grass root petroleum storage & distibution...

IOCL MALKAPUR – POL DEPOT QUANTITATIVE RISK ANALYSIS

QUANTITATIVE RISK AN

Q U A N T I T A T I V E

M/s. INDIANOIL CORPORATION LIMITED

GRASS ROOT PETROLEUM STORAGE & DISTIBUTION

TERMINAL

SY. NO. 120, MALKAPUR VILLAGE, CHOUTUPPAL MANDAL,

BHONGIR DIVISION, YADADRI BHONGIR DISTRICT

TELANGANA

PREPARED BY

SV ENVIRO LABS & CONSULTANTS

Recognized by GOI, MOEF, QCI Accredited

Enviro House, B-1, Block

Visakhapatnam

Andhra Pradesh

POL DEPOT QUANTITATIVE RISK ANALYSIS

QUANTITATIVE RISK ANALYSIS

Q U A N T I T A T I V E R I S K A N A L Y S I S

M/s. INDIANOIL CORPORATION LIMITED

GRASS ROOT PETROLEUM STORAGE & DISTIBUTION

TERMINAL

NO. 120, MALKAPUR VILLAGE, CHOUTUPPAL MANDAL,

BHONGIR DIVISION, YADADRI BHONGIR DISTRICT

TELANGANA

PREPARED BY

SV ENVIRO LABS & CONSULTANTS

Recognized by GOI, MOEF, QCI Accredited

1, Block –B, IDA, Autonagar,

Visakhapatnam-530012

Andhra Pradesh


Page 1

ALYSIS

2018

IOCL MALKAPUR-POL DEPOT QUANTITATIVE RISK ANALYSIS

Page 2

CONTENTS

S.No. Description Page. No.

1.1 Introduction 07-07

1.2 Project Proposal 08-08

1.3 Study Objectives 09-09

1.4 Scope of study 09-10

1.5 Hazard Identification 10-10

1.5.1 Methodology Adopted 11-11

1.6 Risk Analysis & Risk Assessment 13-13

1.7 Methodology 14-14

1.8 General Classification of Petroleum Products 14-14

1.9 Identification of Hazards & Release Scenarios 15-19

1.10 Factors for Identification of Hazards 19-21

1.11 Types of outcome events 21-22

1.12 Fire & Explosion Index 22-22

1.13 Dow F & EI Hazard Classification 23-23

1.14 FEI & TI Methodology 23-25

1.15 Consequence Calculations 25-26

1.16 Selection of Damage Criteria 26-28

1.17 Exposure to Natural Hazards 28-28

1.17.1 Earth quake 28-28

1.17.2 Storm/Cyclone 28-28

1.18 Event Outcomes 29-35

1.19 Maximum credible accident analysis (MCA) approach 35-35

1.19.1 Introduction 35-37

1.20 Consideration for maximum credible accident scenario:

hazard assessment (Quantification)

38-53

1.21 Fire protection and fire fighting system 53-53

1.21.1 Fire Fighting Facilities 53-53

1.21.2 Safety & Security Features in the Proposed Plant 53-54

1.22 Climatological Conditions 54-54

1.23 Mathematical & Analytical Models for Hazard Analysis 54-55


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1.24 Risk Control Measures 55-55

1.24.1 Risk control Measures by IOCL 55-56

1.24.2 Additional Risk Control measures suggested 56-57

1.25 QRA Recommendations 57-58


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LIST OF TABLES

Table No. Description Page No.

1.1 Degree of Hazard for F & EI 23-23

1.2 Effects Due To Incident Radiation Intensity 27-27

1.3 Physiological Effects of Threshold Thermal Doses 27-28

1.4 Damage Effects due to blast over pressure 28-28

1.5 MS tank on fire radiation effects 38-38

1.6 MS pool fire radiation effects 39-39

1.7 MS pipe pool fire radiation effects 40-40

1.8 HSD tank on fire radiation effects 41-41

1.9 HSD pool fire radiation effects 42-42

1.10 HSD pipe pool fire radiation effects 43-43

1.11 ATF tank on fire radiation effects 44-44

1.12 ATF pool fire radiation effects 45-45

1.13 Ethanol Pool Fire Radiation Effects 46-46

1.14 Ethanol Pipe Pool Fire Radiation Effects 47-47

1.15 Biodiesel pool fire radiation effects 48-48

1.16 Biodiesel pipe pool fire radiation effects 49-49

1.17 Transmix pool fire radiation effects 50-50

1.18 SKO tank on fire radiation effects 51-51

1.19 SKO Pool fire radiation effects 52-52


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LIST OF FIGURES

Figure No. Description Page No.

1.1 Site Plan 12-12

1.2 IPRA (Individual Risk per Annum) 13-13

1.3 QRA Methodology flow chart 14-14

1.4 Event Tree for continuous release without rain-out (from PHAST) 29-29

1.5 Event Tree for Instantaneous release without rain-out (from PHAST) 29-29

1.6 Event Tree for Instantaneous release with rain-out (from PHAST) 30-30

1.7 Event Tree for continuous release with rain-out (from PHAST) 30-30

1.8 Event Analysis 31-31

1.9 Release of flammable liquid 31-31

1.10 pipe work rupture by external fire 32-32

1.11 Fire at Pump House 33-33

1.12 Fire at DG Set Room 33-33

1.13 Common mode failure classes 34-34

1.14 Hazard distance in the event of MS Storage tank on fire 38-38

1.15 Hazard distances in case of Pool Fire MS-1500 KL Storage tank 39-39

1.16 Hazard distances in case of pool fire MS-Pipe 40-40

1.17 Hazard distances in the event of HSD storage tanks on fire 41-41

1.18 Hazard Distances in case of Pool Fire HSD 17000 KL Storage Tank 42-42

1.19 Hazard distances in case of Pool Fire HSD Pipe 43-43

1.20 Hazard distances in the event of ATF Storage tank on fire 44-44

1.21 Hazard distance in case of pool fire ATF-11000 KL storage tank 45-45

1.22 Hazard Distances in case of Pool fire Ethanol -1300 KL Storage Tank 46-46

1.23 Hazard Distances in case of Pool fire Ethanol pipe 47-47

1.24 Hazard distances in case of pool fire , Bio Diesel-850 KL storage tank 48-48

1.25 Hazard distances in case if pool Fire-Bio Diesel Pipe 49-49

1.26 Hazard distances in case of Pool Fire Transmix-600 KL Storage Tank 50-50

1.27 Hazard Distances In Case Of Tank On Fire: SKO – 4000 Kl Storage Tank 51-51

1.28 Hazard Distances In Case Of Pool Fire: SKO – 4000 Kl Storage Tank 52-52


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List of Abbreviations used in the Quantitative Risk Analysis:-

1. ROV Remote Operated Valve

2. OISD Oil Industrial Safety Directorate

3. TLF Truck Loading Facility

4. QRA Quantitative Risk Analysis

5. ALARP as low as reasonably practicable

6. MCLS Maximum Credible Loss Scenario

7. ELR Environmental Lapse Rate

8. DALR Dry Adiabatic Lapse Rate

9. UDM Unified Dispersion Model

10. LFL Lower Flammability Limit

11. UFL Upper Flammability Limit

12. VCE Vapour Cloud Explosion

13. F&EI Fire and Explosion Index

14. MSDS Material Safety Data Sheets

15. MSIHC Manufacture, Storage and Import of Hazardous

Chemicals

16. AIHA American Industrial Hygiene Association

17. ERPG Emergency Response Planning Guidelines

18. UDM Unified Dispersion Model

19. LSH Level Safety High

20 FTA Fault Tree Analysis

21. ETA Event Tree Analysis

22. MCA Maximum Credible Accident


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1.1 INTRODUCTION

This Quantitative Risk Analysis has been prepared for the Malkapur POL Storage

Terminal Plant of Indian Oil Corporation Limited. The Malkapur POL Terminal plant of

Indian Oil Corporation Ltd. (IOCL) is situated at Sy.No. 120, Malkapur Village,

Choutuppal Mandal, Bhongir Division, Yadadri Bhongir District, Telangana. Noticing the

damage potential and thus risk arising due to transportation, storage and handling of the

flammable petrochemicals IOCL retained SV Enviro Labs & Consultants,

Visakhapatnam, to undertake the Quantitative Risk Analysis for the POL Storage

Terminal Plant.

Indian Oil Corporation Ltd (IOCL) is a premier public sector company in the Oil & Gas

sector and is engaged in the business of refining and retailing of petroleum products

including LPG in the country. It is the leading Indian corporate in the Fortune “Global

500’ listing ranked at the 168th

position in the year 2017. IOCL has strong network of 129

POL Depot/Terminals, 91 LPG Bottling Plants and 104 Aviation Fueling Stations which

serve every nook and corner of the country. Indane (the trade name of LPG of IOCL) is

supplied to the consumers through a network of about 10230 distributors (50.6% market

share of the industry). The growth in demand of LPG for domestic purpose is increasing

at a rapid pace. To improve safety standards in Petroleum Industry, Ministry constituted

OISD which establishes standards/practices to be followed in petroleum sector from time

to time.

Indian Oil and its subsidiaries account for a 49% share in the petroleum products market,

35% share in refining capacity and 71% downstream sector pipelines capacity in India.

The Indian Oil Group of companies owns and operates 11 of India's 23 refineries with a

combined refining capacity of 80.7 million metric tonnes per year. In FY 2016-17 IOCL

sold 83.49 million tones of petroleum products and reported a profit of Rs.191.06 billion

with a net operating revenue of Rs.4068.28 billion.

IOCL proposes to develop Grass-Root petroleum storage terminal at Sy.No. 120,

Malkapur Village, Choutuppal Mandal, Bhongir Division, Yadadri Bhongir District,

Telangana.


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1.2 PROJECT PROPOSAL

Proposed Facilities of the Project:

SN Class No of

tanks

Type of

Tanks Tank Size

Capacity of

each tank

Total

Tankage

1.

A

(MS,

Ethanol,

Transmix)

4 IFRVT 38 m dia x 16 m high 15000 KL 60000 KL

2. 1 UGHT 3 m dia x 7.5 m long 50 KL 50 KL

3. 2 IFRVT 14 m dia x 11 m high 1300 KL 2600 KL



6.

B

(HSD,

SKO,

ATF)

4 IFRVT 40 m dia x 16 m high 17000 KL 68000 KL


8. 1 UGHT 2.1 m dia x 6 m long 20 KL 20 KL


10. 1 UGHT 1.6 m dia x 2.75 m

long 5 KL 5 KL

11. 2 IFRVT 32 m dia x 16.5 m

high 11000 KL 22000 KL


13. 1 UGHT 1.6 m dia x 2.75 m

long 5 KL 5 KL

14. Excluded

(Biodiesel,

Sludge)

2 CRVT 12 m dia x 9 m high 850 KL 1700 KL


16. 1 CRVT 12 m dia x 9 m high 850 KL 850 KL

CLASS – A 63950 KL

CLASS - B 98080 KL

EXCLUDED 2650 KL

GRAND TOTAL 164680 KL


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1.3 Study Objectives & Scope of Work

1.3.1 Study Objectives

The main objective QRA (Quantitative Risk Analysis) is to determine the potential

risks of major accidents having damage potential to life and property and provide a

scientific basis for decision makers to be satisfied about the safety levels of the

facilities to be set up. This is achieved by the following:

• Identification of hazards that could be realized from plant.

• Identify the potential failure scenarios that could occur within the facility.

• To assess, the potential risks associated with identified hazards to which the plant

and its personal and community outside may be subjected. Consequences analysis

of various hazards is carried out to determine the vulnerable zones for each

probable accident scenario.

• Evaluate the process hazards emanating from the identified potential accident

scenarios.

• Analyze the damage effects to the surroundings due to such accidents.

• Conclusion and Recommendation to mitigate measures to reduce the hazard /

risks.

• To provide guidelines for the preparation of On-site response plan.

1.4 Scope of Study

The scope of work of the QRA study was spilt into the following specific points.

• Identification of hazards and credible accidental events (Maximum Credible

Accident Analysis-MCA)

• Frequency analysis. Evaluate the likelihoods of occurrence of possible events.

Select worst case scenario.

• Consequence modeling and analysis for the identified hazard covering impact on

people and potential escalation.

• Assessment of risk arising from the hazards and consideration of its tolerability to

personnel, facility & environment. Assessment of risk to individual and /or

societal and neighboring areas and contour mapping.

• Determination of maximum over pressure and heat radiation effect which could

act on the critical areas of the location.

• Evaluation of risk against the acceptable risk limit.


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• Estimation of overall risk/risk quantification

• Calculation of physical effects of accidental scenarios

• Damage limits identification and mapping on the layouts

• Hazard mitigation recommendations based on QRA.

• Risk reduction measures to prevent incidents, to control accidents.

1.5 Hazard Identification

1. Identification of potential physical hazards which could trigger loss causing events,

such as fire and explosion leading to major accidents triggering on site due to leakage

of various chemicals as mentioned above.

2. Chemical Hazard Ranking is tabulated to ascertain severity of flammability, health

and reactivity based on NFPA Hazard classifications.

3. DOW’s Fire and Explosive Index (F& EI) is worked out for the above chemicals

during storage to make you aware of the loss potential of your storage conditions.

4. Identifying the Maximum Credible Loss Scenarios (MCLS) for the above identified

chemicals.

5. Risk Analysis (RA) is carried out by using computer model (PHAST) for the major

accidents resulting in Jet Fire – Heat Radiation / Explosion over pressure to

determine maximum impact distance specific to each type of accident.

6. Impact distances derived from the study is plotted on the plot plan to ascertain area

likely to be affected.

Hazard identification is a critical step in Risk Analysis. Many aids are available,

including experience, engineering codes, checklists, detailed process knowledge,

equipment failure experience, hazard index techniques, what – if Analysis, Hazard

and Operability (HAZOP) Studies, failure mode and effects analysis (FMEA),and

preliminary hazard Analysis (PHA). In this phase all potential incidents are identified

and tabulated. Study of operations and documents like drawings, process write-up etc.

are used for hazard identification.

Consequence estimation is the methodology used to determine the potential for

damage for injury from specific incidents. A single incident can have many distinct

incident outcomes.


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1.5.1 Methodology Adopted:

After identifying the study objectives and collection of the data, the team identified

major consequences that are possible due to deviations from design and engineering

intentions. The collection of data and information provided familiarity with the

facilities to the team carrying out the Risk Analysis study. The Risk Analysis

calculations based on the collected data have been carried using PHAST LITE 7.11

software. Finally, risk reduction measure has been suggested.


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Fig 1.1 SITE LAYOUT


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1.6 Risk Analysis and Risk Assessment.

The basic procedure in a risk analysis shall be as follows:

(a) Identify potential failures or incidents (including frequency)

(b) Calculate the quantity of material that may be released in each failure, estimate

the probability of such occurrences.

(c) Evaluate the consequences of such occurrences based on scenarios such as

most probable and worst case events.

(d) The combination of consequences and probability will allow the hazards to be

ranked in a logical fashion to indicate the zones of important risk. Criteria

should then be established by which the quantified level of risk may be

considered acceptable to all parties concerned.

(e) After assessing the risk “maximum tolerable criterion” must be defined and

above which the risk shall be regarded as intolerable. Whatever be the benefit

level must be reduced below this level.

Fig 1.2:

While conducting the risk analysis, a quantitative determination of risk involves

three major steps:-


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1.7 Methodology:

Risk Analysis techniques provide advanced quantitative means to supplement other

hazard identification, analysis, assessment, control and management methods to

identify the potential for such incidents and to evaluate control strategies.

Fig 1.3: The methodology adopted for the QRA Study has been depicted in the Flow

chart given below:

1.8 General Classification of Petroleum Products:

Petroleum products are classified according to their close cup Flash points as given

below:

Class-A Petroleum: Liquids which have flash point below 23oC.

Class-B Petroleum: Liquids which have flash point of 23oC and above but below

65oC

Class-C Petroleum: Liquids which have flash point of 65oC and above but below

93oC

Excluded Petroleum: Liquids which have flash point of 93oC and above.


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1.9 Identification of Hazards & Release Scenarios

A technique commonly used to generate an incident list is to consider potential leaks

and major releases from fracture of all process pipelines. The compilation includes all

pipe work in direct communication, as these may share a significant inventory that

cannot be isolated in an emergency. The following data were collected to envisage

scenarios:

• Flow rate of materials passing through pipelines

• Tank/pipelines conditions(phase ,temperature, pressure)

• Inventory

• Connecting piping and piping dimensions.

Accidental releases of flammable liquids and toxic gases can result in severe

consequences. Delayed ignition of flammable liquid can result in blast over pressure

covering large areas. This may lead to extensive loss of life and property. In contrast,

fires have localized consequences. Fires can be put out or contained in most cases;

there are few mitigating actions one can take once a flammable liquid or a vapour

cloud gets released. Major accident hazards arise, therefore, consequent upon the

release of flammable liquid.

For this study, use of software package PHAST (Process Hazard Analysis Software

Tool). PHAST Professional is a software product for chemical process hazard analysis.

PHAST Professional provides the most advanced collection of consequence models

available for hazard analysis. Regular updates make the latest technical developments

available in a practical format.

PHAST Professional represents the best technology in loss prevention engineering

available in the world today. PHAST Professional is a set of software tools that

calculates the consequences of accidental or emergency atmospheric releases of toxic or

flammable chemicals. It uses mathematical models of discharge, dispersion, fire and

explosion to predict toxic and flammable effects. The results are presented in a tabular

as well as graphical form. PHAST Professional allows engineers to examine the

progress of a potential incident from initial release, through the formation of a cloud

and/or pool, to its dispersion. The program automatically applies the correct entrainment

and dispersion models as the conditions change.


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PHAST Professional integrates these models such that the transition from one behavior

pattern to another is smooth and continuous. From these results, it calculates any

possible effects of ignition, such as jet flames and explosions, where applicable. For the

experienced hazard analyst, PHAST Professional provides an extremely powerful tool,

which aids in quantifying the consequences of accidental releases of hazardous

chemicals. Real benefits can be obtained when engineers consider safety aspects from

the start of a design. PHAST Professional allows analysis of the designs for potential

hazards at the conceptual stage, which can eliminate the need for costly modifications at

the final stage.

PHAST 7.11:

PHAST 7.11 is used for consequence calculations alone while SAFETY is used for

both consequence and risk calculations. It contains a series rate pool evaporation,

atmospheric dispersion, vapour cloud explosion, combustion, heat radiation effects

from fires etc., the software is developed based on the hazard model.

Accident frequency assessment is the methodology used to estimate the frequency or

probability of occurrence of an incident. Estimate may be obtained from historical

incident data on failure frequencies or from failure sequence models, such as fault

trees and event trees.

Risk Estimation combines the consequences and likelihood of all incident outcomes

from all selected incidents to provide a measure of risk.

The scope of the study is a consequence analysis, therefore an estimation of the

damage distances for each of the scenarios considered are developed and risk control

measures are recommended.

Modeling using PHAST Software:

The flammable mixture could ignite or explode if it encounters source of ignition. The

flammable mixture could affect the site as well as population in the vicinity. The

parameters influencing dispersion are:

Atmospheric Stability:

Atmospheric stability is important with regard to the extent to which it suppresses or

enhances the vertical movement of the cloud in the atmosphere. This is a function of the

vertical temperature profile in the atmosphere. If a volume of air rises, it would normally


Page 17

be expected to cool as it equals the vertical temperature profile, then turbulence is neither

suppressed nor enhanced. Such conditions are termed neutral. If the vertical temperature

profile is more marked then turbulence is enhanced and if the profile is less marked

then turbulence is suppressed.

Stability is defined in terms of the vertical temperature gradient in the atmosphere. It is

usually described using the system of categories developed by Pasquill. This system uses

6 categories to cover unstable, neutral and stable conditions; the categories are ranges of

stability identified by the letters A - F.

Neutral stability occurs typically when there is total cloud cover and is designated

category D (the temperature gradient = adiabatic lapse rate). Unstable conditions occur

when the sun is shining because the warming of the ground increases convective

turbulence; unstable conditions are designated by the letters A-C, with A as the least

stable condition. Stable conditions occur on clear, calm nights when the air near the

ground is stratified and free from turbulence, and are designated by the letters E and F;

Wind Speed & Surface Roughness Parameter:

These factors are discussed together because collectively they influence local turbulence.

The wind usually increases atmospheric turbulence and accelerates dispersion. The

surface roughness of the ground induces turbulence in the wind, which flows over it, and

therefore affects dispersion.

Surface roughness determines the amount of turbulence generated by wind of a given

velocity as it passes over the ground. The degree of roughness relates to a comparison

of the average height of surface “protuberances” with the depth of the laminar sub-layer

in the air stream.

Dispersion Models:

Dispersion modeling aims at estimating the distances likely to be affected due to release

of certain quantity of toxic or flammable gas within an acceptable concentration limit.

Depending upon the properties of the material released and the release conditions,

dense gas dispersion, neutral gas dispersion or a buoyant gas release model is used for

estimating the affected areas. Both the models describe the behavior of material

subsequent to its release in the predominant downwind direction, at a particular wind

speed and at the existing meteorological conditions such as humidity, temperature, etc. It


Page 18

should be noted that the release rate would depend on release conditions (temperature

and pressure), the release/failure point, intervention time, the release area and other

factors.

Wind speed and turbulence are significant factors, as the amount of air entrainment into

the released gas would depend on the velocity at which the cloud is travelling and also

turbulence in the surroundings. Varying terrain contours in the area would affect the

dispersion. The atmospheric stability class takes into account atmospheric turbulence

and is another important consideration in modeling. This in turn depends on several

factors such as wind speed cloud cover and the time period i.e. day or night. Stable

atmospheric conditions lead to the least amount of mixing thus resulting in larger areas

for gas dispersion and unstable conditions result in maximum mixing of gas with air

leading to the dilution of the gas. Surroundings of the area including building and other

structures also have a marked effect on the dispersion of released gas. The dispersion

would vary with the size and position of the building relative to the source of release

along with the other factors already discussed above.

Failure Case Identification & Definition:

The first stage in Risk Analysis study is to identify the potential accidents that could

result in the release of the hazardous material from its normal containment. This is

achieved by a systematic review of the facilities together with an effective screening

process.

Chemical hazards are generally considered to be of three types:

1. Flammable

2. Reactive

3. Toxic

Where there is the potential for gas releases, there is also the potential for explosions.

These often produce overpressures, which can cause fatalities, both through direct action

on the body or through building damage and collapse.

Potential accidents associated with any plant, section of a plant or pipeline can be

divided into two categories:

There is a possibility of failure associated with each mechanical component of the

facility (pipes, pumps or compressors). There are generic failures and can be caused by


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such mechanisms as corrosion, vibration or external impact (mechanical or

overpressure). A small event (such as a leak) may escalate to a bigger event, by itself

causing a larger failure.

There is also a likelihood of failures caused by specific operating circumstances. The

prime example of this is human error; however it can also include other accidents, for

example, to reaction runaway or the possibility of ignition of leaking gases due to hot

work.

The first category of accident requires consideration of each component under its normal

operating conditions. Three classes may also require consideration of some components

under abnormal conditions. In principle, an essential first stage in failure case

identification of such a facility is therefore every significant mechanical component in

the plant which could fail, together with its operating conditions, contents and inventory.

The range of possible releases for a given component covers a wide spectrum, from a

pinhole leak up to a rupture. It is both time-consuming and unnecessary to consider

every part of the range; instead, representative failure cases are generated. For a given

component these should represent fully both the range of possible releases and their total

frequency.

1.10 Factors for Identification of Hazards

In an installation, main hazard arises due to loss of containment during handling of

flammable and toxic chemicals. To formulate a structured approach to identification

of hazards, an understanding of contributory factors is essential.

Blast Over Pressure:

Blast over pressures depends upon the reactivity class of material and the amount of

gas between two explosive limits. For example motor spirit, once released and not

ignited immediately is expected to give to a gas cloud. The gases in general have

medium reactivity and in case of confinement of the gas cloud on delayed ignition

may result in an explosion and overpressures

Operating parameters:

Potential vapour release for the same material depends significantly on the operating

conditions. The liquids are likely to operate at atmospheric temperature [and hence

high pressures] .This operating range is enough to release a large amount of liquid


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/gas in case of a leak /rupture therefore the pipeline leaks and rupture, therefore and

the pipe line leaks ruptures need to be considered in the risk analysis calculation.

Inventory

Inventory analysis is commonly used in understanding the relative hazards and short

listing of release scenarios. Inventory plays an important role in regard to the potential

hazard. A practice commonly used to generate an incident list is to consider potential

leaks and major releases from fractures of pipe lines containing sizable inventories.

Range Of Incidents

Both the complexity of study and the number of incident outcome cases are affected

by the range of initiating events and incidents covered. This not only reflects the

inclusion of accident and/or non –accident-initiated events, but also the size of those

events. For instance studies may elevate one or more of the following

• Large hole [large continuous release]

• Smaller hole [continuous release]

• Leaks at fittings or valves [small continuous release]

• ‘’Piping ‘’of relief of valves [short duration limited release]

In general quantitative studies do not include very small continuous releases or short

duration small release if past experience or preliminary consequence modeling shows

that such release do not contribute to the over risk levels.

Selection of Initiating Events and incidents

The selection of initiating events and incident should take into account the goals or

objectives of the study and the data requirements. The data requirements increase

significantly when non – accident – initiated events are included and when the

number of release size increase. While the potential range of release sizes the

tremendous, groupings are both appropriate and catastrophic are to reduce the

conservatism in an analysis and to better understand the relative contribution to risk of

small versus large releases.

For this study initiating events and incidents are chosen considering Maximum

Credible Accident [MCA] scenarios. MCA is defined as an accident that is within the

realm of possibility and has a propensity to cause significant damage [at least one

fatality]. This concept comprises both parameters - Probable damage caused by an

accident and its probability of occurrence.


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There may be number of accidents that may occur quite frequently, but due to proper

control measures or fewer quantities of chemicals released, they are controlled

effectively. A few examples are a leak from a gasket, pump or value, release of a

chemical from a vent or pressure and vacuum valve, or relief valve, and fire in pump

due to overheating. These accidents generally are controlled before they escalate by

using control systems and monitoring devices because such piping and equipment are

known to sometimes fail or malfunction, leading to problems.

On the other hand, there are less problematic areas /units that are generally ignored or

not given due attention. Such MCAs are identified by studying the facilities and Event

Tree Analysis etc. and accidents with less consequence are ignored.

1.11 Types of Outcome Events

In this section of the report we describe the probabilities associated with the sequence

of occurrences which must take place for the incident scenarios to produce hazardous

effect and the modeling of their effects and the modeling of their effects.

Considering the present case of facilities the outcomes expected are

� Jet fire

� Flash fire(FF)

� Vapour Cloud Explosion (VCE)

� Pool Fire

Jet fire

Jet fire occurs when a pressurized release is ignited by any source. They tend to be

localized in effect and are mainly of concern in establishing the potential for domino

effects and employee safety zones rather than for community risks.

The jet fire model is based on the radiant fraction of total combustion energy, which is

assumed to arise from a point slowly along the jet flame path. The jet dispersion

model gives the jet flame length.

Flash Fire

It occurs when a vapor cloud of flammable material burns. The cloud is typically

ignited on the edge and burns towards the release point. The duration of flash fire is

very short (seconds), but it may continue as jet fire if the release continues. The

overpressures generated by the combustion are not considered significant in terms of

damage potential to persons, equipment or structures. The major hazard from flash


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fire is direct flame impingement. Typically, the burn zone is defined as the area the

vapor cloud covers out to half of the LFL. This definition provides a conservative

estimate, allowing for fluctuations in modeling. Even where the concentration may be

above the UFL, turbulent induced combustion mixes the material with air and results

in flash fire.

Vapour Cloud Explosion (VCE)

Vapour cloud explosion is the result of flammable materials in the atmosphere a

subsequent dispersion phase, and after some delay an ignition of the vapour cloud.

Turbulence is the governing factor in blast generation which cloud intensity

combustion to the level that will result in an explosion.

It may be noted that VCEs have been responsible for every serious accidents

involving severe property damage and loss of lives.

Pool fire

This represents a situation when flammable liquid spillage forms a pool over a liquid

or solid surface and gets ignited. Aviation Turbine fuel, Naptha, Kerosene, Motor

Sprit, etc can be involved in pool fires where they are stored in bulk quantities. These

outcomes are then further analyzed in the risk estimation procedure.

1.12 Fire and Explosion Index (F & EI)

F & EI is a rapid ranking method for identifying the degree of hazard in

preliminary hazard analysis considered to have fire & Explosion hazards. The

application of F & EI would help to make a quick assessment of the nature and

quantification of the hazard in these areas. However, this does not provide precise

information.

Material factor (MF) of the material concerned, the General Process hazards and

Special Process Hazards associated with the product are taken into consideration

while computing, using standard procedure of awarding penalties based on

storage, handling & operating parameters.

As regards the storage area is concerned the major potential hazard rests. In addition

F & EI for complete storage area has been evaluated.


Page 23

1.13 Dow F & EI Hazard Classification

The F & EI calculation is used for estimating the damage that would probably result

from an accident in the plant. The following is the listing of F & EI values versus a

description of the degree of hazard that gives some relative idea of the severity of the

F & EI.

Computations & Evaluation of Fire Explosion Index:

The degree of hazard potential is identified based on the numerical value of FEI as per

following criteria:

Table 1.1: Degree of Hazard for F & EI

1.14 FEI & TI Methodology:

In order to estimate FEI & TI, approach given in "Major Hazard Control" (An ILO

Publication) has been referred. Dow's Fire & Explosion Index (FEI) is a product of

Material factor (MF) and hazard factor (HF) while MF represents the flammability

and reactivity of the substances, the hazard factor (HF), is itself a product of General

Process Hazards (GPH) and Special Process Hazards (SPH).

(A) Selection of Pertinent Storage or Process Unit

For the purpose of FEI & TI calculations, a Process Unit is defined as any unit or

pipeline under consideration for the purpose of estimating FEI & TI. Hence, all the

process units, storage tanks and units handling hazardous chemicals etc. can be

termed as process units. However, only pertinent process units that could have an

impact from the loss prevention standpoint need to be evaluated.

The selection of pertinent process / storage units is based on the following factors:

1. Energy potential of the chemical/chemicals in the unit for flammable &

reactive hazards, represented by Material Factor (MF)

2. Inventory/quantity of hazardous material in the process unit

F & EI Range Degree of Hazard

1-60 Light

61-96 Moderate

97-127 Intermediate

128-158 Heavy

159-Up Severe


Page 24

3. Operating temperature and pressure

4. Past accident record

(B) Determination of Material Factor (MF)

MF is a measure of intrinsic rate of potential energy release from fire or explosion

produced by combustion or any other chemical reaction. Hazard potential of a

chemical has been represented by flowing three Indices

Index Indicates

Nh (for health) Toxic hazard potential

Nf (for flammability) Fire hazard potential

Nr (for reactivity) Explosion/Reactive hazard potential

Values of Nh, Nf & Nr ranges from 0 to 4, depending on their hazard potential.

Significance of Nf, Nh & Nr values has been defined, while MF is calculated based

on Nf & Nr.

(C) Computation of General Process Hazard Factor (GPH)

Operations or processing conditions which contribute to a significant enhancement of

potential for fire and explosion have been identified. Accordingly numerical values of

penalties are to be allocated. Sum of these penalties would be GPH for the unit. The

penalties include:

1. Exothermic and endothermic reaction,

2. Handling and transfer of chemicals,

3. Enclosed or indoor process units &

4. Accessibility of equipment and facilities with respect to drainage or spill control

(D) Computation of Special Process Hazard Factor (SPH)

SPH includes the factors that are specific to the process unit, under consideration:

1. Process temperature

2. Low pressure

3. Operation in or near flammable range

4. Operating pressure

5. Low temperature

6. Quantity of flammable or toxic material

7. Corrosion and erosion


Page 25

8. Leakage, joints and packing

(E) Classification of Hazard Categories

By comparing the indices FEI and TI, the unit in consideration is classified into one

of the following three categories based on their hazard potential.

Category FEI TI

Light < 65 < 6

Moderate 65 to 95 6 to 10

Severe > 95 > 10

NATIONAL FIRE PROTECTION AGENCY (NFPA, US) RATINGS:

1.15 Consequence Calculations

In consequence analysis, use is made of a number of calculation model the physical

effects of an accident (spill of hazardous material) and to predict the damage

(lethality, injury, material destruction) of the effects.

Accidental release of flammable liquids/gases can result in severe consequences.

Immediate ignition of the pressurized chemical will result in a jet flame. Delayed

ignition of flammable vapours can result in blast overpressure covering large areas.

This may lead to extensive loss of life and property. In contrast, fires have localized

consequences. Fires can be put out or contained in most cases; there are few

mitigating actions one can take once a vapour cloud gets released.

The calculations can rough be divided in three major groups:

a. Determination of the sources strength parameters;

b. Determination of the consequential effects;

c. Determination of the damage or damage distances;

The basis physical effects models consist of the following.

Source strength parameters

� Calculations of the outflow of liquid, vapors or gas out of a pipe. In case of

rupture. Also two phase outflow can be calculated.

� Calculations, in case of liquid outflow, of the instantaneous flash evaporation

and the dimensions of the remaining liquid pool.

� Calculations of the evaporation rate, as a function of volatility of the material,

pool dimensions and wind velocity.


Page 26

� Source strength equals pump capacities. Etc. in some cases.

Consequential effects

� Dispersion of gaseous material in the atmosphere as a function of source

strength, relative density of the gas, weather conditions and topographical

situation of the surrounding area.

� Energy of vapour cloud explosion [in N/m2], as a function of the distance to the

distance o the exploding cloud.

� Concentration of gaseous material in the atmosphere, due to the dispersion of

evaporated chemical. The latter can be either explosive or toxic.

It may be obvious, that the types of models that must be used in a specific risk study

strongly depend upon the type of material involved:

• Gas, vapour, liquid, solid

• Inflammable, explosive, toxic, toxic combustion products

• Stored at high flow temperature or pressure

• Controlled outflow (pump capacity) or catastrophic failure

1.16 SELECTION OF DAMAGE CRITERIA

The Damage criteria give the extents of the physical effects (exposure) and the effect

of consequence. For assessing the effects on human beings consequences are the

effect of consequences. For assessing the effects on human beings consequences are

expressed in terms of injuries and the effects on equipment / property in terms of

monetary loss.

The effect consequence for release of toxic substances or fire can be categorized as

� Damage caused by heat radiation on material and people.

� Damage caused by explosion on structure and people.

� Damage caused by toxic exposure.

In consequence Analysis studies, in principle three types of exposure to hazardous

effects are distinguished:

1. Heat radiation, from a jet fire, a flash fire. In this study, the concern is that of

pools fires.

2. Explosions

3. Toxic effects from toxic materials or toxic combustion product. However, this is

not applicable to this study.


Page 27

The knowledge about these relations depends strongly on the nature of the exposure.

Following are the criteria selected for damaged estimation:

Heat radiation

The effect of fire on a human being is in the form of burns. The consequences caused

by exposure to heat radiation are a function of:

o The radiation energy onto the human body [KW/m2];

o The exposure duration (sec);

o The protection of the skin tissue(clothed or naked body);

Table 1.2: Effects Due To Incident Radiation Intensity

The actual results would be less severe due to the various assumptions made in the

models arising out of the flame geometry, emissive, angle of incidence, view factor

and others.

Incident

Radiation

intensity, KW/m2

Type of damage

37.5 Can Cause heavy damage to process equipment, piping building

etc. (100% lethality)

32.0 Maximum flux level for thermally protected tanks.

12.5 Minimum energy required for piloted ignition of work (50%

lethality)

8.0 Maximum heat flux for un insulated tanks

4.0-5.0 Sufficient to cause pain to personnel if unable to reach cover

within 20 seconds (first degree burns)

1.6 Will cause no discomfort to long exposure

0.7 Equivalent to solar radiation

Table 1.3: Physiological Effects of Threshold Thermal Doses

Dose

Threshold

KW/m2

Effect

37.5 3rd

Degree Burn

21.50 2nd

Degree Burn

12.5 Degree Burn


Page 28

4.5 Threshold of pain, no reddening of blistering of skin caused.

Table 1.4: Damage Effects due to blast over pressure

Dose

Threshold

KW/m2

Effect

0.3 Major Damage to Structures

0.10 Repairable Damage

0.03 Damage of Glass

0.01 Crack of Windows

1.17 Exposure to Natural Hazards

1.17.1 Earth quake

� As per vulnerability Alas of India falls under Very High damage risk zone

indicating the possibility of Earth quakes with intensity level. This level means

that damage considerable in specially designed structures; well designed framed

structure thrown out of plump; very heavy in substantial buildings with partial

collapse; buildings shifted off foundations; ground cracked conspicuously; and

underground pipes broken.

1.17.2 Storm/Cyclone

� The possible effects due to such risk are boundary walls overturn ,walls on houses

and industrial structures fail; roofing sheets, and tiles or whole roots, fly; large

scale destruction of life-line structures which a lighting and telephone poles; a few

transmission line towers /communication towers may suffer damage; and non-

engineered/semi-engineered constructions suffer heavy damage.

1.18 Event Outcomes

Upon release of flammable / toxic gas & liquids, the hazards could lead to various

events which are governed by the type of release, release phase, ignition etc. PHAST

has an in-built event tree for determining the outcomes which are based on two types

of releases namely continuous and instantaneous. Leaks are considered to be

continuous releases whereas, ruptures are considered to be instantaneous releases.

These types of releases are further classified into those which have a potential for

rain-out and those which do not. Whether the release would leak to a rain-out or not

depends upon droplet modeling which is the main cause of formation of pools.


Figure 1.4: Event Tree for continuous release without rain

Figure 1.5: Event Tree for Instantaneous release without rain


: Event Tree for continuous release without rain-out (from PHAST)

: Event Tree for Instantaneous release without rain-out (from PHAST)


Page 29

out (from PHAST)

out (from PHAST)


Figure 1.6: Event Tree for Instantaneous release with rain

Figure 1.7: Event Tree for continuous release with rain


: Event Tree for Instantaneous release with rain-out (from PHAST)

: Event Tree for continuous release with rain-out (from


Page 30

out (from PHAST)

out (from PHAST)


Page 31

Fig 1.8 Event Analysis

Fig 1.9 Release of flammable liquid

Human activities

GENERAL

LOSS

PRODUCING

EVENTS

Property/Asset

Damage

Potential personnel

harm/Bodily injury

Liability damages

Loss of earnings/Business

and reputation.

Operational/Procedural/Co

ntrol failure effects

Environmental/

Natural

CAUSE EFFECT

Tank rupture

Corrosion/Over

Pressure/

Overheat/Buckling

Pipe rupture/leak

by impact/Fire

Gasket/

Pump Seal leaks

Overfill

Release of Flammable

liquid


Page 32

Fig 1.10 Pipe work rupture by external fire

Pipe work rupture by external fire

Flowing/Burning liquid Heat Radiation rupture

Radiation capable of

causing rupture

Fire protection failure

Heat Radiation

High Heat

Radiation level


Page 33

Fig 1.11: Fire at Pump House

Fig 1.12 Fire at DG Set Room


Page 34

Classification of common mode failures-Event Flow Chart

Fig 1.13 Common mode failure classes

Engineering Operations

Design Construction

Realization

faults

Functional

deficiencies

Installation &

commissioning Fabrication

Hazard

unidentified

Operational

deficiencies

Inadequate

quality control Inadequate

quality control

Environmental Procedural

Maintenanc

e & Cost

Operation Storm/Flood/E

arthquake/Exte

rnal

Fire/Explosion

Subsidence Repair

defect

Operation/com

munication

error

Imperfect

procedure/tes

ting

Imperfect

procedure/testi

ng

Inadequate

inspection.

testing or

commissionin

g

Inadequate

inspection.

testing or

commissionin

g

Inadequate

supervision

Control errors.

Temp/Pr/Humid

ity/Static

vibration/stress

Inadequate

controls

Nonstandard

design

Inadequate

standards Inadequate

standards

Common mode failure classes


Page 35

1.19 MAXIMUM CREDIBLE ACCIDENT ANALYSIS (MCAA) APPROACH

1.19.1 INTRODUCTION

� A Maximum Credible Accident (MCA) can be characterized, as an accident with

a maximum damage potential, which is still believed to be probable.

� MCA analysis does not include quantification of probability of occurrence of an

accident. Moreover, since it is not possible to indicate exactly a level of

probability that is still believed to be credible, selection of MCA is somewhat

arbitrary. In practice, selection of accident scenarios representative for a MCA-

Analysis is done on the basis of engineering judgment and expertise in the field of

risk analysis studies, especially accident analysis.

� Major hazards posed by flammable storage can be identified taking recourse to

MCA analysis. This encompasses certain techniques to identify the hazards and

calculate the consequent effects in terms of damage distances of heat radiation,

toxic releases, vapour cloud explosion etc. A host of probable or potential

accidents of the major units in the complex arising due to use, storage and

handling of the hazardous materials are examined to establish their credibility.

Depending upon the effective hazardous attributes and their impact on the event,

the maximum effect on the surrounding environment and the respective damage

caused can be assessed.

� As an initial step in this study, a selection has been made of the processing and

storage units and activities, which are believed to represent the highest level of

risk for the surroundings in terms of damage distances. For this selection,

following factors have been taken into account:

•••• Type of compound viz. flammable or toxic

•••• Quantity of material present in a unit or involved in an activity and

•••• Process or storage conditions such as temperature, pressure, flow, mixing and

presence of incompatible material.

In addition to the above factors, location of a unit or activity with respect to adjacent

activities is taken into consideration to account for the potential escalation of an

accident. This phenomenon is known as the Domino Effect. The units and activities,

which have been selected on the basis of the above factors, are summarized, accident


Page 36

scenarios are established in hazard identification studies, whose effect and damage

calculations are carried out in Maximum Credible Accident Analysis Studies.

COMMON CAUSES OF ACCIDENTS

Based on the analysis of past accident information, common causes of accidents are

identified as:

� Poor house keeping

� Improper use of tools, equipment, facilities

� Unsafe or defective equipment facilities

� Lack of proper procedures

� Improvising unsafe procedures

� Lack of awareness of hazards involved

� Lack of proper tools, equipment, facilities

� Lack of guides and safety devices, and

� Lack of protective equipment and clothing

FAILURES OF HUMAN SYSTEMS

An assessment of past accidents reveal human factor to be the cause for over 60% of

the accidents while the rest are due to other component failures. This percentage will

increase if major accidents alone are considered for analysis. Major causes of human

failures reported are due to:

� Lack of training in safety and loss prevention

� Indecision in critical situation; and

� Inexperienced staff being employed in hazardous situation

Often, human errors are not analyzed while accident reporting and accident reports

only provide information about equipment and/or component failures. Hence, a great

deal of uncertainty surrounds analysis of failure of human systems and consequent

damages.

MAXIMUM CREDIBLE ACCIDENT ANALYSIS:

� Hazardous substances may be released as a result of failures or catastrophes,

causing possible damage to the surrounding area. This section deals with the

question of how the consequences of release of such substances and the damage to

surrounding area can be determined by means of models.


Page 37

� It is intended to give an insight into how the physical effects resulting from release

of hazardous substances can be calculated by means of models and how

vulnerability models can be used to translate the physical effects in terms of

injuries and damage to exposed population and environment. A disastrous

situation in general is due to outcome of fire, n or toxic hazards in addition to

other natural causes, which eventually lead to loss of life, property and ecological

imbalance.

� Major hazards posed by flammable storage can be identified taking recourse to

MCA analysis. MCA analysis encompasses certain techniques to identity the

hazards and calculate the consequent effect in terms of damage distances of heat

radiation, toxic release, etc. A host of probable or potential accidents of the major

units in the complex arising due to use, storage and handling of the hazardous

materials are examined to establish their credibility. Depending upon the effective

hazardous attributes and their impact on the event, the maximum effect on the

surrounding environment and the respective damage caused can be assessed. The

MCA analysis involves ordering and ranking various sections in terms of potential

vulnerability.


1.20 CONSIDERATION FOR

HAZARD ASSESSMENT (QUANTIFICATION)

Fig: 1.14 HAZARD DISTANCES IN THE EVENT OF

The intensity radii for fire reached maximum distance of

1.5/F at radiation level of 4 KW/m

Table 1.5:

Radiation level 4

Radiation level 12.5



CONSIDERATION FOR MAXIMUM CREDIBLE ACCIDENT SCENARIO:

HAZARD ASSESSMENT (QUANTIFICATION)

MS – 15000 KL STORAGE TANK

HAZARD DISTANCES IN THE EVENT OF MS STORAGE TANK

reached maximum distance of 111.697 m as per weather category

at radiation level of 4 KW/m2.

Table 1.5: MS tank on fire radiation effects:

Distance (m)

Category1.5/F Category5/D

KW/m2 111.697 96.1585

KW/m2 84.9867 70.2422

KW/m2 67.541 53.2576


Page 38

MAXIMUM CREDIBLE ACCIDENT SCENARIO:

STORAGE TANK ON FIRE

m as per weather category

Distance (m)

Category5/D Category1.5/D

111.697

84.9867

67.541


Fig:1.15 HAZARD DISTANCES IN CASE OF POOL FIRE: MS

TANK

The intensity radii for pool fire

category 5/D at radiation level of 4 KW/m

Table 1.6:

Radiation level 4



Consequence:

In case of spillage within the dyke and getting a source of ignition at 37.5 KW/m

radiation will not be attained.


HAZARD DISTANCES IN CASE OF POOL FIRE: MS – 15000

pool fire reached maximum distance of 153.23


Table 1.6: MS pool fire radiation effects:

Distance (m)


KW/m2 127.921 153.233

KW/m2 68.7266 70.5415

KW/m2 Not Reached Not Reached




Page 39

15000 KL STORAGE

m as per weather

Distance (m)


128.08

68.9855

Not Reached Not Reached

In case of spillage within the dyke and getting a source of ignition at 37.5 KW/m2

thermal


Fig: 1.16 HAZARD DISTANCES IN CASE OF POOL FIRE: MS

The intensity radii for pool fire of pipe


Table 1.7:

Radiation level 4



Consequence:

� In case of spillage within the dyke and getting a source of ignition at 37.5 KW/m

thermal radiation will not be attained.

� 12.5 KW/m2 thermal radiation zone shall spread to an area having radius of 29.25

mtrs as per weather category 5/D.


HAZARD DISTANCES IN CASE OF POOL FIRE: MS

pool fire of pipe reached maximum distance of 66.70


Table 1.7: MS pipe pool fire radiation effects:

Distance (m)


KW/m2 51.7548 66.7066

KW/m2 22.5019 29.2539


spillage within the dyke and getting a source of ignition at 37.5 KW/m

thermal radiation will not be attained.

12.5 KW/m2 thermal radiation zone shall spread to an area having radius of 29.25

mtrs as per weather category 5/D.


Page 40

HAZARD DISTANCES IN CASE OF POOL FIRE: MS – PIPE

66.70 m as per weather

Distance (m)


52.0857

22.8395


spillage within the dyke and getting a source of ignition at 37.5 KW/m2

12.5 KW/m2 thermal radiation zone shall spread to an area having radius of 29.25


HSD

Fig:1.17 HAZARD DISTANCES IN THE EVENT OF



Table 1.8:

Radiation level 4




HSD – 17000 KL STORAGE TANK

HAZARD DISTANCES IN THE EVENT OF HSD STORAGE TANKS ON FIRE



Table 1.8: HSD tank on fire radiation effects:

Distance (m)


KW/m2 72.3238 62.5708

KW/m2 53.1262 44.081

KW/m2 39.0526 31.5248


Page 41

RAGE TANK

STORAGE TANKS ON FIRE


Distance (m)


72.3238

53.1262

39.0526


Fig: 1.18 HAZARD DISTANCES IN CASE OF POOL FIRE: HSD



Table 1.9:

Radiation level 4



Consequence:




HAZARD DISTANCES IN CASE OF POOL FIRE: HSD – 17000 KL STORAGE TANK



Table 1.9: HSD pool fire radiation effects:

Distance (m)


KW/m2 53.2386 65.4465

KW/m2 25.937 33.208





Page 42

000 KL STORAGE TANK

m as per weather

Distance (m)


53.6989

26.4532


In case of spillage within the dyke and getting a source of ignition at 37.5 KW/m2

thermal


Fig:1.19 HAZARD DISTANCES IN CASE OF POOL FIRE: HSD

The intensity radii for pool fire of pipe


Table 1.10:

Radiation level 4




HAZARD DISTANCES IN CASE OF POOL FIRE: HSD

pool fire of pipe reached maximum distance of 32.18


Table 1.10: HSD pipe pool fire radiation effects:

Distance (m)


KW/m2 26.687 32.1815

KW/m2 19.14 25.5315

KW/m2 12.1762 17.7886


Page 43

HAZARD DISTANCES IN CASE OF POOL FIRE: HSD – PIPE

32.18 m as per weather

Distance (m)


27.3977

19.8514

12.8881


ATF

Fig:1.20 HAZARD DISTANCES IN THE EVENT OF


1.5/D at radiation level of 4 KW/m

Table 1.11:

Radiation level 4



Consequence:

It is seen from the scenario that thermal radiation level of 37.5 KW/m


ATF – 11000 KL STORAGE TANK

HAZARD DISTANCES IN THE EVENT OF ATF STORAGE TANKS ON FIRE



Table 1.11: ATF tank on fire radiation effects:

Distance (m)


KW/m2 40.5816 34.7359

KW/m2 27.7474 22.9199


It is seen from the scenario that thermal radiation level of 37.5 KW/m2 will not be attained.


Page 44

000 KL STORAGE TANK

STORAGE TANKS ON FIRE


Distance (m)

Category1.5/D

40.5816

27.7474

Not Reached

will not be attained.


Fig: 1.21 HAZARD DISTANCES IN CASE OF POOL FIRE:

TANK



Table 1.12:

Radiation level 4




HAZARD DISTANCES IN CASE OF POOL FIRE: ATF– 11000 KL STORAGE



Table 1.12: ATF pool fire radiation effects:

Distance (m)


KW/m2 37.474 45.2234

KW/m2 22.6094 33.1757

KW/m2 14.3004 19.4572


Page 45

000 KL STORAGE

m as per weather

Distance (m)


38.0723

23.2153

14.9026


Fig: 1.22 HAZARD DISTANCES IN CASE OF POOL FIRE: ETHANOL



Table 1.13:

Radiation level 4




HAZARD DISTANCES IN CASE OF POOL FIRE: ETHANOL – 1300 KL STORAGE TANK



Table 1.13: Ethanol pool fire radiation effects:

Distance (m)


KW/m2 34.8437 41.8245

KW/m2 23.5894 31.8873

KW/m2 13.5528 19.6534


Page 46

00 KL STORAGE TANK

m as per weather

Distance (m)


35.7478

24.4941

14.4579


Page 47

Fig: 1.23 HAZARD DISTANCES IN CASE OF POOL FIRE: ETHANOL – PIPE

The intensity radii for Pool fire reached maximum downwind distance of 37.79 m distance at

Radiation level of 4 KW/m2 as per weather category 5/D.

Table 1.14: Ethanol Pipe Pool Fire Radiation Effects

Distance (m)

Category1.5/F Category5/D Category1.5/D

Radiation level 4 KW/m2 30.4605 37.7993 31.5348

Radiation level 12.5 KW/m2 20.6046 29.1545 21.6769



Fig: 1.24 HAZARD DISTANCES IN CASE OF POOL FIRE:

The intensity radii for pool fire reached maximum distance of


Table 1.15:

Radiation level 4




HAZARD DISTANCES IN CASE OF POOL FIRE: BIODIESEL – 850 KL STORAGE TANK

The intensity radii for pool fire reached maximum distance of 30.29

category 5/D at radiation level of 4 KW/m2.

Table 1.15: Biodiesel pool fire radiation effects:

Distance (m)


KW/m2 24.8188 30.2905

KW/m2 17.985 24.1922

KW/m2 11.62 17.319


Page 48

KL STORAGE TANK

m as per weather

Distance (m)


25.5319

18.6985

12.3338


Page 49

Fig:1.25 HAZARD DISTANCES IN CASE OF POOL FIRE: BIODIESEL - PIPE

The intensity radii for Pool fire of pipe reached maximum downwind distance of 18.75 m

distance at Radiation level of 4 KW/m2 as per weather category 5/D.

Table 1.16: Biodiesel Pipe Pool Fire Radiation Effects

Distance (m)

Category1.5/F Category5/D Category1.5/D

Radiation level 4 KW/m2 15.6717 18.7581 15.7315




Fig :1.26 HAZARD DISTANCES IN CASE OF POOL FIRE: TRANSMIX



Table 1.17:

Radiation level 4




HAZARD DISTANCES IN CASE OF POOL FIRE: TRANSMIX – 600 KL STORAGE TANK



Table 1.17: Transmix pool fire radiation effects:

Distance (m)


KW/m2 28.2594 35.7502

KW/m2 18.7489 27.6768

KW/m2 10.3811 17.3933


Page 50

00 KL STORAGE TANK

m as per weather

Distance (m)


29.296

19.7867

11.42


Fig : 1.27 HAZARD DISTANCES IN CASE OF



Table 1.18

Radiation level 4




HAZARD DISTANCES IN CASE OF TANK ON FIRE: SKO – 4000 KL STORAGE TANK



Table 1.18: SKO tank on fire radiation effects:

Distance (m)


KW/m2 33.0767 28.7578

KW/m2 20.2623 17.4502



Page 51

00 KL STORAGE TANK


Distance (m)

Category1.5/D

33.0767

20.2623

Not Reached


Fig : 1.28 HAZARD DISTANCES IN CASE OF



Table 1.19

Radiation level 4




HAZARD DISTANCES IN CASE OF POOL FIRE: SKO – 4000 KL STORAGE TANK



Table 1.19: SKO pool fire radiation effects:

Distance (m)


KW/m2 29.933 36.3785

KW/m2 20.4604 28.266

KW/m2 11.9494 18.0258


Page 52

00 KL STORAGE TANK

m as per weather

Distance (m)


30.7603

21.2904

12.7813


Page 53

OVERALL DIMENSION OF DYKES

Sr.No. Dyke Product Dimensions

1. Dyke-I HSD 250MX66MX1.8M

2. Dyke-II MS 272MX52MX1.4M

3. Dyke-III ETHANOL 56MX32MX1.8M

4. Dyke-IV BIO-DIESEL 61MX20MX1.5M

1.21 FIRE PROTECTION AND FIRE FIGHTING SYSTEM

The plant will be equipped with a comprehensive fire protection system. Following

facilities will be provided for the fire protection:-

• Fire Water Supply

• Fire Hydrant system, Fire sprinkler system with smoke/fire detectors

• Portable Fire Extinguishers

1.21.1 Fire Fighting Facilities:

� 3 x 6800 KL Fire water storage tanks – water storage for handling 4 hrs of fire

fighting in case of two largest fire scenarios.

� Water Sprinkler system on Class A tanks (MS, Ethanol & Transmix) and

Class B tanks with diameter greater than 30 M as per prevailing safety

guidelines issued by OISD.

� Fixed Foam fighting system on proposed Class A and B tanks with greater

than 18 M as per prevailing safety guidelines issued by OISD.

� Centralized Foam Feeding system for Fixed foam pourers & HVLR.

� Provision of Fire hydrant piping network for the entire Terminal facilities.

1.21.2 Safety & Security Features in the Proposed Plant:

� Gas monitoring system with Sensors at all critical areas

� Vapour Recovery System

� Fire Extinguishers

� PA Paging and Public Announcing System

� Personal Protective Equipment – Fire Entry suit, Water Gel blanket, Fire

Proximity suit / Hand gloves, First aid kit, special tools like Non-Sparking

Tool Kit, Breathing Apparatus, helmets etc.

� CCTV for the Incoming and outgoing vehicles and movement of personnel in


Page 54

the premises and along the boundary line

1.22 Climatological Conditions

The downwind drifting & dispersion of chemical in air would be primarily decided by

following factors:

1. Wind Direction & Wind Velocity

2. Atmospheric Stability. More turbulent atmosphere is characterized by “Un-stable”

Atmosphere

1.23 Mathematical and Analytical Models For Hazard Analysis

Sr. Phenomenon Applicable Models

1 Ou Outflows:

Liquid, Two phase

Mixtures, Gas/vapor

Bernoulli flow equation; phase equilibria;

multiphase flow models; orifice/nozzle flow

equations; gas laws; critical flow criteria

2 DI Discharges:

Spreading liquid

Vapor jets

Flashing liquids

* Evaporation of liquids on land

& water

Spreading rate equation for non-penetrable

surfaces based on cylindrical liquid pools

Turbulent free jet model

Two zone flash vaporization model

Spreading, boiling & moving boundary heat

transfer models; Film & meta stable boiling

phenomenon; cooling of semi infinite medium

3 cvo Dispersion:

∗ Heavy Gas

∗ Natural Gas

• Boundary dominated, stably stratified &

positive dispersion models (similarity)

• 3D Models based on momentum, mass &

energy conservation

Gaussian Dispersion models for naturally


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Sr. Phenomenon Applicable Models

* Atmospheric

Stability

buoyant plumes

Boundary layer theory (turbulence), Gaussian

distribution models

4 Heat Radiation:

∗ Liquid pool fires

∗ Jet fires

Burning rate, heat radiation & incident heat

correlation (semi imperial); Flame propagation

behavior models

Fire jet dispersion model

5 Explosion:

∗ Vapor Cloud Explosion

Deflagration & Detonation models

6 Vulnerability:

∗ Likely damage

Probit functions; Non-Stochastic vulnerability

models

1.24 Risk Control Measures

1.24.1 Risk control Measures by IOCL

The management of IOCL will provide the following safety measures and fire

protection.

• Dyke/Fire Break wall for each group of tanks will be provided.

• Flame proof electrical fittings will be provided based on hazardous area

classification.

• Water sprinkler system will be provided for Class A tanks (MS, Ethanol &

Transmix) and Class B tanks with diameter greater than 30 M as per relevant

OISD standard.

• Foam pourer will be provided on proposed class A and B tanks with diameter

greater than 18 M as per prevailing safety guidelines issued by OISD.

• Fire water reservoirs will be provided.

• Double earthing for each tank.

• Work permit system for hot work in place.


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• Emergency communication facilities like walkie-talkies, PA paging telephone

etc

• Spark arrestor will be provided at the exhaust pipe of each tanker.

• Display of emergency instructions.

• The cross country pipeline will be provided underground wherever, possible.

1.24.2 Additional Risk Control measures suggested

From the scenarios worked out, it is seen that the pool fire or explosion effects of on

class A tank will have an impact on the surrounding facilities as they are in the

nearby vicinity. The emergency management system for the installation may be

strengthened and the following key risk control measures may be adopted.

Thermal barrier wall may be provided in case the deluge value of water spray system

is located closer to the tank to be protected.

• The disaster management plan should include scenario identified in this Risk

analysis study. IOCL may also strengthen their Offsite Emergency Plan in

line with the scenario and damage distances noted in this study.

• The fire hydrant system for the tanks may be checked periodically and

performance test done as per schedule.

• IOCL may follow OISD for design of fire protection system. The capacity of

fire water pumps can be verified based on the above standard.

• Foam compound shall be tested periodically for ensuring its quality and the

deteriorated quantity replaced. The deteriorated foam compound can be used

for fire training purposes. Adequate amount of foam may be stored as per

OISD.

• The fire fighting training may be made compulsory to all officers, operators,

truck drivers and other employees who are likely to be present in the

installation.

• Regular mock fire drills to be conducted once a month and the record of such

drills to be maintained.

• The thickness testing of the tanks may be done regularly as per schedule.

• It may be ensured that all pipelines are hydrostatically tested in accordance

with the requirement of OISD.

• All non-routine work such as gasket replacing, welding etc. should be carried

out under a permit system.


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• Dry vegetation present in the dykes of tank farm should be removed at

periodic intervals.

• The design of the structures should be checked whether they have been

designed for the earth quakes zone.

• Dyke drain valve may be closed under normal circumstances. To drain out

rain water in dyke, the valve may be opened and closed thereafter.

• Every fire water pump should be tested for at least half an hour twice a week.

Every pump should be checked for performance once in a six month. This

may be done by opening required number of hydrants/monitors depending on

the capacity of the pump and by verifying that it is a discharge pressure and

the motor load are in conformity with the design parameters.

• The fire alarm system may be provided for the fire pump room also to detect

fires at the incipient stages. The pumps should be maintained in auto mode.

• Minor containment may be provided around each pump to contain small

leakages.

1.25 QRA Recommendations

S.No. Recommendations

1. Pump loading line failures., Hose failures etc. again have possibility of causing major

damage. Great care is necessary, as the vicinity could have a lot of persons as possible

victims. Supervision by staff, hoses maintenance and following strict procedures is

essential for preventing escalation of such incidents of high frequency and low

outcome. Emergency procedures be well rehearsed and state of readiness to be

achieved.

2. Control the movement of the loading trucks inside the premises and ensure minimum

time is spent inside the facility.

3. Provide standard operating procedures in local languages in loading and unloading

bays and monitor the adherence of the procedures continuously.

4.

Vehicles fitted with spark arrestors and necessary valid inspection certificates only

allowed inside the premises.

5. Water draining operation from the storage tanks should be carried out by trained

personnel under supervision.


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6. Lock out and tag out (LOTO) procedure to be followed in operation of tank drain, dyke

drain and other critical valves with supervisory control and mechanically locking

option.

7. Any commissioning/decommissioning of equipments should be carried out under

supervision (close out procedure with written permission can be used for

commissioning).

8. Effectiveness of the Fire and Explosion mitigation measures shall be periodically

measured recorded and reviewed.

9. Necessary first aid measures to be adopted and followed for the persons who affected

during fire/explosion emergency situations as a life saving measure i

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