Polyair/Mabex Incorporated - Executive Summary |
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Executive Summary Accident Release Prevention and Emergency Response Policies at Polyair/Mabex - Bardstown, Ky. The facility installed the isobutane storage and process equipment according to NFPA-58 and ASME standards. The facility's policy is to adhere to all applicable federal, state, and local laws. If an emergency were to occur, it is company policy and procedure to call the Nelson Co. Fire Department. Facility Description and Regulated Substance Discussion: The facility stores isobutane in an 18,000 gallon above ground tank with a maximum fill of 14,400 gallons (80% capacity). This material is used as a blowing agent to produce expanded foam packing material. The system consists of a storage tank, low pressure pump station, unloading station, high pressure pump system, process use equipment, and safety/system monitors. Isobutane is extremely flammable and the facility has taken a number of steps to insure that the process is both maintained and operated in a safe manner. Worst Case Scenario: The worst case scenario which is extremely unlikely would be loss of 14,400 gallons of isobutane due to the rupture of the tank or complete failure of the piping system connected to the tank during a use or unloading situation. A vapor cloud explosion would have a predicted offsite impact of 1.0 psi overpressure at a maximum radius of 0.3 miles and could potentially impact up to 120 people (as predicted from GIS mapping of 1990 census data). Alternative Case Scenario: Two alternatives considered were the loss of the liquid in the all of the piping and two additional minutes for the automatic safety valves to shut the 3 system normally closed solenoids. The predicted loss of 150 pounds of isobutane and a subsequent vapor cloud explosion would have a 1.0 psi overpressure distance of 0.03 miles or less than 200 feet. This predicted impact would not affect any public receptor. General Accidental Release Prevention Program and Prevention Steps: The installation of this process line in 1996 was according to NFPA 58 and ASME tank standards. The storage tank and piping are located inside a locked chain link fence security area. Installation included the use of mechanical and electrical equipment specifically designed for liquified natural gas service. This system and components were reviewed by the Kentucky State Fire Marshal's office and all safety recommendations have been installed. Numerous safety sensors have been installed in this process and include the following: 5 gas sensors that automatically shut down the process if gas is detected anywhere in the process or storage area; redundant mechanical and automatic shutoffs that shutdown and isolate the system if there is any of the following conditions present: overpressure of the primary or secondary pumping lines, trigger of the automatic fire sprinkler system, loss of ventilation air in th e process area, activation of any emergency stop button on the process, or failure of the ventilation system in the isolated high pressure pump room; or mechanical shutdown initiated by any operator observing an unsafe process condition. Alarm sensors will trigger on loss of humidity or activation of the CO2 deluge system at the process unit. In addition to the installation of equipment and emergency shutdown controls, employee and supplier procedures have been written and training implemented to assure that all employees and suppliers follow specific practices for safe system operation. These procedures include daily, weekly, and annual checks of critical system components in the process area, storage area, unloading area, and use area. Checklists for operation, maintenance, and unloading activities are maintained in the facility's safety files. Five-Year Accident History: There have been no major releases of isobutane from this process since the process was started in 1996. E mergency Response Program: The facility's policy is to immediately call the Bardstown/Nelson County Fire Department and the Nelson County Local Emergency Planning Committee in the event of an emergency involving the isobutane process or storage system. The local responding agencies have reviewed the facility's system and conducted onsite awareness and inspection tours. Planned Changes to Improve Safety - None at present. |