QUANTITATIVE RISK ASSESSMENT MAY 2018 · ULTRA-TECH Environmental Consultancy and Laboratory M/S GANESH BENZOPLAST LIMITED THE LIQUIED CHEMICAL STORAGE TERMINAL QUANTITATIVE RISK

ULTRA-TECH Environmental Consultancy and Laboratory

M/S GANESH BENZOPLAST LIMITED

THE LIQUIED CHEMICAL STORAGE TERMINAL

QUANTITATIVE RISK ASSESSMENT

MAY 2018

WILLINGDON ISLAND

COCHIN, KERALA

PREPARED BY

RISK ANALYSIS

ULTRA-TECH Environmental Consultancy and Laboratory Page 1

To

Shri . Biju George

(Terminal Manager)

M/s Ganesh Benzoplast Limited

Liquid Chemical Storage Terminal

Plot No. A1, A2, A3,

Willingdon Island

Kochi, Kerala

Sub: Quantitative Risk Analysis Study Report of GBL LST Kochi

Dear Sir

We are pleased to submit two softcopy & hardcopy of the Risk Analysis Study Report and

We, on behalf of ULTRA-TECH Environmental Consultancy and Laboratory hereby take

the opportunity of cordially thanking the management and staff members for extending

earnest co- operation to successfully complete the Study.

We have immense pleasure in expressing our gratitude for entrusting us with the

responsibility of carrying out the Risk Analysis Study Report at your esteemed

Organization.

This association will be kept vivid in our record

Thanking you,

Yours faithfully,

S.DE.SARKAR

Page 2 ULTRA-TECH Environmental Consultancy and Laboratory

Contents

CHAPTER - 1: EXECUTIVE SUMMARY ................................................................................... 4

1.1 INTRODUCTION ............................................................................................................ 4

1.2 SCOPE OF THE STUDY ................................................................................................ 4

1.3 TERMINALS LOCATION.............................................................................................. 5

1.4 CLIMATE & METEOROLOGY..................................................................................... 5

1.5 TERMINAL PROFILE .................................................................................................... 5

1.6 UTILITIES ....................................................................................................................... 6

CHAPTER-2 : TERMINAL DETAILS.......................................................................................... 8

2.0 INTRODUCTION ............................................................................................................ 8

2.1 DESCRIPTION OF TERMINAL FACILITY ................................................................ 8

2.2 LOCATION, LAND AND LAYOUT ............................................................................ 8

2.4 PROCESS DESCRIPTION AND OPERATING PROCEDURES ................................. 9

2.5 TANK FARM: ................................................................................................................. 9

2.6 FIRE DETECTION AND PROTECTION SYSTEM ................................................... 11

CHAPTER-3 : RISK ANALYSIS ................................................................................................ 14

3.1 PREAMBLE................................................................................................................... 14

3.2 SCOPE OF THE STUDY .............................................................................................. 14

3.3 HAZARD IDENTIFICATION ...................................................................................... 15

3.4 CONSEQUENCE ANALYSIS ...................................................................................... 15

3.5 GLOSSARY OF TERMS USED IN RISK ASSESSMENT ......................................... 15

3.6 SCOPE OF STUDY ....................................................................................................... 16

CHAPTER-4 : HAZARD IDENTIFICATION ............................................................................ 18

4.1 INTRODUCTION .......................................................................................................... 18

4.2 CLASSIFICATION OF MAJOR HAZARDOUS SUBSTANCE ................................. 18

CHAPTER -5 : MAXIMUM CREDIBLE ACCIDENT ANALYSIS (MCAA) APPROACH .... 20

5.1 INTRODUCTION .......................................................................................................... 20

5.2 METHODOLOGY ......................................................................................................... 21

5.3 COMMON CAUSES OF ACCIDENTS........................................................................ 21

5.4 FAILURES OF HUMAN SYSTEMS............................................................................ 21

5.5 MAXIMUM CREDIBLE ACCIDENT ANALYSIS (MCAA) ..................................... 22

ANALYSIS OF PAST ACCIDENTS ...................................................................................... 23

5.7 HAZARDS OF EQUIPMENT/PIPELINE HANDLING PETROLEUM PRODUCTS

30

5.8 BRIEF REVIEW OF INBUILT DESIGN SAFETY ...................................................... 31

5.9 PRODUCT PIPELINE SYSTEMS ................................................................................ 32

5.10 PUMP HOUSE AT THE TERMINAL ...................................................................... 32

5.11 FIRE DETECTION AND PROTECTION SYSTEM ................................................ 32

5.13 PORTABLE FIRE FIGHTING APPARATUS .......................................................... 33

CHAPTER-6 : RISK ASSESSMENT .......................................................................................... 34

6.1 INTRODUCTION .......................................................................................................... 34

6.2 MODES OF FAILURE .................................................................................................. 35

6.3 DAMAGE CRITERIA..................................................................................................... 35

6.4 DISPERSION AND STABILITY CLASS ................................................................... 37

CHAPTER-7 : CONSEQUENCE ANALYSIS ............................................................................ 39

7.1 INTRODUCTION .......................................................................................................... 39


7.2.1 ALARP CONCEPT: ........................................................................................................ 40

7.2.2 EVENT TREE ANALYSIS & PROBABILITIES FOR THE RELEASE OF

DIFFERENT TYPES ................................................................................................................ 41

7.2.3 FREQUENCY ANALYIS .......................................................................................... 42

7.3 CONSIDERATION FOR MAXIMUM CREDIBLE ACCIDENT SCENARIO: ......... 44

HAZARD ASSESSMENT (QUANTIFICATION) .................................................................. 44

7.4 MODELING SOFTWARE ............................................................................................ 96

7.5 ACTION DURING FIRE............................................................................................... 96

CHAPTER-8 : RISKS AND FAILURE PROBABILITY............................................................ 99

CHAPTER-9 : RECOMMENDATIONS & CONCLUSIONS .................................................. 101


CHAPTER - 1: EXECUTIVE SUMMARY

1.1 INTRODUCTION

M/s Ganesh Benzoplast Limited vide Work Order No. …………dt……..entrusted

ULTRA-TECH Environmental Consultancy and Laboratory to carry out a ‘Risk

Analysis’ of their Liquid Chemical Storage Terminal (LST), Kochi. Our team of experts

had visited Kochi Terminal with a view to collecting relevant data of the plant. For the

purpose of obtaining specification of different onsite facilities, pipe lines, as well as off

site facilities, a detailed questionnaire was prepared. During visit of our team members,

they had collected the required information’s in the format. Pertinent documents like lay

out plan. P&I diagram, Mutual Aid agreement etc were collected from the Terminal. Our

team members along with the staffs of the plant had visited different parts of the

Terminal with a view to familiarize themselves with operation procedure, system of

working, location of different facilities as per the layout. Product handled, monthly

throughput etc. Besides operational aspect, the team was also apprised of the

organizational set up, existing system of handling Emergency Situation, available fire

fighting system.

ULTRA-TECH wants to put on record the excellent co operation they had received from

the officers and staff of the Terminal during entire course of their study. We extend our

thanks specially to Sri.. Biju George (Terminal Manager) for his excellent support in

making the information, documents available.

1.2 SCOPE OF THE STUDY

The risk assessment has been carried out in line with the requirements of various

statutory bodies:

Identification of potential hazard areas:

Identification of representative failure cases:

Identification of possible initiating events:

Assess the overall damage potential of the identified hazardous events and the

impact zones from the accidental scenarios:

Consequence analysis for all the possible events:

Hazard effect of LST


1.3 TERMINALS LOCATION

The Terminal is located at Sy No. 2578/4 at Willingdon Island in Thoppumpady Village,

Kochi Taluk, Eranakulam District, Kerala State.having latitude & longitude of 9o56’13.01”

N and 76o16’16.70” E respectively. The National Highway NH 966B is at a distance of

27m from the Terminal. A part of the Vembanad Lake is on the south west side.. The ATS

Willingdon Hotel is on the north side of the Terminal. IOC Petrol pump occupies the west

side as well as the east side of terminal.

1.4 CLIMATE & METEOROLOGY

The climate of Ernakulam district is mainly governed by the Arabian Sea and the

Western Ghats. Temperature ranges between 37°C to 16°C.. Relative humidity is 60% to

91%. The wind speed ranges from 5 to 6 km/hour with mean speed of 5.5 km/hour.

Annual Rainfall is around 2978 mm.

1.5 TERMINAL PROFILE

The Liquid Chemical Storage Terminal (LST) of GBL,Kochi was established at the

Cochin Port in May 2000, for providing storage for Petroleum Products of Class A, and

C and edible oils and non classified liquid products. Kochi LST caters to the needs of

bulk importers and exporters of liquid chemicals in India.

Kochi LST has three dedicated pipelines for transporting liquids directly from ship to

tank for imported items. The pipelines have a length of 3.2 km and transfers the liquid

chemicals from the Q4 Jetty in the Mattanchery Wharf at the Cochin Port to the LST. The

LST commenced operations with an initial capacity of 16,750 m3 (five Aboveground

Storage Tanks) and was utilised by BPCL for storage and marketing of Low Sulphur

Heavy Stock (LSHS) furnace oil which is a Class C Petroleum Product. Kochi LST also

has three Aboveground Storage Tanks of capacity 13500 m3 which is currently used for

the storage of Class ‘A’ Petroleum Products in bulk. Accordingly, the current storage

capacity of the LST is 30250 m3 and GBL is proposing to augment the storage capacity

of Kochi LST by addition of 4 aboveground storage tanks with aggregate capacity of

15,000 m3, which can be used for storage of Petroleum Products of Class A, B and C and


edible oils and non classified liquid products. The total capacity of Kochi LST after the

proposed expansion will be 45250 m3.

The main facilities are summarized as under:

Storage Existing 08 No’s Above Ground Tank

Proposed 04 No’s Above Ground Tank

TLF Gantry 4 bay gantry

DG Sets. 1 x 160 kVA

FIRE FIGHTING

FACILITIES

Fire Water Storage. 1 x 2750 KL

Jockey Pumps. 1 X 14 m3/hr.

Fire Water pumps. 1 x 60 m3/hr & 1 x 80 m3/hr

Control panel As per Standard

Storage Tank with active water

protection.

I. Fixed Roof tanks are fitted with sprinkler System

and foam system

II. Hydrants Monitors are provided at all strategic

point including TLF area, Tank farms, Pump House,

Tank Truck parking area, etc.

Fire extinguishers. As per OISD-117

Hydrants & Monitors. As per OISD-116

1.6 UTILITIES

Water requirement:-


Required quantity of water for domestic consumption, tank farm washing, fire fighting etc

is supplied by Cochin Port Trust.

LAND:-

A plot measuring 14000m² has been leased out by Cochin Port Trust to GBL for a period

of 30 years for setting up the terminal..

POWER REQUIREMENT:-

Existing energy requirement for the terminal is 60 kW. additional power requirement

after the proposed expansion is 30 kW. Hence after expansion, the total power

requirement will be 90 kW. Required power is taken from Cochin Port Trust.

One 160 kVA stand by generator has been installed for maintaining operation during

power cut.

SAFETY MANAGEMENT SYSTEM:-

There are very rare chances of spillage of hazardous materials in ground water, because

this Terminal is constructed as per various OISD norms and international standards. All

precautions right from designing stage (various controls) are taken so as to eliminate the

chance of spillage of product. The chances of human error and accident thereof are rare

probability.

MAN POWER:-

At present total 12 permanent staffs are available for total operation of Terminal. In

addition contract persons are also engaged for regular maintenance and operation of the

terminal


CHAPTER-2 : TERMINAL DETAILS

2.0 INTRODUCTION

M/s Ganesh Benzoplast Limited (GBL), has set up an liquid chemicals Terminal of

30250M3 at Sy No. 2578/4 at Willingdon Island in Thoppumpady Village, Kochi Taluk,

Eranakulam District of Kerala State for storage and distribution of petroleum products

like Furnace Oil & Methanol,

2.1 DESCRIPTION OF TERMINAL FACILITY

Product pipe line system

Tank Farm

Truck Loading facilities.

Fire- fighting system including 1 nos. fire water tanks

Electrical installation

Instrumentation

Drinking water

Building

Utility

2.2 LOCATION, LAND AND LAYOUT

The Kochi Liquid Chemical Storage Terminal (LST) of Ganesh Benzoplast Limited

(GBL), is located at Willingdon Island in Thoppumpady Village at Eranakulam

District of Kerala State having latitude & longitude 18o92’43.58” N and

72o96’16.26” E respectively. The National Highway NH 966B is at a distance of 27m

from the Terminal.

The Terminal spread over an area of 14000m² was commissioned in May 2000,

The layout has been prepared strictly as per prescribed OISD standards and

guidelines. Safety distances are maintained as per the standard guidelines. The road

network is designed in such a way that the movement of vehicle carrying bulk

petroleum products is smooth.


2.4 PROCESS DESCRIPTION AND OPERATING PROCEDURES

The main activities at the Kochi LST are RECEIPT, STORAGE and DISPATCH. The

LST will receive, store and distribute Petroleum Products of Class A, and C . No by-

products / additional products are generated / manufactured during the operations.

Brief description of operations at Kochi LST is as follows:

Receiving the liquid chemicals through pipelines

o The liquid chemicals at Kochi LST are received in bulk through three

dedicated conduit pipelines having approximate lengths of 3.2 km from

the Q4 Jetty in the Mattanchery Wharf and the SCB Jetty at the Cochin

Port to the LST and vice versa.

Storing the liquid chemicals, maintaining the quality in line with IS

specifications.

Dispatching the liquid chemicals through Tank Trucks to Customers.

2.5 TANK FARM:

The Terminal is provided with storage tanks for Class A & C petroleum products.

Product Methanol Furnace Oil

Class A C

The design and construction of storage tanks are according to Indian regulations IS 803

and/or API 650. All tanks are provided with sprinklers and foam feeding devices as per

the OISD regulations. All the storage tanks are equipped with automatic level indicators

with high / high high level alarms. AOPS system also provided in the tanks.

The design of the Terminal is according to Indian standards OISD 117,116 and as per

recommendation of Chief Controller of Explosives, Nagpur (CCOE)


STORAGE

Storage of products: The following storage capacities are as follows

Table-1

Existing Tank Details

Tank No Tank Dimensions

(diameter in m x

height in m)

Safe Storage Filling

Capacity in m3

Petroleum

Product

Petroleum

Product

Class

T-101 11 x 10.7 1000 Furnace Oil C

T-102 10 x 10 750 Furnace Oil C

T-103 20 x 16.5 5000 Furnace Oil C

T-104 20 x 16.5 5000 Furnace Oil C

T-105 20 x 16.5 5000 Furnace Oil C

T-201 18 x 18 4500 Methanol A

T-202 18 x 18 4500 Methanol A

T-203 18 x 18 4500 Methanol A

Table-2

Proposed Tank Details

Tank No Petroleum

Product

Safe Storage

Filling Capacity

in m3

Tank

Dimensions

(diameter in m x

height in m)

Petroleum

Product

Class

T-204 Liquid

Chemicals

5000 18 x 20 A

T-205 Liquid

Chemicals

5000 18 x 20 A

T-206 Liquid

Chemicals

4000 16 x 20 A

T-207 Liquid

Chemicals

4000 16 x 20 A

TLF Sheds

There are two existing TLF sheds with eight (8) nos. of TLF bays for Tank Truck

loading. The loading facilities are bottom loading. There will not be any modification to

the TLF sheds due to the proposed expansion.

Pump House


The Kochi LST has 2 TLF Pump Houses of dimensions 10 m x 6.3 m and 12 m x 6 m.

The firewater pump house has a dimension of 5m x 5m. The details of the existing pumps

are as shown in Table and the schedule of the pumps for the proposed expansion is given

in Table 4

Table 3: Schedule of Existing Pumps

SN Product Capacity

(m3/h)

Types of Pumps Working +

Standby

1 Methanol 80 Centrifugal 2+1

2 Methanol 60 Centrifugal 1+1

3 Furnace Oil 80 Positive

Displacement

1+1

4 Furnace Oil 100 Positive

Displacement

1+1

Table 1: Schedule of pumps for the proposed expansion

SN Product Capacity

(m3/h)

Types of Pumps Working +

Standby

1 Liquid

Chemicals

40 Centrifugal 1+1

2 Liquid

Chemicals

40 Centrifugal 1+1

2.6 FIRE DETECTION AND PROTECTION SYSTEM

The fire protection and detection system are in accordance with OISD 117. Portable fire

extinguishers of 10-75 kg are installed on pump stations, tank farms and buildings, the

size depending on the object concerned. Electrical rooms are protected by Carbon dioxide

(CO2) fire extinguishers. Mobile fire fighting vehicles with foam monitors, hoses,

etc.have been provided. Fixed fire fighting monitors are located at the pump station and

truck loading gantries, each with a capacity of 144 m3/hr. sufficient hydrants are installed

in the Terminal, with the hydrants spaced at a maximum distance of 30m.


The tanks are equipped with fixed cooling water and foam Terminals and mobile vehicles and

equipment (monitors, hoses, branch pipes, etc.) are provided to handle field fires.

Table below will show fire water storage tank, fire water pumps,

Table-5

Fire Water Storage Tank

Sr.No No’s Total Capacity (KL)

1 1 2750

Table-6

Fire Water Pump

Sr.No Category No’s Capacity

1

Main Pump

( Engine Driven)

2

60 M3/Hr & 80 M3/Hr

2 Jockey Pump

( Electric Motor

Driven)

1 14 M3/Hr

FIRE ALARM SYSTEM

Conventional type Fire alarm systems are provided in following areas;

a) Truck Loading

b) Tank Farm

c) Office / Admn. Building

d) Sub-Stations

Source of Signaling

The source of signaling is considered as ESD These are considered for the areas

where manual warning is to be initiated on notice of fire. They are mostly provided


for open areas or near to access doors, truck loading, pump house, tank farm,

administrative building, etc.

ELECTRICAL SYSTEM

The scope covers the basic concepts of the following:

Receiving of HT Power supply from Main 11kV Power Grid

Distribution Transformer.

Distribution of LT power supply.

Cabling System.

Building and Area Lighting.

Approach Road Lighting

Earthing and Lightning Protection.

Power Factor Improvement.

Battery Bank & Battery Charger.

UPS system.

Diesel Generating Set.

Cylindrical Bullet

of 150 MT


CHAPTER-3 : RISK ANALYSIS

3.1 PREAMBLE

With growth of population, industrialization, urbanization and modernization, demand of

petroleum products are increasing at a very rapid pace. With a view to meeting demand

of industry, capacity addition has become essential.

As the Terminal handle various petroleum products which have got potential of fire /

explosion hazard for itself, hence it is necessary to evaluate the Risk due to the Terminal.

Accordingly, M/s. ULTRA-TECH Environmental Consultancy & Laboratory. (ULTRA-

TECH) has been retained by Ganesh Benzoplast Limited (GBL), as consultant to carryout

Risk Analysis Study for the Kochi LST.

3.2 SCOPE OF THE STUDY


statutory bodies:

Identification of potential hazard areas;

Identification of representative failure cases;

Identification of possible initiating events;


impact zones from the accidental scenarios;

Consequence analysis for all the possible events;


3.3 HAZARD IDENTIFICATION

Identify potentially hazardous materials that can cause loss of human life/injury,

loss of properties and deterioration of the environment due to loss of containment.

Identify potential scenarios, which can cause loss of containment and consequent

hazards like fire, explosion and toxicity.

3.4 CONSEQUENCE ANALYSIS

Analysis of magnitude of consequences of different potential hazard scenarios and

their effect zones.

Consequence analysis is a measure of potential hazards and is important for

taking precautionary measures for risk reduction as well as mitigation of effect in

case of such accidents happening.

This report has been prepared by applying the standard techniques of risk assessment and

the information provided by GBL.

3.5 GLOSSARY OF TERMS USED IN RISK ASSESSMENT

The common terms used in Risk Assessment and Disaster Management are elaborated

below:

“Risk” is defined as a likelihood of an undesired event (accident, injury or death)

occurring within a specified period or under specified circumstances. This may be either

a frequency or a probability depending on the circumstances.

“Hazard” is defined as a physical situation, which may cause human injury, damage to

property or the environment or some combination of these criteria.

“Hazardous Substance” means any substance or preparation, which by reason of its

chemical or physico-chemical properties or handling is liable to cause harm to human

beings, other living creatures, plants, micro-organisms, property or the environment.


“Hazardous Process” is defined as any process or activity in relation to an industry,

which may cause impairment to the health of the persons engaged or connected therewith

or which may result in pollution of general environment.

“Disaster” is defined as a catastrophic situation that causes damage, economic

disruptions, loss of human life and deterioration of health and health services on a scale

sufficient to warrant an extraordinary response from outside the affected area or

community. Disaster occasioned by man is factory fire explosions and release of toxic

gases or chemical substances etc.

“Accident” is an unplanned event, which has a probability of causing personal injury or

property damage or both.

“Emergency” is defined as a situation where the demand exceeds the resources. This

highlights the tropical nature of emergency “It is seen after experience that enough is not

enough in emergency situations. Situations of this nature are avoidable but it is not

possible to avoid them always.” “Emergency Preparedness” is one of the key activities in

the overall management. Preparedness, though largely dependent upon the response

capacity of the persons engaged in direct action, will require support from others in the

organization before, during and after an emergency.

3.6 SCOPE OF STUDY


statutory bodies for similar type of projects:

Identification of potential hazard areas

Identification of representative failure cases

Identification of possible initiating events


impact zones from the accidental scenarios;

Consequence analysis for all the possible events;

Furnish specific recommendations on the minimization of the worst accident

possibilities.


Table-7

FLOW CHART FOR RISK ANALYSIS STUDY

YES

START

PLANT VISIT

DATA COLLECTION

PROCESS DESCRIPTION

PROCESS CONTROL LOOPS

PRI/PFD OPERATING

MANUAL START UP/SHUT DOWN

PLOT PLAN

METEOROLOGICAL DATA

PAST ACCIDENTS DATA

ALL RELEVANT PHYSICAL

CHEMICAL DATA OF

CHEMICALS INV0LVED

SELECT THE

CLASSIFY VESSEL/EQUIPMENT

INVENTORY ANALYSIS

CALCULATE EFFECT

IDENTIFICATION OF HAZARD

IS FE/FET IN

SEVERITY ADOPT CHECK LIST

APPROACH

CONSEQUENCE

PLOT DAMAGE DISTANCE


CHAPTER-4 : HAZARD IDENTIFICATION

4.1 INTRODUCTION

Identification of hazards in the terminal is of primary significance in the analysis,

quantification and cost effective control of accidents involving chemicals and process. A

classical definition of hazard states that hazard is in fact the characteristic of

system/plant/process that presents potential for an accident. Hence, all the components of

a system/plant/process need to be thoroughly examined to assess their potential for

initiating or propagating an unplanned event/sequence of events, which can be termed as

an accident.

Typical schemes of predictive hazard evaluation and quantitative risk analysis suggest

that hazard identification step plays a key role.

Estimation of probability of an unexpected event and its consequence form the basis of

quantification of risk in terms of damage to property, environment or personnel.

Therefore, the type, quantity, location and conditions of release of a toxic or flammable

substance have to be identified in order to estimate its damaging effects, the area

involved and the possible precautionary measures required to be taken. The following

two methods for hazard identification have been employed in the study.

Identification of hazardous storage units based on relative ranking technique, viz,

Fire-Explosion and Toxicity index (FE & TI); and

Maximum Credible Accident Analysis (MCAA)

4.2 CLASSIFICATION OF MAJOR HAZARDOUS SUBSTANCE


Hazardous substances may be classified into three main classes namely flammable

substances, unstable substances and toxic substances.

Flammable substances require interaction with air for their hazard to be realized; under

certain circumstances vapours arising from flammable substances when mixed with air

may be explosive especially in confined spaces. However, if present in sufficient quantity

such clouds may explode in open air also.

Unstable substances are liquids or solids, which may decompose with such violence so as

to give rise to blast waves.

Finally, toxic substances are dangerous and cause substantial damage to life when

released into the atmosphere. The ratings for a large number of chemicals based on

flammability, reactivity and toxicity are given NFPA Codes 49 and 345M.


CHAPTER -5 : MAXIMUM CREDIBLE ACCIDENT ANALYSIS

(MCAA) APPROACH

5.1 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 scenarios are

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

carried out in Maximum Credible Accident Analysis Studies.

5.2 METHODOLOGY

Following steps are employed for visualization of MCA scenarios:

Chemical inventory analysis

Identification of chemical release and accident scenarios

Analysis of past accidents of similar nature to establish credibility to identified scenarios; and

Short-listing of MCA scenarios

5.3 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

Failure to follow prescribed procedures

Jobs not understood

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

5.4 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:

Stress induced by poor equipment design, unfavorable environmental conditions, fatigue, etc.

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.

5.5 MAXIMUM CREDIBLE ACCIDENT ANALYSIS (MCAA)

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.

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, Vapour Cloud explosion 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, 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. The MCA analysis

involves ordering and ranking various sections in terms of potential vulnerability.

ANALYSIS OF PAST ACCIDENTS

Numerous accidents involving different hydrocarbons in process plants have been

reported. Table 9 provides a world wide list of all such accidents reported since 1917.

More than 1000 people have received injuries of various intensity and more than 200

people died due to these accidents. The major causes of accident involving fraction are

given below.

i) Fire, over pressure, explosions 19 Nos

ii) Overfilling, loading/unloading and pipeline ruptures 5 Nos

iii) Collision and impact of rail/road tankers during transportation 21 Nos

---

45 Nos

It can be seen that the storage areas and transportation vehicles of C fractions are most

vulnerable to accidents. More than 10 accidents out of the 45 incidents examined have

ended in BLEVE situation. Rest of them has caused fires and explosions.

The consequences of BLEVE have been found to be most severe in the vicinity of the

accident site. The worst disaster of C fraction had occurred in November 1984 at the C

fractions storage and distribution center in San Juan Ixhautepec in Mexico City. An

extensive fire and a series of violent explosions resulted in chaos.

TABLE – 8

MAJOR ACCIDENT IN PROCESS INDUSTRIES

(LIGHTER FRACTIONS OF HYDROCARBONS)

Sl.

No.

Year Location Chemical Event Deaths/Injuries

01 1944 Cleveland, Ohio Gasoline Fire & Explosion 128 D, 200-400 I

02 1949 Perth, NJ Hydrocarbon Fire 4 D

03 1955 Whiting, Ind. Naphtha Explosion 2 D, 30 I


04 1956 New York, USA Ehylene -- --

05 1958 Signal Hill, California Oil Forth Fire 2 D

06 1962 Ras Tanura, Saudi Arabia Propane Fire 1 D, 114 I

07 1963 Rexas, USA Polypropylene Explosion -

08 1964 Fackass Flats, Mev. Hydrogen Explosion -

09 1966 Feyzin, France Propane Fire & Explosion 18 D, 81 I

10 1966 Larose, La NGL Fire (on pipeline) 7 D

11 1966 W. Germany Methane Explosive (failure of

pipe)

3 D, 83 I

12 1967 Buenos Aires Propane -- --

13 1968 Pernis, Netherlands Oil slopes Explosion 9 D, 85 I

14 1968 Terrylown, USA Propane -- --

15 1968 Kennedale, Texac Gasoline Explosion (on road

tnkers)

28 I

16 1969 Pnerts la Cruz Light Hydrocarbon Explosion 5 D

17 1970 Liden Niji Oil Refinery Fire --

18 1970 Port Hudson, MO Propane Explosion (on pipeline) --

19 1970 Mont Belview, Tex Butane Explosion (on pipeline) --

20 1971 Longview, Tex Ethylene Explosion 4 D, 60 I

21 1972 Hearne, Tex Crude Oil Fire & Explosion 1 D, 2 I

22 1972 Lynchbriod Va Propane Fire & explosion 1 D, 2 I

23 1972 Netherlands Hydrogen Explosion 4 D, 4 I,

24 1972 New Jersey, Turnpike,

New Jersey

Propane Explosion (on road

tanker)

2 D

25 1972 Brazil Butane Explosion UVCE 37 D, 53 I

26 1972 Billings, Mont. Butane Explosion 4 I

27 1973 St. Amandles-Eaux France Propane Explosion (on road

tanker)

5 D, 40 I

28 1973 Staten Island, NY Gasoline Fire (in empty storage

tank)

40 D

Sl.

No

.

Year Location Chemical Event Deaths/Injuries

29 1974 Decatur, III Propane Explosion (on

railway)

7 D, 152 I

30 1974 Florida, USA Propane Explosion --

31 1974 Griffith Ind. Propane Fire --

32 1974 India Crude Oil Explosion --

33 1974 Czechoslovakia Ethylene Explosion UVCE 14 D, 79 I,

34 1974 Mississippi, Butane Explosion UVCE 24 I,


USA

35 1975 Beck,

Netherlands

Hydrocarbons Explosion 1 D

36 1975 Lousiania, USA Propane Flammable --

37 1975 Philadelphia Pa Crude Oil

Vapour

Explosion 8 D, 2 I

38 1975 Antwerp

Belgium

Ethylene Explosion UVCE --

39 1976 Los Angles,

California

Gasoline -- 6 D, many injured

40 1977 India Hydrogen Explosion 20 I

41 1978 Waverly, Tenn Propane Explosion (on

railway)

12 D, 50 I

42 1979 Bantry Bay, Eise Oil Explosion (on oil

tanker at terminal)

50 D,

43 1988 India Naphtha Pool Fire 25 D, 23 I

PAST ACCIDENTS (C3 Fraction)

Table-9

Accidents Year

Date

Country Address Injuries Scene

5230 1951-

0707

USA Port Newwark, New

Jersy

11 Explosion and fire of 70

tanks at a tank yard

3914 1955-

0719

D Ludwigshafen 2 Explosion and fire at tank

wagon

4255 1956-

0729

USA Amarillo, Taxes .> 32 BLEVE of 3 oil tanks


8888 1956-

1022

USA Cottage Grove,

Oregon

12 BLEVE of LPG storage tank

0224 1957-

0108

CDN Montreal 1 Overflow butane sphere

0375 1958-

0103

D Celle Explosion of tank wagons

353 1959-

0528

USA MC KAittrict 2 Explosion of storage tanks

308 1966-

0104

F Feyzin 48 Explosion of tanks at

refinery

3906 1968-

0101

USA Dunreith BLEVE of tank wagon after

derailment caused by broken

rail

307 1969-

1205

USA Laurel, Mississippi 33 Derailment of train with 15

tank wagons, Explosion &

Fire

7624 1969-

1203

NL Unknown Rupture of tank by fire

361 1970-

1621

USA Cresent City,

LLinols

66 Derailment and explosion of

nine tank wagons

373 1971-

1019

USA Houston, Texas 50 Derailment of 18 tank

wagons explosion and fire

3891 1971-

1118

NL Nieuwenhoorm Explosion of cylinder caused

fire of Terminal

3455 1972-

0209

USA Twksburry,

Massachusetts

21 Collision tank vehicle with

lines of tank causing BLEVE

of storage tank

681 1972-

0330

BR RIO De Janerio 53 BLEVE of a l tank

2521 1973-

0705

USA Kingam, Arizona 96 BLEVE of tank wagon

caused explosion and fire of

LPG distribution plant

471 1973 USA New York Rupture of propylene of

storage tank, level of tank

Accidents Year

Date


2549 1974-

0111

USA West Saint Paul,

Minnesoia

6 Explosion of tank

2544 1974-

0212

USA Oneonta, New York 25 Derailment and explosion of

tank wagons

667 1974-

0417

D Bielefeld, Brackwedde Derailment of 36 tank wagons,

fire explosion and BLEVE

7527 1974-

1202

NL Haariennermeer- 1 Fire at car repair

4260 1975-

0622

USA DES Moines, IOWA 3 Derailment and rupture of tank

wagons

7352 1976-

0825

NL Loosdrecht Fire and explosion in car

3918 1976- USA Gadsen, Alabama 28 Explosion of tank vehicle and


0831 storage tanks during

transipment

2071 1976-

1126

USA Belt, Montana 22 Derailment and explosion of

several tank wagons

4137 1977-

0206

USA Boynton Beach, Florida BLEVE of LPG cylinders

caused by derailment freight

train

669 1977-

0220

USA Dallas, Taxas 1 Derailment of tank wagons

4235 1977-

0423

USA Long Island, New York 1 BLEVE cylinders on lorry

3377 1977-

0519

USA Hawley, Pennsylvania Fire and BLEVE of tank on

tar

2522 1977-

0519

USA Pocono Mountains

Pennsylvania

1 Leakage supply line caused

explosion vans

618 1978-

0222

USA Waverly, jernessee 43 Derailment of several tank

wagons caused by broken

wheel

2119 1978-

0530

USA Texas City, Texas 10 11 tank explored by unknown

cause in 45 minutes

209 1978-

1218

NL NIJMEGEN BLEVE of tank vehicle at fuel

station during transshipment

2736 1978-

1218

NL Zwolle 6 Explosion of gas cylinder in

measure car

1591 1979-

0549

NL Vlaardingen 2 Fire in van and explosion of

gas cylinder

1639 1979-

0601

NL S. Gravenzande 2 Explosion of gas cylinder

during fire in barn

1634 1979-

0704

NL Ostflakgee Explosion of two cylinders

and one oil tank

Accidents Year

Date


2575 1979-

0713

NL Rotterdam Explosion of cylinder in

van

1630 1979-

0817

NL De MEEM Overheating of kettle with

tar caused explosion of gas

cylinder

953 1979-

0908

USA Pakton, Taxas 8 Derailment of 33 train

wagons with chemicals,

explosion and fire for 2.5

days

1568 1979-

1203

NL Haarlemmermeer Explosion of tank in car

1181 1980-

0105

NL Rotterdam 1 Fire in bus station, LPG

tank explored

1166 1980-

0108

NL Eriecom, River Waa 2 Collision of tanker “Kombi

21” and vessel “Rodort 6”

explosion, fire

3922 1980- USA Los Angles, California 2 Overturn and explosion of


0303 tank vehicle loaded with gasoline

0706 1980-

0606

NL Rotterdam Fire in factory store

2701 1980-

0804

NL RAAITE Fire in motor compartment

of car, BLEVE of tank

0919 1980 NL Road Breeda to

BAVEL

Mobile milling machine

with gas tank explored

1520 1980-

1125

NL OOSTERMOLDGE 1 Explosion of tank in car

during assemble

3419 1980 D Kries Borken Weseko 2 Fire and explosion of tank

vehicle

1836 1981-

0302

NL Weirden Fire and explosion of gas

cylinders in stored caravans

2052 1981-

0409

NL Apeldoorn Fire of carabans near LPG

Terminal

2092 1981-

0510

NL Haarlem Fire and explosion of

storage Barn

2504 1981-

0713

NL Beuwingen 1 Explosion of gas cylinder in

house

2561 1981-

0816

NL Oldeholtrade,

Wolvega

1 Explosion of gas tank in car

by collision

3988 1981 NL Tiel 1 VW Transporter on fire,

tank exploded

4350 1981 USA Unknown 17 BLEVE of cylinder in

converted coach

5535 1981 6B Yately, Hahpshire Explosion of car tank in

garage

7640 1982-

0113

NL Alkmaar Fire and rupture of cylinder

explosion of a plumber gas

3949 1982-

0525

NL Den hag Cylinder

3960 1982-

0601

NL Haarklem Explosion of a cylinder in

car

Accidents Year

Date


3972 1982-

0621

NL Grootbroek 1 Cycling person hit fatally

by fragment of cylinder

4054 1982-

0626

CDN Blairmore, Alberta Derailment and rupture of

several tank wagons

7642 1982-

0916

NL Unknown Rupture of gas tank in car

by overspeed

5681 1982-

0928

USA Livingston, Louisiana Derailment freightain by

overspeed

4449 1982 ET SUEZ 19 Fire and explosion of gas

pipeline


8227 1984-0315

NL Unknown Plastic deformation of tank due to overtheating by fire

8228 1984-

0709

NL Rosmalen Rupture of a car link due to

fire

7942 1984-

0723

USA Romeoville and

lemont

22 Explosion and fire at

refinery llinois

8235 1984-

0921

NL Bruchterveld,

Hardenberg

Rupture of cylinder

RELEASE OF HAZARDOUS SUBSTANCE

POOL

VAPOUR

FLASH

IGNITION

FIRE

YES

CONTINUOUS

IGNITION

DISPERSION

VAPOUR CLOUD

EXPLOSION

PRESSURE WAVE

HEAT RADIATIONN

EFFECTS


5.7 HAZARDS OF EQUIPMENT/PIPELINE HANDLING PETROLEUM

PRODUCTS

The hazard of equipment/pipeline handling petroleum products is the potential loss of

integrity of the containment with subsequent release of liquid causing fire. The pipelines

carry large quantities of petroleum liquid. A rare pipeline fracture would release large

quantities of hydrocarbons. The products would get collected in the neighbourhood of the

pipeline and may lead to a fire hazard if it gets source of ignition and proper precautions

are not taken.

Catastrophic failures of the shell of a storage tank are very rare phenomenon, which may

occur due to earthquake or due to aerial bombardment during war. However, vapour

coming out through the vent line of fixed roof tank or through vapour seal round the shell

in floating roof tanks may be ignited through lighting. However, such cases are also very

rare. In such cases the whole tank may be on fire. Corrosion in the tanks may cause small

holes causing release of petroleum liquid from the tanks. However, in such cases the oil

will be contained in the dyke. In case of oil spill collected on ground an oil pool will be

formed. An ignited pool of oil is called Pool Fire. It creates long smoky flames. The wind

may tilt the flame towards ground causing secondary fires and damages. Radiation from

the flame can be very intense near the fire but falls of rapidly beyond 3-4 pool diameters.

Such fires are very destructive within the plant area and near the source of generation.

In case of formation of holes on the above ground pipeline the liquid may escape in the

form of jet and may catch fire if it gets an ignition source. Damage due to heat radiation

from such jets is mostly limited to objects in the path. However, the ignited jet can

impinge on other vessels and the pipelines causing domino effect.


5.8 BRIEF REVIEW OF INBUILT DESIGN SAFETY

The followings the minimum consideration have been made for tanks :

a) The design and construction of the tanks are carried out according to the API 650

(latest edition). Fixed roof tanks are designed for 1.0 kPa of over pressure and -0.5

kPa of vacuum. The design product filling and withdrawal rates for tanks shall be

1500 cbm/hr irrespective of the pump-in and pump-out rates. There are separate

nozzles for Product inlet and outlet. All tank drains (rest evacuation and water drain

off) are installed at the lowest point of the tank, in order to guarantee good draining.

b) Annular bottom plates have been provided for all above ground storage tanks.

c) Tank bottom design shall includes butt welded annular plates. Rectangular and sketch

plates are lap welded such that there is positive and uninhibited flow of water across

the tank bottom to the centre sump. Any pad or permanent structure in the tank have

been provided with appropriate weep holes to avoid the entrapment of water.

d) Tank shell is butt welded. Consecutive tiers offset by one third of a plate length such

that the vertical butt welded seams are only in line every third tier.

e) All tanks are equipped with surrounding handrails, staircases etc.

f) Appropriate spiral stairways have been provided to each Tank for efficient operations.

Stair treads and walkways are made of open galvanized grating.

g) Fixed Roof Product tanks have been provided with pressure– vacuum (PV) valves

with 100 % capacity redundancy.

h) Tanks have been fitted with an appropriate number of earthing bosses, holding down

bolts, wind girders and water spray deflectors according to code requirements and

local climatic condition.


i) The tanks are provided with sprinklers and foam feeding devices according to the

regulations.

j) The tanks have been properly earthed for protection against lightning and discharge of

possible static electricity.

5.9 PRODUCT PIPELINE SYSTEMS

The pipeline from railway siding to terminal, Jetty to terminal, and within the terminal is

constructed in accordance relevant API codes/OISD standards.

The entire pipeline system is having protection against thermal expansion by way of a

properly designed pressure relieving system connected to the product tanks.

5.10 PUMP HOUSE AT THE TERMINAL

Sufficient numbers of Loading and Unloading Product Pump Units (PPUs) have been

installed, which are connected to the pipelines.

The thermal relief valve system has been designed in such a way that the outlet of TRV

end up to the corresponding product tank. The pipe material and structural steel are

painted to protect against atmospheric corrosion.

5.11 FIRE DETECTION AND PROTECTION SYSTEM

Fire Protection System has been designed for fighting fire for 4 hrs. The firewater system

has been designed as per OISD standards. In addition portable fire fighting equipments

have been placed at the pump station, tank farms, truck loading station, sub-station and

office building

5.12 FIRE ALARM SYSTEM

Conventional type Fire alarm system have been provided in following areas;

a) Truck Unloading/Loading (Manual Call Points)

b) Tank Farm (Manual Call Points).

c) Office / Admn. Building .


d) Sub-Stations .

Salient features of existing fire detection and alarm system is indicated below.

Emergency shut down (ESD) system and related call points at TLF/ Tank Farm /

Admin Office / MCC have been provided.

5.13 PORTABLE FIRE FIGHTING APPARATUS

Following types of fire extinguishers and other fire fighting apparatus specified for

Terminal in vulnerable areas of the plant, administrative block, control room, fire

water pump house. MCC etc as per OISD guidelines.


CHAPTER-6 : RISK ASSESSMENT

6.1 INTRODUCTION

The Liquid Chemical Storage Terminal (LST) of GBL,Kochi which includes the facilities

for receipt, storage and dispatch of petroleum products mainly poses fire hazard due to

unwanted and accidental release of hydrocarbons. However, due safeguard has been

taken in design, Terminal and operation of the system to prevent any unwanted release of

hydrocarbons & chemical from their containment. However, in the event of release of

hydrocarbons & chemical from their containment, there is a risk of fire. Chances of

explosion are less. This section deals with various failure cases leading to various hazard

scenarios, analysis of failure modes and consequence analysis.

Consequence analysis is basically a quantitative study of hazard due to various failure

scenarios to determine the possible magnitude of damage effects and to determine the

distances up-to which the damage may be affected. The reason and purpose for

consequence analysis are manifolds like.

Computation of risk

Aid better plant layout

Evaluate damage and protective measures necessary for saving properties &

human lives

Ascertain damage potential to public and evolve protective measures

Formulate safe design criteria and protection system

Formulate effective Disaster Management plan

The results of consequences analysis are useful for getting information about all known

and unknown effects that are of importance when failure scenarios occur and to get

information about how to deal with possible catastrophic events. It also gives the terminal

authorities, workers district authorities and the public living in the area an understanding

of the hazard potential and remedial measures to be taken.


6.2 MODES OF FAILURE

There are various potential sources of large/small leakages in any Terminal. The leakages

may be in the form of gasket failure in a flanged joint, snapping of small dia pipeline,

leakages due to corrosion, weld failure, failure of loading arms, leakages due to wrong

opening of valves & blinds, pipe bursting due to overpressure, pump mechanical seal

failure and many other sources of leakage.

6.3 DAMAGE CRITERIA

The damage effect of all such failures mentioned above are mainly due to thermal

radiation from pool fire or jet fire due to ignition of hydrocarbons released since the

petroleum products are highly inflammable.

The petroleum products released accidentally due to any reason will normally spread on

the ground as a pool or released in the form or jet in case of release from a pressurized

pipeline through small openings. Light hydrocarbons present in the petroleum products

will evaporate and may get ignited both in case of jet as well as liquid pool causing jet

fire or pool fire. Accidental fire on the storage tanks due to ignition of vapour from the

tanks or due to any other reason may also be regarded as pool fire.

Thermal radiation due to pool fire or jet flame may cause various degrees of burns on

human bodies. Also its effect on inanimate objects like equipment, piping, building and

other objects need to be evaluated. The damage effects due to thermal radiation intensity

are elaborated in the Table 10


TABLE – 10

DAMAGE DUE TO INCIDENT THERMAL RADIATION INTENSITY

Incident

Thermal

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

4.5 Sufficient to cause pain to personnel if unable to reach cover within 20

sec. (% of 1st Degree Burn)

1.6 Will cause no discomfort to long exposure.

0.7 Equivalent to solar radiation

TABLE – 11

PHYSIOLOGICAL EFFECTS OF THRESHOLD THERMAL DOSES

Dose Threshold

KJ/M2

Effect

375 3rd Degree Burn

250 2nd Degree Burn

125 1st Degree Burn

65 Threshold of pain, no reddening or blistering of skin caused.

1st Degree Burn > Involve only epidermis, blister may occur example-

sun Burn.

2nd Degree Burn > Involve whole of epidermis over the area of burn

plus some Portion of dermis.

3rd Degree Bun > Involve whole of epidermis and dermis;

subcutaneous Tissues may also be damaged.


In case of Motor Spirit having relatively higher vapour pressure, there is a possibility of

vapour cloud explosion. Damage effects due to blast over pressure is given in Table-12

TABLE – 12

DAMAGE EFFECTS DUE TO BLAST OVER PRESSURE

Blast Over Pressure (Bar) Damage Type

0.30 Major Damage to Structures

0.17 Eardrum Rupture

0.10 Repairable Damage

0.03 Damage of Glass

0.01 Crack of Windows

6.4 DISPERSION AND STABILITY CLASS

In calculation of effects due to release of hydrocarbons dispersion of vapour plays an

important role as indicated earlier. The factors which affects dispersion is mainly Wind

Velocity, Stability Class, Temperature as well as surface roughness. One of the

characteristics of atmosphere is stability, which plays an important role in dispersion of

pollutants. Stability is essentially the extent to which it allows vertical motion by

suppressing or assisting turbulence. It is generally a function of vertical temperature

profile of the atmosphere. The stability factor directly influences the ability of the

atmosphere to disperse pollutants emitted into it from sources in the plant. In most

dispersion problems relevant atmospheric layer is that nearest to the ground. Turbulence

induced by buoyancy forces in the atmosphere is closely related to the vertical

temperature profile.

Temperature of the atmospheric air normally decreases with increase in height. The rate

of decrease of temperature with height is known as the Lapse Rate. It varies from time to

time and place to place. This rate of change of temperature with height under adiabatic or

neutral condition is approximately 1 °C per 100 metres. The atmosphere is said to be

stable, neutral or unstable according to the lapse rate is less than, equal or greater than dry

adiabatic lapse rate i.e. 1°C per 100 metres.

Pasquill has defined six stability ranging from A to F

A = Extremely unstable

B = Moderately unstable


C = Slightly unstable

D = Neutral

E = Stable

F = Highly Stable

6.3.1 Selected Failure cases

The mode of approach adopted for consequence is first to select the probable failure

scenarios. The failure scenarios selected are indicated Table-13

TABLE -13

LIST OF FAILURE CASES

Sl.No Failure Scenarios Likely Consequences Credible/

No Credible

1 Tanks on Fire

i. Methanol Tank

ii. FO Tank

Thermal Radiation

Partially credible

2 Vessel connection failure for inlet /

outlet lines of Methanol &

FO(Road tanker loading)

Thermal Radiation for

MS,Methanol,Furnace oil

and also explosion for MS

Partially credible

3 TLF Pumps discharge lines Full

bore failure for Methanol & FO

(Road Tanker Loading)

do

Non Credible

4 Gasket failure in pump discharge

line Methanol & FO (Road Tanker

Loading Pump)

Thermal radiation Credible

5 Failure of 3’ dia loading arm

Methanol & FO

-do- Partially

Credible

6 Failure of 3’ dia unloading hose

Methanol & FO

-do- Credible

It will be seen that most of the probable cases of failures have been considered for

consequence analysis.


CHAPTER-7 : CONSEQUENCE ANALYSIS

7.1 INTRODUCTION

Consequence Analysis of the selected failure cases have been done to evaluate and

identify possible consequences as well as to incorporate suitable measures in operational

phase to prevent such failure events.

7.1.2 STORAGE TANKS IN TERMINAL

Existing Tanks Detail

Tank No Tank Dimensions

(diameter in m x

height in m)

Safe Storage Filling

Capacity in m3

Petroleum

Product

Petroleum

Product

Class

T-101 11 x 10.7 1000 Furnace Oil C

T-102 10 x 10 750 Furnace Oil C

T-103 20 x 16.5 5000 Furnace Oil C

T-104 20 x 16.5 5000 Furnace Oil C

T-105 20 x 16.5 5000 Furnace Oil C

T-201 18 x 18 4500 Methanol A

T-202 18 x 18 4500 Methanol A

T-203 18 x 18 4500 Methanol A

Proposed Tanks Detail

Tank No Petroleum

Product

Safe Storage

Filling Capacity

in m3

Tank

Dimensions

(diameter in m x

height in m)

Petroleum

Product

Class

T-204 Liquid

Chemicals

5000 18 x 20 A

T-205 Liquid

Chemicals

5000 18 x 20 A

T-206 Liquid

Chemicals

4000 16 x 20 A

T-207 Liquid

Chemicals

4000 16 x 20 A


7.2.1 ALARP CONCEPT:

ALARP stands for "as low as reasonably practicable", and is a term used in the milieu of safety-

critical and safety-involved systems. The ALARP principle is that the residual risk shall be as

low as reasonably practicable.

For a risk to be ALARP it must be possible to demonstrate that the cost involved in reducing the

risk further would be grossly disproportionate to the benefit gained. The ALARP principle arises

from the fact that infinite time, effort and money could be spent on the attempt of reducing a risk

to zero. It should not be understood as simply a quantitative measure of benefit against

detriment. It is more a best common practice of judgment of the balance of risk and societal

benefit.

RISK TRIANGLE: ALARP

FIG : ALARP – RISK TRIANGLE

Fundamental

Improvements

needed

Too High: Significant Effort

Required To Improve

High: to be Investigated

Alternative to be considered

Low: Consider Cost Effective

alternative .Negligible Maintain Normal Precautions

Intolerable

Intolerable

The ALARP or Tolerable Region

(Risk is tolerated only)

Broadly Accepted Region (no need for

detail working to demonstrate ALARP)

Acceptable

BLE

Consider lest effectiveness alternatives-

Almost negligible, Maintain Normal

Precaution


If quantitative arguments are used the methods, assumptions and the criteria adopted for decision

making should be explained. For example in the case of fatality risks to people off-site it is

common practice [HSE, 1992] for the maximum tolerable level of individual fatality risk is set at

10-4 per year and for the broadly acceptable level to be set at 10-6 per year. The corresponding

figures for workers are 10-3 and 10-6 ALARP demonstration should be founded on the degree to

which good practice, engineering standards, recognized codes, guidance and standards, etc have

been adopted. The control measures introduced by this process will be usually satisfactory for

low hazard sites. In terms of the TOR framework this amount to using technology-based criteria

for making ALARP decisions, ie qualitative risk assessment. Such criteria will usually be

sufficient when inherently safe design principles have been adopted because then the scale of the

hazard should have been drastically reduced. As the level of proportionality increases, a decision

has to be made as to whether further risk reduction measures are reasonably practicable as

required as per OISD Standards.

7.2.2 EVENT TREE ANALYSIS & PROBABILITIES FOR THE RELEASE

OF DIFFERENT TYPES

Direct ignition Pool fire / Complete

Containment failure

Liquid

Delayed Ignition Explosion

Pool fire

No effect

Figure: 8.1 – Event tree for a release of flammable liquid

In quantitative risk analysis usually generic hypothesis concerning the loss of containment

initiating events are applied, in order to simplify the analysis. For example, for the loss of

containment from a storage tank: instantaneous release of the complete inventory, continuous

release of the complete inventory in 10 min and continuous release from a hole with a diameter


of 10 mm. Once these initiating events specified, it is necessary to develop the corresponding

event trees to establish which are the different sequences –depending on the properties of the

released material, the existing safety barriers, etc.– leading from each initiating event to the

diverse final outcomes or accident scenarios. In this communication a set of generic short event

trees are proposed for the main cases which can be found, as a function of the type of hazardous

material released. Values for the corresponding intermediate probabilities (immediate

ignition, delayed ignition, flame front acceleration, Pool fire, VCE etc.) are also proposed,

following both a literature survey and expert judgment.

A tank is susceptible to fire hazard, if a static charge or a spark ignites the vapour being released

from the rim vent, causing fire. If the fire is not controlled at the initial stage it can lead to

collapse of the roof and total liquid becomes exposed to fire. The hazard posed by such failure

and subsequent fire is intense thermal radiation. The thermal radiation emanating from such tank

fire can cause damage to nearby tanks and persons' in the vicinity. As per IP Code, thermally

protected facilities and storage tanks can withstand a thermal radiation of 32 KW/M2 while

unprotected tanks and process facilities can withstand only upto 8 KW/M2. Normal persons can

withstand an intensity of 1.5 KW/M2 for a long duration. A radiation intensity of 4.5 KW/M2 can

cause 1st degree burn if a man is exposed for more than 20 seconds.

Hazard distances due to thermal radiation as a result of fires in storage tanks and other areas have

been shown in the following pages.

7.2.3 FREQUENCY ANALYIS

The steps deals with determination how often – in terms of frequency per year – fire, explosion

& toxic hazards can occur. Specific event trees will be developed to calculate the frequencies of

scenarios. An event tree is a model that begins with a release case and ends up with various

incidents outcomes.

The likely hood of occurrence of the identified hazard scenarios is assessed by reviewing

historical accident data with previous studies. Event tree analysis is adopted to determine the

possible outcome from the identified hazardous events and to estimate the frequencies.


Estimates have been obtained from historical incident data on failure frequencies & from failure

sequence model (event trees). In this study the historical data available in international renowned

databases will be used.

Sl.No Failure Scenarios Likely Consequences Credible/

No Credible

Failure

Frequency

1 Tanks on Fire

i. Methanol Tank

ii. FO Tank

Thermal Radiation

Partially

credible

5 x 10-6

2 Vessel connection failure for inlet

/ outlet lines of Methanol &

FO(Road tanker loading)

Thermal Radiation for

MS,Methanol,Furnace

oil and also explosion

for MS

Partially

credible

5 x 10-6

3 TLF Pumps discharge lines Full

bore failure for Methanol & FO

(Road Tanker Loading)

do

Non

Credible

3 x 10-6

4 Gasket failure in pump discharge

line Methanol & FO (Road

Tanker Loading Pump)

Thermal radiation Credible 0.5 x 10-6

P/H of

operation.

5 Failure of 3’ dia loading arm

Methanol & FO

-do- Partially

Credible

3 x 10-8

P/H of

operation

6 Failure of 3’ dia unloading hose

Methanol & FO

-do- Credible 3 x 10-

5P/H of

operation


7.3 CONSIDERATION FOR MAXIMUM CREDIBLE ACCIDENT SCENARIO:

HAZARD ASSESSMENT (QUANTIFICATION)

7.3.1 JET FIRE

Scenario – 1: Jet fire on Methanol

Specification considered

1. Product Methanol

2. Tank No T-202

3. Leakage through hole - dia 10 mm

4. Pump discharge 80 KL/H

5. Duration 600 Second

METEROLOGICAL DATA CONSIDERED

Temperature(Max ) 36o C / 309 K

Humidity(Min) 41%

Maximum temperature of 36o C / 309 K and minimum humidity of 41 % have been considered

for the calculation of damage distance in the case of Jet fire radiation heat intensity in

KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. Methanol

1.5F NR NR 7.72

5D NR NR 5.61

RISK ANALYSIS



RISK ANALYSIS


Scenario – 2: Jet fire on Methanol


1. Product Methanol

2. Tank No T-202

3. Leakage through hole - dia CR





Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. Methanol

1.5F NR NR NR

5D NR NR NR


Scenario – 3 : Jet fire on Class A (Propose product)


1. Product Proposed class A product

2. Tank No T-205






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. Proposed

class A

product

1.5F NR NR 7.92

5D NR NR 5.68

RISK ANALYSIS



RISK ANALYSIS


Scenario – 4 : Jet fire on Class A (Proposed product)


1. Product Proposed class A product

2. Tank No T-202






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. Proposed

class A

product

1.5F NR NR NR

5D NR NR NR


Scenario – 5: Jet fire on FO


1. Product FO

2. Tank No T-104






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. FO

1.5F NR NR 3.50

5D NR NR 1.51

RISK ANALYSIS



RISK ANALYSIS


Scenario – 6 : Jet fire on FO


1. Product FO

2. Tank No T-104






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. FO

1.5F NR NR NR

5D NR NR NR


Scenario – 7: Flash Fire on Methanol


1. Product Methanol

2. Tank No T-201






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

1. Methanol

1.5F 6.21

5D 2.96

RISK ANALYSIS



RISK ANALYSIS


Scenario – 8: Flash Fire on Methanol


1. Product Methanol

2. Tank No T-201






Humidity(Min) 68%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

1. MS

1.5F 605.68

5D 262.50

RISK ANALYSIS



RISK ANALYSIS


Scenario – 9: Flash Fire on Class A Product Tank


1. Product Class A

2. Tank No T-205






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

1. Methanol

1.5F 7.21

5D 3.01

RISK ANALYSIS


RISK ANALYSIS


Scenario – 10: Flash Fire on Class A Product


1. Product Class A

2. Tank No T-205






Humidity(Min) 68%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

1. MS

1.5F 805.68

5D 362.50

RISK ANALYSIS


RISK ANALYSIS


7.3.2 POOL FIRE

Scenario – 1 : Pool fire of Methanol


1. Product Methanol

2. Tank No T-202






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. Methanol

1.5F NR 16.94 26.45

5D NR 18.91 26.28

RISK ANALYSIS



RISK ANALYSIS


Scenario – 2: Pool fire on Methanol


1. Product Methanol

2. Tank No T-205






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. Methanol

1.5F 512.67 717.59 1009.38

5D 523.55 745.87 1013.65

RISK ANALYSIS



RISK ANALYSIS


Scenario – 3 : Pool fire on Class A Proposed Product


1. Product Proposed Class A Product

2. Tank No T-205






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. Proposed

Class A

Product

1.5F NR 16.94 26.45

5D NR 18.91 26.28

RISK ANALYSIS



RISK ANALYSIS


Scenario – 4 : Pool fire of Proposed Class A Product


1. Product Proposed Class A Product

2. Tank No T-202






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. Proposed

Class A

Product

1.5F 539.44 752.48 1056.25

5D 551.42 781.27 1060.22

RISK ANALYSIS



RISK ANALYSIS


Scenario – 5 : Pool Fire on FO


1. Product FO

2. Tank No T-104






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. FO

1.5F NR 9.94 15.45

5D NR 10.01 15.21

RISK ANALYSIS



RISK ANALYSIS


Scenario – 6 : Pool Fire on FO


1. Product FO

2. Tank No T-104






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. FO

1.5F 239.44 352.41 556.25

5D 251.42 381.27 560.22

RISK ANALYSIS



RISK ANALYSIS


7.3.2 OVERPRESSURE

Scenario – 1: Overpressure of Methanol


1. Product Methanol

2. Tank No T-202






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

0.2 0.1 0.02

1. Methanol

1.5F 11.06 11.37 15.27

5D NR NR NR

RISK ANALYSIS



RISK ANALYSIS


Scenario – 2: Overpressure of Methanol


1. Product Methanol

2. Tank No T-202






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

0.2 bar 0.1 bar 0.02 bar

1. Methanol

1.5F 701.02 707.17 855.26

5D 331.69 335.11 575.67

RISK ANALYSIS



.

RISK ANALYSIS


Scenario – 3 : Overpressure on Class A Product


1. Product Class A

2. Tank No T-205






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

37.5 kW/m2 12.5 kW/m2 4,kW/m2

1. Class A

1.5F 11.06 11.37 15.27

5D NR NR NR

RISK ANALYSIS



RISK ANALYSIS


Scenario – 4 : Overpressure on Class A (Proposed Product)


1. Product MS

2. Tank No T-205






Humidity(Min) 41%



KW/M2

Result

Sl

no

Scenario

Stability

Condition

Distance in (m)

0.2 bar 0.1 bar 0.02 bar

1. MS

1.5F 334.76 339.07 598.73

5D 718.22 723.55 881.53

RISK ANALYSIS



RISK ANALYSIS


7.4 MODELING SOFTWARE

A site specific consequence analysis of the accidental release scenarios was conducted using the

commercially available Process Hazards Analysis Software Tool (PHAST) consequence

modeling software, version 6.7. M/S DNV’s Software is responsible for the development of a

number of established, world leading, hazard and risk modeling software tools. These

commercially available software tools include the consequence modeling package PHAST, the

risk analysis tools SAFETI /PHAST RISK.

7.5 ACTION DURING FIRE

7.5.1 Storage Tank in Fire

a) A fire burning at the vent will not normally flash back into tank and

explode, if the tank contains product since flame arresters are provided

b) Start cooling of tanks by using water sprinklers provided on tanks as well as by

wet jets.

c) Close all valves since any removal of product will result in air being sucked

inside, with the resultant flash back and explosion.

d) Close manhole covers of other tanks if they are open. Also stop loading /

Receipt of tank wagons, into / out of the tank since it will result in eviction

of vapour due to displacement and subsequent intensification of fire.

e) Use foam to extinguish fire. Small fire can be handled with portable fire

extinguishers.

f) Fire in tank will normally burn quietly till the oxygen is consumed unless

temperature of the product is allowed to increase uncontrolled. Hence, care must


be taken to ensure that product temperature does not go high by cooling with

water sprinklers & jets. This also avoids possibility of tank rupture due to

hydrostatic pressure

g) When sufficient air vapour mixture is available inside the tank as in the case

during removal of products from tank on fire there is a distant possibility of tank

roof collapse or blow out. In such cases, immediate action should be taken to

ensure that the fire does not spread to other areas. If there is product spill to

outside, foam should be used to cover the same.

H) In such cases, foam should be pumped to inside the tank for blanketing the fire

and simultaneously taking action to cool the tank shell with water and also

removing the product by pumping it cut to some other tank.

i) Uncontrolled use of water on the burning product will result in product spill over

and spread of fire. In the case of heavy ends this will result in boil over and

frothing at the surface.

j) When heavy ends like MS or FO burn, a layer of hot oil is formed below the

surface, which extends towards the bottom. Temperature of this layer is of the

order of 250° C to 300° C much above the boiling point of water. When water

turns into steam, it expands appx. 1600 times and this result in boil over. The boil

over may overflow the tank resulting in spreading of fire. Hence, in such fire, cool

down the tank by continuous water jet on the tank shell, transfer the product to

other tanks and judiciously use foam to smoothen fire.

7.5.2 Pool Fire at TLF Gantry.

A) Discharge DCP to prevent fire from spreading.

B) Shut down the pumps by cutting of power supply.

C) Remove any person who is working in the effected area.


D) Close the valves of either side to starve the fire close all tank wagon valves and

manifold valves.

E) Put foam on burning oil spills

F) Put foam on oil spills. Do not splash burning oil.

G) Use DCP or CO2 fire extinguisher on electrical fire.

H) Wet down the structure close to the fire with water

7.5.3 Gasket Failure

a. Stop Pumping

b. Close the valves of either side of flange

c. Dig pits to collect oil.

d. Built earth dykes around the oil pool to prevent spreading of burning oil.

e. Take care of the oil dropping from the leak even after extinguishing fire as

fire may occur again due to heating of oil dropped. Try to collect the oil in

containers.

f. Take action for replacement of gasket/ repair leak with due care.

7.5.4 General

a) Incase of Oil spill the same should be blanketed with foam in order to avoid

contact with source of ignition.

b) Use DCP or CO2 fire extinguisher on Electrical fire.

c) Wet down structure close to the fire with water.

d) Discharge DCP to prevent fire from spreading.

e) In case flammable liquid pool due to containment failure, pipeline rupture within

the dyke area it is suggested to cover the flame with foam blanket.


CHAPTER-8 : RISKS AND FAILURE PROBABILITY

The term Risk involves the quantitative evaluation of likelihood of any undesirable event

as well as likelihood of harm of damage being caused to life,property and environment.

This harm or damage may only occur due to sudden/accidental release of any hazardous

material from the containment. This sudden/accidental release of hazardous material can

occur due to failure of component systems. It is difficult to ascertain the failure

probability of any system because it will depend on the components of the system. Even

if failure occurs, the probability of fire and the extent of damage will depend on many

factors like,

A) Quantity and physical properties of material released.

B) Source of ignition

C) Wind velocity and direction

D) Presence of population, properties etc nearly.

Failure frequency of different components like pipes, valves, instruments, pressure

vessels and other equipment manufactured in India are not available. The statutory

authority has tried to collect the information and form an acceptable data bank to be used

under Indian condition.

Failure frequency data for some components accepted in U.S.A and European

Countries are given Table -14


TABLE -14

FAILURE FREQUENCY DATA

Sl.No Item Failure Frequency /

106 years

1 Shell Failure

a) Process/pressure vessel

b) Pressurized Storage Vessel

3

1

2 Full Bore Vessel Connection Failure

(Diameter MM)

<25

40

50

80

100

>150

30

10

7.5

5

4

3

3 Full Bore Process Pipeline Failure

D< 50mm

50<d<150mm

D>150mm

0.3*

0.09*

0.03*

4 Articulated Loading / Unloading arm

Failure

30 x 108 **

* Failure frequency expressed in (n/106 years)

** Failure frequency expressed in (hr of operation)


CHAPTER-9 : RECOMMENDATIONS & CONCLUSIONS

The recommendations & conclusions as revealed from Risk Analysis study are as

follows:

i) The individual Risk value of 1.0 E-6/ year as evident from the ISO Risk

contour is not always confined within the plant premises. Hazard distances

arrived from the consequence analysis also reveals that in most of the

cases hazard is not always confined within the terminal premises.

ii) Health check and maintenance of the equipment including storage tanks

and pipelines should be done at regular intervals to avoid any major

failure. History sheet of all major equipment giving the details of

fabrication data / design data to be maintained.

iii) Instruments and trip interlocks should be checked and calibrated at regular

intervals to prevent any wrong signaling and consequent failures.

iv) Fire fighting system as well as portable fire-fighting appliances should

be always kept in good working condition. Safety appliances should be

also checked and kept in good working condition.

v) Mock Drills should be conducted at regular intervals.

vi) To reduce the failure frequency due care has been taken in design,

construction, inspection and operation. Well-established codes of practices

have been followed for design, inspection and construction of the facility.

vii) The Terminal should be operated by experienced personnel trained for

operation of such facility and also in fire fighting. Safe operating practice (

SOP) to be drawn and critical SOP to be displayed near the TLF,

Tankfarm, Pump house and manifold.


viii) Smoking should be strictly prohibited inside the Terminal.

ix) Non -sparking tools should be used for maintenance to avoid any spark.

x) The storage tanks, pipelines and facilities in Tank Lorry Filling Shed

should be properly earthed to avoid accumulation of static electricity.

Bounding to be ensured for TLF operation. Tripping arrangement

recommended in case of failure in earthing / bounding system.

xi) Entry of personnel should be restricted inside the licensed area.

xii) A elaborate Disaster Control Management Plan containing a mutual

aid agreement should be drawn to meet major exigencies.

xiii) 2 No. Trolley Mounted Foam Monitors should be maintained in order

xiv) Failure data must be recorded.

xv) Maintenance schedule is to be drawn and the same should be strictly

adhered to.

Documents

QUANTITATIVE RISK ASSESSMENT MAY 2018 · ULTRA-TECH Environmental Consultancy and Laboratory M/S GANESH BENZOPLAST LIMITED THE LIQUIED CHEMICAL STORAGE TERMINAL QUANTITATIVE RISK