Pioneer Chlor Alkali produces chlorine gas through the electrolysis
of sodium chloride (table salt). The chlorine is used primarily for water
treatment and is shipped to clients in railroad tank cars and highway tank
trucks. By-products of the process, including hydrogen gas and sodium
hydroxide, are used by other companies in the BMI complex. The chlorine
is compressed and stored as a liquified gas in a bank of eight storage tanks,
each of 150 ton capacity. The system has a storage capacity of
approximately 1,200 tons, although company officials indicate that their
policy is to limit the storage on hand to 300 tons or less.
Chlorine (Cl2)
Molecular Weight
Boiling Temperature
Immediate Danger to Life or
70.9
29°F
Health 30 parts per million (ppm)
Short Term Exposure Limit 3 ppm
Expansion Ratio (Liquid to Gas) 450-500
The liquified chlorine is stored in tanks at a pressure of
approximately 50 psi and temperature of approximately 30°F. The chlorine
is dried in the process of compression and, when dry, is noncorrosive. If it
is contaminated by water or water vapor, hydrochloric acid is produced and
the resulting product is extremely corrosive. It is believed that a tube
failure in a heat exchanger allowed water to mix with the chlorine going
into one of the storage tanks. When workers began to transfer the
contents of that tank to a railroad tank car, the corrosive liquid began to
rapidly deteriorate the steel piping system.
The leak was first detected by automatic monitoring equipment,
located near the storage tanks, at approximately 0110 hours. Employees
responding to the alarm found a pinhole-size leak in a 2-inch elbow,
located on a catwalk level approximately 10 feet above ground. The leak
was a few feet beyond the valve on the discharge side of the pump which
was used to transfer the liquid from the storage tanks to the rail car
loading rack.
Attempts were made by plant personnel to stop the flow and patch
the leak. The pump was shut down and the discharge valve was closed to
stop the flow from the storage tanks to the leaking pipe. Management
personnel were notified and members of the company’s emergency team
were called to respond to the plant. At this time the leak was considered
to be minor and employees believed that it could be controlled without
causing a major hazard to the plant or the surrounding area.
Plant employees were considered to be proficient in handling
situations of this type. The Chlorine Institute, a trade association of
companies involved in the manufacturing, distribution, and use of chlorine
and related products, coordinates a system of mutual aid emergency
response teams. These CHLOREP teams are made up of member
company employees who are trained and equipped to respond to
emergency incidents involving chlorine. Pioneer Chlor Alkali operates the
CHLOREP team for Southern Nevada and surrounding areas and the
emergency response team equipment is stored within its facility. Joint
training exercises had been conducted with the Clark County Fire
Department HazMat Team and other area fire departments.
Next » Emergency Response
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