CLOVERLEAF COLD STORAGE PLANT #1 - Executive Summary |
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Cloverleaf Cold Storage owns and operates a refrigerated warehouse facility at 2800 Cloverleaf Court in Sioux City Iowa. The facility is known as Cloverleaf Cold Storage Plant #1. Plant #1 houses an engine room, which contains 16 compressors ranging in size from 40-horse power through to 350-horse power. This engine room also contains all of the ammonia holding vessels except for one vessel, which is located outside of the building structure. A licensed Class A engineer operates the ammonia refrigeration system. The system comprises of various refrigeration components including compressors, evaporators, vessels, pumps and condensers. The ammonia refrigeration system is operated with a variety of safety devices employed within the system, included are high and low pressure automated shutdown systems and high level automated shutdown systems. Alarm systems are utilized to provide early detection of problems within the system before shutdowns occur. Equipment operating parameters are m onitored throughout the day and logged for comparison to indicate potential problems. There have been no reportable releases of ammonia at this facility within the last five years. This facilities emergency response program is an action plan to evacuate the facility and allow the local Fire Departments Hazmat Team to intervene and bring the situation under control. This plan has been discussed with the responding Hazmat Team. Cloverleaf is in the process of upgrading their emergency response to a higher level of participation and plans to have training and procedures in place before the year 2001. Worst-Case Scenario. - Failure of the largest storage vessel when filled to the greatest amount allowed would release 14,900 pounds of ammonia. This vessel normally contains a maximum 9,200 pounds of ammonia but if the makeup valve stuck open it could contain 14,900 pounds of ammonia before the high-level system shutdown would occur. The EPA requires that calculations of th e worst-case scenario be based on a 10-minute time interval for the vessel to completely empty its contents. The distance to the toxic endpoint for this scenario of 14,900 pounds of ammonia being released over a 10-minute time frame would be a 1.5-mile radius around the facility. Alternate-Scenario. - The scenario chosen for the alternate scenario is one of a pipe being broken clear through and to have a wide-open, undeformed, open end. The pipe size is a 3/4-inch schedule 80 type, with an operating pressure of 57psig. The release rate from a pipe fracture of this type would be 860 pounds per minute. Calculations for release time duration of 2 through 30 minutes showed the toxic end point to be no greater than a .2 mile radius around the facility. |