Tenth Avenue Marine Terminal Cold Storage Facility - Executive Summary |
|
SECTION 1 RMP EXECUTIVE SUMMARY The County of San Diego Hazardous Materials Division (HMD) has requested that a California Accidental Release Prevention (CalARP) Program be prepared for the ammonia refrigeration system at the Tenth Avenue Marine Terminal Cold Storage Facility (Facility) owned by the San Diego Unified Port District (SDUPD) in San Diego, California. Harborside Refrigerated Services operates the Facility. Ogden Environmental and Energy Services Co., Inc. (Ogden) has prepared this update to the CalARP Risk Management Plan (RMP), formerly referred to as a Risk Management and Prevention Program (RMPP), and the United States Environmental Protection Agency (USEPA) RMP on behalf of the property owner, SDUPD, at the request of the Ports Department of Environmental Services (ES). An original RMPP was prepared by Parsons Engineering Science, Inc. in 1992; the County of San Diego Department of Environmental Health (DEH) determined the original RMPP to be complete o n March 17, 1992. The original RMPP is used as a basis for this RMP. General Description The site of concern is the cold storage facility located on the Tenth Avenue Marine Terminal. The Facility is located on a land area of approximately 100 acres of waterfront property and consists of over 300,000 square feet of space in Warehouse B. Approximately 150,000 square feet of that space is divided into nine rooms for storage of various commodities. All of these rooms are capable of cool storage of commodities at approximately 32 degrees Fahrenheit (0F). In addition, three of the rooms are capable of frozen storage at -100F. The refrigeration system uses a combination of chilled brine system when used for cool storage and direct-expansion ammonia system. In the cool mode, ammonia is used to chill the brine, which is then circulated throughout the room. The mechanical area containing the chillers, compressors, and Stage 1 pumps consists of a 6,300-square-foot fenced-in area immediately adjacent to the building. The system became operational in December 1992 and was designed by VZM of Oakland, California, with assistance from FES-West. The Facility received its first shipment for storage on or about February 25, 1993. Accidental Release Prevention and Emergency Procedures The system is designed so that when problems occur the system shuts itself down in a manner designed to reduce the opportunity for releases to occur. In addition, sensors connected to alarms are in place to detect releases of ammonia. Employees are trained to help ensure their safety as well as the safety of others in the vicinity. Emergency response plans and evacuation plans are in place to allow for quick, effective response when necessary. Description of Regulated Process and Regulated Substances Ammonia is used as a refrigerant in the refrigeration system as a part of the Brine Cooling, Freezer Storage, and Vestibule Systems. The refrigeration system contain s 22,000 pounds (4,300 gallons) of anhydrous ammonia. The material is used in a closed loop system only and no product is stored. Anhydrous ammonia is a clear, nonflammable, heavy, colorless gas with a characteristic odor. It is soluble in water, forming a corrosive liquid. Contact with the skin can cause frostbite. The major concern is a potential accidental release is toxicity of the ammonia gas. Worst-case and Alternative Scenarios An Offsite Consequence Analysis (OCA) for ammonia handling at the Facility was prepared for the 1992 RMPP. Based on the Hazard Operability Study (HAZOP) and preliminary risk analysis, ammonia accident scenarios were selected for detailed OCA. The alternative release scenario used for both the 1992 RMPP and the 1999 RMP is the release of ammonia from the oil pot. Each month approximately 1 gallon of oil collects and is removed. There is the potential for ammonia release if the Standard Operating Procedures are not followed. If ammoni a is released it will be detected by the ammonia sensors located in the Mechanical/Electrical Area and alarmed in the control room. It is assumed that ammonia would flow out for 15 minutes before an operator stops the release. The distance to the endpoint to where the anhydrous ammonia would disperse enough to no longer pose a hazard to the public, based on conservative meteorological conditions, is 529 meters (579 yards). The worst-case scenario is the release of all of the ammonia from the ammonia receiver. To model the release, it was assumed that the maximum amount of anhydrous ammonia stored in this vessel was 22,000 pounds (4,300 gallons) and was released over a 10-minute period from a 1-inch-diameter hole in the receiver. It was assumed that the release would consist of a mixture of 81 percent liquid and 19 percent vapor that would form an aerosol and initially act as a dense gas. The release was assumed to occur at ground level (0 meter high). The distance t o the endpoint to where the anhydrous ammonia would disperse enough to no longer pose a hazard to the public, based on conservative meteorological conditions, is 1,513 meters (0.94 mile). Accidental Release Prevention Program The accidental release prevention program consists of the following: RMP Process Safety Management Plan Hazardous Operability Study Compliance Audit Program Preventative Maintenance Program Detection and Monitoring System Automatic Shutdown System with Remote Controls Management of Change Program Standard Operating Procedures Training Program Emergency Response Plan Drills Coordinated with Emergency Responders Five-year Accident History Since operations began on or about February 25, 1993, there have been no significant ammonia releases at the Facility. Planned Changes to Improve Safety Review and maintenance of fire alarms. |