Garland Product Supply Center - Executive Summary |
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The Garland Product Supply Center is a food distribution warehouse that contains refrigerated areas for perishable items. The refrigerated areas of the warehouse are cooled by two anhydrous ammonia refrigeration systems. Anhydrous ammonia, a substance regulated by EPA, is one of the most economical refrigerants available. However, the properties of ammonia makes it necessary to observe certain safety precautions while operating the refrigeration systems to prevent employee exposure, and to reduce the threat of exposure to nearby members of the community. The Garland Product Supply Center has chosen to follow the EPA's Chemical Accident Prevention Program, Program Level 3, to prevent a release of ammonia from the refrigeration systems. The amount of ammonia estimated to be contained inside each refrigeration system is 10,000 pounds. The Garland Product Supply Center complies with EPA's Accidental Release Prevention Program, and applicable state codes and regulations to prevent a c atastrophic release of ammonia. The ammonia refrigeration systems have been constructed according to the International Institute of Ammonia Refrigeration guidelines (IIAR). The operators of the systems are required to complete a training and certification program to operate the ammonia refrigeration systems. The Accidental Release Prevention Program does not guarantee against an accidental release. An offsite consequence analysis was completed using a computer model to simulate a release of the ammonia from one of the refrigeration systems. The worst case scenario considered the loss of the total charge of 10,000 pounds of anhydrous ammonia in one of the refrigeration systems over a 10-minute period. The analysis showed that the ammonia vapor could travel 3,168 yards, or 9,504 feet. There are approximately 24,848 residents who could be potentially affected in the identified radius. There are public receptors (residences, schools, and industrial/commercial buildings) in the pote ntially affected area. There are no environmental receptors in the potentially affected area. The alternative release scenarios, which are the most likely scenario, considered a release of ammonia from a broken line inside the building. A release of 2,000 pounds of ammonia over a 10-minute period was considered. The computer model showed that the ammonia vapor could travel approximately 369 yards, or 1,107 feet. There are public receptors (industrial/commercial buildings) in the potentially affected area. No administrative controls or mitigation measures were used to limit the chemical release distances for either scenario. The Garland Product Supply Center has an established Emergency Response Plan to respond to emergencies. The plan was developed in accordance with 29 CFR 1910.120 Emergency Response Plan. The plan requires Fleming associates to exit the facility during a fire or ammonia release to a safe area. The emergency agencies will be notified of the emergency. The e mergency agencies will notify any potentially affected neighbors. Fleming maintenance associates will be available as a resource during an ammonia release emergency. The plan also addresses natural hazard emergencies, fires, bomb threats, civil disturbances, and utility outages. This location has not experienced an ammonia release in the past 5 years. The Garland Product Supply Center wanted to evaluate the potential failures of the refrigeration system, and if the safeguards were sufficient to prevent a catastrophic release of ammonia. A Process Hazard Analysis was completed on the refrigeration systems in February 1995. Planned changes to improve safety resulting from this analysis are documented in the Process Hazard Analysis reports in the Accidental Chemical Release Prevention Program. Also, the guidelines from the International Institute of Ammonia Refrigeration (IIAR) will be followed where applicable, to manage the refrigeration systems. |