Bullet Statutory 80 20 80 20 70 30 60 40 Safety Management System 80 20 60 40 30 70 10 90 Emergency Preparedness 90 10 90 10 70 30 70 30 Risk Analysis and Consequence Modeling 70 30 80 20 50 50 60 40

Environment Impact Assessment 80 20 80 20 70 30 70 30

Impact Results and Damage Contour 20 80 90 10 40 60 40 60





119


Description

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

Posi

tive

Impa

ct

Neg

ativ

e Im

pact










120


Description

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

Posi

tive

Impa

ct

Neg

ativ

e Im

pact

Posi

tive

Impa

ct

Neg

ativ

e Im

pact









List of Factories 33 34 35

LPG Bullet Statutory 100 0 80 20 80 20 Safety Management System 90 10 80 20 70 30 Emergency Preparedness 90 10 70 30 90 10 Risk Analysis and Consequence Modeling 80 20 80 20 60 40

Environment Impact Assessment 90 10 70 30 70 30

Impact Results and Damage Contour 100 0 70 30 20 80

121

The above results were further compiled element wise to arrive at

the average positive and negative impact results of all thirty-five factories as

shown in Table 4.6.

Table 4.6 Compiled Impact Results of all Sample Industries

Impact of Factories Total Positive

Impact Total Negative

Impact

LPG Bullet Statutory 75% 25%

Safety Management System 63% 37%

Emergency Preparedness 74% 26%

Risk Analysis and Consequence Modeling 69% 31%

Environment Impact Assessment 66% 34%

Impact Results and Damage Contour 49% 51%

The performance of each establishment in terms of compliance was

recorded. Both these organized data were taken for the analysis along with the

parameters such as location of LPG installations, safety management system

in the site, effective emergency preparedness as per statutory requirement,

risk analysis and consequence modeling, environment impact assessment and

damage contour onsite as well as offsite in case of emergency.

4.5.2 Preparation of Histogram

The histogram is a graphical representation of the distribution of

the data as shown in Figures 4.34. This histogram represents the number of

industries complying the set criteria mentioned in the questionnaire. The ‘yes’

status means the positive impacts of compliance of relevant statutes by the

industry and no status represent negative impact i.e. Non-compliance to the

statutory.

122

Figure 4.34 The Number of Sample Industries with ‘YES’ Status only.

123

In Figure 4.35, the bar chart represents the comparative value of

each element in percentage for all the 35 industries indicating both ‘Yes’ and

‘No’ status.

Figure 4.35 The Number of ‘YES’ Status and ‘NO’ Status of the Selected 35 Industries.

124

The analysis suggests that the study factors differ from each other

and the salient observations are as follows:

1) Impact results of LPG bullet installation and statutory

requirements:

Figure 4.36 shows the average results of 35 industries on LPG

bullet and statutory requirement.

Figure 4.36 LPG Bullet and Statutory Requirement

The average results indicate a 75% positive impact and 25%

negative Impact.

Further, all the thirty-five factories surveyed have valid PESO

(Petroleum and Explosives Safety Organization) license. Also, more than

70% of the industries have functional safety equipments and other facilities

mentioned in the items. Deficiency observed was, that they do not have

adequate and intact dyke wall facility. Referring to Figure 4.35, seventh,

eleventh, fourteenth and thirty-third industries satisfy all the requirements of

LPG bullet storage. But fifth, nineteenth, twenty fifth, twenty seventh

125

companies do not satisfy even half the criteria set by the researcher in line

with statutory requirement and hence these companies need to be more

concerned about the LPG bullets storage conditions.

2) Impact results of safety management system:

Figure 4.37 shows the average results of 35 industries on safety

management system.

Figure 4.37 Safety Management System


negative Impact.

Investigating the safety management system at automobile

industries, there appeared to have adequate supervision during unloading and

effective access control but there was no adequate display of unloading

procedures in 75% of the companies. One third of the factories do not have

wooden wheel stoppers and hazardous area classification system. Referring to

Figure 4.35. The 11th industry satisfies all the requirements of safety

management system. But third, fourth, eighth, twenty seventh and twenty

126

eighth companies do not satisfy even half the criteria set by the statutory

authority. These companies need to focus more on the safety management

system.

3) Impact results of emergency preparedness:

Figure 4.38 shows the average results of 35 industries on

Emergency Preparedness.

Figure 4.38 Emergency Preparedness


negative Impact.

As per the emergency preparedness plan requirement, about 94 %

of automobile industries surveyed have emergency plans and the necessary

equipments. One third of the industries lack emergency siren system and

hydrant lines with static water storage. It was observed that 43 % of the

industries do not have wind sacks installation and 72 % of mutual aid

facilities.

127

4) Impact results of risk analysis and consequence Modeling:

Figure 4.39 shows the average results of 35 industries on Risk

Analysis and Consequence Modeling.

Figure 4.39 Risk Analysis and Consequence Modeling


negative Impact.

As per the Risk and consequence modeling, nearly half the

automobile industries do not have enough space for dispersion of leaked gases

during emergency release of LPG. The space looks very confined. In this

condition, damage level goes up very high in case of emergency. 49% of

industries do not have vehicles with spark arrester. Approximately half the

industries are nearer to the public roads, which may cause severe damage

during accidents. Besides, most of the automobile industries do not take over-

pressure concept into account.

128

5) Impact Results of environment impact assessment:

Figure 4.40 shows the average results of 35 industries on

Environment Impact Assessment.

Figure 4.40 Environmental Impact Assessment


negative Impact.

Analyzing the environment of surrounding industries, it is observed

that more than half the factories are located at sites surrounded by agricultural

land. The deposition of the air pollutants might reach these lands and cause

damage to the crops.

6) Impact results and damage contour:

Figure 4.41 shows the average results of 35 industries on Impact

results and damage contour.

129

Figure 4.41 Impact Results and Damage Contour


negative Impact.

Nearly 81% of the factories do not have proper facility inside the

damage zone except second, twelfth, twenty-seventh, thirty-second, thirty-

fourth factories.

4.6 SUMMARY

Of the 80 software models used widely, DNV Phast was selected

for the calculation and analysis of data collected from 35 industries. For easy

understanding of the scenario and results, data with respect to five industries

out of 35 industries, were chosen for detailed calculation and results discussed

in detail with graphs and damage contours in layout map. The data with

respect to35 industries on thermal radiation level, shock wave pressure level,

and damage contour etc., were calculated and the results consolidated as

percentage. Accordingly, histograms and compliance status charts for all the

industries were prepared based on the data results. Further, the main element

130

wise consolidation of data of 35 industries was compiled and results were

obtained.

The compliance to the statutory requirements of the LPG bullets is

only 75%, which clearly indicates that a lot needs to be done in legal

compliance even though the same is only a bare minimum requirement.

The Safety Management System is implemented only for 63%,

which clearly demonstrates that the remaining industries, elements of safety

management system such as safety organization, accident investigation,

hazard identification, standard operating procedure, standard maintenance

procedure, work permit, corrosion monitoring etc. are having deficiencies

which may result in accidents or LPG releases, if these deficiencies are

aligned and allowed to occur in series.

Emergency Preparedness in terms of onsite and offsite emergency

planning is the last layer of protection after the LPG release or accidental

scenarios. Immediate interventions without any time delay in a methodical

manner can minimize the effects and consequences of such releases. This

element is also lagging to the extent of 26%, which necessitates the LPG

handling automobile industries to strengthen the emergency preparedness

system.

Risk Analysis and Consequence modeling studies are neither

carried out nor implemented in31% of the sample LPG handling automobile

industries, thus depriving them the knowledge on understanding of damage

distances, losses and socio-economic consequences.

Environmental Impact Assessment is lagging to the extent of 34%

among the sample industries which demonstrates that the environmental

aspects are not given enough focus and the impact assessment need to be

131

understood and appreciated in proper perspective for having least impact on

the environment.

The impact results and damage contour of 51% effect on the

facilities in and around the plant clearly establishes that half of the LPG

handling industries are prone to major losses in and around the plant, thus

putting the facility, operating personnel and public living in and around the

premises in jeopardy.

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