hpcl qra

7/25/2019 HPCL QRA

1/104

DET NORSKE VERITAS

Report on

QRA for POL IRDs/ depots

BHARATPUR

For

Hindusthan Petroleum Corporation Limited

Mumbai 400 001Maharashtra, India

7/25/2019 HPCL QRA

2/104

DET NORSKE VERITAS

QRA for POL IRD/depot

MANAGING RISKBharatpur

QRA for POL IRDs/ depots

Bharatpur

DET NORKSE VERITAS AS

EMGGEN CHAMBERS,

10C.S.TROAD,VIDHYANAGARI,

SANTACRUZ (E),KALINA

MUMBAI 400098

TEL:+912226676400

FAX: +912226653380

http://www.dnv.com

For:

Hindusthan Petroleum Corporation LimitedGresham Assurance Building, Sir P.M. Road,

Post Box No. 198, Fort,

Mumbai 400 001

Maharashtra, India

Account Ref.:

K Somashekhar Rao, Sr. Manager HSE-O&D

[email protected]

Date of First Issue: 2013-05-29 Project No. PP046380

Report No.: 12QR1P2-27 Organisation Unit: Maritime & Oil and Gas, India

Revision No.: 02 Subject Group: SHE

Summary:

DNV conducted Quantitative Risk Assessment (QRA) for HPCL POL IRDs/ depots. This QRA Study aimsto identify Individual and Societal Risk associated with the Bharatpur location. This report presents the

DNVs findings and conclusion from the study.

Prepared by:Vishalakshi Daine

ConsultantSignature

Verified byAnil Bhat Avvari

ConsultantSignature

Approved by:

Salian Varadaraja

Project Sponsor Signature

No distribution without permission from the client or responsibleorganisational unit (however, free distribution for internal use

within DNV after 3 years)Indexing Terms

No distribution without permission from the client or responsible

organisational unitKeyWords

QRA

Strictly confidentialServiceArea

SHE Risk Management

Unrestricted distributionMarket

Segment

Oil & Gas

Rev. No. / Date: Reason for Issue: Prepared by: Verified by Approved by:

02/30-07-2013 Draft report issued to HPCL

for comments

VDAI AVAB VASAL

All rights reserved. This publication or parts thereof may not be reproduced or transmitted in any form or

7/25/2019 HPCL QRA

3/104

DET NORSKE VERITAS



Executive Summary

Det Norske Veritas (DNV) conducted a Quantitative Risk Assessment (QRA) study

covering the entire HPCL POL IRDs/ depots. The presentation of results is in line with

UK HSE guidelines. This report presents the DNVs study findings and conclusion from

the study for the Bharatpur.

The overall objective of the QRA study is to quantify the level of individual fatality risks

associated with the Bharatpur; and to demonstrate that the level of risks is in compliance

with the UK HSE guidelines

Based on the QRA study for the Bharatpur, the following conclusions and

recommendations can be drawn:

Area under Study Major HazardRecommended Control

/Mitigation

Tank Farm

Pool fire and Tank fire are

major events in the Tankfarm area, leading to the

escalation of the fire fromone tank to the another

Ensure availability ofwater spray system in thetank farm area for

protecting the tank from

the external fire

Ensure regularmaintenance procedure to

reduce likelihood of failureof the valves, flanges and

pipes

Pump House Area

Release of pressurizedinventories from the pump

house may cause severe

damage in the Depotpremises

Consider providing HC

detectors in Pump house

area

Gantry Operations

Fire due to Leak during TT

loading operations. Major

events of pool fire due toleak or spillage, flash fire

are observed Hazardous

As the gantry area is ahigh risk

and high consequencezone, ensure minimum

activity of trucks andpersonnel in this area.

7/25/2019 HPCL QRA

4/104

DET NORSKE VERITAS




/Mitigation

gantry and TT crew.

Consider provision of HCdetectors for early

detection of

hazardous leaks.

Ensure training, SOP,emergency procedures

established andimplemented for all

personnel at gantry.

Ensure PPE usage by all

personnel.

Ensure that the loaded

trucks spend minimumtime near the gantry after

the loading operations

Office Building

Fire radiation due to leak

from the loaded tanker

trucks.

Ensure that the loadedtrucks spend minimum

time near the gantry after


Even though the Individual and societal risk levels of the Bharatpur has been found to be

in ALARP region in assessing with HSE UK risk criteria, In order to maintain the level of

risk at this level, cost effective risk mitigation measures should be implemented to

mitigate the risks to a level that is As Low As Reasonably Practicable (ALARP).

7/25/2019 HPCL QRA

5/104

DET NORSKE VERITAS



GLOSSARY

ALARP: As Low As Reasonable Practical

HSE : Health Safety Environment

IR : Individual Risk

JF : Jet Fire

kW/m2 : Kilo Watt per Square Metre, a measure of heat flux or radiant heat

LFL : Lower Flammable LimitLOC : Loss of containment

LSIR : Location Specific Individual Fatality Risk per year

P&ID : Piping and Instrumentation Diagram

PLL : Potential Loss of Life

QRA : Quantitative Risk Assessment

UFL : Upper Flammable Limit

UK HSE: UK Health and safety Executive

VCE : Vapour Cloud Explosion

7/25/2019 HPCL QRA

6/104

DET NORSKE VERITAS



TABLE OF CONTENTS

Executive Summary .......................................................................................................... III

1

INTRODUCTION .......................................................................................................... 1

1.1 Background ............................................................................................................ 1

1.2 Objectives ............................................................................................................... 1

1.3

Scope of Study ........................................................................................................ 1

1.4 Report Structure ...................................................................................................... 2

1.5 Facility Description................................................................................................. 3

1.6 Input Data ............................................................................................................... 5

1.6.1 Material Inventory ................... ......................................................................... 5

1.6.2 Process Conditions ........................................................................................... 5

1.6.3 Material Composition ....................................................................................... 5

1.6.4

Weather ............................................................................................................ 5

1.6.5 Ignition Sources................................................................................................ 5

1.6.6 Population ........................................................................................................ 5

2

RISK ASSESSMENT CRITERIA ................................................................................ 6

2.1 UK HSE criteria ...................................................................................................... 6

2.2 Individual Risk Criteria ........................................................................................... 7

2.3 Societal Risk Criteria .............................................................................................. 8

3

RISK RESULTS ............................................................................................................ 9

3.1 Individual Risk ....................................................................................................... 9

3.2 Societal Risk ......................................................................................................... 11

3.2.1 FN Curve ........................................................................................................ 11

4

CONCLUSIONS AND RECOMMENDATIONS ....................................................... 13

5

REFERENCES ............................................................................................................ 15

7/25/2019 HPCL QRA

7/104

DET NORSKE VERITAS



List of Tables

Table 2-1: Societal Risk Criteria Onsite ............................................................................................................... 8

Table 3-1: LSIR ....................................................................................................................................................... 9

List of Figures

Figure 1-1: Bharatpur Layout ............. ............ .............. ............. .............. ............ ............. .............. .............. .......... 3Figure 1-2: Bharatpur Layout .................................................................................................................................. 4

Figure 2-1: ALARP Principle .................................................................................................................................. 6

Figure 2-2: FN Curve and Criterion Line ................................................................................................................ 7

Figure 3-1: Individual Risk Contours for Bharatpur ............................................................................................. 10

Figure 3-2: FN Curve Onsite ................................................................................................................................. 11

Figure 3-3: FN Curve Offsite ................................................................................................................................ 12

7/25/2019 HPCL QRA

8/104

DET NORSKE VERITAS



1

INTRODUCTION

1.1 Background

Det Norske Veritas (DNV) conducted a Quantitative Risk Assessment (QRA) study

covering the entire HPCL POL IRDs/ depots. The presentation of results is in line with

UK HSE guidelines. This report presents the DNVs study findings and conclusion from

the study for the Bharatpur.

1.2 Objectives

The overall objective of the QRA study is to

- Quantify the level of individual fatality risks associated with the Bharatpur; and

- Demonstrate that the level of risks is in compliance with the UK HSE guidelines

1.3 Scope of Study

DNV has performed the work in accordance to the UK HSE guidelines. Following are the

important aspects of this study:

- Verify the individual and societal risk levels in accordance with UK HSE criteria

- Tabulation of the consequences in terms of:

Distances to radiation levels, Lower Flammability Limit (LFL) and

explosion overpressure for different weather classes according to specific

criteria classes.

7/25/2019 HPCL QRA

9/104

DET NORSKE VERITAS



1.4

Report Structure

This report presents:

Section 1 Introduction

This section provides a general introduction of the project, the main

objectives of the QRA study, the scope of study, and the structure of this

report.

Section 2 Risk Assessment Criteria

This action outlines the risk criteria applied in this QRA study.

Section 3 Risk Results

This section provides the risk results due to process hazard

Section 4 Conclusions and Recommendation

This section outlines the overall conclusions of the study and provides the

recommendation to be implemented in order to ensure ALARP

performance in the operation.

Section 5 Reference

This section details the reference used in this QRA.

Annexe 1 QRA Methodology

This appendix explains the QRA methodology applied in this QRA.

Annexe 2 Assumptions Register

The assumptions presented are applied in the modelling and preparation

of the reports/technical notes.

Annexe 3 Failure case and frequency analysis

This appendix defines the failure cases selected for analysis, as well asthe corresponding frequencies.

Annexe 4 Consequence Analysis

This appendix presents outcome of an event in terms of toxic, fire and

explosion.

7/25/2019 HPCL QRA

10/104

DET NORSKE VERITAS



Report No.: 12QR1P2-27

Rev 02, 30thJuly, 2013

Page 3

1.5 Facility Description

The Bharatpur layout is shown in the figure below.

Figure 1-1: Bharatpur Layout

7/25/2019 HPCL QRA

11/104

DET NORSKE VERITAS


MANAGING RISK

Bharatpur



Page 4

Figure 1-2: Bharatpur Layout

7/25/2019 HPCL QRA

12/104

DET NORSKE VERITAS



s

1.6 Input Data

1.6.1

Material Inventory

Material required for the QRA study is taken from the Mass and Energy balance sheet

provided by the client. The static and dynamic inventory is calculated based on the flow

rate and equipment dimension provided by the client. The inventory details with respect

to vessel and pipelines is given at Annexe 3 - Failure case and frequency analysis.

1.6.2 Process Conditions

The process conditions like temperature and pressure required for the QRA study is taken

from the Mass and Energy balance sheet and Process flow diagram provided by the client.

The details are placed in a table at Annexe 3 - Failure case and frequency analysis.

1.6.3

Material Composition

Material required for the QRA study is taken from the Mass and Energy balance sheet

provided by the client for most of the cases. If the data is not available suitable

representative material is considered as per DNV Technical note 13 and international

standard. This is explained in Assumption Register (Annexe 2) in detail.

1.6.4

Weather

Meteorological data are required at two stages of the QRA. First, various parts of the

consequence modelling require specification of wind speed and atmospheric stability.

Second, the impact (risk) calculations require wind-rose frequencies for each combination

of wind speed and stability class used.

1.6.5 Ignition Sources

In order to calculate the risk from flammable materials, information on the ignition

sources (which are present in the area over which a flammable cloud may drift) is

required.

1.6.6

Population

All the population details are provided to the study and the presence factor is explained with

respect to the unit is given in details in Assumption Register (Annexe 2).

7/25/2019 HPCL QRA

13/104

DET NORSKE VERITAS



s

2

RISK ASSESSMENT CRITERIA

In order to determine acceptability, the risk results are assessed against a set of risk

criteria as per UK HSE criteria.

2.1 UK HSE criteria

Following points details the UK HSE guidelines:

- An individual risk below 1 x 10-6 fatalities per year is considered as acceptable for

both plant workers and public. An individual risk above 1 x 10-4

fatalities per year for

public is considered as unacceptable and an individual risk above 1 x 10-3

fatalities

per year for workers is considered unacceptable. Between these limits the risk is

considered as ALARP (As Low as Reasonably Practicable). An indication of this is

shown in the below figure

Figure 2-1: ALARP Principle

7/25/2019 HPCL QRA

14/104

DET NORSKE VERITAS



s

Often casualties are defined in a risk assessment as fatal injuries, in which case N is

the number of people that could be killed by the incidents.

Figure 2-2: FN Curve and Criterion Line

2.2 Individual Risk Criteria

The UK HSE Individual Risk Criteria was considered to assess the risk for HPCL POL

IRDs/ depots. Individual risk above 10-3 per annum for any person shall be considered

intolerable and fundamental risk reduction improvements are required.

Risk criteria for Individual Risk for on-site are as follows:

- Individual risk levels above 1 x 10-3per yearwill be considered unacceptable and

will be reduced, irrespective of cost

- Individual risk levels below 1 x 10-6per yearwill be broadly acceptable

- Risk levels between 1 x 10-3 and 1 x 10-6per year will be reduced to levels as low as

7/25/2019 HPCL QRA

15/104

DET NORSKE VERITAS



s

2.3

Societal Risk Criteria

When considering the risk associated with a major hazard facility, the risk to an

individual is not always an adequate measure of total risks; the number of the individuals

at risk is also important. Catastrophic incidents with the potential multiple fatalities have

a little influence on the level of risk but have a disproportionate effect on the response of

society and impact of company reputation.

The concept of societal risk is much more than that for individual risk. A number offactors are involved which make it difficult to determine single value criteria for

application to a number of different situations. These factors include;

- The hazard, the consequential risks and the consequential benefits

- The nature of assessment

- Factors of importance to the company, government, regulators and authorities, public

attitudes and perception and aversion to major accidentSocietal risk is the relationship between frequency of an event and the number of people

affected. Societal risk from a major hazard facility can thus be expressed as the

relationship between the number of potential fatalities N following a major accident and

frequency F at which N fatalities are predicated to occur. The relationship between F and

N, and the corresponding relationship involving F, the cumulative frequency of events

causing N or more fatalities, are usually presented graphically on log-log axis.

DNV has used following societal risk criteria. Societal risk should not be confused as

being the risk to society or the risk as being perceived by society. The word societal is

merely used to indicate a group of people and societal risk refers to the frequency of

multiple fatality incidents, which includes workers and the public. Societal risk is usually

represented by an FN (Frequency Number of Fatality) curve.

Table 2-1: Societal Risk Criteria Onsite

Maximum Tolerable

Intercept With N=1

Negligible

Intercept With N=1

10-2

10-4

7/25/2019 HPCL QRA

16/104

DET NORSKE VERITAS



s

3

RISK RESULTS

3.1

Individual Risk

Location specific individual risk (LSIR) is used to indicate the risk at a particular

location. It is the risk for a hypothetical individual who is positioned there for 24 hours

per day, 365 days per year. It is a standard output from a QRA. In onshore studies, the

geographical variation of LSIR may be represented by iso-risk contour plots and used for

land-use planning. In offshore studies, an LSIR value is normally computed for each

separate module on the installation. Since in reality people do not remain continually at

one location, this is not a realistic risk measure.

Table 2.1 presents the LSIR

Table 3-1: LSIR

S.No Location LSIR Remarks

1 D.G Control room 5.62E-07 Acceptable

2 Gantry 7.38E-07 Acceptable

3 Office Building 3.60E-06 Acceptable

4 Workers change room 3.34E-06 Acceptable

Table 3-2: Major Risk Contributors to office building

S.No Location Risk/yr %

1 Large Leak from MS Tanker 8.42E-07 23.40

2 Large Leak from SKO Tanker 7.22E-07 20.08

3 Large Leak from HSD Tanker 6.25E-07 17.39

4 Medium leak from MS Tanker 3.91E-07 10.88

5 Medium leak from SKO Tanker 2.97E-07 8.27

7/25/2019 HPCL QRA

17/104

DET NORSKE VERITAS


MANAGING RISK

Bharatpur



Page 10

Figure 3-1: Individual Risk Contours for Bharatpur

7/25/2019 HPCL QRA

18/104

DET NORSKE VERITAS



3.2

Societal Risk

3.2.1 FN Curve

FN curve defines the societal risk. It represents the relationship between the frequency

and the number of people suffering a given level of harm from the realisation of specified

hazards. It is usually taken to refer to the risk of death and usually, expressed as a risk per

year.

The following figure presents the onsite societal risk FN Curve for Bharatpur. The blueline represents the upper limit of risk and the green line represents the lower level of

risk. The region between this two represents the risk in the ALARP (AS LOW AS

REASONABLY PRACTICABLE) region. The region beyond the blue line indicates the

unacceptable region and the region below blue line represents the broadly acceptable

region. The red line represents the level of societal risk that has been realised around

Bharatpur.

Figure 3-2: FN Curve Onsite

7/25/2019 HPCL QRA

19/104

DET NORSKE VERITAS



-

Compared to the UK HSE risk criteria, the FN Curve shows that societal risk is withinthe Acceptable region and does not exceed the unacceptable criteria.

FN Curve Offsite

No Risk curve found for offsite population

7/25/2019 HPCL QRA

20/104

DET NORSKE VERITAS



4

CONCLUSIONS AND RECOMMENDATIONS


/Mitigation

Tank Farm

Pool fire and Tank fire are

major events in the Tank

farm area, leading to the

escalation of the fire fromone tank to the another

Consider providing waterspray system in the tank

farm area for protectingthe tank from the external

fire

Ensure regularmaintenance procedure to

reduce likelihood of failureof the valves, flanges and

pipes

Pump House Area

Release of pressurizedinventories from the pump

house may cause severe

damage in the Depot

premises

Consider providing HCdetectors in Pump house

area

Dyke should be provided

to the pumps to limit poolformation of the release

inventory

Gantry Operations

Fire due to Leak during TTloading operations. Major

events of pool fire due to

leak or spillage, flash fireare observed. Hazardous

radiation levels of 12.5kw/m2 and 37.5 kW/m2 are

observed close to gantry.

As the gantry area is ahigh riskand high consequencezone, ensure minimum

activity of trucks andpersonnel in this area.

Ensure emergency escape

routeis provided and informedto all

gantry and TT crew.

Consider provision of HC

detectors for early

7/25/2019 HPCL QRA

21/104

DET NORSKE VERITAS



Area under Study Major Hazard Recommended Control/Mitigation

Ensure training, SOP,emergency procedures

established and

implemented for allpersonnel at gantry.

Ensure PPE usage by allpersonnel.


time near the gantry afterthe loading operations

Office Building

Fire radiation due to leak

from the loaded tanker

trucks.


time near the gantry after


7/25/2019 HPCL QRA

22/104

DET NORSKE VERITAS



5

REFERENCES

- Methods for the calculation of physical effects due to releases of hazardous

materials (liquids and gases) TNO Yellow Book, CPR 14E, 2005

- A Flack / B Bain / T Lindberg / J R Spouge Process Equipment Failure

Frequencies Rev. 04, October 2009 for Process Pipes, Pumps, Atmospheric

Storage Tank

- CCPS, Guidelines for Consequence Analysis of Chemical Releases, American

Institute of Chemical Engineers, 1999.

- Lees, F. P., Loss Prevention in the Process Industries, Butterworth-Heinemann,

1996

- Oil Industry Safety Directorate (OISD), First Edition, August 2007.

- Robin Pitblado, Andreas Flack, Phil Crosthwaite, David Worthington,

Consequence Handbook, Report no.:70037714, August 2008

- TNO, Guidelines for Quantitative Risk Assessment, The Purple Book, 2009

7/25/2019 HPCL QRA

23/104

Det Norske Veritas:

Det Norske Veritas (DNV) is a leading, independent provider of services for managing risk witha global presence and a network of 300 offices in 100 different countries. DNVs objective is tosafeguard life, property and the environment.

DNV assists its customers in managing risk by providing three categories of service:classification, certification and consultancy. Since establishment as an independent foundationin 1864, DNV has become an internationally recognised provider of technical and managerialconsultancy services and one of the worlds leading classification societies. This meanscontinuously developing new approaches to health, safety, quality and environmental

management, so businesses can run smoothly in a world full of surprises.

Global impact for a safe and sustainable future:

Learn more on www.dnv.com

7/25/2019 HPCL QRA

24/104

DET NORSKE VERITAS

QRA for POL terminal/depot


Annexe 1

QRA Methodology

7/25/2019 HPCL QRA

25/104

DET NORSKE VERITAS



Table of Contents

1 QRA METHODOLOGY ............................................................................................... 1

1.1 Introduction to Risk Assessment ............................................................................. 1

1.2 What is QRA? ......................................................................................................... 2

1.3 Key Components in QRA ....................................................................................... 2

2 QRA APPROACH ......................................................................................................... 5

2.1.1 Hazard Identification ........................................................................................ 5

2.2 Consequence Modelling/Phast Software ................................................................. 6

2.3 Frequency Analysis................................................................................................. 7

2.4 Risk Calculation/PHASTRISK Software ................................................................. 7

2.4.1 Built-In Event Trees ......................................................................................... 7

2.4.2 Atmospheric Condition ................................................................................... 10

2.4.3 Risk Presentation: .................... ....................................................................... 10

3 QRA SOFTWARE TOOL ........................................................................................... 12

D N V

7/25/2019 HPCL QRA

26/104

DET NORSKE VERITAS



List of TablesTable 2-1: Explosion Overpressure Effects ............................................................................................................. 6Table 2-2: Effects of Thermal Radiation ................................................................................................................. 7Table 3-1 PHAST RISK Default Vulnerability Parameters .................................................................................. 17

List of Figures

Figure 1-1: QRA methodology ................................................................................................................................ 3Figure 1-2: ALARP Principle .................................................................................................................................. 4Figure 2-1 : Event Tree 1 Continuous Vapour Release ........................................................................................ 8Figure 2-2: Event Tree 2 Continuous Release with Rainout ................................................................................ 8Figure 2-3: Event Tree 3 Instantaneous Vapour Release...................................................................................... 9Figure 2-4: Event Tree 4 Instantaneous Release with Rainout ............................................................................. 9

DET NORSKE VERITAS

7/25/2019 HPCL QRA

27/104

DET NORSKE VERITAS



1

QRA METHODOLOGY1.1 Introduction to Risk Assessment

This section is presented to assist the reader who is not familiar with the terms used in

this document and for those who are familiar to confirm DNV understanding of the terms

and their application in the context of this document. An oil & gas facility has the

potential to cause harm such as:

- Sickness, injury or death of workers and people in the surrounding community- Damage to property and investments

- Degradation of the physical and biological environment

- Interruption to production and disruption of business

A state or condition having the potential to cause a deviation from uniform or intended

behaviour which, in turn, may result in damage to property, people or environment, is

known as hazard. Thus a scraper trap is a hazard because it has the potential to cause a

fire; processes such gas compression is a hazardous activity because it has the potential to

cause fires and explosions. The word hazard does not express a view on the magnitude

of the consequences or how likely it is that the harm will actually occur. A major

hazard is associated with Loss of Containment and has the potential to cause significant

damage or multiple fatalities. Again, the term does not imply that such events are likely.

Incidents are the actual realization of a hazard, i.e. an event or chain of events, which has

caused or could have caused personal injury, damage to property or environment. Theyare sudden unintended departures from normal conditions in which some degree of harm

is caused. They range from minor incidents such as a small gas leak to major accidents

such as Flixborough, Mexico City, Bhopal, Pasadena, Texas City, etc. Sometimes, the

more neutral term event is used in place of the more colloquial term incident. For

flammable incidents, ignition has to take place for a hazard to be realized.

Risk is the combination of the likelihood and the consequences of such incidents. More

scientifically, it is defined as the likelihood of a hazard occurrence resulting in an

undesirable event. The likelihood may be expressed either as a frequency (i.e. the rate of

events per unit time) or a probability (i.e. the chance of the event occurring in specified

circumstances). The consequence is defined as an event or chain of events that result from

the release of a hazard The impact or effect is the degree of harm caused by the event

DET NORSKE VERITAS

7/25/2019 HPCL QRA

28/104

DET NORSKE VERITAS



1.2

What is QRA?Quantitative risk assessment (QRA) is a means of making a systematic analysis of the

risks from hazardous activities, and forming a rational evaluation of their significance, in

order to provide input to a decision-making process.

QRA is sometimes called probabilistic risk assessment term originally used in the

nuclear industry. The term Quantified Risk Assessment is synonymous with QRA as

used here. The term quantitative risk analysis is widely used, but strictly this refers to

the purely numerical analysis of risks without any evaluation of their significance.

QRA is probably the most sophisticated technique available to engineers to predict the

risks of accidents and give guidance on appropriate means of minimizing them.

Nevertheless, while it uses scientific methods and verifiable data, QRA is a rather

immature and highly judgmental technique, and its results have a large degree of

uncertainty. Despite this, many branches of engineering have found that QRA can give

useful guidance. However, QRA should not be the only input to decision-making aboutsafety, as other techniques based on experience and judgment may be appropriate as well.

1.3 Key Components in QRA

The study is based on the premises of a traditional Quantitative Risk Assessment. The key

components of QRA are explained below, and illustrated in Figure 1-1.

The first stage in a QRA is defined as system definition where the potential hazardsassociated with a facility or activities are to be analyzed. The scope of work for a QRA

should be to define the boundaries for the study, identifying which activities are to be

included and which are excluded, and which phases of the facilitys life are to be

assessed. The hazard identification consists of a qualitative review of possible accidents

that may occur, based on previous accident experience or judgment where necessary.

There are several formal techniques for this, which are useful in their own right to give a

qualitative appreciation of the range and magnitude of hazards and indicate appropriatemitigation measures. This qualitative evaluation is described in this guide as hazard

assessment.

DET NORSKE VERITAS

7/25/2019 HPCL QRA

29/104

DET NORSKE VERITAS



In a QRA, hazard identification uses similar techniques, but has a more precise purpose defining the boundaries of a study in terms of materials to be modelled, release conditions

to be modelled, impact criteria to be used, and identifying and selecting a list of failure

cases that will fully capture the hazard potential of the facilities to be studied. Failure

cases are usually derived by breaking the process system down into a larger number of

sub- systems, where failure of any component in the sub-system would cause similar

consequences. In pipeline case, this can be performed by breaking the line into sections

depending on availability of isolation valves along the line.

Figure 1-1:QRA methodology

O th t ti l h d h b id tifi d th f l i ti t h

DET NORSKE VERITAS

7/25/2019 HPCL QRA

30/104

DET NORSKE VERITAS



In parallel with the frequency analysis, consequence modelling evaluates the resulting

effects if the accidents occur, and their impact on people, equipment and structures, the

environment or business, depending on the defined scope of the QRA study. Estimation

of the consequences of each possible event often requires some form of computer

modelling. Consequence analysis requires the modelling of a number of distinctive

phases, i.e. discharge, dispersion, fires and explosions (for flammable materials).

Closely liaised with the consequence assessment is the impact assessment, i.e. how does

the fire, explosion or toxic cloud affect human beings. When the frequencies and

consequences / impact of each modelled event have been estimated, they can be

combined to produce risk results. Various forms of risk presentation may be used,

commonly grouped as follows:

- Individual risk - the risk experienced by an individual person

- Group/Societal risk - the risk experienced by a group of people exposed to the

hazard

The next stage is to introduce criteria, which are yardsticks to indicate whether the risks

are acceptable, or to make some other judgment about their significance. Risk assessment

is the process of comparing the level of risk against a set of criteria as well as the

identification of major risk contributors. The purpose of risk assessment is to develop

mitigation measures for unacceptable generators of risk, as well as to reduce the overall

level of risk to As Low as Reasonably Practical (Figure 1-2).

Figure 1-2: ALARP Principle

High Risk

ALARP

Region

Unacceptable

Region

Given immediate

attention and a response

developed commensurate

with the scale of the threat

Broadly acceptableonly if risk reduction

is impracticable or if

its cost is grossly

disproportionate to

the improvement

gained

High Risk

ALARP

Region

Unacceptable

Region

Given immediate

attention and a response

developed commensurate

with the scale of the threat

Broadly acceptableonly if risk reduction

is impracticable or if

its cost is grossly

disproportionate to

the improvement

gained

DET NORSKE VERITAS

7/25/2019 HPCL QRA

31/104



2

QRA APPROACH2.1.1 Hazard Identification

Hazard identification is the structured study of a plant in order to produce a list of

foreseeable, potentially hazardous releases. In a plant, there is a wide range of substances

that, if released, could cause injury or fatality. The hazards applicable for the plant have

been identified through:

- Knowledge transfer from other risk assessments for boosting station plants carried

out by DNV within the applicable confidentiality constraints

- Site specific parameters

- The selection of appropriate hazards considered a range of issues, including:

Nature of potential hazards

Position of plant in relation to the surrounding community

Complexity of the process

DNV has concentrated on the flammable hazards.

A list of the main process streams is defined from the Process Flow Schemes (PFS). Of

these, some were considered to be non-hazardous (e.g., water streams) or only likely to

give a local hazard (e.g., small pool fires), and were not analyzed further. The streams

identified to be hazardous were further analyzed in the QRA.

The range of possible releases for a given stream covers a wide spectrum, from a pinholeleak up to a catastrophic rupture (of a vessel) or full bore rupture (of a pipe). It is both

time-consuming and unnecessary to consider every part of the range; instead, a finite

number of failure cases are generated to characterize each unit. The number of specific

cases and the distribution of the cases in terms of the size which are analyzed

quantitatively take into account the potential consequences and the format of the

frequency data that are being used.

DET NORSKE VERITAS

7/25/2019 HPCL QRA

32/104



2.2

Consequence Modelling/Phast SoftwareThe consequence analysis is performed using DNV proprietary software PHAST. PHAST

is a consequence and impact assessment module integrated within DNV risk calculation

software PHASTRisk. PHAST calculates wide range of possible consequences from the

LOC events, including:

- Jet Fire, causing thermal radiation impact

- Pool Fire, causing thermal radiation impact

- Flash Fire, causing thermal radiation impact within the flammable cloud envelope

- Explosion, causing overpressure impact

Various factors affecting the extent of consequence are also considered within the

PHAST model which includes:

- Atmospheric conditions, including solar radiation flux, ambient temperature,humidity and wind speed/direction as well as weather stability

- Release location- Release orientation

Detailed findings of the consequence analysis for selected failure cases are presented in

Section 6. The qualitative levels of explosion and heat radiation effects are described in

Table 2-1 and

DET NORSKE VERITAS

7/25/2019 HPCL QRA

33/104



Table 2-2 respectively are used to assess the likelihood of harm to people or thelikelihood of further loss of containment and / escalation as per DNV Technical note.

Table 2-1: Explosion Overpressure Effects

Overpressure (bar) Effects Within Zone

0.02 10% window glass broken

0.05 Window glass damage causing injury0.1 Repairable damage to buildings and house facades

0.2 Structural damage to buildings

0.35 Heavy damage to buildings and process equipment

DET NORSKE VERITAS

7/25/2019 HPCL QRA

34/104



Table 2-2: Effects of Thermal Radiation

Radiation Intensity

(kW/m2) Observed Effect

37.5 Sufficient to cause damage to process equipment

25Minimum energy required to ignite wood at indefinitely long

exposures (non piloted)

12.5Minimum energy required for piloted ignition of wood,

melting plastic tubing

9.5Pain threshold reached after 8 sec, second degree burns after

20 sec

4

Sufficient to cause pain to personnel if unable to reach cover

within 20 s, however blistering of the skin (second degree

burns) is likely; 0% lethality

1.6 Will cause no discomfort for long exposure

2.3

Frequency Analysis

The failure frequencies for the scenarios developed are obtained from DNVs Technical

Notes (TN 14).

2.4 Risk Calculation/PHASTRISK Software

As mentioned earlier, DNV proprietary software PHASTRisk is used for the main risk

calculation in the study. PHASTRisk combines consequence results from the PHAST

module with a range of risk-related information in order to produce risk results.

2.4.1

Built-In Event Trees

PHASTRisk has 4 built-in consequence outcome event trees, i.e. continuous vapour

release, continuous release with rain-out1, instantaneous vapour release,

release with rain-out. These event trees are presented in

to

. It is noted that No Ignition event leads to No Effect for flammable-only material

release.

DET NORSKE VERITAS

7/25/2019 HPCL QRA

35/104



Figure 2-1 : Event Tree 1 Continuous Vapour Release

Figure 2-2: Event Tree 2 Continuous Release with Rainout

DET NORSKE VERITAS

7/25/2019 HPCL QRA

36/104



DET NORSKE VERITAS

QRA f POL i l/d

7/25/2019 HPCL QRA

37/104



Figure 2-3: Event Tree 3 Instantaneous Vapour Release

Figure 2-4: Event Tree 4 Instantaneous Release with Rainout

PHAST RISK also accounts for a short duration continuous release an event where a

DET NORSKE VERITAS


7/25/2019 HPCL QRA

38/104



Further, in the event of an instantaneous vapour release, PHASTRisk models the event as

a pure fireball, in which the thermal radiation impact defines the level of human fatality,

discounting the overpressure wave which may accompany the event.

Various probability factors which will determine the route of event within the event trees

are also determined in the PHASTRisk model. These include:

Immediate Ignition:This is directly specified and will be different depending on the size

of the release.

Delayed ignition:This is a calculated value within PHASTRisk, unique to each release

case and release direction. The calculation is based on the strength, location and presence

factor of all ignition sources specified, and the extent and duration of dispersing

flammable vapour clouds being exposed to those sources. Delayed ignition sources can be

modelled as point sources (e.g. ground flares), line sources (roads, power lines) or area

sources (e.g. to cater for background sources posed by a variety of human activity).

Fireball / flash fire / explosion probability in the event of immediate ignition ofinstantaneous release. This is directly specified in PHASTRisk. Flash fire/explosion

probability in the event of delayed ignition. This is also directly specified in PHASTRisk.

Entire Complex has been considered as Ignition source with ignition probability 0.09 and

operating probability 1 as per DNV Technical Note.

2.4.2

Atmospheric Condition

Variation in wind direction defines the apparent orientation of consequences. PHASTRiskaccounts for the different wind directions from the wind distribution probability input and

combine the values into the risk calculation. Atmospheric conditions, which include

temperature and humidity, are also addressed.

2.4.3

Risk Presentation:

Risk would be presented in terms of Individual and Societal (group).

Individual Risk per Annum (IRPA) is the annual frequency that any individual in aspecific worker group becomes a fatality. Individual risk criteria are intended to ensure

that individual workers are not exposed to excessive risk levels on an installation. They

are largely independent of the number of workers exposed, and hence in principle may be

applied to different situations

DET NORSKE VERITAS


7/25/2019 HPCL QRA

39/104



separate module on the installation. Since in reality people do not remain continually at

one location, this is not a realistic risk measure.

IRPA = LSIR x presence factor

Risk is defined as the product of the consequences (here measured as harm to people) and

the likelihood of occurrence (i.e. an expected rate of occurrence per year). Societal (or

group) risk measures the risk of an operation to the company, the industry or a

community. There are several ways of presenting societal risk, but the measure, which is

found to be most useful for offshore installations, is the Potential Loss of Life (PLL).

PLL is defined as the long term average number of fatalities per year due to a specific

cause and can be expressed mathematically as:

PLL = f . N

Where:

= sum for all outcomes

f = frequency of an outcome (per year)

N = number of fatalities caused by the outcome

Potential Loss of Life (PLL) is the measure of the average number of statistical fatalities

that may be expected within a given time period. "PLL per year" is another term for

annual fatality rate. Potential loss of life (PLL) is a societal or group risk measure and istypically used in cost benefit analysis for assessing remedial measures, or for comparing

alternatives during the design stages of any project. There is no acceptance criterion for

PLL.

DET NORSKE VERITAS


7/25/2019 HPCL QRA

40/104



3

QRA SOFTWARE TOOLThe basis for this QRA study is DNVs proprietary risk modelling software, PHAST

RISK software version 6.7.

The PHAST RISK software has been in existence since the 1970s, and has been under

continual development and improvement ever since, which is managed by DNVs

London-based software development division.

An electronic database of approximately 1400 materials is available to the PHAST RISK

software, with the material properties regularly reviewed and if required re-adjusted,

based on the latest available data. The PHAST RISK consequence modelling results (for

each material) are regularly reviewed and where required re-calibrated, based on the latest

available accident and test data.

The PHATS RISK software will calculate dispersion and consequence modelling resultsfor all specified weather classes and wind speeds with the failure case specified release

frequency data, specified weather class, wind speed, wind directional probability data,

specified immediate ignition probability data, software calculated delayed ignition

probability data, built-in event tree alternate consequence outcome branch probability

data, fatal impact probability data for each alternate consequence outcome (e.g. jet fire,

flash fire, explosion), based on the specified consequence impact criteria levels, and

specified population data by location, to produce individual and societal risk results, as

required.

This PHAST RISK modelling software requires the following inputs to be able to

produce risk results:

- Import an electronic map of the study area, on which individual fatality risk

contour results may be produced.

- The electronic map may be programmed in PHAST RISK to:

- Superimpose all on-site and off-site populations within the study area by

DET NORSKE VERITAS


7/25/2019 HPCL QRA

41/104

Q p


Delayed ignition sources may be specified as point sources (e.g. flares, fired

heaters, diesel-generators, and transformers), area sources (e.g. welding work

shops) or line sources (e.g. roads, railway lines, and overhead power lines). Each

ignition source carries additional specification in terms of presence factor and

ignition source strength (probability of ignition per unit time, when in contact with

a flammable vapour cloud between LFL and UFL). The actual delayed ignition

probability of any release is calculated by PHAST RISK, based on the dispersion

modelling results and event duration.

The immediate ignition probability associated with each flammable failure case is

a risk analyst programmed value, based on historical ignition data, which varies

with leak size and release phase (Gas / Liquid / 2-Phase) (the larger the leak

vapour flow rate, the higher the ignition probability, typically varying from 1% to

30%, unless above auto ignition, then 100%).

Prepare and import weather class, wind speed and wind direction probability data

for the study area. Normally separate day / night, weather class, wind speed, wind

directional probability files are entered into PHAST RISK, most often broken

down into 16 wind directions.

Enter all identified failure cases, which are defined in terms of: Location, Material

released, Quantity released (or release duration), Temperature, Pressure, Leak

size, Leak direction (e.g. horizontal, vertical), Leak elevation, Leak frequency and

Immediate ignition probability.

Each failure case calculation in PHAST RISK starts with discharge modelling.

Based on release duration and release phase (gas, liquid, 2-phase), PHAST RISK

directs the dispersion and consequence calculations to one of 4 alternate, built-in

consequence outcome event trees (continuous vapour release, continuous releasewith rain-out, instantaneous vapour release, instantaneous release with rain-out),

where each event tree branch probability carries default values, which may be re-

programmed by the risk analyst.

DET NORSKE VERITAS


7/25/2019 HPCL QRA

42/104


So far the calculations performed in PHAST RISK only relate to the alternate

consequence outcomes and the consequence hazard ranges, for each specified

failure case. To produce risk results, PHAST RISK will perform impact frequency

calculations, using the failure case specified leak frequency as starting point.

Frequency aspects of the risk calculations relate to the:

Risk analyst defined failure case leak frequency.

Weather class, wind speed and wind directional probability, for each of the 16

wind directions.

Specified immediate ignition probability and PHAST RISK calculated delayed

ignition probability. The delayed ignition probability calculation is based on the

strength and location of all specified ignition sources and the failure case

dispersion hazard range, combined with vapour cloud persistence (duration).

PHAST RISK selected event tree and branch probabilities, for each alternate

consequence out come.

Fatal Impact probability for each alternate consequence outcome. This is based on

the PHAST RISK calculated magnitude of each consequence and the PHAST

RISK default impact probability criteria or risk analyst specified impact criteria

for that type of consequence.

Location and number of people (or equipment) within hazard area for societal risk

results, with separate calculations for day and night, indoors and outdoors.

PHAST RISK performs its individual and societal risk calculations based on a 200

x 200 grids (40,000 points), with the grid point spacing automatically varied,

based on the consequence hazard range results.

For each release case, PHAST RISK takes the failure case release frequency as

initial input, multiplies this by the first weather class / wind speed probability, for

the first of 16 wind directions.

DET NORSKE VERITAS


7/25/2019 HPCL QRA

43/104


These 2 results are multiplied by the first of the event tree consequence branch

probabilities, relating to immediate or delayed ignition branch path.

PHAST RISK takes the calculated consequence hazard range and verifies which

grid points are within the consequence hazard area. For each grid point within

range PHAST RISK then calculates the magnitude of the consequence at each grid

point (e.g. explosion overpressure at a particular grid point may be 3psi).

The calculated consequence magnitude at each grid point is then compared to thePHAST RISK programmed impact criteria level, and the likelihood of fatality or

damage calculated, based on the impact probability criteria specified in PHAST

RISK, for the type of consequence and the magnitude of the consequence.

This calculation is repeated for each event tree alternate consequence outcome at

each grid point, for that weather class / wind speed and wind direction, and the

result added to the previous risk level, at each grid point.

The above calculations are then repeated for each of the 16 wind directions,

cumulatively adding to the risk level at each grid point.

The above calculations are repeated for all day / night weather classes, wind

speeds and wind directions, cumulatively adding these risk results at each grid

point.

Once all risk calculations at these grid points have been completed for the first

failure case, the next failure case will be calculated, again adding all results

cumulatively at each grid point. This is repeated until all failure cases have been

calculated, while PHAST RISK also tracks the risk contribution made by each

failure case at each grid point.

Once completed, PHAST RISK produces individual risk contour results by

linking points of equal risk, based on the pre-specified levels of individual fatality

risk (or equipment damage) to be plotted, and using linear interpolation between

relevant grid points. The risk contour results are super imposed on the electronic

DET NORSKE VERITAS


7/25/2019 HPCL QRA

44/104


The above discussion demonstrates that the meteorological data, ignition data and

population data entered into the PHAST RISK software are critical to the risk

results.

Note that with default settings the risk modelling within PHAST RISK aims to

produce conservative offsite fatality risk results. This is in line with the intention

of performing a QRA as per the Guidelines for QRA Study (Revision April

2008) for a purpose of land-use planning. This is achieved by the build-in but

programmable parameter settings, which include:

Indoor & outdoor people fatality impact criteria levels, for each alternate

consequence outcome.For flammable releases the alternate consequences would

be spill fires, fire balls, jet fires, flash fires and vapour cloud explosions (VCEs),

each with predefined values for the impact levels that will affect people. For jet

fires, pool fires and fire balls the varying percentage fatalities (with distance) is

calculated based on the Eisenberg Probit equation. For flash fires the LFL

envelope is used and for VCE overpressure two impact criteria levels are used, 1.5

psi (0.1 barg) and 5 psi (0.34 barg).

For jet fires, pool fires and fire balls the varying percentage fatalities (with

distance) is calculated based on the Eisenberg Probit equation. For flash fires the

LFL envelope is used and for VCE overpressure two impact criteria levels are

used, 0.5(0.034) psi, 1.0 psi (0.068 barg) and 5 psi (0.34 barg).

4 built-in event trees (Continuous No Rain Out; Continuous With Rain Out;

Instantaneous No Rain Out; Instantaneous With Rain Out) that are automatically

selected based on the type of material and the release conditions. Each event-tree

assigns a split between alternate consequence outcomes (spill fires, fire balls, jet

fires, flash fires, VCEs and no hazard), based on the immediate ignition, delayed

ignition and no ignition probabilities.

People vulnerability criteria, which pre-determines the fraction of fatalities

resulting indoor & outdoor from being exposed to specific consequence outcomes

DET NORSKE VERITAS


Bh t

7/25/2019 HPCL QRA

45/104


Table 3-1 PHAST RISK Default Vulnerability Parameters

DET NORSKE VERITAS


Bharatpur

7/25/2019 HPCL QRA

46/104


Annexe 2

Assumption Register

DET NORSKE VERITAS


Bharatpur

7/25/2019 HPCL QRA

47/104


Table of Contents

1 RISK CALCULATION TOOL ..................................................................................... 1

2 METEOROLOGICAL DATA ...................................................................................... 2

2.1 Day Weather Class.................................................................................................. 2

2.2 Night Weather Class ............................................................................................... 2

3 IGNITION ...................................................................................................................... 4

3.1.1 Identification of Ignition Sources ...................................................................... 5

4 POPULATION ............................................................................................................... 5

5 MATERIAL COMPOSITION ...................................................................................... 5

6

IMPACT CRITERIA..................................................................................................... 6

6.1 Jet fire, pool fire and fireball ................................................................................... 6

6.2 Flash fire ................................................................................................................. 6

6.3 Explosion ................................................................................................................ 6

7

RELEASE SIZES........................................................................................................... 7

DET NORSKE VERITAS


Bharatpur

7/25/2019 HPCL QRA

48/104


1 RISK CALCULATION TOOL

The risk analysis within this study is conducted using DNV Softwares Phast Risk

program Version 6.7, which is an industry standard method for carrying out QRA of

onshore process and pipelines (chemical and petrochemical) facilities.

- Phast Risk allows efficient identification of major risk contributors, so that time

and effort can then be directed to mitigating these highest risk activities.

- Phast Risk analyses complex consequences from accident scenarios, taking

account of local population, land usage and weather conditions, to quantify the

risk associated with the release of hazardous materials.

- Phast Risk incorporates the industry standard consequence modeling of Phast.

Phast Risk is intended as a set of models for risk analysts to enable them to provide

timely, accurate and appropriate advice on safety related issues. It models all stages of a

release from outflow through a hole or from a pipe end, through atmospheric dispersion,

rain-out and re-evaporation of liquid, to thermal radiation from fires, explosion

overpressures and toxic lethality. PhastRisk combines recognized and validated models

for the various physical phenomena, automatically selecting the appropriate model

depending on the circumstances of the release. It provides an experienced risk analystwith a tool that allows them to focus their attention and experience on the real problem

areas rather than the administration of large quantities of data.

DET NORSKE VERITAS


Bharatpur

7/25/2019 HPCL QRA

49/104

MANAGING RISKp

2 METEOROLOGICAL DATA

Data on the wind speed and stability category have been obtained from the client and this

will be used for this particular QRA study. There are two different weather classes for

Day and Night which are listed below:

2.1 Day Weather Class

- D11 : D stability (neutral) and 11 m/s wind speed.

- B2 : B stability (Unstable) and 2 m/s wind speed.

2.2 Night Weather Class


- F3 : F stability (very stable) and 3 m/s wind speed.

This distribution is combined with the wind rose information to generate likelihood for

the wind to be from a particular direction and of a specified speed and stability.

Table 2-1: Wind Speed Distribution (Day)

Wind Direction

Weather Categories

3B 5D

N 0.042958904 0.00460274

NE 0.042958904 0.00460274

E 0.104328767 0.011178082SE 0.024547945 0.002630137

S 0.006136986 0.000657534

SW 0.018410959 0.001972603

W 0.085917808 0.009205479

NW 0.110465753 0.011835616

Calm 0.177972603 0.019068493

DET NORSKE VERITAS


Bharatpur

7/25/2019 HPCL QRA

50/104

MANAGING RISK

Table 2-2: Wind Speed Distribution (Night)

Wind Direction

Weather Categories

3B 5D

N 0.060931507 0.005041096

NE 0.038082192 0.003150685

E 0.060931507 0.005041096

SE 0.038082192 0.003150685

S 0.022849315 0.001890411

SW 0.060931507 0.005041096

W 0.167561644 0.013863014

NW 0.190410959 0.015753425

Calm 0.121863014 0.010082192

Referring to the same study, the following meteorological parameters will be applied:

An average ambient condition as follow is used in the study:

- Atmospheric temperature : 15-25C

- Surface temperature : 15-25C

- Humidity : 70%

- Solar radiation flux : 0.5kw/m2for day and 0kw/m2for night

DET NORSKE VERITAS


A AG G SBharatpur

7/25/2019 HPCL QRA

51/104

MANAGING RISK

3 IGNITION

In order to calculate the risk from flammable materials, information on the ignition

sources (which are present in the area over which a flammable cloud may drift) is

required. For each ignition source considered, the following factors need to be specified:

- Presence Factor

- This is the probability that an ignition source is active at a particular location.

- Ignition Factor

- This defines the strength of an ignition source. It is derived from the probability

that a source will ignite a cloud if the cloud is present over the source for a

particular length of time.

- Location

The location of each ignition source must be specified on the site layout. This allows the

position of the source relative to the location of each release to be calculated. The resultsof the dispersion calculations for each flammable release are then used to determine the

size and mass of the cloud when it reaches the source of ignition.

If these factors are known for each source of ignition considered, then the probability of a

flammable cloud being ignited as it moves downwind over the sources can be calculated.

The data is entered into the risk quantification software, namely PHAST RISK, for eachsource (as that used for population data). The PHAST RISK software then calculates

equivalent combined ignition factors and presence factors for all sources based on its

location on the map.

Ignition sources in a QRA study may be of 3 types:

Point sources Known specific sources such as flares, workshops, etc.

Line sources Roads, railways, electrical transmission lines.

Area sourcesPopulation, industrial sites where location of specific ignition

sources is unknown.

DET NORSKE VERITAS



7/25/2019 HPCL QRA

52/104

MANAGING RISK

3.1.1 Identification of Ignition Sources

The ignition sources identified for the proposed expansion project are near-by Industrial

plants and onsite ignition sources like hot machinery surfaces, electrical sources. No

specific field survey is performed for the neighbouring industrial plants in this risk study;

however, generally a process petro-chemical plant has various types of ignition sources

on-site, e.g. hot work, hot surface, flare, turbine, compressor and vehicles movement etc.

In summary, the ignition sources considered in this QRA study are listed below:

- It is assumed that stringent ignition control is maintained, as is the standard

prevailing in the HPCL Bharatpur

- Entire Complex has been considered as Ignition source with ignition probability

0.9 and operating probability 0.1 as per DNV Technical Note.

4 POPULATION

A representative estimate of the exposed populations is sufficient to determine the

acceptability of societal risks by determining the order of magnitude of potential fatalities

within a population group.

The basis of the population assigned to the facility will be based on the data given by

HPCL Bharatpur. Further analysis of the population will be conducted in order to define

various factors associated with the population presence, e.g. day/night variation, fraction

of time spent indoor etc.

5 MATERIAL COMPOSITION

The material composition used for the study is provided by HPCL Bharatpur.

DET NORSKE VERITAS



7/25/2019 HPCL QRA

53/104

MANAGING RISK

6

IMPACT CRITERIAThe following impact criteria are used.

6.1 Jet fire, pool fire and fireball

Two sets of criteria are used to determine impact from combination of these events. Areas

exposed to radiation levels of 37.5 kW/m2are assumed to give 100% fatality level. The

fatality levels in areas exposed to lower radiation levels are determined using the

following Probit function.

Pr = -36.38 + 2.56 ln(I1.333 . t)

Where:

Pr : Probit

I : thermal radiation level in W/m2

t : exposure duration in second

The maximum exposure duration for these events is set to 20 seconds.This is assumed as the time that someone will remain within the

radiation envelope before attempting to escape.

6.2

Flash fire

The area within the LFL envelope of flammable vapor cloud is used as single value

criteria and it is assumed that this area gives 100% fatality level.

6.3 Explosion

The study applies the TNT Correlation Model which utilizes two fixed coefficients to

establish ranges to specified damage levels (these coefficients are 0.03 for heavy damage

to buildings and 0.06 for repairable damage to buildings). These damage levels are not

explicitly associated with overpressure levels but are generally considered to be

equivalent to 0.3 and 0.1 bar for heavy and repairable damage, respectively. The damage

levels are used as single criteria to establish the human fatality rate.

DET NORSKE VERITAS



7/25/2019 HPCL QRA

54/104

MANAGING RISK

7 RELEASE SIZES

The following representative leak sizes have been applied:

Release Sizes:

- Small release through 5 mm equivalent hole,representative of 3 to 10 mm hole

sizes.

- Medium release through 25 mm hole, representative of 10 to 50 mm hole sizes.

- Large release through 100 mm hole, representative of 50 to 100 mm hole sizes.

- Catastrophic Rupture at vessel diameter/ Full bore release at pipeline diameter,

representative of releases larger than 150mm.

DET NORSKE VERITAS



7/25/2019 HPCL QRA

55/104

MANAGING RISK

Annexe 3

Frequency Analysis

DET NORSKE VERITAS



7/25/2019 HPCL QRA

56/104

N G NG S

Table of Contents

1 HAZARD IDENTIFICATION ...................................................................................... 3

1.1 Failure case scenarios .................... ......................................................................... 3

1.2 Continuous Releases ............................................................................................... 5

1.3 Instantaneous Releases ................... ......................................................................... 5

1.4 Events which could lead to a Release .................... ......................................... ......... 5

1.5 Failure Cases ............................................................................... ........................... 6

1.6 Release duration ..................................................................................................... 8

2 FREQUENCY DISCUSSION ....................................................................................... 8

List of TablesTable 1-1 : Failure case scenarios ............ .............. ............. ............ .............. ............. ............ .............. .............. ...... 3

Table 1-2 : List of Failure Cases ............................................................................................................................. 6

Table 2-1 : Failure frequencies of the identified scenarios ...................................................................................... 9

DET NORSKE VERITAS



7/25/2019 HPCL QRA

57/104

MANAGING RISK

1

HAZARD IDENTIFICATION

1.1

Failure case scenarios

Following scenarios have been identified for the Bharatpur

Table 1-1 : Failure case scenarios

Sr. No Failure Case MaterialHandled Temp Pressure

1 TK-1 HSD ambient atmospheric


3 TK-3 SKO ambient atmospheric

4 TK-4 SKO ambient atmospheric

5 TK-5 MS ambient atmospheric

6 TK-6 MS ambient atmospheric7 TK-7/UG MS ambient atmospheric

8 TK-8/UG MS ambient atmospheric

9 TK-9/UG HSD ambient atmospheric

10 TK-10 WATER ambient atmospheric

11 TK-11 WATER ambient atmospheric


13 TK-13 HSD ambient atmospheric14 TK-14 MS ambient atmospheric





19 HSD Pump_2400 LPM HSD ambient 2.5bar

20 SKD Pump_1200 LPM SKO ambient 2.5bar21 MS Pump 2400 LPM MS ambient 2.5bar

22 Receipt Pipeline to Tank MS MS ambient 2.5bar

23 Receipt Pipeline to Tank HSD HSD ambient 2.5bar

24 Receipt Pipeline to Tank SKO SKO ambient 2 5bar

DET NORSKE VERITAS



7/25/2019 HPCL QRA

58/104

MANAGING RISK

Sr. No Failure CaseMaterialHandled Temp Pressure

28

PL from pump house to

gantry_MS MS ambient 2.5bar

29


gantry_SKO SKO ambient 2.5bar

30

PLfrom pump house to

gantry_HSD HSD ambient 2.5bar

DET NORSKE VERITAS



7/25/2019 HPCL QRA

59/104

MANAGING RISK

1.2 Continuous Releases

If ignited immediately, a continuous release will form a jet fire. If ignition is delayed, a

flammable cloud would be formed and drifted with the wind. In such situation, if the

cloud is ignited (after some delays), a flash fire or Vapour Cloud Explosion (VCE) may

result, depending upon the degree of congestion within area and energy strength of the

ignition source.

1.3

Instantaneous Releases

An instantaneous release would result from catastrophic rupture of a storage vessel (such

as the storage cylinders, the trailers etc.) or reactors. If ignition is immediate, a fireball

may be formed depending on the nature of the material. If ignition occurs after some

delay similar to continuous release, a flash fire or VCE may be the consequence.

1.4 Events which could lead to a Release

Releases can be caused by:

- Impact event;

- Natural event (e.g. tide, waves, tsunamis, strong winds);

- Failure or leak from other equipment, pipe-work or fittings;

- Internal explosion in ship;

- Incorrect operation;

- Release occasioned from other operations or maintenance;

- Vandalism/sabotage

DET NORSKE VERITAS



7/25/2019 HPCL QRA

60/104

1.5 Failure Cases

The failure cases with the hole sizes considered for each of the release is as follows

Table 1-2 : List of Failure CasesSr. No Failure Case Hole Size (mm)

Small Medium Large Cata/ FBR

Tank

Fire

1 TK-1 5mm NA 100 mm

catastrophic

Rupture

Tank

Fire


catastrophic

Rupture

Tank

Fire


catastrophic

Rupture

Tank

Fire

4 TK-4 5mm NA 100 mmcatastrophic

RuptureTankFire


catastrophic

Rupture

Tank

Fire


catastrophic

Rupture

Tank

Fire

7 TK-7/UG 5mm NA NA

catastrophic

Rupture NA

8 TK-8/UG 5mm NA NA

catastrophic

Rupture NA

9 TK-9/UG 5mm NA NA

catastrophic

Rupture NA

10 TK-10 5mm NA 100 mm

catastrophic

Rupture

Tank

Fire

11 TK-11 5mm NA 100 mm

catastrophic

Rupture

Tank

Fire

12 TK-12 5mm NA 100 mm

catastrophic

Rupture

Tank

Fire

DET NORSKE VERITAS



7/25/2019 HPCL QRA

61/104

Sr. No Failure Case Hole Size (mm)

Small Medium Large Cata/ FBR

Tank

Fire

16 TK-16 5mm NA 100 mm

catastrophic

Rupture

Tank

Fire

17 TK-17 5mm NA 100 mm

catastrophic

Rupture

Tank

Fire

18 TK-18 5mm NA 100 mm

catastrophic

Rupture

Tank

Fire

19 HSD Pump_2400 LPM NA NA NA FBR NA

20 SKD Pump_1200 LPM NA NA NA FBR NA

21 MS Pump 2400 LPM NA NA NA FBR NA

22

Receipt Pipeline to

Tank MS 5mm 25mm 100 mm FBR NA

23

Receipt Pipeline to

Tank HSD 5mm 25mm 100 mm FBR NA

24

Receipt Pipeline to

Tank SKO 5mm 25mm 100 mm FBR NA

25

pl from tank to pump

house_MS 5mm 25mm 100 mm FBR NA

26

PL from tank to pump

house_HSD 5mm 25mm 100 mm FBR NA

27

PL from tank to pump

house_SKO 5mm 25mm 100 mm FBR NA

28


gantry_MS 5mm 25mm 100 mm FBR NA

29


gantry_SKO 5mm 25mm 100 mm FBR NA

30

PLfrom pump house to

gantry_HSD 5mm 25mm 100 mm FBR NA

NA stands for Not Applicable

DET NORSKE VERITAS



7/25/2019 HPCL QRA

62/104

1.6 Release duration

Release duration of 600 seconds is chosen for this study. This includes the time to detect,

isolate and the subsequent blow down (if possible) of the node from which leak occurs.

After the leak is detected and the section is isolated it is understood that no more

inventory is entering the section.

2 FREQUENCY DISCUSSION

Estimation of the likelihood of occurrence of each of the failure cases modelled has been

done based on historical failure frequencies of process equipment. The historical failure

data are based on an extensive research by DNV on several failure frequency databases

worldwide. DNV has ensured that the most reputable, comprehensive and appropriate

data are selected for each of the equipment failure frequencies quoted.

The below Table shows the failure frequencies that are considered for the failure case

scenarios

DET NORSKE VERITAS


Bharatpur

7/25/2019 HPCL QRA

63/104


Report No.: 12QR1P2-27Rev 02, 30thJuly, 2013

Page 9

Table 2-1 : Failure frequencies of the identified scenarios

Case Description Small Medium Large FBR

Atmospheric Storage tank Failure 2.50E-03 1.00E-04 5.00E-06 2.00E-03

Underground Tank Failure 3.80E-04 4.30E-05 8.40E-06 1.00E-05

Pipeline from Tank to Pump House9.00E-07 1.10E-06 2.50E-07 5.60E-08

Receipt Lines to Tanks9.00E-07 1.10E-06 2.50E-07 5.60E-08

HSD, SKD, Ethanol, MS pump failure 0 0 0 3.00E-05

HSD, SKD, MS loading arm Failure 7.80E-03 1.80E-02 7.10E-03 1.40E-03

HSD,SKD, MS Road Tanker Failure 9.00E-05 9.00E-05 1.00E-05 5.00E-07

DET NORSKE VERITAS



7/25/2019 HPCL QRA

64/104

Annexe 4

Consequence Analysis

DET NORSKE VERITAS



7/25/2019 HPCL QRA

65/104

Table of Contents

1 CONSEQUENCE ASSESSMENT ................................................................................ 4

1.1 Pool Fire ................................................................................................................. 5

1.2 Jet Fire .................................................................................................................... 6

1.3 Flash Fire ................................................................................................................ 7

1.4 Vapour Cloud Explosion (VCE).............................................................................. 8

DET NORSKE VERITAS



7/25/2019 HPCL QRA

66/104

List of Tables

Table 1-1 : Consequence Results ............. .............. ............. ............ .............. ............. ............ .............. .............. ...... 9

DET NORSKE VERITAS



7/25/2019 HPCL QRA

67/104

1

CONSEQUENCE ASSESSMENT

For each defined failure case for the POL Terminal Bharatpur, the consequence

modelling is carried out to determine the potential effects of releases, the results of which

are discussed in terms of hazard distances.

The corresponding consequences in terms of flammable and explosive effects are

modelled and analysed by using PHAST RISK software version 6.7. The flammable

consequences that may potentially arise from failure of equipments or lines are:

- Jet fires;

- Flash fires;

- Fireball; and/or

- Explosions.

The hazard distances for each event depend on the leak size, operating conditions,

weather conditions, the release location, the release conditions and the dispersion

characteristics as calculated by the PHAST RISK software. Each failure case is entered

into PHAST RISK software, where the corresponding consequences and risk impact are

calculated, based on built-in programmable event trees.

The dispersion of gas releases from different hole sizes are modelled using state-of-art

methods. For flammable and explosive consequence, the effect zones for the various

possible outcomes of such a release are determined for both early and delayed ignition

presents the consequence hazard distances for the failure case scenarios identified in the

POL Terminal Bharatpur.

Consequence distances for the following weather conditions have been evaluated in the

tables below,


- F3 : F stability (very stable) and 3 m/s wind speed.

DET NORSKE VERITAS



7/25/2019 HPCL QRA

68/104

The consequence analysis is performed using DNV proprietary software PHAST. PHASTis a consequence and impact assessment module integrated within DNV risk calculation

software PHAST Risk. The following descriptions are based on the different hazard types

modeled, which are jet fires, flash fires, vapor cloud explosions, pool fires.

1.1

Pool Fire

A pool fire in the open air and in an enclosed area may take place when there is anignition of a liquid spill which is released on a horizontal, solid surface in the open air or

within an enclosure. A liquid pool fire can be either fuel controlled or ventilation

controlled.

In general terms, outside pool fires rarely cause fatalities as the time between when the

fire starts until the time when the fire is fully developed is usually sufficient for people to

escape. If there are fatalities, these tend to be people caught within the pool itself or laterfire fighting personnel in the event of a boil-over (due to burning oil not thermal

radiation).

The extent of the consequence of a Pool fire is represented by the thermal radiation

envelope. Three levels of radiation are presented in this report, i.e.:

- 4 kW/m2; this level is sufficient to cause personnel if unable to reach cover

within 20s; however blistering of the skin (second degree burn) is likely; 0:

lethality.

- 12.5 kW/m2; this level will cause extreme pain within 20 seconds and

movement to a safer place is instinctive. This level indicates around 6% fatality

for 20 seconds exposure.

- 37.5 kW/m2; this level of radiation is assumed to give 100% fatality.

In Case of tanks small, medium leaks are considered from the fittings around the tanks

like flanges, valves etc, and tank fire and bund fire scenarios are considered as the worst

i T bl 1 1 b l i i f il i h h

DET NORSKE VERITAS



7/25/2019 HPCL QRA

69/104

1.2

Jet Fire

A jet fire may result from ignition of a high-pressure leakage of gas from process plants

or storage tanks. Jet fires are characterized by a high momentum jet flame that is highly

turbulent. The flame is lifted above the exit opening from which the gas is discharged

generally at high pressure. This distance appears because the combustion process can

only take place when the flow velocity is reduced sufficiently to allow stable combustion.

Another feature of such fires is the high entrainment of air into the flame plume due tothe highly turbulent flame.

The extent of the consequence of a Jet fire is represented by the thermal radiation

envelope. Three levels of radiation are presented in this report, i.e.:

- 4 kW/m2; this level is sufficient to cause personnel if unable to reach cover

within 20s; however blistering of the skin (second degree burn) is likely; 0:

lethality,

- 12.5 kW/m2; this level will cause extreme pain within 20 seconds and

movement to a safer place is instinctive. This level indicates around 6% fatality

for 20 seconds exposure.

- 37.5 kW/m2; this level of radiation is assumed to give 100% fatality.

Jet fires are a direct hazard to people and structures caught within the flame envelope or

exposed to high thermal radiation levels. This scenario is considered for the whole

boosting station in which material is handled at the significant pressures. Table 1-1below

summarises representative failure cases with the associated jet fire conse

hpcl qra

Documents