rapid risk assessment studies...

RAPID RISK ASSESSMENT STUDIES

FOR

BPCL IRUGUR INSTALLATION

IRUGUR, NEAR COIMBATORE, TAMILNADU

Submitted to:

Bharat Petroleum Corporation Limited

Prepared by:

Vimta Labs Ltd.

142 IDA, Phase-II, Cherlapally Hyderabad–500 051

[email protected], www.vimta.com (NABET & QCI Accredited, NABL Accredited and ISO 17025 Certified Laboratory,

Recognized by MoEF, New Delhi)

November, 2014

Bharat Petroleum Corporation Limited New Delhi

For and on behalf of VIMTA Labs Limited Approved by : M. Janardhan Signed : Position : Head & Vice President (Env) Date : November 05, 2014

This report has been prepared by Vimta Labs Limited with all reasonable

skill, care and diligence within the terms of the contract with the client,

incorporating our General Terms and Conditions of Business and taking

account of the resources devoted to it by agreement with the client.

PREFACE

RAPID RISK ASSESSMENT STUDIES

FOR BPCL IRUGUR INSTALLATION

IRUGUR, NEAR COIMBATORE, TAMILNADU

Rapid Risk Assessment Studies for BPCL Irugur Installation, near Coimbatore, Tamil Nadu

VIMTA Labs Limited, Hyderabad 1

Table of Contents

_______________________________________________________________

Chapter Title Page

_______________________________________________________________

Table of Contents 1

List of Figures 2

List of Tables 2

1.0 Introduction

1.1 Background 3

1.2 RRA Study 3

2.0 Facility Description

2.1 BPCL Terminal at Irugur 4

3.0 Scope, Objective & Methodology

3.1 Scope 6

3.2 Objective 6

3.3 Methodology 6

4.0 Rapid Risk Analysis

4.1 Input Data 12

4.2 Population Data 13

4.3 Ignition Sources 13

4.4 Weather Data 14

4.5 Consequence Analysis Results 17

4.6 RRA Results 29

5.0 Conclusions & Recommendations

5.1 Conclusions 34

5.2 Recommendations 34

Annexure-I Irugur Top Installation – Layout Plan showing Facilities



List of Figures

_______________________________________________________________

Figure Title Page

_______________________________________________________________ 3.1 Flow Diagram of Rapid Risk Assessment (RRA) 7 3.2 ISO-Risk Contours on Site Plan (Typical) 9 3.3 Individual Risk Criteria 10 3.4 Societal Risk Criteria 11 4.1 Wind rose Diagrams 15 4.2 Dyke Fire – MS Tank (T-20) Pool Fire Radiation Intensity 20 4.3 MS Tank (T-20) – Vapour Cloud Explosion Overpressure 21 4.4 Dyke Fire – New HSD Tank (T-21) Pool Fire Radiation Intensity 22 4.5 Dyke Fire – New HSD Tank (T-23) Pool fire Radiation Intensity 23 4.6 Dyke Fire – Existing HSD Tank (T-1) Pool Fire Radiation Intensity 24 4.7 Dyke Fire – Existing HSD Tank (T-3) Pool Fire Radiation Intensity 25 4.8 Dyke Fire – Existing HSD Tank (T-7) Pool Fire Radiation Intensity 26 4.9 Pipeline Pump Discharge Leak (25 mm) Pool fire Radiation Intensity 27 4.10 Pipeline Pump Discharge Leak (25 mm) VCE Overpressure 28 4.11 ISO- Risk Contours for Individual Risk at BPCL Irugur Terminal 29 4.12 ISO- Risk Contours for Individual Risk at BPCL Irugur-Terminal 30 4.13 Individual Risk at BPCL Irugur Terminal 32 4.14 Societal Risk at BPCL Irugur Terminal 33

List of Tables

Tables Title Page

2.1 Details of Storage Tanks at BPCL Irugur Terminal 4

4.1 Failure Scenarios and the Relevant Input Data 12

4.2 Population Data – BPCL Irugur Terminal 13

4.3 Climatological Data – Coimbatore 14

4.4 Definition of Pasquill Stability Classes 16

4.5 Weather Parameter for Risk Analysis 17

4.6 Effects of Heat Radiation 17

4.7 Effects of Overpressure 18

4.8 Consequence Analysis Results 19

Rapid Risk Assessment Studies for BPCL Irugur Installation, Coimbatore, Tamil Nadu


1.0 INTRODUCTION

1.1 Background

Bharat Petroleum Corporation Limited (BPCL) operate a large POL terminal at

Irugur near Coimbatore in Tamil Nadu. Expansion of facilities at Irugur Terminal

is planned to handle the requirement for evacuation of white oil products after

capacity expansion of Kochi Refinery and commissioning of Irugur – Bengaluru

Pipeline.

1.2 Rapid Risk Assessment Study

BPCL being an organization with commitment to high standards of process safety

management wish to identify the hazards associated with the expanded facilities

at Irugur Terminal and implement all necessary measures to ensure that the risk

due to the pipeline are kept as low as reasonably practicable. With this objective,

BPCL have engaged the services of Vimta Labs, Hyderabad, for carrying out a

Rapid Risk Assessment (RRA) study for the Irugur installation.

Vimta Labs have wide experience in conducting environmental impact assessment

(EIA) study and risk analysis for a large number of oil & gas facilities, petroleum

installations, chemical/ fertilizer plants, power plants, mines & mineral

installations etc.

The Rapid risk assessment (RRA) report for the BPCL Irugur Terminal near

Coimbatore was submitted in December 2013. This RRA report is now updated for

provision of rail tank wagon loading gantry.



2.0 FACILITY DESCRIPTION

2.1 BPCL Terminal at Iruguru

The details of storage and pumping facilities at Irugur Terminal of BPCL near

Coimbatore are shown below in Table 2.1.

TABLE-2.1

DETAILS OF STORAGE TANKS AT BPCL IRUGUR TERMINAL

Tank No.

Product Tank diameter

(m)

Tank height/ length (m)

Class Tank type Tank Capacity

New Tanks (Above-Ground Type)

T-20 MS 40.00 15.00 A Floating roof 17,117 KL

T-21 HSD 38.00 18.00 B Cone roof 20,000 KL



FW-3 Fire water 20.00 12.00 - Cone roof 3,770 KL


Existing Tanks (Above-Ground Type)



T-3 HSD 30.00 15.00 B Floating roof 9,585 KL

T-4 SKO 24.00 15.00 B Floating roof 6,128 KL

T-5 SKO 24.00 15.00 B Floating roof 6,131 KL

T-6 HSD 36.57 15.00 B Floating roof 14,298 KL

T-7 HSD/ MS 40.00 15.00 B Floating roof 17,157 KL


T-9 LPPHSD/ SKO 24.00 15.00 B Floating roof 6,130 KL

T-10 LPPHSD 24.00 15.00 B Floating roof 6,128 KL

T-12 Slop 13.00 9.00 A Cone roof 1,201 KL

T-13 Slop 13.00 9.00 A Cone roof 1,204 KL

T-14 Ethanol 3.20 13.20 A Horizontal 100 KL

T-15 Ethanol 2.75 13.00 A Horizontal 70 KL



Existing Tanks (Under-Ground Type)

T-11 Slop 2.00 5.00 A Horizontal 15 KL

T-16 MS (Speed) 3.20 13.20 A Horizontal 100 KL

T-17 HSD (Speed) 3.20 13.20 B Horizontal 100 KL

T-18 MS (Speed

97) 2.75 8.00 A Horizontal 45 KL

T-19 HSD (Speed) 2.012 6.75 A Horizontal 20 KL

The layout drawing titled for BPCL Irugur Terminal is attached at Annexure-1.

Irugur Top Installation – Layout Plan Showing Facilities (BPCL

Drawing No. IRG-001)

BPCL Irugur terminal has been made fully automated terminal with entry and exit

control, integrated tank farm management system, automated truck tanker

loading facility, automated fire alarm/ fighting facility and network communication

system.



It is proposed to provide a railway gantry for loading of tank Wagons for

transporting products from Irugur to various locations. Broad details are as

follows.

Products to be handled: MS (Euro 3 & Euro 4 ), HSD (Euro 3 & Euro 4), SKO

and ATF (future)

The gantry will be about 700 m long located parallel to north compound wall.

No of Wagons to be filled simultaneously: One full rake of 50 wagons of

approx. capacity 58-68 KL each

Filling in tank wagons will be through loading arms and flow meters with

automation provided for monitoring and control.

Fire protection facilities have been provided fully meeting the requirements of Oil

Industry Safety Directorate Standard (OISD-117). These include the following:

Fire water storage tanks

Main fire water pumps and jockey pumps

Fire water network with hydrants, monitors and medium-velocity sprinkler

systems

Fixed foam system

Mobile fire fighting equipment

Portable fire extinguishers

Fire detection & alarm system including manual call points

Medium velocity spray will be provided for full length of gantry as per

OISD/MBLR for fire fighting. Network of water hydrant/ monitor at 30 m

spacing will also be provided all around the gantry.

Fire and gas detectors are provided in the pipeline pump house with safety

interlock to shut down the pumps in case of hydrocarbon leak.

An Emergency Management System has been provided in total operation

management and in emergency, on operating ESD switch, all operation in the

terminal will stop the pumps and close the motor operated valves at the tank

outlets.



3.0 SCOPE OBJECTIVE & METHODOLOGY

3.1 Scope

The scope of this RRA study covers the complete Irugur installation of BPCL

including the existing facilities and the proposed additional facilities for storage

tanks and pumping systems to handle the movement of white oil products by

Irugur – Bengaluru Pipeline.

3.2 Objective

The objectives of this study are as follows:

Identify major accident scenarios associated with the storage and handling of

hydrocarbons in the installation,

Carry out consequence analysis for the significant accident scenarios

Carry out Rapid Risk Assessment (RRA), and

Identify measures for risk reduction wherever warranted.

3.3 Methodology

Risk arises from hazards. Risk is defined as the product of severity of

consequence and likelihood of occurrence. Risk may be to people, environment,

assets or business reputation. This study is specifically concerned with risk of

serious injury or fatality to people.

The following steps are involved in Rapid Risk Assessment (RRA):

Study of the plant facilities and systems.

Identification of the hazards.

Enumeration of the failure incidents.

Estimation of the consequences for the selected failure incidents.

Risk analysis taking into account the failure frequency, extent of

consequences and exposure of people to the hazards.

Risk assessment to compare the calculated risk level with risk tolerability

criteria and review of the risk management system to ensure that the risk is

“As Low As Reasonably Practicable” (ALARP)

The process of Rapid Risk Assessment (RRA) is shown in the following block

diagram in Figure-3.1.



FIGURE-3.1

FLOW DIAGRAM OF RAPID RISK ASSESSMENT (RRA)

3.3.1 Consequence Analysis

Consequence analysis for the selected failure scenarios is carried out using DNV

Phast software which provides results for selected failure scenarios such as the

following:

Dispersion of toxic clouds to defined concentrations

Heat radiation intensity due to pool fire and jet fire

Explosion overpressure

Phast stands for ‘Process Hazard Analysis Software Tool’. It uses Unified

Dispersion Modeling (UDM) to calculate the results of the release of material into

the atmosphere.

Phast has extensive material database and provides for definition of mixtures.

Phast software is well validated and extensively used internationally for

consequence and risk analysis.



3.3.2 Rapid Risk Analysis (RRA)

The Rapid Risk Analysis is carried out using the renowned DNV software Phast

Risk Micro (previously known as SAFETI Micro) version 6.6.

The following input data are required for the risk calculation:

Process data for release scenarios (material, inventory, pressure,

temperature, type of release, leak size, location, etc.)

Estimated frequency of each failure case

Distribution of wind speed and direction (wind rose data).

Distribution of personnel/ population in the plant/ adjoining area during the

day and night time.

Ignition sources

Failure frequencies are estimated using generic failure databases published by

organizations such as International Oil & Gas Producers Association (OGP).

OGP Report No. 434-1 “Process Release Frequencies” for equipment & piping

OGP Report No. 434-3 “Storage Incident Frequencies”

For objective and comprehensive risk analysis, range of leak sizes is considered in

each section containing large inventory of hazardous material

Small leak (5 mm diameter)

Medium leak (25 mm diameter)

Large leak (100 mm diameter)

Full bore leak.

In case of storage tanks, dyke fire is also considered.

The results of RRA are commonly represented by the following parameters:

Individual Risk

Societal Risk

Individual risk is the risk that an individual remaining at a particular spot would

face from the plant facility. The calculation of individual risk at a geographical

location in and around a plant assumes that the contributions of all incident

outcome cases are additive. Thus, the total individual risk at each point is equal

to the sum of the individual risks, at that point, of all incident outcome cases

associated with the plant.

The individual risk value is a frequency of fatality, usually chances per million per

year, and it is displayed as a two-dimensional plot over a locality plan as contours

of equal risk in the form of iso-risk contours as shown in Figure 3.2.



FIGURE-3.2

ISO-RISK CONTOURS ON SITE PLAN (TYPICAL)

3.3.3 Risk Tolerability Criteria

For the purpose of effective risk assessment, it is necessary to have established

criteria for tolerable risk. The risk tolerability criteria defined by UK Health &

Safety Executive (UK-HSE) are normally used for risk assessment in the absence

of specific guidelines by Indian authorities.

UK-HSE has, in the publications “Reducing Risk and Protecting People” and

“Guidance on ALARP decisions in control of major accident hazards (COMAH)”

enunciated the tolerability criteria for individual risk .

Indian Standard IS 15656:2006 provides guidelines for hazard identification and

risk analysis.

The risk tolerability criteria are as follows:

An individual risk of death of one in a million (1 x 10-6) per annum for

both workers and the public corresponds to a very low level of risk and should

be used as a guideline for the boundary between the broadly acceptable and

tolerable regions.

An individual risk of death of one in a thousand (1 x 10-3) per annum

should on its own represent the dividing line between what could be just

tolerable for any substantial category of workers for any large part of a

working life, and what is unacceptable.

For members of the public who have a risk imposed on them ‘in the wider

interest of society’ this limit is judged to be an order of magnitude lower, at 1

in 10,000 (1 x 10-4) per annum.



Intolerable Risk

Risk Tolerable If ALARP

Broadly Acceptable

10-3

per year

10-6

per year

10-4

per year

10-6

per year

Risk to Personnel

Risk to Public

The upper limit of tolerable risk to public, 1 x 10-4 per year, is in the range of risk

due to transport accidents. The upper limit of broadly acceptable risk, 1 x 10-6 per

year, is in the range of risk due to natural hazard such as lightning.

The tolerability criteria for individual risk are shown in Figure-3.3.

FIGURE-3.3

INDIVIDUAL RISK CRITERIA

3.3.4 Societal Risk (or Group Risk) Criteria

Societal Risk parameter considers the number of people who might be affected by

hazardous incidents. Societal risk is represented as an F-N (frequency-number)

curve, which is a logarithmic plot of cumulative frequency (F) at which events

with N or more fatalities may occur, against N.

Societal risk criteria indicate reduced tolerance to events involving multiple

fatalities. For example a hazard may have an acceptable level of risk for one

fatality, but may be at an unacceptable level for 10 fatalities. The tolerability

criteria for societal risk as defined by UK-HSE are shown in the following Figure

3.4.



FIGURE-3.4

SOCIETAL RISK CRITERIA

3.3.5 Risk Assessment

Based on the results of RRA, necessary measures to reduce the risk to ALARP are

to be formulated. For this purpose the information regarding top risk contributors

provided by Phast Risk software is useful.



4.0 RAPID RISK ANALYSIS

4.1 Input Data

The failure scenarios and the relevant input data for RRA of BPCL Irugur Terminal

are tabulated below in Table 4.1.

TABLE 4.1

FAILURE SCENARIOS AND THE RELEVANT INPUT DATA

Item Description Failure Scenario Failure Rate for Each Item

New Storage Tanks Dyke fire

Surface fire

6.0E-05 per year

9.0E-05 per year MS Tank (T-20)

HSD Tanks (T-21/22/23)

Existing Storage Tanks

Dyke fire

Surface fire

6.0E-05 per year

1.2E-04 per year

MS/ Slop (T-1/2/7/8/12/13)

HSD/SKO (T-3/4/5/6/9/10)

Ethanol/MTO (T-14/15)

Product Pumps

5 mm leak

25 mm leak

100 mm leak

2.1E-03 per year

3.8E-04 per year

6.8E-05 per year

Truck Tanker Loading Gantry

5 mm leak

25 mm leak

100 mm leak

1.3E-03 per year

1.2E-04 per year

2.9E-05 per year

Rail Tank Wagon Loading Gantry

5 mm leak

25 mm leak

100 mm leak

1.3E-03 per year

1.2E-04 per year

2.9E-05 per year

Pipeline Pumps

5 mm leak

25 mm leak

100 mm leak

2.1E-03 per year

3.8E-04 per year

6.8E-05 per year

Notes:

Inventories are based on the data shown in Table 3.1

Failure rate notation: 6.0E-05 per year means 6.0 x 10-5 per year

Considering fully manned operations in the Terminal and provision of

fire & gas detection system with safety shut down interlock, release

duration for leaks in pump house/ gantry is estimated as 1 minute.



4.2 Population Data

The distribution of personnel in BPCL Irugur Terminal is shown in Table 4.2.

TABLE 4.2

POPULATION DATA – BPCL IRUGUR TERMINAL

S. No Area Number of Persons

1 Control room 2

2 Loading area 18

3 Pump house 2

4 Tank farms 3

5 Security 5

6 Admin building 20

7 Parking area 10

4.3 Ignition Sources

Flammable liquid hydrocarbons (MS, HSD, SKO etc.) are stored and handles in

the Devangonthi Terminal. In case of leakage or spillage, ignition of the

hydrocarbon will result in damage due to fire or explosion. Therefore,

identification of ignition sources is important in risk analysis.

The electrical and instrument items in the installation will conform to the

electrical hazardous area classification. Flame-proof electrical items will be

installed in the classified areas, and these will not be ignition sources.

Road tanker vehicles entering the depot will be provided with spark arrestors for

engine exhaust.

The following ignition sources are identified for input to Phast Risk software.

MCC room, transformer yard DG room etc. which are in unclassified area

The main road adjacent to the Depot.



4.4 Weather Data

The weather data for the site required for dispersion analysis and RRA are

provided in Table-4.3.

TABLE-4.3

CLIMATOLOGICAL DATA- COIMBATORE

Month Atmospheric

Pressure (hPa)

Temperature

(0C)

Relative

Humidity (%)

Rainfall

(mm)

0830 Hrs

1730 Hrs

Max. Min. 0830 Hrs

1730 Hrs

Monthly Total

January 999.5 995.6 32.2 19.9 76 51 10.4

February 998.6 994.2 35.0 20.7 75 42 5.3

March 997.4 992.7 37.5 22.5 73 38 13.3

April 995.3 990.7 38.9 24.9 71 46 44.3

May 992.6 988.8 39.9 25.9 63 48 55.1

June 992.3 989.0 39.0 25.8 59 48 48.5

July 992.4 989.3 38.0 25.5 60 51 57.6

August 992.9 989.4 37.8 25.1 62 52 85.5

September 994.0 990.1 36.9 24.3 66 55 108.8

October 995.8 992.1 35.5 23.4 76 65 189.9

November 997.3 993.8 32.8 22.4 79 69 153.1

December 998.7 995.2 31.5 21.0 78 64 63.5



Wind rose diagrams for Coimbatore showing the distribution of wind direction and

wind speed during a year are shown in Figure-4.1.

FIGURE-4.1

WIND ROSE DIAGRAMS

C-6.4%

2.4% WSW

08-30hrs

17-30hrs

13.9

% S

W

18.6

% S

SW

2.2

% S S

E 7.0%

E 1.3%

ENE 3.1%NE 3

.8%

NN

E 2

6.6

%

N 2

.7%0

.8%

NN

W

5.1% N

W

1.8% WNW

1.3% W

C-12.4%

SS

E 2

.8%

ESE 0.6%

4.7%

SW

0.9% N

W

0.3

% N

NW

NN

E 9

.3%

19.0

% S

SW

2.3% WSW

10

.4%

S

6.9% W

ESE 1.5%

SE 5.1%S

SE

6.1

%

ENE 4.0%

E 13.0%

N 3

.2%

NE 0

.9%

0% WNW

19

SPEED CALM

1 5 11

SCALE 4%

>19 Km/hr



The consequences of releases of flammable materials into the atmosphere are

strongly dependent upon the rate at which the released material is diluted and

dispersed to safe concentrations. The rate of dispersion is dependent on the

meteorological conditions prevailing at the time of release, particularly the wind

speed and the degree of turbulence in the atmosphere. The wind direction is also

of importance as it determines the direction in which the cloud of material will

travel. Meteorological data are thus required at two stages of the risk analysis.

Firstly, various parts of the consequence modelling require specification of wind

speed and atmospheric stability. Secondly, the impact calculations require wind-

rose frequencies for each combination of wind speed and stability specified.

The primary requirement is to choose a suitable number of combinations of wind

speed ranges and stabilities for the dispersion modelling. The procedure is to

group these combinations into representative weather classes which together

cover all conditions observed.

Whilst speed and direction are clear in definition, stability is not a widely used

term. Stability is determined by the temperature gradient in the lowest tens of

metres of the atmosphere; this in turn depends on the heating (in the day) or

cooling (at night) at the ground and on the mean wind speed. The stability

determines the degree of turbulence in the atmosphere and hence of mixing-in of

air to a released gas cloud by ambient turbulence: very unstable conditions

(occurring in the middle of a calm, sunny day) lead to much turbulence and

hence rapid dispersion while very stable conditions (occurring on a clear night)

inhibit turbulence and hence dispersion. Stability is conventionally classified by

Pasquill stability classes, denoted A to F.

Table-4.4 shows the typical split of Pasquill Stability categories according to

surface wind speed and atmospheric conditions.

TABLE-4.4

DEFINITION OF PASQUILL STABILITY CLASSES

Surface Wind

Speed (m/s)

Insolation Day Time Night Sky

Strong Moderate Thinly Overcast <3/8 Cloud

< 2 A A/B - -

2-3 A/B B E F

3-5 B B/C D E

5-6 C C/D D D

> 6 C D D D



Atmospheric stability categories A (very unstable), D (neutral) and F (stable) are

described below.

Category A (very unstable) occurs typically on a warm sunny day with light winds

and almost cloudless skies when there is a strong solar heating of the ground and

the air immediately above the surface. Bubbles of warm air rise from the ground

in thermals. The rate of change (decline) of temperature with height (lapse rate)

is very high.

Category D (neutral) occurs in cloudy conditions or whenever there is a strong

surface wind to cause vigorous mechanical mixing of the lower atmosphere.

Category F (stable) occurs typically on a clear, calm night when there is a strong

cooling of the ground and the lowest layers of the atmosphere by long wave

radiation. There is a strong inversion of temperature (i.e. warm air over cold

air).

The data needed for this study should be split by wind speed, wind direction

stability class and day/night conditions. The weather data used in present

analysis and presented in Table-4.5.

TABLE-4.5

WEATHER CATEGORIES FOR RISK ANALYSIS

Description Unit Weather #1 Weather #2 Weather #3

Temperature C 25 35 35

Relative humidity % 70 70 70

Wind speed m/s 2 3 5

Atmospheric stability - F D D

4.5 Consequence Analysis Results

In BPCL Irugur Terminal, the hazards are mainly pool fire and/or vapour cloud

explosion due to accidental release of flammable liquids such as MS, HSD, SKO,

Ethanol, etc.

Pool Fire Heat Radiation

The effects of heat radiation from pool fire are shown in the following Table-4.6.

TABLE-4.6

EFFECTS OF HEAT RADIATION

Heat Radiation Level

(kW/m2) Observed Effect

4 Sufficient to cause pain to personnel if unable to reach cover within 20 seconds; however blistering of the skin (second-degree burn) is likely; 0% lethality.

12.5 Minimum energy required for piloted ignition of wood,

melting of plastic tubing.

37.5 Sufficient to cause damage to process equipment.



Vapour Cloud Explosion (VCE)

When a large quantity of flammable vapour or gas is released, mixes with air to

produce sufficient mass in the flammable range and is ignited, the result is a

vapour cloud explosion (VCE).

In BPCL Iruguru Terminal large release of MS product in the worst case scenario

involving catastrophic tank failure has potential for vapour cloud explosion (VCE).

The damage effect of VCE is due to overpressure,

The effects of overpressure due to VCE are shown in the following Table 4.7.

TABLE 4.7

EFFECTS OF OVERPRESSURE

Over-pressure

Observed Effect bar(g) psig

0.021 0.3 “Safe distance” (no serious damage below this value);

some damage to house ceilings; 10% of window glass

broken.

0.069 1 Repairable damage; partial demolition of houses, made

uninhabitable; steel frame of clad building slightly

distorted.

0.138 2 Partial collapse of walls of houses.

0.207 3 Heavy machines (3000 lb) in industrial buildings

suffered little damage; steel frame building distorted

and pulled away from foundations.

Results of consequence analysis by Phast software for significant scenarios

relevant to Iruguru Terminal are shown in the Table-4.8. Graphical results of

consequence analysis plotted on the site map are also presented in the following

pages.



TABLE 4.8

CONSEQUENCE ANALYSIS RESULTS

Description Downwind Effect Distances (Metres)

Wind speed & Atm. Stability class 2 m/s; F 3 m/s; D 5m/s; D

New Tanks

MS Tank T-20 (Floating Roof)

Dyke fire heat radiation intensity

4 kW/m2 103 109 122

12.5 KW/m2 42 42 44

37.5 kW/m2 Not reached Not reached Not reached

VCE Overpressure

0.021 barg (0.3 psig) 329 254 174

0.069 barg (1 psig) 204 196 118

0.207 barg (3 psig) Not reached Not reached Not reached

HSD Tank T-21 (Cone Roof)


4 kW/m2 100 106 116

12.5 KW/m2 42 42 44


Existing Tanks

MS Tank T-1 (Floating Roof)


4 kW/m2 103 109 122

12.5 KW/m2 42 42 44


HSD Tank T-3 (Floating Roof)


4 kW/m2 100 106 116

12.5 KW/m2 42 42 44


HSD Tank T-7 (Floating Roof)


4 kW/m2 100 106 116

12.5 KW/m2 42 42 44


Pipeline Pump Discharge Leak (20 mm) - MS

Pool fire heat radiation intensity

4 kW/m2 46 49 53

12.5 KW/m2 18 18 20


VCE Overpressure

0.021 barg (0.3 psig) 100 124 114

0.069 barg (1 psig) 49 58 55

0.207 barg (3 psig) Not reached Not reached Not reached

Rail tank wagon loading – HSD/ MS leak

Pool fire heat radiation intensity

4 kW/m2 59 64 67

12.5 KW/m2 30 32 37




FIGURE 4.2

DYKE FIRE - MS TANK (T-20) POOL FIRE RADIATION INTENSITY

Observations:

In case of pool fire in dyke due to failure of new MS tank T-20, the heat radiation

intensity 12.5 kW/m2 falls on adjacent tank T-6 which therefore will require

cooling by water spray. Heat radiation intensity on other tanks is less than 12.5

kW/m2.

Heat radiation intensity on the tanker truck loading gantry is less than 4 kW/m2.

This provides adequate time to persons working in the gantry for safe escape as

pool fire develops slowly



FIGURE 4.3

MS TANK (T-20) - VAPOUR CLOUD EXPLOSION OVERPRESSURE

Observations:

In case of vapour cloud explosion (VCE) due to failure of new MS tank T-20, there

is no overpressure radii for 0.201 barg (3 psig) which has potential to cause

damage of structure. The explosion overpressure of 0.069 barg (1 psig) also does

not reach the new control room/ substation. The overpressure radii for 0.021

barg (0.3 psig) falls within the terminal boundary.



FIGURE-4.4

DYKE FIRE – NEW HSD TANK (T-21) POOL FIRE RADIATION INTENSITY

Observations:

In case of pool fire in dyke due to failure of new HSD tank T-21, the heat

radiation intensity on adjacent tank is less than 12.5 kW/m2. This of pool fire heat

radiation intensity within allowable limits and will not cause damage. Heat

radiation intensity radius for 4 kW/m2 falls within the terminal boundary.



FIGURE-4.5

DYKE FIRE – NEW HSD TANK (T-23) POOL FIRE RADIATION INTENSITY

Observations:

In case of pool fire in dyke due to failure of new HSD tank T-23, the heat

radiation intensity on adjacent tank is less than 12.5 kW/m2. This of pool fire heat

radiation intensity within allowable limits and will not cause damage. Heat

radiation intensity radius for 4 kW/m2 falls within the terminal boundary.



FIGURE-4.6

DYKE FIRE – EXISTING MS TANK (T-1) POOL FIRE RADIATION INTENSITY

Observations:

In case of pool fire in dyke due to failure of existing MS tank T-1, the heat

radiation intensity 12.5 kW/m2 falls on adjacent MS tank T-2 which therefore will

require cooling by water spray. Heat radiation intensity on other tanks is less

than 12.5 kW/m2.

Heat radiation intensity on the nearest new fire water tank, fire water pump

house and gantry is less than 4 kW/m2.



FIGURE-4.7

DYKE FIRE – EXISTING HSD TANK (T-3) POOL FIRE RADIATION INTENSITY

Observations:

In case of pool fire in dyke due to failure of existing HSD tank T-3, the heat

radiation intensity 12.5 kW/m2 falls on adjacent MS tank T-2 and HSD tank T-5

which therefore will require cooling by water spray. Heat radiation intensity on

other tanks is less than 12.5 kW/m2.

Heat radiation intensity on the nearest new fire water tank, fire water pump

house and gantry is less than 4 kW/m2.



FIGURE-4.8

DYKE FIRE – EXISTING HSD TANK (T-7) POOL FIRE RADIATION INTENSITY

Observations:

In case of pool fire in dyke due to failure of existing HSD tank T-7, the heat

radiation intensity on adjacent tank MS tank is less than 12.5 kW/m2.



FIGURE 4.9

PIPELINE PUMP DISCHARGE LEAK (25 MM)

POOL FIRE RADIATION INTENSITY

Observations:

In case of pool fire due to leak of MS through 25 mm diameter hole in the

discharge of pipeline pump, the pool heat radiation intensity 4 kW/m2 falls inside

the installation boundary.



FIGURE 4.10

PIPELINE PUMP DISCHARGE LEAK (25 MM) - VCE OVERPRESSURE

Observations:

In case of vapour cloud explosion (VCE) due to leak of MS through 25 mm

diameter hole in the discharge of pipeline pump, there is no overpressure radii for

0.201 barg (3 psig) which has potential to cause damage of structure.

The control room/ substation building falls outside the overpressure radius for

0.067 barg (1 psig).

The overpressure radii for 0.021 barg (0.3 psig) falls within the terminal

boundary.



FIGURE 4.11

RAIL WAGON LOADING ARM LEAK (25 MM)

POOL FIRE RADIATION INTENSITY

Observations:

In case of pool fire due to leak of diesel/MS through 25 mm diameter hole in the

loading arm of rail wagon gantry, the pool heat radiation intensity 4 kW/m2 falls

inside the installation boundary.



4.6 RRA Results

4.6.1 Individual Risk

Iso-risk contours for individual risk at BPCL Irugur Terminal due to existing as

well as new facilities including the proposed rail loading gantry are shown in the

Figure-4.11 and FIGURE 4.12.

FIGURE-4.11

ISO-RISK CONTOURS FOR INDIVIDUAL RISK AT BPCL IRUGUR TERMINAL



FIGURE-4.12

ISO-RISK CONTOURS FOR INDIVIDUAL RISK AT BPCL IRUGUR TERMINAL

(ENLARGED)

Risk contour of 1 x 10-6 per year is within the boundary of Terminal on all sides.

Thus the individual risk to members of the public is less than 1 x 10-6 per year

and falls in the Acceptable region.



The maximum iso-risk contour in the Terminal is 1 x 10-5 per year in the pump

houses and inside some dykes. Personnel are expected to be in the pump houses

for long periods whereas normal work inside dyke area is expected to be only for

very short periods.

By taking risk transect, the maximum individual risk in pump houses is found to

be 1.2 x 10-5 per year.

This corresponds to risk a person standing at the location all the time during the

year.

As the work is limited to 8 hours in a day, the maximum individual risk to person

working in the depot will be

(1.2 x 10-5) x (8/24) = 4 x 10-6 per year.

This is in the lower part of “as low as reasonably practicable (ALARP)” region as

shown in Figure 4.13.



FIGURE-4.13

INDIVIDUAL RISK AT BPCL IRUGUR TERMINAL

Intolerable Risk

Risk Tolerable if ALARP

Broadly Acceptable

10-3

per year

10-6

per year

10-4

per year

Risk to Personnel

Risk to Public

Max. Individual Risk to Personnel:

4 x 10-6

per year Max. Individual Risk to

Public: 1 x 10-6

per year



4.6.2 Societal Risk

The FN Curve for societal risk at BPCL Irugur Terminal is shown in Figure-4.14.

FIGURE-4.14

SOCIETAL RISK AT BPCL IRUGUR TERMINAL

It is seen that the societal risk is well within the Acceptable region.



5.0 CONCLUSIONS & RECOMMENDATIONS

5.1 Conclusions

The results of this RRA study for the complete BPCL Irugur Terminal including the

existing facilities and new facilities for pumping of white oil products by Irugur –

Bengaluru Pipeline lead to the following conclusions.

Individual risk to members of the public is less that 1 x 10-6 per year and

therefore in the Acceptable level.

Maximum individual risk to personnel working in the Terminal is 4 x 10-6 per

year, which is in the lower part of “As low as reasonably practicable (ALARP)”

region.

Societal risk is generally in the Acceptable region.

Consequence analysis for worst case scenarios and maximum credible scenarios

indicates that the significant effect distances for pool fire heat radiation intensity

and vapour cloud explosion overpressure fall within the terminal boundary and

are not expected to cause major damage of equipment and structures.

The above results indicate that BPCL Irugur Terminal conforms well to the risk

criteria. BPCL are expected to ensure the best practices for safety management

system, engineering, construction, operation and maintenance for the Terminal.

The installation design and construction conform to relevant Indian and

international codes & standards including OISD standards. In particular the

following safety features are note-worthy:

Layout of the Terminal is properly made conforming to OISD guidelines.

Adequate fire protection facilities including fire water storage and pumps are

provided.

The Terminal is continuously manned all the time so that any incidence of rim

seal fire in floating roof tanks can be handled without delay.

5.2 Recommendations

The following recommendations are provided to ensure that the safety standards

are in line with the current best industry practices.

Remote operated valves are to be provided in each pipe connecting to the

tank bottom. These valves are independent of the valves used for normal tank

transfer operation.

Reliable tank level instrumentation, alarm and safety interlock system need to

be provided using guided wave radar type level transmitters. The tank overfill

protection system should be independent of the tank gauging system to

ensure multiple independent protection layers to prevent tank overfill hazard.



Fixed water spray system is to be provided for MS tanks as per OISD

guidelines.

Semi-fixed foam system with suitable heat detection and alarm system for the

rim seal is provided for the floating roof tanks storing MS product to ensure

timely application of foam to prevent escalation of rim seal fires.

Emergency push buttons to stop loading pumps and close tank outlet valves

are to be provided at safe locations in the Terminal to limit the quantity of fuel

released in case of a leak. This is required for rail wagon loading gantry also.

It shall be ensured that the instruments and electrical fittings installed in the

terminal conform to the electrical hazardous area classification. Special

attention is required in maintenance of explosion-proof electrical equipment.

Suitable arrangement for containment and collection of spillages are to be

provided in loading area.

Tank dykes should be maintained in sound condition without openings or

cracks. The dyke drain valves are to be kept closed except during rain.

Alcohol-resistant foam is available at the installation for use in fighting ethanol

fire.

A Committee headed by Mr. M. B. Lal constituted by MoPNG has made

valuable recommendations in its report dated September 2009 on the Jaipur

fire incident. It shall be ensured that all relevant recommendations are

incorporated in the design, construction, operation and maintenance of the

installation.

- - - - x - - - -



ANNEXURE–1

IRUGUR TOP INSTALLATION – LAYOUT PLAN SHOWING FACILITIES

(BPCL DRAWING NO. IRG-001)

rapid risk assessment studies...

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