SAChE Source Models (ELA965 ) Practice Test

These questions are part of the practice quiz. Start practicing

• _______ is a measure of the expected effects of an incident scenario.
• Which property is typically pulled from a database for a hydrocarbon in a release model?
• Which variable below is used in the determination of the mass flow rate of a free expansion gas release but is NOT used in the determination of the maximum flow rate of choked flow?
• During leakage through a hole, which energy form is converted to thermal energy due to friction?
• Which of the following is NOT typically used in SAChE simplified source term estimation?
• In a vented flare scenario, which two factors are modeled to account for hazard changes?
• Protective action distances inform which actions during a chemical release?
• Source modeling is utilized in which part of the overall risk assessment?
• In the equation P represents what?
• In choked flow, how does increasing upstream pressure P0 affect the mass flow rate when downstream pressure is below critical?
• At what time did the operator notice a drop in pressure in the benzene pipeline?
• True or False: When liquid is released through a hole in a tank and the hole is some distance above the bottom of the tank, the velocity of the liquid released decreases as the tank empties.
• A jet fire is typically quantified by which measures of hazard?
• Pchoked refers to which physical condition?
• Name two common correlations used to estimate jet flame length in source models.
• Two-phase flow in pipelines is typically a flow of which phases?
• Liquids with high saturation vapor pressure evaporate _______ those with lower saturation vapor pressure.
• Why is sensitivity analysis important in source term modeling?
• Which statement best describes the factors used to specify a source model?
• In consequence analysis, which term describes the overall health, environmental, and economic impacts of an incident?
• How does vapor pressure relate to flashing of a liquid?
• When considering consequences, how is low usually measured?
• Which geometric factors influence whether a release is choked?
• What distinguishes a fully developed flame from a developing flame in fire consequence analysis?
• Why is it important to know the evaporation rate of a spilled liquid in a pool?
• Which scenario is considered a realistic release?
• When released from a refrigerated vessel, butane will:
• What is the effect of a stable atmosphere on dispersion?
• Which of the following is not a direct effect of wind speed on a surface pool fire hazard near ground level?
• For downstream pressure less than the choked pressure, which statements are valid?
• In the choked flow equation, which symbol represents the throat area through which gas flows?
• Explain the concept of radiative heat flux threshold in pool fires.
• The equation shown is used to determine the Fanning friction factor for laminar flow.
• Dispersion models are selected based on the phase of the material being modeled in a release scenario. True or False?
• Which statement correctly describes adiabatic flow?
• True or False: For flowing gases it's generally assumed that the kinetic energy changes are negligible.
• Liquids stored under pressure ________ their normal boiling point temperature cause increased hazards because of flashing.
• What is the significance of the evaporation rate in pool fires?
• Which description correctly contrasts instantaneous and quasi-steady releases?
• In an adiabatic pipe, a gas flows through a pipe and expands. This expansion leads to:
• True or False: In the case of an adiabatic choked flow through a long pipe, the gas exiting the pipe makes an abrupt change from Pchoked to the ambient pressure.
• How are emergency response considerations integrated with source models?
• Describe how confinement affects vapor cloud explosion severity.
• In two-phase releases, what is flashing ratio and why is it significant?
• What is the relationship between density and plume rise in airborne releases?
• In release geometry, what does blockage factor refer to?
• Which type of release is characterized by little energy conversion to kinetic energy?
• True or False: In all adiabatic flows, the temperature of the gas when it exits the pipe will be higher than when it entered the pipe.
• In adiabatic flow, what is assumed about heat transfer?
• A ______ is the undesirable result of a loss event, usually measured in health and safety effects, environmental impacts, loss of property, and business interruption costs.
• Two-phase releases include which phases?
• Isothermal flow is described as compressible flow with constant temperature. Which statement best reflects this property?
• When stored under pressure, butane is in ______ form.
• How is the hazard quotient used in toxic release evaluation?
• How are ignition sources categorized in source models?
• In the flashing liquid model, which statement describes the mass flow rate parameter Qm?
• Explosion severity in SAChE models depends on which factors?
• How does temperature affect vapor pressure and release behavior?
• In dispersion modeling, what role does atmospheric stability play?
• What is an area source and give an example in process safety?
• For sharp-edged orifices, what is the recommended discharge coefficient Co?
• True or False: Loss of mechanical energy occurs when liquid flows through fittings (e.g. valves, elbows and orifices), pipes entrances and exits, as well as the pipe itself.
• Which statement defines the flash point?
• What are other names for a chocked gas release?
• When released from a vessel under pressure, butane will:
• For a gas release, which pair correctly describes the fluid states before and after release?
• What does the question mark on the left side of the energy equation represent?
• Which factor is commonly used alongside flame length to assess jet fire hazard?
• In pool fire source terms, the latent heat of vaporization primarily affects what aspect?
• If the largest pipe connected to a vessel becomes disconnected, this scenario is described as a realistic release.
• Which property is most directly linked to the potential for vapor release in a pool fire scenario?
• When friction converts kinetic energy into thermal energy, what effect does this have on the pressure of the liquid within the pipe?
• All flashing liquids are combustible.
• What is a typical use of results from the SAChE practice test?
• In protective action distance modeling, what primarily determines the extent of the downwind hazard footprint?
• True or False: Stiver and Mackay's Method and the US EPA Method are intended to predict the rate at which liquid evaporates from a pool near ambient temperature.
• In consequence modeling, why are protective action distances important?
• Two-phase flow reliefs are typically associated with which scenario?
• What is a vented flare scenario and when is it modeled?
• For volatile materials, which term describes the temperature at which the liquid develops sufficient vapor pressure to form a vapor-air mixture capable of ignition after external energy input?
• What is atmospheric stability and why does it matter for dispersion modeling?
• What is the main objective of the SAChE Source Models practice test?
• All source models have uncertainties. True or False?
• Which statement about jet flame length correlations is true?
• Gas discharges are classified into which two general types of releases?
• When fluid flows through a hole in a vessel, friction forces between the moving liquid and the wall of the leak convert some of the kinetic energy of the liquid into thermal energy, resulting in:
• If a liquid is under pressure and above its atmospheric boiling point, a leak below the liquid level will result in what phenomenon?
• In the mass flow rate equation, hL represents which quantity?
• What is a Mach (Ma) number?
• What is the worst-case scenario in SAChE source models?
• In the mechanical energy balance equation, which symbol represents fluid density?
• True or False: Runaway reactions nearly always result in two-phase flow reliefs.
• Which of the following is a characteristic of a source model?
• In a pressure versus time plot for runaway reactions, what does Curve B represent?
• In an insulated pipe with no heat transfer, the flow is described as which?
• An overpressuring of a vessel resulting in an explosion is an example of which release type?
• Two-phase flow most commonly refers to a flow of which phases in a pipe?
• A __________ is a thermally unstable reaction system which exhibits an uncontrolled accelerating rate of reaction leading to rapid increases in temperature and pressure.
• Deflagration is subsonic and detonation is supersonic. What determines the category of an explosion scenario?
• To what value was the gauge pressure restored after the drop?
• In a ______ release, little of the energy inherent to the gas pressure is converted to kinetic energy.
• True or False: A single source model generally describes a given release scenario.
• Mach number is defined as which of the following?
• What is a toxic release assessment in SAChE source models?
• What is a vent gas recovery option and its effect on hazard?
• Which statement is true about source models?
• In source models, what is an isolation strategy?
• Choked flow occurs under what condition for a gas escaping through an orifice?
• When stored refrigerated, butane is in what form?
• Which type of flow corresponds to rapid gas flow through an insulated pipe where no heat is lost or gained by the pipe?
• In which type of release would you expect large frictional losses as the gas escapes?
• What is a hazard radius and how is it used?
• What is the effect of a passive venting strategy on source terms during a release?
• If a leak lasts 3 hours at 1.5 kg/s, spilled mass would be:
• What is the purpose of using a simplified source model in SAChE?
• HRR stands for heat release rate; what influences it?
• In the choked-flow equation for gases, what does P0 denote?
• How does geometry of equipment influence the source term?
• REL and ERPG are exposure limits used in toxic release assessment. Which of the following best describes their purpose?
• Which statement best distinguishes radiative from convective heat transfer in fire modeling?
• Which data types do sources such as NIST or DIPPR provide to support source term calculations?
• What is the purpose of a Gaussian plume dispersion model?
• Why are worst-case wind conditions used when defining protective distances in SAChE models?
• What is the primary purpose of the discharge coefficient Co in orifice discharge calculations?
• How are explosion scenarios categorized in SAChE source models?
• Gas discharges are classified into two general types of releases: which two are they?
• Liquids with high saturation vapor pressure are generally more ______ than liquids with lower vapor pressure.
• In the mechanical energy balance equation shown, what does the symbol rho represent?
• In the context of release modeling, which scenario describes a gas that has been liquified by refrigeration and stored at atmospheric pressure?
• Choked flow occurs when the velocity at the throat reaches what value?
• The phase in which a material is released may be impacted if the material is stored under pressure.
• Which of the following fluid state transitions could occur for a liquid that forms both aerosol and pool after release?
• Which statement describes an example of a release associated with a wide aperture?
• Which step in the Consequence Analysis procedure yields results such as total quantity released, release rate, and material phase?
• In the benzene pipeline scenario, the mass flow rate is approximately which value?
• In a throttling release, which characteristic is typically observed?
• How does pressure relief venting influence the hazard footprint?
• Which statement about the flash point is true?
• Friction between the liquid and the pipe wall converts kinetic energy into which form of energy?
• In the equation shown, what does (gamma) represent?
• Flash vaporization occurs when a liquid near its boiling point experiences what change?
• Why are LFL and UFL important in hazard analysis of vapor releases?
• True or False: In flowing gases the density is generally constant.
• A gas is liquified by refrigeration and stored at atmospheric pressure. The model assumes that the liquid is released at its normal boiling point. This is considered a/an ______ release.
• How does wind speed influence the hazard of a surface pool fire near ground level?
• True or False: Source models predict the dispersion of released material considering the release’s phase and aperture.
• Which statement best describes isothermal flow through an uninsulated pipe kept at a constant temperature?
• What does ground-level concentration indicate in dispersion modeling?
• How does humidity influence vapor cloud dispersion?
• Source models are specific to both the aperture and material phase of the scenario. True or False?
• In the flashing liquid model, what does Qm represent?
• What role does vapor pressure play in two-phase liquid releases into air?
• In a two-phase release, which quantity determines how much liquid flashes to vapor upon release?
• The left-hand side question mark in the energy balance equation represents which quantity?
• _______ flow is a compressible fluid flow whereby the flow remains at the same temperature while flowing in a conduit.
• Which of the following is a common environmental assumption in SAChE source models?
• In gas releases, vented energy affects which aspects of the hazard?
• What does vented energy refer to in gas releases?
• What chemical was being transported in the pipeline in the scenario?
• In the mass flow rate equation shown, what does hL represent?
• The temperature of a spilled liquid has little or no impact on the spill's evaporation rate.
• What is BLEVE and why is it a critical scenario in source models?
• Which property is relevant for estimating energy release in a hydrocarbon release model?
• How do stability modifiers affect dispersion calculations?
• How do you validate a simplified source model?
• True or False: For flowing gases the physical properties (including density) are generally
• In the equation, Qm represents what?
• In a two-phase release scenario, which phase is expected to be released as a liquid stream?
• How many seconds are in 2.5 hours?
• What is the purpose of the conservative default assumption in SAChE modeling?
• Which statement best distinguishes a point source from an area source in release modeling?
• Which parameter in the choked flow equation represents the ratio of specific heats?
• In the benzene scenario, which unit is used to specify pressure?
• Which factor is NOT listed as an influence on dispersion in the material?
• Choked gas release occurs when the throat velocity reaches which speed?
• Which type of calculation does not require details of the piping?
• A pipeline leak lasts 2.5 hours before it can be stopped. The mass flow rate of the leak is 1.5 kg/s. What is the quantity of the liquid spilled (in kg)?
• Which type of flow corresponds to flow through an uninsulated pipe maintained at a constant temperature?
• For a pool fire, which parameter primarily controls its heat release rate (HRR)?
• What is the common characteristic of incidents described in the material?