report-tank-farm-pdf.pdf

CHAPTER13

Land Use

Quant i tat ive Risk Assessmentprepared by

ModuSpec Austral ia Pty Limited

A p p e n d i x D

Ref: AUS0352.8, Release 01 Page 1 of 267 July 2006

CALTEX REFINERIES (NSW) PTY LTD

Kurnell Refinery

Tank 632

Quantitative Risk Assessment

6th Floor, 34 Queen Street, Melbourne VIC 3000,

Tel: +61 3 9614 1285 Fax: +61 3 9614 3917 Email: [email protected] Website: www.moduspec.com

Enquiries regarding this report please contact the author

For other ModuSpec services contact Lachlan Dreher

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Abstract

Ref: AUS0352.8, Release 01 Page 2 of 267 July 2006

Project Title Tank 632 Quantitative Risk Assessment

Client Name Caltex Refineries (NSW) Pty Ltd

Job No. AUS0352.8

Project Manager Lachlan Dreher

Project Analyst (s) Lachlan Dreher, Marian Magbiray, Patrick Walker

Report Author (s) Marian Magbiray, Patrick Walker

ABSTRACT

ModuSpec Australia Pty Ltd was engaged to undertake a quantitative risk assessment to analyse the risks associated with the installation of the proposed new crude oil tank

(Tank 632).

This report details the results of the individual components of the risk assessment, including the hazard identification, frequency assessment and consequence assessment.

The individual risk was evaluated in terms of risk of fatality and risk of injury. These

results were compared with the applicable criteria to determine the acceptability of the risks associated with the proposed installation. In determining the acceptability of the

risks, the impact on the adjacent industrial facilities to the west of the refinery boundary was assessed, with particular emphasis on the Serenity Cove Development.

Key Words: PETROL, QRA, BUNDFIRE, STOR

ReleaseNo.

Date of Issue

Reviewed by Approved by Reason for Update

Draft A 19 April 2006 L. Dreher

S. Masterton

L. Dreher Client Review

Draft B 15 June 2006 L. Dreher S. Masterton


Draft C 22 June 2006 L. Dreher

S. Masterton


Draft D 29 June 2006 L. Dreher

S. Masterton


Release 01 7 July 2006 L. Dreher

S. Masterton

L. Dreher Release To Client

This report, prepared by ModuSpec, is confidential. It has been prepared on behalf of the client mentioned on

the cover page (“the client”) and is issued pursuant to an agreement between ModuSpec and the client. It has

been produced according to the scope of work and is only suitable for use in connection therewith.

All measures and decisions based on this analysis and these findings are the sole responsibility of the client.

ModuSpec does not accept:

any liability for the identification, indication or elimination of dangers and non-compliances (in the broadest

sense of the word), nor for any damage caused by any of these;

any obligation to report all facts or circumstances established during the visit. This obligation comes

completely under the authority and responsibility of the client

any liability for the client’s obligations resulting from (legal) rules and/or statutes;

any liability or responsibility whatsoever in respect of or reliance upon this report by any third party.

The execution of improvements recommended by ModuSpec does not indemnify the client against any legal or

contractual obligations and offers no safeguard against the elimination of dangers or damages resulting from

the client’s products, services, company assets, et cetera.

No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by

any means, electronic, mechanical, photocopying, recording, or otherwise without prior permission, in writing,

of ModuSpec, except for restricted use within the client’s organisation.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Table of Contents

Ref: AUS0352.8, Release 01 Page 3 of 26 7 July 2006

TABLE OF CONTENTS

1. EXECUTIVE SUMMARY .............................................................................51.1. Fatality Risk ........................................................................................... 5

1.2. Injury Risk ............................................................................................. 5

2. ACRONYMS & GLOSSARY .........................................................................8

3. INTRODUCTION.....................................................................................103.1. Project Scope ....................................................................................... 10

3.2. Locations ............................................................................................. 10

4. STUDY METHODOLOGY ..........................................................................12

5. RISK CRITERIA......................................................................................145.1. Individual Fatality Risk Criteria................................................................ 14

5.2. Individual Injury Risk Criteria.................................................................. 14

6. FACILITY AND OPERATION DESCRIPTION .............................................166.1. Facility Description ................................................................................ 166.2. Process Description ............................................................................... 16

6.3. Meteorological Conditions ....................................................................... 16

7. HAZARD IDENTIFICATION.....................................................................177.1. Hazardous Materials .............................................................................. 17

7.2. Hazardous Scenarios ............................................................................. 17

8. FAILURE FREQUENCY AND EVENT TREE ANALYSIS.................................188.1. Failure Frequency.................................................................................. 18

8.2. Equipment Failure Scenarios ................................................................... 18

8.3. Event Tree Analysis ............................................................................... 188.4. Full Surface Tank Fire ............................................................................ 19

8.5. Bund Fire ............................................................................................. 20

9. CONSEQUENCE MODELLING...................................................................22

10. RISK RESULTS .......................................................................................2310.1. Individual Risk................................................................................... 2310.2. Comparison with Risk Criterion ............................................................ 23

10.2.1. Fatality Risk................................................................................... 2310.2.2. Injury Risk .................................................................................... 24

10.3. Major Risk Contributors ...................................................................... 2410.3.1. Fatality Risk................................................................................... 25

10.3.2. Injury Risk .................................................................................... 25

10.4. Maximum Consequence Impact............................................................ 25

11. REFERENCES..........................................................................................26

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Table of Contents


APPENDICES:

APPENDIX A – PROJECT ASSUMPTIONS...........................................................A1 APPENDIX B – HAZARDOUS SCENARIOS AND PROCESS CONDITIONS..............B1 APPENDIX C – FAILURE FREQUENCY DATA ......................................................C1 APPENDIX D – HAZARDOUS SCENARIOS AND FAILURE CONTRIBUTORS ..........D1 APPENDIX E – EVENT TREE ANALYSIS ............................................................. E1 APPENDIX F – CONSEQUENCE LEVEL IMPACT CRITERIA .................................. F1 APPENDIX G – CONSEQUENCE RESULTS ..........................................................G1

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Executive Summary


1. EXECUTIVE SUMMARY

Caltex Refineries (NSW) Pty Ltd has proposed the installation of an additional crude oil

storage tank (Tank 632), for the Kurnell Refinery. The proposed location for the tank is in the south crude storage area, immediately to the west of Tank 633. Several industrial

facilities, most notably the Serenity Cove Industrial Facility, are situated to the west of the refinery boundary, neighbouring the southern crude tank farm and the proposed

location of Tank 632. Hence, a quantitative risk assessment (QRA) was undertaken to

assess the risk impacts associated with the new installation, and to establish whether these risks comply with the applicable criteria.

The full range of potential hazardous scenarios and consequence events associated with

the installation and operation of the proposed tank was considered in the analysis. The individual risk was assessed in terms of risk of fatality and risk of injury to determine the

impact the proposed installation would have on the surrounding area.

1.1. Fatality Risk

The 5 x 10-6 per year risk criterion applied in the assessment was based on the guidelines

for risk acceptance levels to neighbouring commercial developments, as published by the NSW Department of Urban Resources and Planning (DUAP) [1]. The 5 x 10-6 per year

risk contour is presented in Figure 1.1.

The 5 x 10-6 per year individual risk contour level is confined within the refinery boundary. This risk level represents the limit of acceptability for risk impact on the

neighbouring commercial area of the Serenity Cove Development and therefore with this risk level contained within Caltex’s site, the risk criterion is satisfied.

A review of the consequence events that contribute to the western region of the 5 x 10-6

per year individual risk contour indicated that a bund fire associated with the new

installation constitutes a major contribution to the risk.

The risk assessment was based on whole crude oil service. The modelling of whole crude oil represents the worst-case scenario.

1.2. Injury Risk

Continued exposure to heat flux of 4.7 kW/m2 is considered sufficient to cause injury [1].

Hence, injury risk was assessed based on exposure to this level of heat flux or greater.

The acceptance criteria for risk of injury posed by industrial facilities onto neighbouring residential areas is 50 chances per million per year (i.e. 50 x 10-6 per year) [1]. The

50 x 10-6 per year injury risk contour is depicted in Figure 1.2.

The areas bordering the Caltex site near the proposed location of Tank 632 are not residential areas and hence application of this criterion to the neighbouring land-uses

represents a high degree of conservatism. Although no injury risk criteria has formally been specified, it is reasonable to consider that less stringent criteria would be applied to

commercial and industrial land use, as bounds the Caltex site near the proposed location

of Tank 632.

With the 50 x 10-6 per year individual injury risk contour lying inside the site boundary,

the risk exposure at the site boundary with the Serenity Cove Development is therefore less than this value. This is considered acceptable.



632

633

622

623

100 m

N

5 10-6

Figure 1.1: Individual Risk of Fatality Contour – 5 10-6 per year



632

633

622

623

100 m

N

50 10-6

Figure 1.2: Individual Risk of Injury Contour – 50 10-6 per year

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Acronyms & Glossary


2. ACRONYMS & GLOSSARY

ACRONYMS

ADG Australian Dangerous Goods

ALARP As low as reasonably practicable

Caltex Caltex Refineries (NSW) Pty Ltd

CDU Crude Distillation Unit

DUAP Department of Urban Affairs and Planning

HUM Hold up mass

IR Individual risk

ModuSpec ModuSpec Australia Pty Ltd

MV Motorised valve

NSW New South Wales

PHA Preliminary hazard analysis

P&ID Piping and instrumentation diagram

QRA Quantitative risk assessment

GLOSSARY

Acceptance Criteria Defines the level of risk to which an individual is exposed, as either tolerable (negligible risk), intolerable or within

the ALARP region.

Bund An embankment or wall which may form part or all of the

perimeter of a compound around a storage tank, intended

to contain any release of liquid.

Consequence This is the severity associated with an event in terms of

toxic doses, fire or explosion etc., i.e. the potential effects of a hazardous event.

Frequency This is the number of occurrences of an event expressed

per unit time. It is usually expressed as the likelihood of an event occurring within one year.

Hazard A physical situation with the potential for human injury,

damage to property, damage to the environment or some combination of these.

Hazardous Scenario The identified isolatable sections and/or those which have

been broken down into scenarios for specific items of equipment.

Individual Risk The frequency at which an individual may be expected to

sustain a given level of harm from the realisation of specified hazards.

Individual Risk of Fatality Individual risk with “harm” measured in terms of fatality.

It is calculated at a particular point for a stationary, unprotected person for 24 hours per day, 365 days per

year. Normally measured in chances of fatality per million years.

Individual Risk of Injury Similar to individual risk of fatality, however with “harm”

measured in terms of injury.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Acronyms & Glossary


GLOSSARY

Individual Risk Contours As IR (Individual Risk) is calculated at a point, calculating the IR at many points allows the plotting of IR contours,

these being lines that indicate constant levels of risk. Most

commonly used are the 1 chance per million-year contour and the 10 chances per million-year contour.

Isolatable Section A system of pipes or vessels containing the hazardous materials that are bounded by specific isolation points.

Isolation Point A point in the process, which can be used to isolate one

part of the process from the rest of the system.

Probability The expression for the likelihood of an occurrence of an event or an event sequence or the likelihood of the

success or failure of an event on test or demand. By definition, probability must be expressed as a number

between 0 and 1.

Quantitative Risk Assessment

A risk assessment undertaken by combining quantitative evaluations of event frequency and consequence.

Risk The combination of frequency and consequences, the

chance of an event happening that can cause specific consequences.

Risk Reduction The process of risk assessment coupled to a systematic

consideration of potential control measures and a

judgement on whether they are reasonably practicable to implement.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Introduction


3. INTRODUCTION

3.1. Project Scope

Caltex Refineries (NSW) Pty Ltd has proposed the installation of an additional crude oil storage tank, to be designated as Tank 632, for the Kurnell Refinery. A Preliminary

Hazard Analysis (PHA) was initially conducted to provide a semi-quantitative assessment of the risks associated with the proposed new installation and the acceptability of these

risks [2]. The PHA was unable to conclusively demonstrate that the risk impact onto the

adjacent industrial facility complied with the adopted risk acceptance criterion.

The PHA was conducted as a semi-quantitative analysis, based on a series of simplifying assumptions. In order to draw more definitive conclusions about the acceptability of the

offsite risk exposure, more detailed quantitative analysis was conducted, i.e. a quantitative risk assessment (QRA). The QRA involved the assessment of the likelihood

and consequence for scenarios associated with the process in a quantitative manner, based on data specific to the operation.

3.2. Locations

The proposed storage tank is to be located in the southern crude storage area, adjacent to the refinery's western boundary. The location of the tank and the bunded area within

which it is located was taken from information provided by Caltex [3], which indicated tank size, tank location and the configuration of the bunded area. These specifications

have been reproduced in Figure 3.1.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Introduction


Figure 3.1: Proposed Location of Tank 632.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Study Methodology


4. STUDY METHODOLOGY

The study methodology followed the standard risk assessment steps outlined below.

Figure 4.1 presents a flow chart of the risk assessment steps followed.

Hazard identificationHazard identification was carried out by a review of the proposed operations and

materials handled, in order to identify the equipment and pipelines containing potentially

hazardous materials and to define representative hazardous scenarios.

Frequency assessmentThe frequency assessment stage of the analysis involved defining the potential release sources and subsequently determining the likelihood (frequency) of the various releases.

The failure frequencies were determined using failure item counts for each of the failure items identified and publicly available historical failure rate data. Details of the failure

rate values used are provided in Appendix C. Ignition probability data was used to estimate the probability of a release subsequently being ignited.

Consequence assessmentThe potential consequences from the hazardous scenarios were determined and the impact zones modelled using appropriate software tools. Where possible, the effects of

existing mitigation measures at the facility were also taken into account in the

consequence assessment. The primary consequence type was a pool fire following a fuel spill.

Details of these steps are described in the appropriate sections of the report. A number of assumptions were made during the analysis. Details of the assumptions are presented

in Appendix A.

Risk assessment:The frequency and consequence assessments were combined to calculate individual risk for both fatality and injury. The risk results have been presented as contours on a site

plan. The risk results were then assessed against the selected risk criteria to determine risk acceptability.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Study Methodology


HAZARD IDENTIFICATION

FREQUENCY ASSESSMENT

CONSEQUENCE ASSESSMENT

RISK ASSESSMENT

Detailed process

information including

plans, process flow

diagrams and

emergency detection

and shutdown systems

Identification of

Hazardous Substance

Identification of

Failure Modes

Definition of Failure Case

Event Tree Analysis

End Event Identification

End Event Frequency

Determination

Failure Rate Data

Component Data

Specific System Data

Ignition Probabilities

Explosion Probabilities

Detection Strategies

Isolation Strategies

Chemical Data

- Flammability

- Specific Properties

Meteorological Data

Equipment layout and

release control and

protection systems

Emergency Response

Capabilities

Consequence Modelling

- Fire

- Flammable Vapour Dispersion

Determination of Impact Zones

Select Appropriate

Risk Criteria

Identify Major Risk

Contributors and

propose risk

reduction measures

to achieve acceptable

risk levels

Individual Risk, calculations

Determine Acceptability

of Risk

Comparison withRisk Criteria

AcceptableNot Acceptable

Figure 4.1: Risk Assessment Study Methodology

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Risk Criteria


5. RISK CRITERIA

A comparison of the risk against an appropriate target or criterion is required in order to

assess the acceptability of that risk. The risk criterion applied for this assessment was obtained from the criteria published by the NSW Department of Urban Affairs and

Planning (DUAP) [1].

5.1. Individual Fatality Risk Criteria

The NSW criteria are based on a principle that if the risk from a potentially hazardous

installation is less than most risks being experienced by the community (e.g. voluntary risks, transportation risks), then that risk may be tolerated. This principle is consistent

with the basis of risk criteria adopted by most authorities internationally. The individual risk criteria are as follows:

Hospitals, schools, child-care facilities and old age housing development should not be exposed to individual fatality risk levels in excess of half in one million per

year (0.5 x 10-6 per year) Residential developments and places of continuous occupancy, such as hotels and

tourist resorts, should not be exposed to individual fatality risk levels in excess of

one in a million per year (1 x 10-6 per year) Commercial developments, including offices, retail centres, warehouses with

showrooms, restaurants and entertainment centres, should not be exposed to individual fatality risk levels in excess of five in a million per year (5 x 10-6 per

year) Sporting complexes and active open space areas should not be exposed to

individual fatality risk levels in excess of ten in a million per year (10 x 10-6 per year).

These criteria apply to new industry and surrounding land use proposals. In theory, the criteria should apply to existing facilities, however this may not be possible in practice.

For existing facilities, an overall planning approach is necessary. In terms of criteria, the following principles should apply [1]:

The 1 x 10-6 per year individual fatality risk level is an appropriate criterion within which no intensification of residential development should take place

Safety updates/reviews and risk reduction at facilities where resultant levels are in excess of the 10 x 10-6 per year individual fatality risk level should be

implemented to ensure that operational and organisational safety measures are in

place to reduce the likelihood of major hazardous events to low levels. A target level is to be established on an area basis

Intensification of hazardous activities in an existing complex accommodating a number of industries of a hazardous nature should only be allowed if the resultant

1 x 10-6 per year individual fatality risk level is not exceeded by the proposed facility and subject to cumulative risk threshold considerations

Mitigating the impact on existing residential areas from existing hazardous activities (in addition to safety review/updates) should include specific area-based

emergency plans. Emergency planning should be developed on the basis of

consequences for credible scenarios with emphasis on areas within the 1 x 10-6

per year risk contour.

5.2. Individual Injury Risk Criteria

The NSW individual injury risk criterion for exposure to heat radiation is as follows [1]: Incident heat flux radiation at residential areas should not exceed 4.7 kW/m2 at

frequencies of more than 50 chances in a million per year.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Risk Criteria


Exposure to heat flux of greater than 4.7 kW/m2 is considered high enough to trigger the possibility of injury for persons who are unable to be evacuated or seek shelter. This

amount of heat radiation would cause injury after an exposure period of 30 seconds.

This criterion is applicable to residential areas. Injury risk criteria for neighbouring commercial developments or industrial facilities have now been published. The land uses

along the site boundary in the area of interest in this study are commercial and

industrial. Similar to the relationship between individual fatality risk criteria for residential, commercial and industrial land uses, higher acceptability criteria for injury

risk would be expected for commercial and industrial land uses, as compared to that for residential areas. On this basis, for neighbouring commercial land uses, injury risk less

than 250 chances in a million per year would be deemed acceptable.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Facility and Operation Description


6. FACILITY AND OPERATION DESCRIPTION

6.1. Facility Description

The location proposed for Tank 632 is the southern crude tank area, directly to the west of the existing Tank 633. There are several light industrial facilities neighbouring the

southern crude tank area, including the Serenity Cove Development adjacent to the proposed location. The H.C.E Extractions Facility is located to the north of Serenity Cove.

6.2. Process Description

The product to be stored in Tank 632 would be whole crude oil. Tankers transporting crude oil are unloaded at the Kurnell wharf and the oil is transferred via pipeline to the

storage tanks in the southern crude tank area. The crude oil in the storage tanks is transferred to the refinery Crude Distillation Units (CDU) for further processing. The

inventory of crude oil stored in Tank 632 will cycle up and down in line with the transfer of the cargo from the ships and subsequent transfer for processing. Tank 632 would tie-

in to the existing crude receiving and process plant suction lines.

The proposed design and operation of Tank 632 has been modelled on the existing Tank

633. Therefore, the design and operating parameters associated with Tank 633 have been used in the QRA. Tank 633 is a floating roof tank in whole crude oil service.

6.3. Meteorological Conditions

The local meteorological data was taken from the 2001 and 2002 CALMET weather data

files, supplied by Caltex [4]. From this data, the probability of the various atmospheric stability conditions at the site, in addition to the average temperature and wind speed at

these stability classes were determined. These values are presented in Table 6.1. The overall average temperature was 18.1 C and the average wind speed was 3.4 m/s. The

value for the average humidity used in the analysis (57%) was obtained from the nearby weather station at Sydney Airport [5].

Table 6.1: Meteorological Conditions Analysed

Stability B C D D E F

Wind speed (m/s)

2.4 3.7 7.2 3.5 4.0 1.9

Temperature

( C)

21.7 20.0 18.0 18.1 16.9 15.7

Probability 0.140 0.182 0.126 0.126 0.134 0.292

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Hazard Identification


7. HAZARD IDENTIFICATION

The hazard identification phase involved the review of relevant process information, the

site layout, and the proximity of the neighbouring industrial facilities. The following information was used:

The proposed location of Tank 632 and the layout of its bunded area The proposed piping and instrumentation diagram (P&ID) for the facility

Process conditions, such as flow rates, temperatures, pressures

Frequency and duration of storage tank filling and emptying operations Typical flow rates of transfer pumps

Local meteorological data.

7.1. Hazardous Materials

The QRA was based on the storage of whole crude oil in Tank 632. Whole crude oil is a complex mixture containing many different hydrocarbon compounds. The components of

the mixture may range from light hydrocarbons having low boiling points, such as ethane, propane and butane, to large heavy components, having very high boiling points.

Whole crude oil is highly flammable due to the presence of the light components. It is

classified as a Class 3 dangerous good (i.e. flammable liquid) under the Australian Dangerous Goods Code. Whole crude oil therefore presents a potential fire hazard.

7.2. Hazardous Scenarios

The hazardous scenarios identified for the operation under consideration are associated

with the release of crude oil from the tank or associated piping and equipment, or the transfer piping and associated connections (valves, flanges etc.). Depending on the

amount of inventory released, such a scenario would result in the formation of a pool of crude oil, with the potential to extend to the full surface area of the bund. Ignition of the

spill would subsequently result in a pool fire.

In addition to the potential for a fire as a result of a spill, there is also the potential for a

tank fire scenario. A full tank surface fire may occur as a result of: The sinking of the floating roof tank and subsequent product ignition

The escalation of a rim seal fire Lightning strike.

The dispersion of flammable vapour from spills of crude oil to ground or from a tank (e.g.

crude oil exposed to atmosphere in the case of a sunken tank roof) was considered

during the analysis. The distance to which flammable vapours would extend was short for all cases. Flash fires were therefore not analysed further in the QRA.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Failure Frequency and Event Tree Analysis


8. FAILURE FREQUENCY AND EVENT TREE ANALYSIS

8.1. Failure Frequency

The potential for the release of product is attributed to the potential for the failure of any item of equipment within the process.

The hazard identification phase involved the identification of specific isolation points

within the process under consideration. Any items of equipment and fittings located

between these isolation points were therefore assessed as items that could potentially fail and cause a release. The frequency assessment step involved the calculation of the

likelihood (ie. frequency) of releases from each of these sources, based on the failure frequency of the individual items within the isolatable section. The Caltex Kurnell Crude

System P&ID, inclusive of the proposed tank, was used to identify these isolation points and associated items of equipment and fittings.

The failure frequencies were estimated using generic failure frequency data obtained

from industry databases. The failure rate data for different types of failure items are

summarized in Appendix C. These values are dependent on the equipment/pipe sizes. The leak frequency applied for a mixer seal is detailed in Appendix A.

8.2. Equipment Failure Scenarios

The overall failure frequency represents the rate at which an item of equipment or pipe

will fail, but provides no indication of the magnitude of the failure. Hence, a distribution of hole sizes was assigned to represent the full range of potential failure scenarios. A

representative selection of four hole sizes was modelled for each scenario.

The guidelines for selecting the sizes were:

Select sizes that fall into the following categories: Small hole up to 10 mm

Medium hole 10 mm to 75 mm Large hole 75 mm to 100 mm

Rupture Size of pipeline or 1000 mm for vessel. Examine the spread of hole sizes in conjunction with the failure rates of the

contributing failure items. If necessary, adjust the selected hole sizes to ensure that the spread of hole sizes and the associated failure rate is an appropriate

representation for the particular line/vessel.

A summary of the failure frequency for each of the hazardous sections, according to the

representative hole sizes is presented in Appendix D.

8.3. Event Tree Analysis

Event trees are used to determine the potential consequence events that may result for a given release scenario. Event tree analysis provides a systematic means of determining

which factors will influence the release, in addition to the probability associated with each of those factors.

The possible outcomes of a release scenario are dependent on the following factors: Characteristics of the release (e.g. hole size, product released etc.)

Release conditions (e.g. temperature, pressure) Release detection systems

Intervention systems (i.e. to isolate or contain a release)



Ignition sources Consequence mitigation measures.

The event tree analysis includes the following factors: The probability of detection of a release (by personnel, the standard process

control system or via automatic release detection systems) Following detection of a release, the probability that the release can be

successfully isolated The probability of ignition – both immediate ignition and delayed ignition.

The data used in the development of the event trees is presented in Appendix E. An event tree diagram depicting the frequency and probability values associated with the

scenario involving a loss of containment of product from Tank 632 as a result of the rupture of the tank is presented in Figure 8.1.

Figure 8.1: Event Tree Diagram for the Rupture of Tank 632

8.4. Full Surface Tank Fire

For the scenario of a full surface tank fire, insufficient data is available on the causation mechanisms to enable the fire frequency to be estimated directly based on the detailed

tank design. Therefore, for the purposes of the QRA, generic frequency data must be used. In selecting an appropriate frequency to apply for a full surface tank fire in the

QRA, an extensive review of numerous published sources was undertaken [6 ,7, 8, 9, 10]. Of these, the two sources considered most applicable was the LASTFIRE Project [6]

and Technica’s “SingaporeStudy” [10].



The Singapore Study provided data taken from three studies covering storage tank operations in the Netherlands, USA and Scotland, as well as from oil and petrochemical

companies operating terminals in Singapore from 1945. The full surface tank fire frequency derived from the USA/Europe and Singapore operations were 2.0 x 10-4 per

year and 9.3 x 10-4 per year respectively.

The LASTFIRE Project involved the largest study to date undertaken to determine the fire

frequency for large floating roof storage tanks. It involved data obtained from 16 companies, operating 2,420 tanks at 164 sites throughout 36 countries over a survey

period from 1981 to 1996. The study derived a full surface tank fire frequency of 1.2 x 10-4 per year.

The frequency considered most applicable for the Kurnell refinery is 1.2 x 10-4 per year,

derived from the LASTFIRE project. This value has been selected because it has been derived from the widest sample set of events and tank locations. Statistically, this can

be expected to provide a more appropriate representation of the true event frequency.

In addition, both data sources reviewed suggested that there is a correlation between the

frequency of storage tank fires and the number of thunderstorm days experienced in the area. When compared with Singapore, the number of thunderstorm days experienced in

the Kurnell area is relatively low. This suggests that the expected frequency for a full surface tank fire in Singapore should be higher than at Kurnell. The selected frequency is

consistent in this respect, in that it is lower than the value determined solely for operations in the Singapore area.

8.5. Bund Fire

A bund fire is generated by the ignition of a major release of flammable liquid from a pipe or storage tank into a bunded area. The QRA assessed the frequency of a bund fire

based on the release of product from a failure of the tanks or associated fittings in conjunction with the likelihood of ignition. The intervention measures implemented are

also considered in the derivation of the consequence frequency values. The likelihood of ignition is dependent on the release rate of the product.

The failure frequencies were determined by identifying the various items associated with

the tank that may fail. The failure rate for these items, in combination with the failure rate data for the tank itself were combined to determine the overall failure frequency.

The LASTFIRE Project estimated the frequency for a large bund fire resulting from a major spill to be 6 x 10-5 per tank per year [6]. The bund fire frequency used in the QRA

was determined from a specific analysis of the proposed tank and associated equipment. Failure events that would lead to a major spill into the tank bund, would include large

and catastrophic equipment failures. A bund fire would result if such a spill was subsequently ignited.

Of the two large bund fire events described in the LASTFIRE Project, one had a release rate1 of ~4.5 m3/min and the other had a pool fire surface area of 232 m2. The failure

cases analysed as part of the QRA with an equivalent hole size greater than 100 mm would result in spills of this magnitude. The total frequency of bund fires caused by

1 This event is described as resulting in an 8,000 m2 bund fire, however the magnitude of this bund fire was due to the flooding of the bund with water, which was done as part of

the efforts to control the fire. If the bund had not been flooded, the fire area would have been limited to well below this value.



these failures is 6.1 x 10-5 per year. This is comparable to the bund fire value determined by the LASTFIRE Project.

The bund fire frequency calculated as part of the QRA were considered a more

reasonable representation of the scenarios at the proposed facility, as they were derived from a specific analysis of the proposed design. Specific design information was used in

the analysis, including equipment parts counts and the proposed failure detection and

mitigation measures. This gives an assessment that is more specific to the system under consideration, rather than a more generic frequency value that may be based on widely

differing systems.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Consequence Modelling


9. CONSEQUENCE MODELLING

The consequence scenarios associated with the installation of the proposed Tank 632

were modelled to determine their potential impact on the surrounding area. The modelling took into account the chemical properties of the product released and the

meteorological conditions, where applicable.

The consequences modelled were based on a release of whole crude oil from the

following: Tank 632 or associated fittings

Transfer piping or associated fittings.

The Bernoulli equation was used to determine the liquid release rate for the scenarios considered. The release rate provides a measure of the magnitude of the spill. For

releases that are bunded, the size of the liquid pool would be contained, thereby limiting

the magnitude of any subsequent pool fire. The effect of bunding has been accounted for

in the consequence analysis.

The consequence types that could result from the scenarios under consideration

included: Pool fires

Full surface tank fires.

Pool fires result from the ignition of a flammable liquid spill. The heat radiation emitted

by pool fires was modelled using the Mudan & Croce model [11].

The results of the analysis were used to determine the impact on personnel (fatality rate). The probability of fatality from exposure to heat radiation from a pool fire was

determined using a probit equation. The heat flux exposure was calculated at 2 m above ground level, to represent an upper limit of heat flux exposure to a person present near

the flame. The heat radiation levels modelled, the resulting fatality probabilities, along

with a detailed description of the criteria, are presented in Appendix F.

Full surface tank fires were also modelled using the Mudan & Croce model. The likelihood of fatality from heat radiation was determined in a similar manner to pool fires.

Tables presenting the impact distances at the specified heat criteria for all the individual

events analysed are presented in Appendix G.

Although large storage tank fires and bund fires are very hazardous events, if managed

correctly, the likelihood of fatality is low. The most likely mechanism for fatality is when a person is involved in the initial flash that ignites the fire. The likelihood of fatalities for

members of the public or fire fighters is extremely low and such fatalities are rare. A notable exception to this was an incident in which a number of people were killed when

too close to a tank fire when a boilover occurred. This phenomenon is now well understood and any such risks can be well managed by appropriate emergency response

procedures.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Risk Results


10. RISK RESULTS

10.1. Individual Risk

The overall risk was determined by combining the frequency and consequence data for the individual scenarios examined. The results of the analysis are presented as individual

risk contours. Contours were generated for individual risk of fatality and individual risk of injury. These are illustrated in Figure 1.1 and Figure 1.2 respectively.

10.2. Comparison with Risk Criterion

The quantified risk results were compared with the applicable risk criteria for land use established by DUAP. This provides the basis for determining the acceptability of the

risk.

10.2.1.Fatality Risk

Focus was placed on the risk exposure on the Serenity Cove Development located to the west of the refinery border, adjacent to the proposed Tank 632. The Serenity

Cove Development is an office building and hence the applicable risk criterion for individual risk of fatality level is 5 chances in a million per year (5 x 10-6 per year).

The 5 x 10-6 per year individual risk contour is shown in Figure 1.1. This contour is confined within the beyond the site boundary. Therefore, the risk criterion for

individual risk of fatality is satisfied.

An overall individual risk contour for the Caltex Refinery has not been developed at this point and hence was not available to enable a risk contour to be developed

representing the cumulative risk, including the addition of the proposed tank. In the absence of a risk contour for the existing activities, the cumulative risk exposure on

neighbouring facilities from the addition of Tank 632 has been assessed qualitatively.

The existing refinery activities in the area where the proposed tank is to be installed

include other atmospheric storage tanks and several pipelines. The distance between these other storage tanks and their bunds and the Serenity Cove

Development is large (i.e. shortest distance is well in excess of 100 m). Based on

this separation distance, there would be negligible contribution to risk of fatality from

events involving these tanks and their bunds because the impact distances for most of the scenarios will not extend this far.

Several pipelines run near the site boundary. These are as follows: Lube oil shipping line

Flare line.

The lube oil shipping line runs along the site boundary, whereas the flare line is separated from the site boundary by an internal road.

The risk exposure associated with pipeline operations is typically low compared to

the risk from other items such as process vessels, storage tanks, pumps etc. High

risk exposure normally only results when large numbers of pipes run together.



Considering the lube oil shipping line, the risk exposure may considered lower again for the following reasons:

The pipeline is not in continuous use for lube oil transfers The ignition probability is very low due to the high flash point of the oils being

transferred.

The risk exposure to adjacent areas from the flare line may be considered low for the

following reasons: The pressure in the flare line would normally be low

The pipeline is separated from the boundary by a short distance.

The pressure in the flare line would normally be low as the there would be minimal

transfer through the line unless a process upset was in progress. Therefore, if there were a failure of the line, the release rate of vapour from the leak would be low and

have a very limited impact zone. The separation distance between the flare line and

the Caltex boundary would reduce the likelihood of offsite impacts even further.

Based on the discussions above, the existing risk exposure to the Serenity Cove

Development and the HCE site from operations in the vicinity of the proposed storage tank is expected to be well within the risk acceptance criteria applicable for

these land uses.

Given that the existing operations on the Caltex site are not expected to impose high

levels of risk to the neighbouring areas, and the risk associated with the addition of Tank 632 does not exceed the criteria, it can reasonably be assumed that the

cumulative individual fatality risk from the existing and proposed operations does not exceed the acceptance criteria. For the Serenity Cove Development, the individual

risk of fatality from Caltex’s operations considering the addition of the proposed storage tank would be less than 5 x 10-6 per year, and the cumulative individual risk

of fatality risk imposed from Caltex on HCE site would be less than 50 x 10-6 per year

(i.e. the applicable criteria for neighbouring industrial sites).

10.2.2.Injury Risk

The 50 10-6 per year individual risk of injury contour is presented in Figure 1.2.

This contour represents the criterion applicable to residential areas. The risk contour is contained within the site boundary west of Tank 632. Its containment within the

site boundary therefore satisfies the injury risk criterion, regardless of the land use

beyond the site boundary in this region.

10.3. Major Risk Contributors

The following events contribute to the individual risk to the west of Tank 632, both in terms of risk of fatality and injury:

Significant release from the crude oil tank resulting in a large ignited spill Full surface tank fire.

The contribution to the risk associated with these events is primarily attributed to the

magnitude of the resulting fires. In the case of major spills into the bunded area, the

entire surface of the bund would be covered and resulting fires would have large impact distances.

A full surface tank fire is essentially a large pool fire located at the top of the storage

tank. Such fires generate a large amount of heat. The proposed size and location of Tank 632 mean that a full surface tank fire would result in significant heat radiation at

the western boundary of the refinery.



10.3.1.Fatality Risk

The major risk contributor to the western sector of the 5 x 10-6 per year fatality risk

contour is a major release from Tank 632, resulting in a large bund fire. As the bund surrounding Tank 632 has a very large surface area, the heat radiation from a full

bund fire will extend well beyond the western boundary of the refinery into the neighbouring area. The heat radiation impact from smaller fires will typically not

extend a sufficient distance to contribute to the risk at this location.

The events that contribute the most to the risk in the eastern sector of the 5 x 10-6

per year risk contour are releases from the transfer piping. These risks impact the adjacent Tanks 622, 623 and 633, however are limited to the bunded areas through

which they pass.

10.3.2.Injury Risk

The major risk contributor to the 50 x 10-6 per year injury risk contour is a full surface tank fire. The 4.7 kW/m2 heat flux associated with this event has the

potential to extend a distance of 83.6 m downwind from the tank centre. Another

significant risk contributor is a pool fires resulting from the ignition of significant releases (representative a range in hole sizes starting from 100 mm).

10.4. Maximum Consequence Impact

Based on the heat radiation impact distances, the installation of the proposed crude tank

at the location nominated will have the potential to generate offsite heat radiation impacts. The major consequence event with the potential to generate offsite impact is a

full bund fire resulting from a major release of whole crude oil from Tank 632. This event also represents the maximum extent of heat flux to the west of the refinery boundary.

Although this worst-case event will produce large impact zones, the frequency of the event is low (calculated to be in the order of 1 x 10-7 per year). The low event frequency

leads to a low contribution to the overall individual risk from this event. Consequently, the impacts of a bund fire can be considered acceptable from a risk perspective.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment References


11. REFERENCES

1 Department of Urban Affairs and Planning – Planning NSW, “Risk Criteria for Land Use Safety Planning”, Hazardous Industry Planning Advisory Paper No. 4,

March 2002.

2 ModuSpec Australia Pty Ltd, “Caltex Refineries (NSW) Pty Ltd Preliminary Hazard

Analysis, Storage Tank 632”, Reference: AUS 0352.1, August 31 2005.

3 Email from Kevin Houlihan (Caltex RPIP Project Engineer (Kurnell) Shedden Uhde Pty Ltd), Lachlan Dreher to (General Manager, ModuSpec Australia Pty Ltd)

“Caltex Crude Tank QRA”, 4th May 2006.

4 Email from Ramez Aziz (Senior Risk Engineer, Caltex Refineries (NSW) Pty Ltd), to

Marian Magbiray (Risk Engineer, ModuSpec Australia Pty Ltd) “MET Data for

Kurnell” (AUSPLUME files for Caltex Kurnell site), 2nd June 2005.

5 Bureau of Meteorology, “Climate Averages for Australian Sites”;

http://www.bom.gov.au/climate/averages/tables/cw_066037.shtml,June 14 2005.

6 LASTFIRE PROJECT, Large Atmospheric Storage Tank Fire Project – LASTFIRE

Technical Working Group, June 1997.

7 Offshore Hydrocarbon Release Statistics, Offshore Technology Report – OTO 97

950, UK Health and Safety Executive, December 1997

8 Guidelines for Process Equipment Reliability Data, Center for Chemical Process Safety of the American Institute of Chemical Engineers, 1989, Vessels –

Atmospheric-Metallic, page 203, Lower Value.

9 Quantitative Risk Assessment Datasheet Directory, E&P Forum Report No 11.8/250, October 1996, Chapter 10 “Storage Tank Incidents”, Table 3.1 page 6,

Atmospheric storage tank-mild steel.

10 Atmospheric Storage Tank Study for Oil and Petrochemical Industries Technical

and Safety Committee Singapore, by Technica Ltd, London, April 1990

11 Mudan, K.S. & Croce P.A., "Fire Hazard Calculations for Large Open Hydrocarbon Fires", The SFPE Handbook of Fire Protection Engineering, 1st Edition, 1988.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Appendix A: Project Assumptions

Ref: AUS0352.8, Release 01 Page A.1 of 7 7 July 2006

APPENDIX A: PROJECT ASSUMPTIONS

TABLE OF CONTENTS

1. INTRODUCTION........................................................................................2

2. ASSUMPTIONS .........................................................................................3Assumption 1: Modelling Boundaries .................................................................... 3Assumption 2: Scenario 1 – Crude Receiving......................................................... 3

Assumption 3: Scenario 2 – Transfer of Crude Oil from Tank 632 ............................. 3

Assumption 4: Scenario 3 – Static Tank 632 ......................................................... 4Assumption 5: Pipelines ..................................................................................... 4

Assumption 6: Frequency Assessment – Tank and Piping Utilisation.......................... 4Assumption 7: Frequency Assessment – Full Surface Tank Fires............................... 4

Assumption 8: Frequency Assessment – Tank Mixers............................................. 5Assumption 9: Meteorological Data ...................................................................... 6

3. REFERENCES ............................................................................................7



1. INTRODUCTION

This appendix documents the assumptions made during the risk analysis. The

assumptions have been based on information provided by Caltex. The justification for the assumptions has been included where applicable.



2. ASSUMPTIONS

Assumption 1: Modelling Boundaries

The analysis is bounded by the proposed Tank 632 and the associated crude

receiving and discharge piping to the eastern bund wall of Tank 633.

ModuSpec Analyst: Marian Magbiray Date: 21/09/05

Assumption 2: Scenario 1 – Crude Receiving

Isolation section: Crude Receiving Line Pipe 9-P610-KA1-650 at the boundary of the eastern bund wall of Tank 633 to the motorised valve (MV) at the inlet of Tank 632.

Product: Whole Crude Oil Temperature: 30 C

Pressure: 88 kPa(g) Flowrate: 4000 m3/hr [1].

Utilisation: See Assumption 6.

Justification

Due to the significant distance from the ship pump, the pressure in the pipeline was

assumed to be the same as the hydrostatic head in the tank.


Assumption 3: Scenario 2 – Transfer of Crude Oil from Tank 632

Crude Suction Line 9-P611-KA1-450

Isolation section: MV at Tank 632 outlet along the suction piping 9-P611-KA1-450 to the eastern bund wall of Tank 633.


Pressure: 88 kPa(g)

Flowrate: 400 m3/hr [1]

Utilisation: See Assumptions 6

Isolation section: MV at Tank 632 outlet along the suction piping 9-P962-B4-250 to the eastern bund wall of Tank 633.


Pressure: 88 kPa(g) Flowrate: 400 m3/hr [1]





Assumption 4: Scenario 3 – Static Tank 632

Tank 632 was modelled at 85% level [2]


Pressure: atmospheric


ModuSpec Analyst: Patrick Walker Date: 09/06/06

Assumption 5: Pipelines

The pipe lengths were estimated from the site plan provided [3]. The largest

pipe diameter in each isolatable section was used to represent the pipe sizing

during the modelling.


Assumption 6: Frequency Assessment – Tank and Piping Utilisation

The tank utilisation was assumed to be 100%.

Based on the frequency and duration of the tank filling and emptying operations, the

utilisation for the crude receiving pipeline was estimated to be 10%. The transfer piping for the delivery of crude to the CDU was assumed to be 90%.


Assumption 7: Frequency Assessment – Full Surface Tank Fires

Based on a review of several sources that have published the frequency values for a

full surface tank fire, the frequency considered most applicable for the Kurnell refinery is 8.9 x 10-5 per year, derived from the LASTFIRE project [4]. This value

has been selected because it has been derived from the widest sample set of events and tank locations. Statistically, this can be expected to provide a more appropriate

representation of the true event frequency.




Assumption 8: Frequency Assessment – Tank Mixers Assumption

Failure of a tank mixer was considered in terms of the failure of the mixer seal and a leak from that seal. It was assumed that a mixer seal is comparable to a pump seal

and that external leaks are considered to be the only reasonable foreseeable failure mode. Referring to OREDA-97 [5], the mean failure rate for pumps and the pump

seal failure percentage of the overall failure rate is as follows:

Critical Failure Mode Failure Rate

(per 10-6 hrs) Seal Failure Mode

Percentage Total Failure

Mode Percentage

External Leakage 3.64 9.02% 22.92%

Significant External Leakage

0.63 0.26% 0.26%

Degraded Failure Mode

External Leakage 9.61 9.02% 22.92%

Significant External

Leakage0.63 0.26% 0.26%

Applying the seal failure and total failure mode percentages presented above to the mean failure rate gives the following failure rates that have been applied for seal failures for

each failure mode:

Failure Mode (Seal) Critical Failure Degraded Failure

External Leakage 1.19 x 10-2 per year 3.31 x 10-2 per year

Significant External Leakage 5.52 x 10-3 per year 5.52 x 10-3 per year

This corresponds to a total seal mean failure frequency of 5.61 x 10-2 per year. It is

assumed that a mixer seal failure equates to a maximum hole size of 12 mm.



Assumption 9: Meteorological Data

The local meteorological data, extracted from the 2001 and 2002 CALMET files were

supplied by Caltex Kurnell. [6].

The average temperature is 18.1 C and the average humidity is 57%. Humidity data

was taken from the nearby weather station at Sydney Airport [7].

A total of 16 wind directions and 6 stability classes were used in the analysis. The

values used are listed below.

Stability B C D D E F Average

of all Stabilities

Wind Speed (m/s)

2.4 3.7 7.2 3.5 4.0 1.9 3.4

Probability of Atmospheric Conditions

0.140 0.182 0.126 0.126 0.134 0.292 1.0

WindDirection

Probability of wind direction

N 0.031 0.029 0.012 0.021 0.051 0.072 0.042

NNE 0.050 0.085 0.062 0.058 0.108 0.078 0.075

NE 0.128 0.113 0.077 0.079 0.069 0.062 0.085

ENE 0.128 0.094 0.031 0.067 0.025 0.038 0.062

E 0.078 0.051 0.002 0.048 0.024 0.038 0.041

ESE 0.094 0.044 0.005 0.072 0.025 0.045 0.047

SE 0.084 0.065 0.035 0.111 0.059 0.044 0.063

SSE 0.052 0.064 0.082 0.127 0.045 0.030 0.060

S 0.071 0.116 0.221 0.135 0.090 0.046 0.102

SSW 0.025 0.056 0.101 0.064 0.059 0.049 0.057

SW 0.020 0.027 0.053 0.019 0.041 0.060 0.040

WSW 0.025 0.051 0.123 0.041 0.107 0.081 0.071

W 0.051 0.069 0.105 0.048 0.127 0.085 0.081

WNW 0.067 0.061 0.054 0.046 0.100 0.099 0.075

NW 0.069 0.049 0.027 0.036 0.038 0.106 0.063

NNW 0.029 0.026 0.010 0.029 0.031 0.066 0.037



3. REFERENCES

1 Caltex Refineries (NSW) Pty Ltd, “Additional Crude Storage Project, Process Data for Phase 2 Preliminary Hazard Analysis”.

2 Email from Tracey Hyland (Environmental Engineer, Kurnell, Caltex Refineries

(NSW) Pty Ltd), Lachlan Dreher to (General Manager, ModuSpec Australia Pty Ltd)

“Fw: Tank 632 QRA Report”, 9th June 2006.

3 Caltex Kurnell Refinery Neighbourhood Layout for Risk Assessment, Drawing number 127103, Revision 0.

4 LASTFIRE Technical Working Group, “LASTFIRE PROJECT, Large Atmospheric

Storage Tank Fire Project” June 1997.

5 Sintef Industrial Management, “OREDA Offshore Reliability Data Handbook”,

OREDA Participants, 3rd Edition, 1997.

6 Email from Ramez Aziz (Senior Risk Engineer, Caltex Refineries (NSW) Pty Ltd), to Marian Magbiray (Risk Engineer, ModuSpec Australia Pty Ltd), “MET data for

Kurnell” (AUSPLUME files for Caltex Kurnell site), 2nd June 2005.

7 Bureau of Meteorology, “Climate Averages for Australian Sites”; http://www.bom.gov.au/climate/averages/tables/cw_066037.shtml, 14th June

2005.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Appendix B: Hazardous Scenarios and

Process Conditions

Ref: AUS0352.8, Release 01 Page B.1 of 3 7 July 2006

APPENDIX B: HAZARDOUS SCENARIOS AND PROCESS

CONDITIONS

TABLE OF CONTENTS

1. INTRODUCTION........................................................................................2

2. HAZARDOUS SCENARIOS AND PROCESS CONDITIONS..............................3


Process Conditions


1. INTRODUCTION

This appendix provides details of the hazardous scenarios identified in the analysis and

the process conditions relating to them. The definition of the data presented in the

tables is outlined below:

Scenario Name The name of the isolatable section or specific equipment considered as the scenario

Product The product representing the material in the scenario Utilisation (%) The percentage of time the scenario is in use

Temperature ( C) Temperature in the process

Pressure (kPa) Pressure in the process

Diameter (mm or m) Diameter of pipeline or vessel Length (m) Approximate length of pipeline

Height (m) Height of the vessel Liquid Level (%) Liquid level in vessel

Total HUM The hold up mass for the isolatable section

Vessel Capacity (t) The capacity of the vessel


Process Conditions


2. HAZARDOUS SCENARIOS AND PROCESS CONDITIONS

Table 2.1 details the tank scenario modelled. Table 2.2 presents the process conditions for the transfer pipelines (crude receiving line and

transfer lines to CDU for further processing).

Table 2.1: Summary of Vessel Scenario

Scenario Name Product Diameter (m)

Height (m)

Vessel Capacity

(t)

Utilisation (%)

Temperature ( C)

Pressure (kPa)

Liquid Level (%)

Tank 632 Whole

crude oil

77.5 20.5 5.4 x 104 100 30 101 85

Table 2.2: Summary of Representative Pipeline Scenarios

Scenario Name Product Diameter (mm)

Length (m)

Total HUM (kg)

Utilisation (%)

Temperature ( C)

Pressure (kPa)

Crude receiving

(Pipe 9-P610-KA1-650)

Whole crude

oil

650 240 55,748 10 30 189

Crude suction to CDU (Pipe 9-P611-KA1-450)

Whole crude oil

450 220 24,493 45 30 189

Crude suction to CDU

(Pipe 9-P962-B4-250)

Whole crude

oil

450 220 24,493 45 30 189

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Appendix C: Failure Frequency Data

Ref: AUS0352.8, Release 01 Page C.1 of 87 July 2006

APPENDIX C: FAILURE FREQUENCY DATA

TABLE OF CONTENTS

1. INTRODUCTION........................................................................................2

2. FAILURE FREQUENCY DATA ......................................................................32.1. Process Pipes........................................................................................... 32.2. Valves .................................................................................................... 4

2.3. Flanges................................................................................................... 6

2.4. Small Bore Fittings ................................................................................... 72.5. Tank Mixers............................................................................................. 7

2.6. Storage Tanks ......................................................................................... 72.7. Full Surface Tank Fires.............................................................................. 7

3. REFERENCES ............................................................................................8



1. INTRODUCTION

For each of the hazardous scenarios examined, items such as tanks, pipework, valves,

flanges and fittings termed “failure items” associated with the scenario were identified. Failure modes of each failure item were represented as a range of hole size releases.

Frequencies of hole size releases of each failure item were obtained using historical industry data.

This appendix presents the failure frequency values applied in the analysis.



2. FAILURE FREQUENCY DATA

2.1. Process Pipes

Table 2.1: Process Piping Failure Frequency [1]

Pipe Size (mm)

Hole Size (mm)

Failure Frequency (x10-6 /year per 10 m

length)

25 5 317.26

25 25 58.74

40 5 178.88

40 25 50.81

40 40 5.31

50 5 135.40

50 25 45.39

50 50 7.21

60 5 107.58

60 25 40.44

60 60 8.65

75 5 80.98

75 25 34.23

75 50 7.74

75 75 2.39

80 5 74.56

80 25 32.48

80 50 7.81

80 80 2.66

100 5 55.95

100 25 26.70

100 50 7.75

100 100 3.60

125 5 41.91

125 25 21.54

125 50 7.27

125 125 4.47

150 5 33.06

150 25 17.87

150 50 6.68

150 150 5.06

200 5 22.70



Pipe Size (mm)

Hole Size (mm)

Failure Frequency (x10-6 /year per 10 m

length)

200 25 13.07

200 100 9.42

200 200 1.80

250 5 16.94

250 25 10.14

250 75 6.96

250 250 3.56

300 5 13.33

300 25 8.19

300 100 7.29

300 300 2.53

350 5 10.88

350 25 6.81

350 100 6.45

350 350 2.72

400 5 9.12

400 50 8.77

400 200 4.71

400 400 0.90

450 5 7.81

450 50 7.64

450 200 4.42

450 450 1.02

2.2. Valves

Table 2.2: Valve Failure Frequency Data [2]

Valve Size (mm)

Hole Size (mm)

Failure Frequency (x10-6 /year)

25 5 108.16

25 25 2.84

40 5 102.70

40 25 8.29

40 40 0.01

50 5 98.88

50 25 12.06

50 50 0.05

60 5 95.26



Valve Size (mm)

Hole Size (mm)


60 25 15.58

60 60 0.16

75 5 90.33

75 25 20.20

75 50 0.46

75 75 0.01

80 5 88.83

80 25 21.55

80 50 0.61

80 80 0.01

100 5 83.43

100 25 26.14

100 50 1.38

100 100 0.05

125 5 77.87

125 25 30.29

125 50 2.64

125 125 0.20

150 5 73.30

150 25 33.17

150 50 4.06

150 150 0.47

200 5 66.20

200 25 36.50

200 50 6.87

200 200 1.43

250 5 60.90

250 25 37.99

250 75 11.38

250 250 0.73

300 5 28.37

300 25 19.26

300 100 7.63

300 300 0.24

350 5 26.69

350 25 19.26

350 100 9.11

350 350 0.44



Valve Size (mm)

Hole Size (mm)


400 5 25.29

400 25 19.12

400 200 11.06

400 400 0.03

450 5 24.10

450 25 18.90

450 200 12.44

450 450 0.06

500 5 23.08

500 25 18.64

500 200 13.68

500 500 0.10

2.3. Flanges

Table 2.3: Flange Failure Frequency [2]

Flange Size

(mm)

Hole Size (mm)


25 5 108.38

25 12 2.61

40 5 106.70

40 12 4.26

50 5 110.06

50 12 0.94

60 5 109.65

60 12 1.35

75 5 109.03

75 12 1.97

100 5 107.84

100 12 3.14

125 5 108.99

125 12 2.01

150 5 108.61

150 12 2.38

200 5 107.37

200 12 3.60

250 5 108.70

250 12 2.29

300 5 53.91

300 12 1.58

350 5 54.28

350 12 1.21



Flange Size

(mm)

Hole Size (mm)


400 5 54.00

400 12 1.49

450 5 54.36

450 12 1.13

500 5 54.00

500 12 1.49

600 5 53.49

600 12 1.99

2.4. Small Bore Fittings

The failure frequency value used for small bore fittings is 7.19 X 10-4 [3]. This has been applied for fittings having a diameter less than 25 mm.

2.5. Tank Mixers

Failure of a tank mixer was considered in terms of the failure of the mixer seal and a leak

from that seal. The total seal mean failure frequency used was 5.61 x 10-2 per year. Refer to Appendix A for further details.

2.6. Storage Tanks

Table 2.4: Storage Tank Failure Frequency Data [4].

Hole Size (mm)

Failure Frequency

(x10-6 /year)

10 1543.75

75 617.50

100 302.75

Rupture 6.00

2.7. Full Surface Tank Fires

The frequency of full surface tank fires used in the analysis was 8.9 x 10-5 per year [5]. Refer to Appendix A for additional details of the derivation of this frequency.



3. REFERENCES

1 “Hydrocarbon Leak and Ignition Data Base”, E&P Forum, February 1992, N658/Final Report, Section III.3, Appendix III, page 2.

2 “Classification of Hazardous Locations”, A.W. Cox, F.P. Lees and M.L. Ang,

IChemE, 1993, Table 18.1, page 68.

3 Geometric mean of data obtained from source 2 and “Hydrocarbon Leak and

Ignition Data Base”, E&P Forum, February 1992, N658/Final Report, page 25.

4 “Offshore Hydrocarbon Release Statistics, Offshore Technology Report – OTO 97 950”, UK Health and Safety Executive, December 1997.

5 LASTFIRE PROJECT, Large Atmospheric Storage Tank Fire Project – LASTFIRE

Technical Working Group, June 1997.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Appendix D: Hazardous Scenarios and

Failure Frequency

Ref: AUS0352.8, Release 01 Page D.1 of 6 7 July 2006

APPENDIX D: HAZARDOUS SCENARIO AND FAILURE

FREQUENCY

TABLE OF CONTENTS

1. INTRODUCTION........................................................................................2

2. HAZARDOUS SCENARIOS AND FAILURE CONTRIBUTORS ..........................32.1. Tank 632 ................................................................................................ 32.2. Crude Receiving ....................................................................................... 4

2.3. Crude Suction to CDU ............................................................................... 5

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Appendix D: Hazardous Scenarios and

Failure Frequency


1. INTRODUCTION

This appendix contains a listing of the hazardous scenarios identified and the process

failure items and overall failure frequency relating to them. The definitions for each of

the headings presented are detailed below:

Item Failure item or specific equipment included in the isolatable section.

Count The number of failure items associated with the isolatable section. Diameter Diameter of failure item (mm).

Hole Size 1 Representative hole size for a small release.

FFreq. 1 Failure Frequency of pipeline release for hole size 1 (x 10-6 per year).

Hole Size 2 Representative hole size for a medium release. FFreq. 2 Failure Frequency of liquid release for hole size 2 (x 10-6 per

year).Hole Size 3 Representative hole size for a large release.

FFreq. 3 Failure Frequency of liquid release for hole size 3 (x 10-6 per year).

Hole Size 4 Representative hole size for a rupture scenario. This equates to

the maximum size of the equipment, or 1000 mm for vessels. FFreq. 4 Failure Frequency of liquid release for hole size 4 (x 10-6 per

year).Frequency total Sum of frequencies at individual hole sizes.

The rupture case for storage tanks was represented by a hole size of 1000 mm. The

rupture cases for the pipelines were represented by the hole size equivalent to the pipe diameter.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Appendix D: Hazardous Scenarios and Failure Contributors


2. HAZARDOUS SCENARIOS AND FAILURE CONTRIBUTORS

The following section lists the failure item parts count within each respective isolatable section.

2.1. Tank 632

Table 2.1: Failure Items for Tank 632

Item Count Diameter

(mm)

Hole Size 1 (mm)

FFreq 1 (x10-6/y)

Hole Size 2 (mm)

FFreq 2 (x10-6/y)

Hole Size 3 (mm)

FFreq 3 (x10-6/y)

Hole Size 4 (mm)

FFreq 4 (x10-6/y)

Associated pipework 60 m 350 25 106.14 100 38.7 350 16.32 1,000 0

Associated pipework 40 m 500 25 27.16 100 27 350 16.56 1,000 4.4800

Flange 2 25 25 221.98 100 0 350 0 1,000 0

Flange 1 100 25 110.98 100 0 350 0 1,000 0

Flange 4 350 25 221.96 100 0 350 0 1,000 0

Flange 1 500 25 55.49 100 0 350 0 1,000 0

Flange 1 600 25 55.48 100 0 350 0 1,000 0

Small bore fitting 6 N/A 25 4,314.18 100 0 350 0 1,000 0

Tank Mixer Seal 5 N/A 25 280,500.00 100 0 350 0 1,000 0

Valve 2 25 25 222.00 100 0 350 0 1,000 0

Valve 1 100 25 109.57 100 1.43 350 0 1,000 0

Valve 3 350 25 137.85 100 27.33 350 1.32 1,000 0

Valve 1 500 25 41.72 100 0 350 13.68 1,000 0.1

Process Vessel -floating roof 1 77.5 m 25 1,543.75 100 920.25 350 0 1,000 6

Frequency Total 287,668.26 1,014.71 47.88 10.58



2.2. Crude Receiving

Table 2.2: Failure Items for the Crude Receiving Line (Pipe 9-P610-KA1-650)

Item Count Diameter

(mm) Hole Size1 (mm)

FFreq 1 (x10-6/y)

Hole Size2

(mm)

FFreq 2 (x10-6/y)

Hole Size3

(mm)

FFreq 3 (x10-6/y)

Hole Size4

(mm)

FFreq 4 (x10-6/y)

Flange 1 25 10 10.84 25 0.26 100 0 650 0

Flange 4 100 10 43.14 25 1.26 100 0 650 0

Flange 4 500 10 21.60 25 0.60 100 0 650 0

Flange 4 600 10 21.40 25 0.80 100 0 650 0

Process Pipe 240 m 650 10 9.53 25 0 100 9.91 650 9.50

Small bore fitting 11 N/A 10 158.19 25 632.74 100 0 650 0

Valve 1 25 10 10.82 25 0.28 100 0 650 0

Valve 4 100 10 33.37 25 10.46 100 0.57 650 0

Frequency Total 308.89 646.40 10.48 9.50



2.3. Crude Suction to CDU

Table 2.3: Failure Items for the Crude Suction Line to CDU (Pipe 9-P611-KA1-450)

Item Count Diameter

(mm)

Hole Size1

(mm)

FFreq 1 (x10-6/y)

Hole Size2

(mm)

FFreq 2 (x10-6/y)

Hole Size3

(mm)

FFreq 3 (x10-6/y)

Hole Size4

(mm)

FFreq 4 (x10-6/y)

Flange 2 300 25 49.94 100 0 250 0 450 0

Flange 1 350 25 24.97 100 0 250 0 450 0

Flange 1 350 25 24.97 100 0 250 0 450 0

Flange 3 450 25 74.91 100 0 250 0 450 0

Process Pipe 220 m 450 25 77.32 100 75.64 250 43.76 450 10.1

Small bore fitting 6 N/A 25 1,941.38 100 0 250 0 450 0

Valve 2 300 25 42.87 100 6.87 250 0 450 0.22

Valve 1 350 25 20.68 100 4.10 250 0 450 0.2

Frequency Total 2,257.04 86.61 43.76 10.52



Table 2.4: Failure Items for Crude Suction Line to CDU (Pipe 9-P962-B4-250)

Item Count Diameter

(mm)

Hole Size1

(mm)

FFreq 1 (x10-6/y)

Hole Size2

(mm)

FFreq 2 (x10-6/y)

Hole Size3

(mm)

FFreq 3 (x10-6/y)

Hole Size4

(mm)

FFreq 4 (x10-6/y)

Flange 1 25 25 49.95 100 0 250 0 450 0

Flange 1 250 25 49.95 100 0 250 0 450 0

Flange 2 250 25 99.89 100 0 250 0 450 0

Flange 1 300 25 24.97 100 0 250 0 450 0

Flange 1 350 25 24.97 100 0 250 0 450 0

Process Pipe 220 m 450 25 77.32 100 75.64 250 43.76 450 10.10

Small bore fitting 2 N/A 25 647.13 100 0 250 0 450 0

Valve 1 25 25 49.95 100 0 250 0 450 0

Valve 2 250 25 89.00 100 10.24 250 0.66 450 0

Valve 1 300 25 21.43 100 3.43 250 0 450 0.11

Frequency Total 1,134.56 89.31 44.42 10.21

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Appendix E: Event Tree Analysis

Ref: AUS0352.8, Release 01 Page E.1 of 6 7 July 2006

APPENDIX E: EVENT TREE ANALYSIS

TABLE OF CONTENTS

1. INTRODUCTION........................................................................................2

2. EVENT TREE DATA ....................................................................................32.1. Operator Nearby ...................................................................................... 32.2. General Assumptions ................................................................................ 4

3. REFERENCES ............................................................................................6



1. INTRODUCTION

Data acquired for the event tree considered the following for both a release and fire:

Probability of detection Probability of isolation

Time to detect a release Isolation time.

The assumptions relating to leak detection and intervention measures for the proposed Tank 632 were based on previous analysis for the gasoline storage tanks at the Kurnell

Refinery. The inlet and outlet lines of Tank 632 are to be fitted with motorised valves, whereas the event tree data for the gasoline tanks was based on the absence of remote

isolation. Therefore, the isolation strategies for Tank 632 were modified accordingly to incorporate the provision for remote isolation. This is reflected in the time allowed for

“1st isolation”. The event tree input data was collected by Caltex, based on discussions

with relevant Kurnell Refinery operations personnel [1].



2. EVENT TREE DATA

Descriptions of the main headings on the event tree table are provided below.

% chance of seeing or % time person near unit - This is related to detection of the

release or fire. There are two options for detecting a release or fire. The first is “Process” which is the chance that the basic process control system (e.g. an alarm or

other indication) will alert a process operator to an anomaly. The second is “Person”,

which is the chance that a person will detect the release or fire if they are in or near the unit. The “% time” is the percentage of time that a person will be in or near the unit.

Note that for the case where the probability of detection is quoted as 100%, the value used in the calculation was 99.5%, to allow for human error.

% chance of achieving isolation/time taken (min) – This is the probability of

achieving isolation within a specific time frame. This occurs only once the release or fire

has been detected. There are two chances for isolation (1st isol and 2nd isol) and each

has an associated time. The 1st isolation time is typically associated with the automated

isolation of the release or fire. The 2nd isolation time is related to the manual isolation, in the absence or failure of any automatic isolation.

Worse case time to detect - This is the maximum time that the leak could proceed

undetected. Generally this is for a release occurring in the middle of the night, when the likelihood of detection is low.

2.1. Operator Nearby

The proportion of time that an operator / personnel are within the vicinity of the relevant

unit was estimated based on weekday and weekend operations. Table 2.1 presents the

number of hours that different personnel are in the vicinity of the particular plant areas. The average value, based on weekday and weekend operation is listed in the final row.

The data acquired for the gasoline tank farm quantitative risk assessment was applied to

the south crude tank farm, the area where Tank 632 is to be located.



Table 2.1: Typical Presence of Personnel in the Crude Tank Farm.

Number of Hours

WEEKDAYS Crude Tank Farm

Operator 3.6

Security 0.5

General maintenance 1

Maintenance, vessel maint. routine 0

Personnel drive pass 1.5

Public 0

Total 6.6

% time a person at or nearby unit 27.5

WEEKEND Crude Tank Farm

Operator 3.6

Security 0.5

General maintenance 0

Maintenance, vessel maint. routine 0

Personnel drive pass 1

Public 0

Total 5.1

% time a person at or nearby unit 21.25

Average % time a person at or nearby theunit

25.71

2.2. General Assumptions

The following general assumptions associated with detection and isolation of a release

and fire in the Kurnell refinery were applied during the analysis: The operator has no or minimal chance of detecting a small release or fire through

indications on the basic process control system

There are no gas detectors at the facility The probability of detection (process and person) increases as hole size increases

Fire is generally more readily detected than a release for any given hole size

For any given hole size, isolation times will be greater for fires than releases, as

access to isolation points may be more difficult There are no heat or fire detectors at the facility

All releases are liquid.

Caltex has supplied data for the time to detect a release or fire for each of the individual

scenarios analysed [1]. The values used in the analysis for the “time to detect” were the average of the time to detect a release and the time to detect a fire. The “worst case”

time for detection (i.e. longest duration for which a release may go undetected) was assumed to be the time to detect a release.



Table 2.2: Event Tree Data (probability of detection and successful isolation for a release or fire at each section)

No. 1 1 1 2 2 2

Name Tank 633Tank 633Tank 633Pipelines PipelinesPipelines

Hole Size s m r s m r

Operatoron/near

unit

% time

26 26 26 26 26 26

Detector 0 0 0 0 0 0

Process 10 15 80 0 15 80 Release

Person 20 60 90 20 60 100

Detector 0 0 0 0 0 0

Process 10 15 80 0 20 80 % c

han

ce o

f seein

g

Fire

Person 80 90 100 80 100 100

Detect Time min 727.5 67.5 17.5 247.5 122.5 17.5

Time R/FNote 1440/15 120/15 30/5 480/15 240/5 30/5

1st isol. 90 90 90 90 90 90

Time min 1 1 1 2 2 2

2nd isol. 95 95 95 95 95 95

Release

Time min 15 15 15 15 15 15

1st isol. 70 60 50 90 80 80

Time min 2 2 2 2 2 2

2nd isol. 15 15 15 80 80 80

%ch

an

ce

of

ach

ievin

g iso

lati

on

/ ti

me t

aken

(m

ins)

Fire

Time min 30 30 30 20 20 20

Worst case

detectionTime min 1440 120 30 480 240 30



3. REFERENCES

1 E-mail from Ramez Aziz (Senior Risk Engineer, Caltex Refineries NSW, Pty Ltd) to Kate Filippin (Principal Risk Engineer, ModuSpec Australia) and Marian Magbiray

(Risk Engineer, ModuSpec Australia), “Event Tree Data (again),” 12th July 2005.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Appendix F: Consequence Impact Level Criteria

Ref: AUS0352.8, Release 01 Page F.1 of 4 7 July 2006

APPENDIX F: CONSEQUENCE LEVEL IMPACT CRITERIA

TABLE OF CONTENTS

1. INTRODUCTION........................................................................................2

2. HEAT FLUX CRITERIA ...............................................................................3

3. REFERENCES ............................................................................................4



1. INTRODUCTION

This appendix provides details of the criteria used to evaluate the risk of fatality for pool

fires. The general effects of thermal radiation are summarised in Table 1.1 [1].

Table 1.1: Thermal Radiation Effects.

Heat Flux (kW/m2)

Effect

1.2 Received from the sun at noon in summer.

2.1 Minimum to cause pain after 1 minute.

4.7 Will cause pain in 15-20 seconds and injury after 30 seconds exposure (at

least second degree burns).

12.6 Significant chance of fatality for extended exposure. High chance of injury. After extended exposure, causes the temperature of wood to rise to a point

where it can be readily ignited by a naked flame.

Thin steel with insulation on the side away from the fire may reach a thermal stress level high enough to cause structural failure.

23 Likely fatality for extended exposure and chance of fatality for

instantaneous exposure. Spontaneous ignition of wood after long exposure. Unprotected steel will

reach thermal stress temperatures which can cause failure. Pressure vessel needs to be relieved or failure will occur.

35 Cellulosic material will pilot ignite within one minute’s exposure.

Significant chance of fatality for people exposed instantaneously.



2. HEAT FLUX CRITERIA

The effect of human exposure to a fire is a function of both the intensity of heat radiation

and the duration of exposure. The harmful effect can be characterised by a thermal dose that is defined by the function (tI4/3), where I is the heat radiation intensity and t is the

exposure duration.

A probit function has been used to evaluate the likelihood of fatality for different heat flux

exposures. The probit equation utilised is the Eisenberg equation [2]:

Equation 2.1:

Y 14.9 2.56 ln tI

4

3

where: Y= probit value

t = exposure time (seconds) I = radiation intensity from fire (kW/m2)

In terms of human exposure, it is generally accepted that an exposure of 12.6 kW/m2 will

result in a 50% chance of fatality. Based on Equation 2.1, the required exposure time

would be 81 seconds.

To account for all the possible means that adverse outcomes can occur, a range of heat flux levels need to be assessed. The values used in the analysis were based on an

exposure time of 81 seconds and are presented in Table 2.1.

Table 2.1: Heat Flux Levels and Corresponding Fatality Probability

Heat Flux (kW/m2) 8.7 9.7 11.7 13.6 16.1

% Fatality 10 20 40 60 80

The actual heat flux received at a point located between two contours will be a value

between the heat flux values corresponding to each contour. Similarly, the probability of fatality at this location will be between the fatality probabilities for two contours. In

determining the risk at such a location, the higher fatality probability is applied in the calculation process. For example, all points lying between the 13.6 kW/m2 and 16.1

kW/m2 heat flux contours for a given scenario are treated as resulting in fatality to 80% of the exposed population. For the case of heat flux exceeding 16.1 kW/m2, the a

probability of fatality of 100% is assumed.



3. REFERENCES

1 NSW Department of Urban Affairs and Planning; “Risk Criteria for Land Use Safety Planning”, Hazardous Industry Planning Advisory Paper No. 4”, Sydney, 1990.

2 Lees, F.P., "Loss Prevention in the Process Industries, Hazard Identification

Assessment and Control", Butterworth & Heinemann, 1996, 2nd Edition,

Volume 1, p9/64.

Caltex Refineries (NSW) Pty Ltd ModuSpecTank 632 Quantitative Risk Assessment Appendix G: Consequence Results

Ref: AUS0352.8, Release 01 Page G.1 of 9 7 July 2006

APPENDIX G: CONSEQUENCE RESULTS

TABLE OF CONTENTS

1. INTRODUCTION........................................................................................2

2. CONSEQUENCES .......................................................................................32.1. Pool Fires ................................................................................................ 32.2. Full Surface Tank Fires.............................................................................. 9



1. INTRODUCTION

This appendix contains the consequence results. The results are presented in table

format. The following list provides a definition for each of the headings presented.

Scenario Name The name of the isolatable section or specific equipment considered as the scenario.

Hole Size (mm) The specific hole size considered for the consequence

scenario. Release Rate (kg/s) The rate at which the product is expected to be released.

Duration (s) The time taken for the product to be released. Frequency (x10-6/y) Failure frequency for the scenario.

Distance (m) to Heat Criteria (kW/m2)

The maximum distance at which the consequence is experienced for the given heat flux level from the centre

of the pool.



2. CONSEQUENCES

2.1. Pool Fires

Table 2.1: Consequence Modelling Results for Pool Fires.

Distance (m) to Heat Criteria (kW/m2)Scenario

Hole size

(mm)

Release Rate Used

(kg/s)

Duration (s) Frequency(x10-6/y) 8.70 9.70 11.70 13.60 16.10

Crude Receiving 10 0.57 113352 0.3 14 13 13 12 12

Crude Receiving 10 0.57 114402 0.03 14 13 13 12 12

Crude Receiving 10 0.57 128352 2.25 14 13 13 12 12

Crude Receiving 25 3.5 30711 1.28 28 27 26 25 24

Crude Receiving 25 3.5 31761 0.12 28 27 26 25 24

Crude Receiving 25 3.5 45711 0.02 28 27 26 25 24

Crude Receiving 25 3.5 45711 9.67 28 27 26 25 24

Crude Receiving 100 57 8454 0.16 65 62 57 52 46

Crude Receiving 100 57 9504 0.02 65 62 57 52 46

Crude Receiving 100 57 16554 0.35 65 62 57 52 46

Crude Receiving 650 778 1193 0.55 128 121 110 103 100

Crude Receiving 650 778 2243 0.08 128 121 110 103 100

Crude Receiving 650 778 2993 0.01 128 121 110 103 100

Crude Receiving 650 778 2993 0.11 128 121 110 103 100

Crude Suction (Line 9-P962-B4-250) 25 3.5 21886 2.25 28 27 26 25 24




Crude Suction (Line 9-P962-B4-250) 100 57 7902 1.33 65 62 57 52 46





Hole size

(mm)

Release Rate Used

(kg/s)












Crude Suction (Line 9-P611-KA1-450) 25 3.54 21886 4.48 28 27 26 25 24




Crude Suction (Line 9-P611-KA1-450) 100 57 7902 1.29 65 62 57 52 46












Tank 632 25 4.4 12442307 926.11 30 29 28 27 26

Tank 632 25 4.4 12443657 127.34 30 29 28 27 26




Hole size

(mm)

Release Rate Used

(kg/s)


Tank 632 25 4.4 12486407 104.19 30 29 28 27 26

Tank 632 25 4.4 12486407 4208.88 30 29 28 27 26

Tank 632 100 70.1 779050 13.23 70 67 61 55 48

Tank 632 100 70.1 780400 2.43 70 67 61 55 48

Tank 632 100 70.1 783550 1.98 70 67 61 55 48

Tank 632 100 70.1 783550 38.56 70 67 61 55 48

Tank 632 350 64,041 953 0.14 177 168 155 150 149

Tank 632 350 64,041 954 2.63 177 168 155 150 149

Tank 632 350 60,891 963 0.17 177 168 155 150 149

Tank 632 350 59,541 967 0.90 177 168 155 150 149

Tank 632 Rupture N/A Instantaneous 0.10 209 198 176 176 176






Table 2.2: Consequence Modelling Results for the 4.7 kW/m2 Heat Criteria for Pool Fires

Scenario Hole size

(mm) Release Rate Used (kg/s)

Duration (s) Frequency (x10-6 / y)

Distance (m) to 4.7kW/m2 Heat Criteria

Crude Receiving 10 0.6 113352 0.30 16

10 0.6 114402 0.03 16

10 0.6 114402 0.00 16

10 0.6 128352 2.25 16

25 3.5 30711 1.28 32

25 3.5 31761 0.12 32

25 3.6 45711 0.02 32

25 3.6 45711 9.67 32

100 56.7 8453 0.16 78

100 56.7 9503 0.02 78

100 56.7 16553 0.00 78

100 56.7 16553 0.35 78

650 778 1193 0.55 159

650 778 2243 0.08 159

650 778 2993 0.01 159

650 778 2993 0.11 159

PLT 2 Suction 25 3.5 21885 2.25 32

25 3.5 22935 0.22 32

25 3.6 36885 0.03 32

25 3.6 36885 16.96 32

100 56.7 7902 1.33 78

100 56.7 8952 0.21 78

100 56.7 16002 0.03 78



Scenario Hole size




100 56.7 16002 2.98 78

250 78 7539 1.04 159

250 78 8589 0.16 159

250 78 15639 0.02 159

250 78 15639 2.33 159

450 78 1191 0.59 159

450 78 2241 0.09 159

450 78 2991 0.01 159

450 78 2991 0.12 159

PLT 45 Suction 25 3.5 21885 4.48 32

25 3.5 22935 0.44 32

25 3.6 36885 0.06 32

25 3.6 36885 33.75 32

100 56.7 7902 1.29 78

100 56.7 8952 0.20 78

100 56.7 16002 0.03 78

100 56.7 16002 2.89 78

250 78 7539 1.02 159

250 78 8589 0.16 159

250 78 15639 0.02 159

250 78 15639 2.30 159

450 78 1191 0.61 159

450 78 2241 0.09 159

450 78 2991 0.01 159



Scenario Hole size




450 78 2991 0.13 159

Tank 632 25 4.4 12442307 926.11 34

25 4.4 12443657 127.34 34

25 4.4 12486407 104.19 34

25 4.4 12486407 4,208.88 34

100 70.1 779050 13.23 85

100 70.1 780400 2.43 85

100 70.1 783550 1.98 85

100 70.1 783550 38.56 85

350 64,042 953 0.14 224

350 64,042 953 2.63 224

350 60,892 963 0.17 224

350 59,542 967 0.90 224

Rupture N/A Instantaneous 0.10 258






2.2. Full Surface Tank Fires

Table 2.3: Consequence Modelling Results for Full Surface Tank Fires

Downwind Distance (m) to Heat Criteria (kW/m2)Scenario Frequency (x10-6/y)

4.7 8.7 9.7 11.7 13.6 16.1

Tank 632 Full Surface Tank Fire 120 81 81 81 81 81 81

report-tank-farm-pdf.pdf

Documents

widest sample set

serenity cove development

serenity cove development

event tree analysisref

nearby weather station

local meteorological data

event tree data

marian magbiray date