Power Logistics, Inc.--Manteno - Executive Summary |
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Power Logistics is a frozen warehouse engaged in storing and distributing frozen food products to area retail outlets. To maintain frozen conditions in the warehouse, Power Logistics operates a mechanical refrigeration system in which the refrigerant is anhydrous ammonia. No manufacturing is done at the site, but wome final packaging of pre-made products is done on a contract basis. Products are brought to the site by truck for storage; various assortments of these products are then assembled for reshipment to area outlets. This refrigeration plant was newly constructed in 1987. Power Logistics has long been committed to employee safety and to being a good community neighbor. To this end, Power Logistics maintains an active safety management program to prevent accidental releases of ammonia. The facility complies with OSHA's PSM rule, and maintains a written Process Safety Plan onsite. Periodic drills are conducted to ensure familiarity with all emergency procedures. A rigoro us program of operator training, preventive maintenance, and periodic inspections is maintained, to prevent the accidental release of ammonia, and all required safety programs are in force at the facility. While the facility is a relatively new one, there have been no reportable accidental releases of ammonia since start-up, and no accidents involving the release of ammonia. Power Logistics has coordinated emergency response activities with the local (Manteno) Fire Department. The nearest Fire Department Substation is less than one (1) mile distant. The facility is located to the East of the Village of Manteno, in a county location which remains rural in nature. The refrigeration system is sized adequately for the amount of cooling needed, and is capable of holding 14,000 lbs of anhydrous ammonia. All ammonia is stored in the system; there is no additional storage on-site. The worst case scenario is considered to be the rupture of the high-pressure receiver, which contains mos t of the ammonia at any given time. It is considered that this rupture would cause loss of all the ammonia in the system over a period of 10 minutes at a constant rate. The toxic endpoint is taken to be an ERPG-2 of 200 ppm for an exposure time of one hour, and was estimated at 2.1 miles from the source. The consequences are modeled in atmospheric stability category F weather conditions with a windspeed of 1.5 m/s. These assumptions are taken from the "Model Risk Management Program and Plan for Ammonia Refrigeration", prepared by Science Applications International Corporation, Reston, VA. These assumptions were adopted because of the significant cost of doing modeling studies that are site specific, and because the final conclusions were not likely to change significantly even though site-specific information was used. This scenario has off-site receptors. There are no active mitigation systems in use. The bulding enclosure was considered and dismissed as a passive mitigation s ystem, as the enclosure is of a construction not expected to withstand a 1 psi overpressure that is likely to occur on rupture of the high pressure receiver. The alternative scenario, one more likely to occur, is a pipe leak, gasket rupture or pump seal leak equivalent to a small orifice of diameter 1/4 to 1/2 inch. A typical rate of release would be 100 pounds/minute. Atmospheric Stability Category D with a moderate windspeed (e.g., 3 m/s) was chosen from the model. The toxic endpoint of 1,000 feet was chosen from the model plan as typical of a rural site, and the smallest rate of release which would have off-site receptors. This alternate scenario does have off-site receptors. Passive mitigation to a release of 100 pounds/minute is considered to be the bulding in which the high pressure receiver and process piping is housed, because such a release would not be expected to inflict structural damage on the building housing the receiver. Such a release could be contained until a utomatic and manual shutoff systems could be activated. Responders could further mitigate the release by absorption in water from a fire hose, and neutralizing the resulting aqueous mixture with acids, or releasing the solution to the sewer. Power Logistics personnel are trained to respond to minor releases and minor repair/maintenance problems. However, for a major release, the facility would call upon the Manteno Fire Department for emergency response. Facility personnel are trained in response actions which consist of minimizing damage to the facility while assisting the orderly evacuation of all personnel. Power Logistics regularly evalutes and implements any appropriate measures to further improve safety. |