ARTICLE IN PRESS
Journal of Loss Prevention in the Process Industries 19 (2006) 399–408
www.elsevier.com/locate/jlp
Aspects of risk analysis associated with major failures of fuel pipelines
M. Dziubińskia,, M. Fra˛ tczaka, A.S. Markowskib
a
Department of Chemical Engineering, Faculty of Process and Environmental Engineering, Technical University of Lodz,
93-005 Łódź, ul. Wólczańska 213, Poland
b
Department of Environmental Engineering Systems, Faculty of Process and Environmental Engineering, Institution of Process and Ecological Safety,
Technical University of Lodz, 93-005 Łódź, ul. Wólczańska 213, Poland
Received 1 December 2004; received in revised form 20 June 2005; accepted 7 October 2005
Abstract
This paper presents a methodology of risk assessment for hazards associated with transportation of dangerous substances in long
pipelines. The proposed methodology comprises a sequence of analyses and calculations used to determine basic reasons of pipeline
failures and their probable consequences, taking individual and societal risk into account. A specific feature of this methodology is a
combination of qualitative (historical data analysis, conformance test and scoring system of hazard assessment) and quantitative
techniques of pipeline safety assessment. This enables a detailed analysis of risk associated with selected hazard sources by means of
quantitative techniques. On the ground of this methodology typical problems that usually pose serious threat and constitute part of risk
analysis for long fuel pipelines are also presented. To verify above methodology, complete risk analysis was performed for the long
distance fuel pipeline in Poland.
r 2005 Elsevier Ltd. All rights reserved.
Keywords: Long pipeline; Risk analysis; Methodology; Failure; Consequences
1. Introduction
Transport of liquid and gas materials in pipelines is a
significant element of modern technological solutions
applied in various branches of industry. The main hazard
for safe transportation of substances is a pipeline failure
taken as a loss of its tightness and release of the
transported medium to the environment. Although transport in pipelines is considered one of the safest methods of
long-range transport, the databases of accidents reveal that
the risk associated with pipeline operation is often on the
same level as that of stationary refinery installations (The
Accident Database Software, Version 4.1).
A general classification of methods used for risk analysis
is shown in Fig. 1.
To perform risk analysis and so an estimation of level of
accident risk, three methods, qualitative, semi-quantitative
and quantitative, can be used. The semi-quantitative
Corresponding author. Tel.:+48 42 631 37 34; fax: +48 42 636 92 51.
E-mail address: dziubin@wipos.p.lodz.pl (M. Dziubiński).
0950-4230/$ - see front matter r 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.jlp.2005.10.007
methods are applied to identify hazards and to select the
so-called creditable failure events. Main tools used for this
purpose are HAZOP, PHA and What if methods
(Markowski, 2000). Results given in the form of relevant
risk categories enable an easy identification of risk levels.
The qualitative methods are used first of all in the
verification of concordance of a safety level with valid
principles contained in legal regulations and standards.
These rules usually refer to separate devices and represent
minimum requirements that must be satisfied to reach some
acceptable safety level. However, for long pipelines, it is
often required that risk assessment be made using
quantitative (probabilistic) techniques based on the concept of risk. The quantitative risk assessment is a complex
series of analyses and calculations that employ many
simulation models, particularly in the analysis of physical
effects. A full risk analysis of a selected object is a complex
task that requires specialist software (i.e. PHAST,
EFFECT, SAFETI) and intensive training in theory and
practice of risk analysis to interpret results correctly
(Arendt & Lorenzo, 2000).
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400
RISK ASSESMENT
Quantitative
Semi-quantitative
Qualitative
(Deterministic)
(Probabilistic)
Creditable
accident scenario
Creditable
accident scenario
Calculations:
- consequences
- probability
Classification:
- consequences
- probability
Creditable
accident scenario
General hazard
estimation
Conformity
test
Identification of
Creditable
Failure Event
Are the safeguards
sufficient for control
creditable
accident scenario?
NO
Consequences
YES
Consequences
Failure
frequency data
Pipeline
identification
Historical data
Calculation of
Creditable
Failure Event
frequen cy
Layer of protection
analysis
Consequence
analysis
Risk analysis
Probability
Estimation of
failure frequency
Probability
Unacceptable risk
Risk must be reduce
im mediately
Tolerable risk
Risk is undertaken only
if a benefit is desired, action
is based on ALARP principle
Acceptable risk
Any activity not be required
Acceptable
Individual and
societal risk
Unacceptable
Acceptable
Additional safety
measures
Safety
assurance
Risk
assess ment
Fig. 1. General division of methods for risk analysis.
Unacceptable
2. Methodology of risk assessment for long pipelines
The proposed methodology comprises a sequence of
analyses and calculations used to determine basic reasons
of pipeline failures and their probable consequences, taking
individual and societal risk into account. A specific feature
of this methodology is a combination of qualitative
(historical data analysis, conformance test and scoring
system of hazard assessment) and quantitative techniques
of pipeline safety assessment.
This enables a detailed analysis of risk associated with
selected hazard sources by means of quantitative techniques. A general scheme of the risk assessment methodology
for long pipelines is shown in Fig. 2.
Below, some steps of risk analysis methodology are
discussed briefly with reference to the methods and
techniques used to perform it and to necessary information. It is worth stressing that each step of the analysis may
consist of several stages. This refers specially to the analysis
of physical effects and consequences.
Fig. 2. Methodology of risk assessment for long pipelines.
The collected data are necessary for starting the work on
the second stage of risk analysis, i.e. the identification of
hazard sources.
2.2. Identification of general hazard sources
To identify hazard sources, we should consider all
factors that may be potentially a source of hazard for a
pipeline, personnel and environment which can be done
using an expert’s assessment method based on
historical data survey,
conformance test of the technical documentation with
legal requirements and
‘‘scoring’’ methodology for relative risk assessment.
2.1. Pipeline characteristics
2.3. Historical data
This is a stage at which the pipeline data are collected.
To do this, the installation should be checked over.
In the case of long pipelines, this is quite complicated
because of the pipeline length and its position (e.g.
underground). The main data source is the documentation.
The historical data comprise the information on
accidents and failures that involve hazardous substances
which have occurred so far and are stored in the world
databases, e.g. The Accident Database Software, Version
4.1, Institution of Chemical Engineers.
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2.4. Conformity test
The conformance test is a check list (a set of questions or
checking procedures) that covers all stages of the pipeline
life (designing, construction and operation) affecting its
safety. The basis for preparation of the control lists are
legal requirements and a number of standards (e.g. API,
ASME, ANSI) related to long pipelines. A result of the test
is a list of regularities and departures from regularity
following from the standards or legal requirements.
2.5. Scoring methodology for relative risk assessment
The main causes of pipeline failures are specified and
next scored depending on the applied safety measures. This
system can be used for determining priorities of repairs and
exchange of particular parts of the pipeline. A detailed
description of scoring system of hazard assessment for
pipelines can be found elsewhere (Muhlbauer, 1996;
Borysiewicz & Potempski, 2001).
2.6. List of creditable failure events
On the basis of the above-mentioned hazard assessment
methods, a list of main sources of hazards is prepared. It
specifies potential locations of releases of the hazardous
substances for a given pipeline type. Due to a possibility of
repeated listing of the same events within one segment of
the pipeline which differ only, e.g., in the spot where they
take place, the list is reduced to the list of creditable failure
events which represent the worst consequences and
probability of their occurrence. The creditable failure
events are then subjected to failure scenario modelling
(Markowski, 2000). Creating this representative set of
creditable failure events, we used our experience and
information from historical records, e.g. The Accidents
Database. A detailed description of selection of accidents
can be found in the study (Guidelines for Chemical Process
Quantitative Risk Analysis, CCPS, AIChE, 2000).
2.7. Layer of protection analysis
Layer of protection analysis (LOPA) is a simplified risk
assessment used to identify safeguards to meet the risk
acceptance criteria. Safety and protection measures in
pipelines are formed into a multi-layer protection system
which functions in a specified sequence. In a multi-layer
protection system, three main types of protection layers
can be distinguished, namely prevention, protection and
counteraction. The aim of these layers is to prevent
initiating events which can lead to fuel release from the
pipeline, to protect the pipeline and employees against
consequences of the release, and to minimise consequences
of short releases. The LOPA assumes that no layer of
protection is perfect; every layer has some probability
failure on demand (PFD). Therefore, the risk of the
occurrence of unwanted consequences depends on the
401
failure of the safeguards. In the determination of the final
risk level for a selected accident scenario, the event tree
method is applied. The application of LOPA for pipelines
risk assessment as a alternative method to QRA is given by
Markowski (Markowski, 2003).
2.8. Failure event frequency
Failure event frequency to be determined based on
reliability models using fault and event tree analysis. It
requires number of frequency data for initiating events
which are very difficult to establish for pipelines. Each
failure scenario must take into account protection layers
and specified conditions, mainly environmental ones, that
would determine further development of the scenario. To
determine the probability of failure scenarios reliability
models, generic data available in literature (HSE, Contract
Research Report 210, 1999; HSE Contract Research
Report No. 82, 1994; HSE Contract No. 3273/R73.05)
are used. A detailed description of the application of
reliability models can be found in the study Guidelines for
Hazard Evaluation Procedures (1992).
2.9. Consequences analysis
The analysis of physical effects and consequences
consists in determination of the consequences of particular
physical effects in hazard zones. A hazard zone is the
region in which physical effect of the hazard exceeds
critical threshold values and induces negative effects for
people, environment and property. Type of the hazard and
related physical effects and consequences depend on many
factors, first of all on the properties and volume of released
substance, the state of aggregation, process conditions, the
way of release and possible interactions with the environment (Guidelines for Ecological Risk Assessment, 1998).
The model of physical effects and consequences analysis
is shown in Fig. 3.
It is worth noting that real hazard zones caused by
overpressure (explosion) and thermal radiation (fire) are
circular areas of a radius equal to the assumed threshold
value. In the case of release of flammable and toxic
substances without ignition, the hazard zones will depend
on wind direction. As it is difficult to predict wind direction
in the moment of failure, hence in the analyses, all possible
Physical effects analysis
Release
source data
Vaporization
rate
Consequence analysis
Dispersion
models
Hazard
zones
Consequence
analysis
Topographic
models
Rescue
plan
Sensitivity
models
Fig. 3. Structure of model for calculation of potential consequences.
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402
Boundaries of potential
hazard zones
Dominant wind
direction
Pipeline failure
Leakage on
the surface of
water
Leakage into
the ground
RA
Physical effects
Place
of failure
Directional hazard zone
for substance A
Is there
ignition?
YES
RB
Direction al hazard zone
for substan ce B
Hazard zone for substance A, radius RA
Pool fire
Flash fire
Explosion
Fire on the surface
of water
wind directions should be considered. Next, taking wind
rise into account, relevant directional hazard zones should
be specified (Fig. 4). In this way, one can distinguish a
potential hazard zone which encompasses a circle of a
determined radius which corresponds to the threshold
concentration and a directional zone of real hazard
depending on the current wind direction (User’s Manual
for PHAST v. 6.1, 2002; Fra˛ tczak & Markowski, 2003;
Nieuwstadt, 1982).
Fig. 5 shows a general diagram of the formation of
environmental consequences of an accidental fuel release
from a pipeline. It should be kept in mind that the range of
undesirable effects of chemical hazards need not only cover
a given pipeline but can refer to the regions which are not
in an immediate neighbourhood of the pipeline system. As
follows from historical data, the probability of explosion
caused by a release of fuel (gasoline or diesel oil) from a
long pipeline is statistically very small and is related to a
probable occurrence of an ignition source (96% of gasoline
or diesel oil pools does not ignite) (HSE, Contract
Research Report 210, 1999). This is due to the fact that
pipelines are laid underground and on sparsely inhabited
areas. Among various types of fire, pool fire is most
prevalent. Estimation of fire impact on the environment is
based on the assumption that in the fire region, i.e. in the
immediate fire region, the effects are catastrophic. It is
necessary to analyse the consequences beyond the immediate hazard zone, where potential losses depend first of
all on the distance from the release source.
This refers mainly to degradation of soil, underground
and surface water. It follows from long-term observations
that grounds situated up to 400 m from the pipeline are
100% contaminated, i.e. a band 800 m wide along the
pipeline should be treated as a hazard zone. In the case of
grounds with soil of high moisture content, it is assumed
that the hazard zone is a 1100 m wide band of land around
the pipeline (Borysiewicz & Potempski, 2002a, b). Many
research projects aim at determination of the time of the
pool edge transport, identification of regions where
Is there
ignition?
NO
NO
Is the ground
permeable?
NO
Liquid pool formation
on the ground and
spillage into the sewers
Hazard zone for substance B, radius RB
Fig. 4. Potential hazard zones for accidental release of a dangerous
substance to the air.
YES
Liquid pool formation
on the surface of water
and pool transportation
with water
YES
Is there
pollution
of ground water?
NO
Soil pollution
YES
Is the connection
between system of
underground and
ground water ?
NO
Ground water
pollution
YES
Underground water
pollution
Fig. 5. General diagram of formation of the environmental consequences
due to pipeline failure.
hazardous compounds can accumulate and estimation of
the residence time of substances at a given concentration in
water (Fafara, 2002; Markowski & Petera, 2001; Nagy &
Macuda, 2001).
However, the loss estimation can be dubious because
results presented in the reports refer only to the time of
failure (the so-called short-term consequences, e.g. casualties in the personnel and uninvolved people, wounded
people—costs of hospitalisation) and do not cover future
losses (the so-called long-term consequences, e.g. costs of
production losses in the company, costs of environment
decontamination/treatment, regions of contaminated soil,
underground and surface water) that occur in subsequent
years (Borysiewicz & Markowski, 2002).
3. Application of risk analysis method for long pipelines
A complete risk analysis was performed for the fuel
pipeline located in central part of Poland. The pipeline is
under soil surface at the depth from 1.4 to 1.5 m and serves
for the transportation of gasoline, heating and diesel oil.
The total pipeline length is about 200 km, inner diameter
400 mm and rated pressure 6.3 MPa. Along the pipeline,
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403
Table 1
Assumed times of fuel release
Kind of release
Detection time
Time to stop pumps
and close the gate valve
Time of pressure phase
Time of drainage phase
Total time of fuel
release
Full bore rupture
20 s
140 s
160 s
Depends on the
segment
Leak (1%)
Leak (0.01%)
20 s
424 h
140 s
140 s
300 s
424 h
Release of the
complete section
inventory of pipeline
2h
2h
there are 23 gate valve stations which form separate
segments for analysis. By expert’s estimation method,
places of probable leakage from the pipeline caused by
external factors were identified. Twenty-three failure
release points were specified. Places of potential hazard
of a pipeline failure are, among the others,
passing of the pipeline near buildings, gate valve
stations,
42 h
426 h
Table 2
Generic data used in calculations
Kind of failure event
Accident frequency
Full bore rupture
Leak ( 1%)
Leak (0.01%)
Pool formation from spray release
Spillage into the rivers, sewers
Ignition
0.051 [1/1000 km year]
0.164 [1/1000 km year]
0.206 [1/1000 km year]
0.5
0.08
0.05–0.12
crossing of the pipeline with existing pipelines, roads,
railways and infrastructure,
crossing over watercourses, meliorated and drained
grounds and
passing through the grounds with high groundwater
level.
Software (2002); Nieuwstadt, 1982). Using classical relations of fluid mechanics, the volumes of released substances
were calculated. Calculations were made for 23 creditable
failure events for gasoline and diesel oil.
3.1. Assumptions for calculation
3.2. Probability of results of fuel release
The following assumptions were made to calculate
release from the pipeline:
As can be seen from fault tree presented in Fig. 6, the
frequency of the pipeline failure depends on many basic
events which cannot be quantitatively established. Using
the event tree technique and taking into account the
historical data that refer to the fuel release phenomenon
(HSE, Contract Research Report 210, 1999; HSE Contract
Research Report No. 82, 1994; HSE, Contract No. 3273/
R73.05), diagrams representing formation of actual failure
scenarios and probability of their occurrence were developed.
An event tree is shown in Fig. 7, while total data
obtained from the event tree are given in Table 3. Numbers
on particular branches of the event tree denote the
probability of occurrence of the conditions describing the
tree branch. For a branch describing success (yes), the
probability of success PS is assumed, while for the branch
standing for failure (no), the probability PN ¼ 1–PS is
assumed. The probability of single scenarios is a product of
probabilities of conditions describing a given branch. Final
probability of potential consequences is obtained by
summing up partial probabilities for a given type of
consequences. A detailed description of reliability model
applications, formation of actual failure scenarios and
probability determination can be found elsewhere (Guidelines for hazard evaluation procedures, 1992).
Table 3 provides summary data for particular selected
segment of the pipeline.
3.1.1. Hole sizes
Full bore rupture: release through the whole pipe cross
section,
Leak: release through a hole of surface area equal to 1%
and 0.01% of the pipe cross section.
3.1.2. Determination of time of accidental fuel release
Assumed times of fuel release result from sensitivity of
leakage detection systems on the pipeline and necessary
time to stop leakage by emergency services (Table 1).
3.1.3. Generic data
To determine the probability of failure scenarios and to
calculate the risk of specific environmental consequences
we used generic data available in literature (HSE, Contract
Research Report 210, 1999; HSE Contract Research
Report No. 82, 1994; HSE Contract No. 3273/R73.05)
(Table 2).
Mean air temperature 10 1C and its humidity equal to
70% as well as two types of weather conditions, typical
ones with stability class D, wind velocity 5 m/s, i.e. D5, and
unfavourable ones with stability class F and wind velocity
2 m/s, i.e. F2, were assumed (DNV Risk Management
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404
Pipeline failure
OR
Decrease of
the strength of
the pipeline
Water hammer
(Operational error)
A
OR
Corrosion
Errors in
construction
Design
factors
External
hazards
OR
OR
OR
OR
External
Internal
Buried pipe
B
C
D
Defect of
wall material
Badly
weld
E
F
Bad selection Bad selection
of wall
of material
thickness
G
H
Natural
hazards
Third Party
Activity
OR
OR
Ground
settlement
Earth
pressure
Ditching,
bulldozing
Sabotage
I
J
K
L
Fig. 6. Fault tree for pipeline failure.
Spillage to water
Spillage
Failure Jet
Liquid
event release Ignition pool Ignition to sewage systems (rivers,
drainages)
systems
0.05
Late
ignition
0.1
0.16
0.0
0.9
0.95
0.08
0.1
0.9
1.0
0.92
0.12
Pipeline
Failure
0.1
0.0
0.5
0.9
0.88
0.08
0.9
1.0
0.84
0.1
0.92
0.1
0.0
0.9
0.5
0.08
0.1
0.9
1.0
0.92
Consequences
Probability
Jet fire
8.0x 10-3
Explosion in sewage system
0.0
Sewage system pollution
0.0
Fire on the water
1.2x 10-3
Water pollution
1.1x 10-2
Ground pollution
Pool fire
Flash fire
Explosion in sewage system
1.4x 10-1
Sewage system pollution
0.0
Fire on the water
3.0x 10-3
Water pollution
2.7x 10-2
Ground pollution
3.4x 10-1
Explosion in sewage system
0.0
Sewage system pollution
0.0
Fire on the water
3.4x 10-3
Water pollution
3.0x 10-2
Ground pollution
3.9x 10-1
5.0x 10-2
0.0
Fig. 7. Event tree for pipeline failure.
3.3. Estimation of the consequences of released substance
propagation in soil
The size of a pool of released substances was calculated
according to the method quoted in the study by Litlle
(1996). Local conditions concerning soil permeability were
not considered in the calculations. It was assumed that
along the pipeline, the soil consisted of fine sand with
constant permeability coefficient equal to 104 m/s. As the
calculations made for the pipeline full bore rupture and
permeable soil show, the pool diameter is 31.3 m in the case
of immediate ignition, and 43.3 m for delayed ignition. For
1% leak, the values are smaller and reach 25 m from the
pipeline axis, and for 0.01%, do not exceed 2–3 m.
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405
Table 3
Probability of results of fuel release
No.
Type of consequences
Probability
1.
2.
3.
4.
Ground pollution
Water pollution
Fires/explosions
Fires on the surface of water
1.4 101+3.4 101 +3.9 101 ¼ 8.7 101
1.1 102+2.7 102+3.0 102 ¼ 6.8 102
8.0 103+5.0 103 ¼ 1.3 102
1.2 103+3.0 103+3.4 103 ¼ 7.6 103
Table 4
Results of calculations of depth of fuel penetration into the ground
Full bore rupture
Product
Gasoline
Diesel oil
Leak 1%
Volume of
released
product (m3)
Depth of seep Volume of
into the
released
ground (m)
product (m3)
Depth of seep
into the
ground (m)
23.4
447
1114
20.8
444
1111
3.2
15.2
21
0.18
3.8
10
1.67
1.75
—
0.42
0.47
—
24
28.1
—
12.8
22.8
—
The maximum oil seep depth was calculated using the
relation presented in the study by Michalowski and Trzop
(1996). Results are given in Table 4 for one selected
segment of pipeline. In view of a big number of data on
released liquid volume, in the calculations, three different
volumes for a rupture and two for 1% leak were taken (the
least, mean and the biggest—see Table 4). This seems
reasonable for a holistic approach to the problem. Selected
data can be treated as creditable because they determine
small, mean and biggest environmental impacts induced by
accidental release of hazardous liquids from a pipeline. The
depth of seep for 0.01% leak was not calculated due to a
small volume of the released substance, the seep depth did
not exceed several centimetres.
3.4. Estimation of released substance propagation on a river
surface
Calculations were made using a model applied by EPAUSA (40 Code of Federal Register, Ch I (7-1-97 Edition)).
It is assumed that fuel spill reaches the same velocities as
water current when no wind activity is observed. This
model takes only the effect of water flow rate and
roughness coefficient into account. The size of pool and
wind velocity are not considered. Calculations were made
for five rivers crossed by the pipeline, namely the Wisla,
Warta, Ner, Skrwa and Prosna. Results obtained for
hazard zones for the rivers are given in Table 5. The zone
range was calculated considering the rescue system
response time, i.e. the time at which a dam was made to
stop the oil spill (12 and 24 h alternatively since the
moment of the pipeline failure).
Table 5
Range of hazard zone of oil spill on rivers surface
Rescue service
Range of hazard zones (km)
response time (h)
Rivers
12
24
Wisla
Warta
Ner
Skrwa
Prosna
14.1
28.2
6.3
12.6
4.4
8.9
4.9
9.9
5.4
10.8
3.5. Calculation of thermal radiation and blast wave hazard
zones
Calculations were made using a PHAST v.6.1 software
for a constant value of mass stream characteristic of
pipeline rupture and three values of mass streams of spilled
gasoline for full bore rupture, 0.1% and 0.01% spills.
Examples of printouts are shown in Figs. 8 and 9. Table 6
gives results for gasoline. Results based on equivalent spill
values and meteorological conditions reveal more severe
failure consequences for gasoline than for diesel oil. As can
be seen from Table 6, heat radiation effects are limited to
radii 30–50 m whereas the overpressure effects are within
200–600 m.
3.6. Calculation of individual and societal risk
Calculations were made using SAFETI Micro software
for 19 cases which correspond to the number of rural
districts situated along the pipeline path. The necessary
population data were obtained from real population
density in every rural district. Individual and societal risk
was calculated for the population satisfying the following
conditions:
people are always present (100% inhabitants),
people spend 10% of their spare time outdoor and 90%
indoor and
people live in typical houses.
Percentage of day (0.7) and night (0.3) was considered.
Examples of printouts concerning individual and societal
risk (F–N curve) for Plock town are shown in Figs. 10 and
11. Results of studies on individual and societal risk caused
by gasoline and diesel oil reveal that the risk is variable
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Fig. 8. Range of heat radiation from pool fire in case of pipeline rupture—the weather conditions F2.
Fig. 9. Range of overpressure wave from explosion of steam cloud in case of pipeline rupture—the weather conditions F2.
along the pipeline path and ranges from 105 to 108
l/year, depending on the rural district.
To calculate the probability of specific consequences, the
quantitative analysis of event tree and data from Tables 2
and 3 were used. By multiplying values characteristic of
failure frequency for rupture and spill by the probability of
specified consequences, one can obtain the value of risk of
these consequences. Results of calculations are given in
Table 7.
Results of risk studies show that the risk of specified
consequences is variable depending on the type of impact.
One can say that, for instance, the frequency of soil
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407
316/56
283/56
257/56
215/42
—
—
—
338/60
307/60
279/60
234/45
—
—
—
627/118
613/118
562/119
477/89
—
—
—
0.2 bar
0.14 bar
0.02 bar
Levels of overpressure
Levels of heat flux
Fig. 10. Results of individual risk calculations for Plock town.
—
—
—
—
—
—
—
37.5 kW/m
32/34
33/36
31/33
27/29
12/12
11/12
10/10
12.5 kW/m
2
48/48
50/51
47/47
41/41
18/17
17/16
15/14
4 kW/m
2
247/45
200/45
185/42
153/37
7/7
6/7
6/6
Cloud range at
lower flammable limit
concentration (m, F2/D5)
Fig. 11. Results of societal risk calculations (F–N curve) for Plock town.
pollution due to pipeline rupture is 9.48 103 which
means that such an event can occur 9.48 times per 1000
years or once per 105.4 years. Other risks such as water
pollution, fires, explosions and fires on water surface can be
interpreted in a similar way. These data refer to the entire
pipeline length.
108.8
74.8
63.7
47.4
0.75
0.63
0.47
Rupture
Leak (1%)
Leak (0.01%)
Mass release
rate (kg/s)
4. Conclusions
Failure type
Table 6
Results of calculations of the physical effects for fuel pipeline failure
2
Range of overpressure caused by explosion (late
ignition) (m, F2/D5)
Range of thermal radiation from pool fire (m,
F2/D5)
246/45
200/45
185/42
153/37
7/7
6/7
6/6
Range of flash fire (m,
F2/D5)
M. Dziubiński et al. / Journal of Loss Prevention in the Process Industries 19 (2006) 399–408
A methodology of risk assessment for hazards associated
with hazardous substance transport in long pipelines is
discussed in this paper. Taking this methodology as
example, subsequent stages of risk analysis are considered
paying special attention to the applied techniques and
calculation models. A specific feature of this methodology
is a combination of qualitative and quantitative techniques
which offer a possibility of a full risk assessment for long
pipelines. A complete risk analysis was made for a
ARTICLE IN PRESS
408
M. Dziubiński et al. / Journal of Loss Prevention in the Process Industries 19 (2006) 399–408
Table 7
Risk values for specified environmental consequences
Consequences type
Probability
Failure frequency, fa: (a) Risk as a result of full
full bore rupture (1/year), bore rupture (1/year)
(b) leak 1% (1/year), (c)
leak 0.01% (1/year)
Risk as a result of leak,
1% (1/year)
Risk as a result of leak,
0.01% (1/year)
Soil pollution
Water pollution
Fires /explosions
Fires on surfaces of
water
8.7 101
6.8 102
5.8 102
7.6 103
(a) 1.09 102
(b) 3.5 102
(c) 4.4 102
3.04 102
2.38 103
2.03 103
2.66 104
3.8 102
2.99 103
2.55 103
3.34 104
200-km-long fuel pipeline in Poland. The authors realise
that the environmental hazard assessment for long
pipelines requires individual approach in every case. This
is determined mainly by a changing specificity of pipeline
location. It refers particularly to the calculation of
consequences of hazardous substance release for particular
ecosystems (air, water, soil). A computer aid is required for
efficient data acquisition, their storage and processing at
every risk assessment stage. The available software, e.g.
PHAST, EFFECTS, enables modelling of consequences of
hazardous substance release from pipelines. However, a
practical implementation of this software, and especially
interpretation of simulation results, requires competence in
risk analysis.
References
Arendt, J. S., & Lorenzo, D. K. (2000). Evaluating process safety in the
chemical industry. A User’s Guide to Quantitative Risk Analysis,
CCPS.
Assessing the risk from gasoline pipelines in the United Kingdom based on a
review of historical experience. Prepared by WS Atkins Safety &
Reliability for the Health and Safety Executive (HSE), Contract
Research Report 210, 1999.
Borysiewicz, M., & Markowski, A. S. (2002). Risk acceptability criteria of
major industrial failures. CIOP-PIB, Warsaw.
Borysiewicz, M., & Potempski, S. (2001). Methodology of risk assessment
for long pipelines. Institute of Atomic Energy, Otwock-Swierk.
Borysiewicz, M., & Potempski, S. (2002a). Fifth national technical
conference ‘‘risk management in pipeline operating’’. 23–24 May, Plock
(p. 19).
9.48 103
7.41 104
6.32 104
8.28 105
Borysiewicz, M., & Potempski, S. (2002b). Risk of major failures of
pipelines transporting dangerous substances. CIOP-PIB, Warsaw.
DNV Risk Management Software—User’s Manual for PHAST v. 6.1,
2002.
Fafara, Z. (2002). Wiert. Nafta Gaz, R. 19, cz.1 (pp. 69–78).
Fra˛ tczak, M., & Markowski, A. S. (2003). Second national technical
conference ‘‘technical safety in industry’’. 4–5 June, Kedzierzyn–Kozle
(p. 40).
Guidelines for chemical process quantitative risk analysis, CCPS, AIChE,
2000.
Guidelines for ecological risk assessment, EPA/630/R-95/002F, April, 1998.
Guidelines for hazard evaluation procedures, CCPS, AIChE, 1992.
Litlle, A. D. (1996). Risks from gasoline pipelines in the UK. HSE books.
Markowski, A. S. (2000). Loss prevention in industry. Part III—Management of process safety. Technical University of Lodz.
Markowski, A. S. (2003). Centre of Excellence ‘‘Manhaz’’, 17–21 October,
http://manhaz.cyf.gov.pl.
Markowski, A. S., & Petera, J. (2001). Second national technical conference
‘‘risk management in chemical and process industry’’, 23–24 October,
Lodz (p. 211).
Michalowski, W., & Trzop, S. (1996). Long pipelines. Warsaw: ENERGOPOL.
Muhlbauer, W. K. (1996). Pipeline risk management manual (2nd ed.).
Gulf Publishing Co.
Nagy, S., & Macuda, J. (2001). Wiert. Nafta Gaz, R. 18, cz.1 (pp.
149–161).
Nieuwstadt, F. M. (1982). Atmospheric turbulence and air pollution
modeling. Boston: Riedel.
Risks from gasoline pipelines in the United Kingdom. HSE Contract
Research Report No. 82, 1994.
Risks from gasoline pipelines in the United Kingdom. Health and Safety
Executive Books (HSE), Contract No. 3273/R73.05, 1999.
The Accident Database Software, Version 4.1, Institution of Chemical
Engineers, 2001.