Lecture 7

Question 1

is usually done as part of Quantitative Risk Analysis (QRA) in the design phase to define the limits of the design envelope and to ensure that the resulting engineering design to mitigate or remove the hazard is overdesigned.

Answer 1

Source Modelling

Question 2

could be an outflow from a vessel, evaporation from a liquid pool, etc.

Answer 2

release

Question 3

A release may be:

Answer 3

instantaneous
continuous

Question 4

source strength is total mass released

Answer 4

instantaneous

Question 5

source strength is rate of mass released

Answer 5

continuous

Question 6

is characterized by the amount of material released

Answer 6

strength of a source

Question 7

technical information needed

Answer 7

rate of discharge
total quantity discharged
state of discharge

Question 8

other types of hazardous material event models:

Answer 8

Dispersion Model
Fire & Explosion Model
Effect Model

Question 8

to describe how the material is transported downwind and dispersed to some concentration levels

Answer 8

dispersion model

Question 8

to convert the source model information into energy hazard potentials

Answer 8

fire & explosion model

Question 9

to evaluate potential loss/damage on people, properties, and environment

Answer 9

effect model

Question 10

mode of release

Answer 10

wide aperture release
limited aperture release

Question 11

releasing a substantial amount of material in a short time
large hole developing in process unit

Answer 11

wide aperture release

Question 12

slow release of material that causing non-immediate effect to upstream

Answer 12

limited aperture release

Question 13

number of possible release points from a chemical vessel

Answer 13

crack, relief valve, hole, valve, severed or ruptured pipe, pipe connection, flange, pump seal

Question 14

source models describing a material release

Answer 14

1. flow of liquid through a hole
2. flow of liquid through a hole in a tank
3. flow of liquid through pipes
4. liquid flashing
5. liquid pool evaporation or boiling
6. flow of gases/vapor through holes from vessels or pipes

Question 15

normally occurs when a liquid stored under pressure above their normal boiling point is experiencing sudden ambient environment causing the liquid flash to vapor, sometimes explosively

Answer 15

flashing

Question 16

the rate of evaporation from a pool depends on:

Answer 16

liquid’s properties
subsoil’s properties