10. Assessing Consequence of Failure Flashcards
1
Q
- 1 Introduction to Consequence Analysis
- 1.1 General
- COF analysis shall be performed to estimate the consequences that are likely to occur due to
A
a failure mode typically resulting from an identified damage mechanism(s)
2
Q
- 1 Introduction to Consequence Analysis
- 1.1 General
- Consequence should typically be categorized as:
a) safety and
b) environmental
c) economic
A
a) health impacts,
b) impacts,
c) impacts.
3
Q
- 1 Introduction to Consequence Analysis
- 1.1 General
- An RBI program will be managed by plant inspectors or inspection engineers, normally managing the POF with
A
inspection and maintenance planning.
4
Q
- 1 Introduction to Consequence Analysis
- 1.1 General
- Management and process safety personnel may desire to manage
A
the consequence side of the risk equation.
5
Q
- 1 Introduction to Consequence Analysis
- 1.2 Loss of Containment
- Generally evaluated as
A
loss of fluid to the external environment.
6
Q
- 1 Introduction to Consequence Analysis
- 1.2 Loss of Containment
- The consequence effects can be generally considered to be in the following categories:
a) safety and
b) environmental
c) production
d) maintenance
A
a) health impact,
b) impact,
c) losses,
d) and reconstruction costs.
7
Q
- 1 Introduction to Consequence Analysis
- 1.3 Other Functional Failures
a) Functional or mechanical failure of
b) Heat exchanger
A
a) internal components of pressure-containing equipment (e.g. column trays, demister mats, coalescer elements, distribution hardware, etc.).
b) tube failure.
8
Q
- 1 Introduction to Consequence Analysis
- 1.3 Other Functional Failures
c) Heat exchanger tube failures may result in
d) Pressure-relief
e) Rotating
A
c) contamination and consequent loss of containment.
d) device failure.
e) equipment failure
9
Q
- 1 Introduction to Consequence Analysis
- 2.3 Quantitative Consequences Analysis
- Involves using a logic model depicting combinations of events to represent the effects of
A
failure on people, property, the business, and the environment.
10
Q
- 1 Introduction to Consequence Analysis
- 2.3 Quantitative Consequences Analysis
- Results of a quantitative analysis are
A
usually numeric
11
Q
- 1 Introduction to Consequence Analysis
- 2.3 Quantitative Consequences Analysis
Quantitative models factors for create failure scenarios and calculate COF
a) type of process
b) state of the process
A
a) fluid in equipment;
b) fluid inside the equipment (solid, liquid, or gas);
12
Q
- 1 Introduction to Consequence Analysis
- 2.3 Quantitative Consequences Analysis
Quantitative models factors for create failure scenarios and calculate COF
c) key properties of
d) process operating
A
c) process fluid (molecular weight, boiling point, autoignition temperature, ignition energy, density, flammability, toxicity, etc.);
d) variables such as temperature and pressure;
13
Q
- 1 Introduction to Consequence Analysis
- 2.3 Quantitative Consequences Analysis
Quantitative models factors for create failure scenarios and calculate COF
e) mass of inventory available for
f) failure mode and
g) state of fluid after
A
e) release in the event of a leak;
f) resulting leak size;
g) release in ambient conditions (solid, gas, or liquid).
14
Q
- 3 Units of Measure in Consequence Analysis
- 3.1 General
The analyst should bear in mind that the resultant consequences should be comparable, as much as possible, for
A
subsequent risk prioritization and inspection planning
15
Q
- 3 Units of Measure in Consequence Analysis
- 3.2 Safety
- Safety consequences are often expressed as a numerical value or
A
characterized by a consequence category associated with the severity of potential injuries.
16
Q
- 3 Units of Measure in Consequence Analysis
- 3.2 Safety
- For example, safety consequences could be expressed based on the severity of an injury (e.g. fatality, serious injury, medical treatment, first aid) or
A
expressed as a category linked to the injury severity (e.g. A through E)
17
Q
- 3 Units of Measure in Consequence Analysis
- 3.3 Cost
- Consequence may be expressed in relative monetary units (e.g. dollars) to the maximum extent practical with an understanding that the numbers are
A
typically not absolute (For example, low, moderate, and high categories could be assigned values of $100,000; $1,000,000; and $10,000,000, respectively)
18
Q
- 3 Units of Measure in Consequence Analysis
- 3.3 Cost
- It is possible, although not always practical, to assign a monetary value to
A
almost any type of consequence
19
Q
- 3 Units of Measure in Consequence Analysis
- 3.3 Cost
- Consequences may be placed into
A
categories that have pre-defined ranges
20
Q
- 3 Units of Measure in Consequence Analysis
- 3.3 Cost
Typical consequences that can be expressed in “cost”
a) production loss due to
b) deployment of emergency response
c) lost product from
d) degradation of
e) replacement or repair of
A
a) rate reduction or downtime;
b) equipment and personnel;
c) a release;
d) product quality;
e) damaged equipment;
21
Q
- 3 Units of Measure in Consequence Analysis
- 3.3 Cost
Typical consequences that can be expressed in “cost”
f) property damage
g) spill/release cleanup on-site or
h) business interruption
i) loss of market
j) injuries or
k) land
l) litigation;
m) fines;
n) goodwill.
A
f) off-site;
g) off-site;
h) costs (lost profits);
i) share;
j) fatalities;
k) reclamation;
l) litigation;
m) fines;
n) goodwill.
22
Q
- 3 Units of Measure in Consequence Analysis
- 3.4 Affected Area
- Represents the amount of surface area of the plot plan that
A
experiences an effect (toxic dose, thermal radiation, explosion overpressure, etc.) greater than a pre-defined limiting value.
23
Q
- 3 Units of Measure in Consequence Analysis
- 3.4 Affected Area
- In order to rank consequences according to affected area, it is typically assumed that
A
equipment or personnel at risk are evenly distributed throughout the unit.
24
Q
- 3 Units of Measure in Consequence Analysis
- 3.4 Affected Area
- The affected area approach has the characteristic of being able to compare toxic and
A
flammable consequences by relating to the physical area impacted by a release
25
10. 3 Units of Measure in Consequence Analysis
10. 3.5 Environmental Damage
Environmental consequence measures are the
least developed among those currently used for RBI
26
10. 3 Units of Measure in Consequence Analysis
10. 3.5 Environmental Damage
Typical parameters used that provide an indirect measure of the degree of
a) acres of land
b) miles of shoreline ;
c) number of biological or
a) affected per year;
b) affected per year
c) human-use resources consumed;
27
10. 3 Units of Measure in Consequence Analysis
10. 3.5 Environmental Damage
Typical parameters used that provide an indirect measure of the degree of
d) portrayal of environmental damage almost invariably leads to the use of cost, in terms of dollars per year, for the
loss and restoration of environmental resources.
28
10. 3 Units of Measure in Consequence Analysis
| 10. 3.6 Categorizing Safety, Health, and Environmental Consequences
table 4 y 5
29
10. 3 Units of Measure in Consequence Analysis
10. 3.7 Other Considerations uences
It is usually possible to develop a monetary estimate for these considerations:
a) loss of reputation leading to
b) future
c) regulatory actions curtailing production or raising costs.
a) loss of market share,
b) insurability,
c) production or raising costs.
30
10.4 Volume of Fluid Released
1. The volume released is typically derived from a combination of
a) volume of fluid
b) failure
c) leak
d) detection and
available for release (Volume of fluid in the piece of equipment and connected equipment items. In theory, this is the amount of fluid between isolation valves that can be quickly closed.);
b) mode
c) rate;
d) isolation time.
31
10. 4 Volume of Fluid Released
| 2. In some cases, the volume released will be the same as the volume
available for release and other cases not ( due procedure and safeguards)
32
10. 4 Volume of Fluid Released
| 3. The cost of the lost fluid may be calculated by:
loss of fluid = volume of fluid lost × value of fluid per unit volume
33
10. 5 Consequence Effect Categories
10. 5.1 General
1. The major factors to consider in evaluating the consequences of failure shall include:
a) flammable
b) toxic
c) release of other
a) events (fire and explosion),
b) releases,
c) hazardous fluids.
34
10. 5 Consequence Effect Categories
10. 5.1 General
Additionally, other impacts that may be considered include the following:
a) environmental
b) production
c) maintenance and
a) consequences,
b) consequences (business interruption),
c) reconstruction impact.
35
10. 5 Consequence Effect Categories
10. 5.2 Flammable Events (Fire and Explosion)
1. Occur when both a
leak and ignition occur.
36
10. 5 Consequence Effect Categories
10. 5.2 Flammable Events (Fire and Explosion)
2. Can cause damage in two ways:
thermal radiation and blast overpressure
37
10. 5 Consequence Effect Categories
10. 5.2 Flammable Events (Fire and Explosion)
3. Thermal effects tends to occur at close range, but blast effects can cause
damage over a larger distance from the blast center
38
10. 5 Consequence Effect Categories
10. 5.2 Flammable Events (Fire and Explosion)
Typical categories of fire and explosion events
a) vapor cloud
b) pool
c) jet
d) flash
e) boiling liquid
a) explosion,
b) fire,
c) fire,
d) fire,
e) expanding vapor explosion (BLEVE).
39
10. 5 Consequence Effect Categories
10. 5.2 Flammable Events (Fire and Explosion)
Causes of the flammable events consequence
a) inherent tendency to
b) volume of
c) ability to flash to
d) possibility of
e) effects of higher pressure or higher
f) engineered
g) personnel and equipment
a) ignite,
b) fluid released,
c) a vapor,
d) auto-ignition,
e) temperature operations,
f) safeguards,
g) exposed to damage
40
10. 5 Consequence Effect Categories
10. 5.3 Toxic Releases
1. In RBI, toxic releases are only addressed when
they affect personnel (site and public)
41
10. 5 Consequence Effect Categories
10. 5.3 Toxic Releases
2. These releases can cause effects at greater distances than
flammable events.
42
10. 5 Consequence Effect Categories
10. 5.3 Toxic Releases
3. The RBI program typically focuses on acute toxic risks that create an immediate
danger, rather than chronic risks from low-level exposures
43
10. 5 Consequence Effect Categories
10. 5.3 Toxic Releases
Causes of the toxic consequence
a) volume of fluid
b) ability to disperse under
c) detection and mitigation systems;
d) population in the vicinity of
a) released and toxicity;
b) typical process and environmental conditions;
c) detection and mitigation systems;
d) the release.
44
10. 5 Consequence Effect Categories
10. 5.4 Releases of Other Hazardous Fluids
1. Common fluids, including steam,
hot water, acids, and caustics
45
10. 5 Consequence Effect Categories
10. 5.4 Releases of Other Hazardous Fluids
2. The consequence of this type of release is significantly lower than for flammable or toxic release because
the affected area is smaller and the magnitude of the hazard is less.
46
10. 5 Consequence Effect Categories
10. 5.4 Releases of Other Hazardous Fluids
Key parameters in this evaluation
a) volume of fluid
b) personnel density in
c) type of fluid and nature of
d) safety
a) released;
b) the area;
c) resulting injury;
d) systems (e.g. personnel protective clothing, showers, etc.);
47
10. 5 Consequence Effect Categories
10. 5.4 Releases of Other Hazardous Fluids
Key parameters in this evaluation
e) environmental damage if
f) equipment
e) the spill is not contained;
f) damage (for some reactive fluids, contact with equipment or piping may result in aggressive deterioration and failure).
48
10. 5 Consequence Effect Categories
10. 5.5 Environmental Consequences
1. The RBI program typically focuses on acute and immediate environmental risks, rather than
chronic risks from lowlevel emissions.
49
10. 5 Consequence Effect Categories
10. 5.5 Environmental Consequences
2. Liquid releases may result in
contamination of soil, groundwater, and/or open water.
50
10. 5 Consequence Effect Categories
10. 5.5 Environmental Consequences
3. Gaseous releases are more difficult to assess since the consequence typically relates to local regulatory constraints and
the penalty for exceeding those constraints.
51
10. 5 Consequence Effect Categories
10. 5.5 Environmental Consequences
4. The cost may be calculated as follows:
environmental cost = cost for cleanup + fines + other costs
52
10. 5 Consequence Effect Categories
10. 5.5 Environmental Consequences
5. The fine component cost will depend on the regulations and
laws of the applicable local and federal jurisdictions
53
10. 5 Consequence Effect Categories
10. 5.5 Environmental Consequences
6. The other cost component would include costs that may be associated with
the spill such as litigation from landowners or other parties
54
10. 5 Consequence Effect Categories
10. 5.5 Environmental Consequences
Causes of the environmental
a) volume of
b) ability to flash to
c) leak containment
d) environmental resources affected;
e) regulatory
a) fluid released;
b) vapor;
c) safeguards;
d) environmental resources affected;
e) consequence (e.g. citations for violations, fines, potential shutdown by authorities).
55
10. 5 Consequence Effect Categories
10. 5.5 Environmental Consequences
The cleanup cost will vary depending on many factors
a) type of spill—aboveground,
b) type of
c) method of
d) volume of
e) accessibility and terrain at
a) belowground, surface water, etc.,
b) liquid,
c) cleanup,
d) spill,
e) the spill location.
56
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
1. Generally occur with any loss of containment of the process fluid and
often with a loss of containment of a utility fluid.
57
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
2. The main production consequences for
RBI are financial.
58
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
3. The cost of the lost fluid can be calculated by
multiplying the volume released by the value of the fluid lost.
59
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
4. This equation is a simple method for estimating the business interruption consequence:
business interruption = process unit daily value × downtime (days)
60
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
5. The unit daily value could be on a revenue or profit basis. The downtime estimate would represent the
time required to get back into production.
61
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
The selection of a specific method depends of
a) the scope and level of detail of
b) availability of business
a) the study,
| b) interruption data.
62
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
Factors to take account for other methods in estimating business interruption consequences
a) ability to compensate for
b) potential for damage to
c) potential for production loss to
a) damaged equipment (e.g. spare equipment, rerouting, etc.);
b) nearby equipment (knock-on damage);
c) other units.
63
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
Site-specific circumstances should be considered in the business interruption analysis to avoid overstating or understating this consequence
a) Lost production may be compensated at
another under-utilized or idle facility.
64
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
Site-specific circumstances should be considered in the business interruption analysis to avoid overstating or understating this consequence
b) Loss of profit could be compounded if other facilities use the
unit’s output as a feedstock or processing fluid.
65
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
Site-specific circumstances should be considered in the business interruption analysis to avoid overstating or understating this consequence
c) Repair of small damage cost equipment may take as long as large
damage cost equipment.
66
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
Site-specific circumstances should be considered in the business interruption analysis to avoid overstating or understating this consequence
d) Extended downtime may result in losing customers or market share, thus
extending loss of profit beyond production restart.
67
10. 5 Consequence Effect Categories
10. 5.6 Production (Business Interruption) Consequences
Site-specific circumstances should be considered in the business interruption analysis to avoid overstating or understating this consequence
e) Loss of hard-to-get or unique equipment items may
f) Insurance
e) require extra time to obtain replacements.
| f) coverage.
68
10. 5 Consequence Effect Categories
10. 5.7 Maintenance and Reconstruction Impact
1. Represents the effort required to correct the failure and to fix or replace
equipment damaged in the subsequent events.
69
10. 5 Consequence Effect Categories
10. 5.7 Maintenance and Reconstruction Impact
2. Generally be measured in monetary terms and typically includes the following:
a) repairs,
b) equipment
a) repairs,
| b) replacement.
70
10. 6 Determination of COF
10. 6.1 General
1. The consequences of releasing a hazardous material can be estimated in six steps (see Figure 5)
2. Steps:
a) estimate the release
b) estimate total volume of
c) determine if the fluid is dispersed in
2. Steps:
a) rate;
b) fluid that will be released;
c) a rapid manner (instantaneous) or slowly (continuous);
71
10. 6 Determination of COF
10. 6.1 General
1. The consequences of releasing a hazardous material can be estimated in six steps (see Figure 5)
2. Steps:
d) determine if the fluid disperses in the
e) estimate the impacts of any
f) estimate the
d) atmosphere as a liquid or a gas;
e) existing mitigation system;
f) consequences.
72
10. 6 Determination of COF
10. 6.2 Factors for Estimating Consequence
1. Factors: Physical properties of the contained material, its toxicity and flammability, type of release and release duration,
weather conditions and dispersion of the released contents, escalation effects, and mitigation actions.
73
10. 6 Determination of COF
10. 6.2 Factors for Estimating Consequence
2. Factors: Consider the impact on plant personnel and equipment, population in
the nearby communities, and the environment.
74
10. 6 Determination of COF
10. 6.2 Factors for Estimating Consequence
3. Factors: Lost production, loss of raw material, and
other losses should also be considered.
75
10. 6 Determination of COF
10. 6.2 Factors for Estimating Consequence
how a consequence scenario may be constructed
a) Consequence Phase 1—Discharge: Consider the type of
discharge (sudden vs slow release of contents) and its duration.
76
10. 6 Determination of COF
10. 6.2 Factors for Estimating Consequence
how a consequence scenario may be constructed
b) Consequence Phase 2—Dispersion: Consider the dispersion of the released contents due
to weather conditions.
77
10. 6 Determination of COF
10. 6.2 Factors for Estimating Consequence
how a consequence scenario may be constructed
c) Consequence Phase 3—Flammable Events: The consequences should be estimated for the scenario based on the
flammability of the released contents (i.e. impact of a resulting fire or explosion on plant personnel and equipment, community, environment); see 10.5.2.
78
10. 6 Determination of COF
10. 6.2 Factors for Estimating Consequence
how a consequence scenario may be constructed
d) Consequence Phase 4—Toxic Releases: The consequences should be estimated for the scenario based on the
toxicity of the released contents (i.e. impact due to toxicity on plant personnel, community, and the environment); see 10.5.3.
79
10. 6 Determination of COF
10. 6.2 Factors for Estimating Consequence
how a consequence scenario may be constructed
e) Consequence Phase 5—Releases of Other Hazardous Fluids: The consequences should be estimated for the scenario based on the
characteristics of the released contents (i.e. impact due to thermal or chemical burns on plant personnel, community, and the environment); see 10.5.4.
80
10. 6 Determination of COF
10. 6.2 Factors for Estimating Consequence
how a consequence scenario may be constructed
f) Consequence Phase 6—The potential number of fatalities and injuries resulting from each scenario should be estimated. Different scenarios, with different associated probabilities, should be
developed as appropriate.
81
10. 6 Determination of COF
10. 6.3 Factors for More Rigorous Methods
acceptable ways to list consequences include the following.
a) Classify consequence into three or
more categories (e.g. a five-category classification system might be very low, low, moderate, high, very high).
82
10. 6 Determination of COF
10. 6.3 Factors for More Rigorous Methods
acceptable ways to list consequences include the following.
b) Rank consequence on a
scale (e.g. a scale might be from 1 to 10).
83
10. 6 Determination of COF
10. 6.3 Factors for More Rigorous Methods
acceptable ways to list consequences include the following.
c) Measure consequence (e.g. determine the estimated number of fatalities for a scenario and the economic losses in monetary units).
c) Measure consequence (e.g. determine the estimated number of fatalities for a scenario and the economic losses in monetary units).
