Identify the initiation, propagation, and termination steps for the following accident reports. 18..

Identify the initiation, propagation, and
termination steps for the following accident reports. 18 Suggest ways to
prevent and contain the accidents.

a. A contractor accidentally cut into a
10-in propane line operating at 800 psi at a natural gas liquids terminal. The
large vapor cloud estimated to cover an area of 44 acres was ignited about 45
min later by an unknown source. Liquid products from 5 of 26 salt dome caverns
fed the fire with an estimated 18,00030,000 gal of LPGs for almost 6 hr before
being blocked in and the fires extinguished. Both engine-driven fire pumps
failed, one

Identify the initiation, propagation, and
termination steps for the following accident reports. 18 Suggest ways to
prevent and contain the accidents.

a. A contractor accidentally cut into a
10-in propane line operating at 800 psi at a natural gas liquids terminal. The
large vapor cloud estimated to cover an area of 44 acres was ignited about 45
min later by an unknown source. Liquid products from 5 of 26 salt dome caverns
fed the fire with an estimated 18,00030,000 gal of LPGs for almost 6 hr before
being blocked in and the fires extinguished. Both engine-driven fire pumps
failed, one because intense radiated heat damaged its ignition wires and the
other because the explosion broke a sight glass fuel gauge, spilling diesel
fuel, which ignited, destroying the fire pump engine. b. An alkylation unit was
being started up after shutdown because of an electrical outage. When adequate
circulation could not be maintained in a deisobutanizer heater circuit, it was
decided to clean the strainer. Workers had depressurized the pipe and removed
all but three of the flange bolts when a pressure release blew a black material
from the flange, followed by butane vapors. These vapors were carried to a
furnace 100 ft away, where they ignited, flashing back to the flange. The
ensuing fire exposed a fractionation tower and horizontal receiver drums. These
drums exploded, rupturing pipelines, which added more fuel. The explosions and
heat caused loss of insulation from the 8-ft _122-ft fractionator tower,
causing it to weaken and fall across two major pipelines, breaking piping
which added more fuel to the fire. Extinguishment, achieved basically by
isolating the fuel sources, took 2 hours. The fault was traced to a 10-in
valve that had been prevented from closing the last -inch by a fine powder of
carbon and iron oxide. When the flange was opened, this powder blew out,
allowing liquid butane to be released.