Quality Chef - C Street - Executive Summary |
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1.0 SOURCE The Quality Chef Foods, Inc. C Street Facility (C Street facility) in Cedar Rapids, Iowa is subject to the USEPA's Risk Management Program (RMP) for Accidental Chemical Release regulations (40 CFR 68) because it has a refrigeration system that contains more than the threshold quantity (10,000 pounds) of anhydrous ammonia (CAS Number 7664-41-7). The anhydrous ammonia (ammonia) refrigeration system is used to control the temperature for processing and freezing food products. The entire system contains approximately 32,000 pounds of ammonia in various physical states (gas, liquid, and saturated vapor). The largest vessel is the controlled pressure receiver that operates at approximately 80 psig and can contain as much as 31,000 pounds of liquid ammonia, assuming a 90 percent fill volume. However, during typical operation, the vessel holds only 7,750 pounds. 2.0 POTENTIAL RELEASE SCENARIOS As required by the RMP rule requirements, two specifically defined release scenarios (a worst-case release and an alternative-case release) were analyzed to determine the maximum distance to an endpoint where the ammonia concentration is 200 parts per million in air, or 0.02 percent. The release scenarios analyzed are based upon the guidance contained in the USEPA's Model Risk Management Program and Plan for Ammonia Refrigeration (the "Model Plan"), dated May 1996. 2.1 Worst-case Release The worst-case release is defined as the catastrophic rupture and complete loss of the contents of the largest vessel and associated piping (approximately 32,000 pounds of ammonia) over a 10-minute period. Using the specified worst-case meteorology contained in the "Model Plan" and assuming the facility is located in a rural area, the distance to the endpoint for a worst-case release extends beyond the facility boundary. Although the worst-case consequence analysis is required by the RMP, it should be considered a highly unlikely event. Design, construction, and operation of the controlled pressure receiver is such that catastrophic failure is extremely remote. The receiver was designed and constructed in strict accordance with the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Section VIII), and was certified and stamped by the National Board of Pressure Vessel Inspectors (National Board). The vessel is operated well below the design pressure (i.e., maximum allowable working pressure) and because of the safety factors built into the ASME Code, a fourfold pressure excursion would have to occur before catastrophic vessel failure. If this were to occur, the vessel is equipped with dual safety relief valves (SRVs) set to relieve internal pressure at 250 psig. A high pressure excursion would not occur as long as the SRVs continued to function. Actuation of the SRVs would result in an ammonia release similar to that described in Section 2.2 for the alternative release scenario. The worst-case release scenario is unlikely for the following additional reasons: * The facility has a training program designed to ensure that the system is operated by qualified personnel; * The facility has emergency response procedures which enable trained personnel to respond quickly to isolate any potential releases; 2.2 Alternative-case Release The alternative-release scenario is defined as a release of ammonia that is more likely to occur than the worst-case scenario, and reaches an endpoint offsite. The "Model Plan" scenario was used for this analysis, which assumes a release of ammonia through a 1/4-inch effective diameter hole in a high side (i.e., 150 psig) pipe or vessel, releasing 100 pounds of ammonia per minute. Using the specified meteorology contained in the "Model Plan", the distance to the endpoint for the "more likely" release scenario extends beyond the facility boundary. The alternative release scenario is unlikely for the following reasons: * Industrial standards were followed for the manufactur e and quality control of these lines; * The facility has a training program designed to ensure that the system is operated by qualified personnel; and * The facility has emergency response procedures which enable trained personnel to respond quickly to isolate any potential releases by closing isolation valves in the liquid lines. 3.0 PREVENTION PROGRAM The facility has carefully considered the potential for accidental releases of ammonia, such as the occurrence of the worst-case and alternative-release scenarios described in Section 2.0. To help minimize the probability and severity of an ammonia release, a prevention program that satisfies the Occupational Safety and Health Administration (OSHA), Process Safety Management (PSM) of Highly Hazardous Chemicals (29 CFR 1910.119) has been implemented. The key components of the prevention program are summarized below: * The development of an employee participation program, which includes C Street facility employees from all areas withi n the plant. * The development, documentation, and operator availability of critical process safety information regarding the hazards of ammonia, the design basis of the system, and the equipment. This information is used to fully understand and safely operate the ammonia refrigeration system. * The performance of a formal process hazard analysis (PHA) on the ammonia refrigeration system using a "What-If" Protection Analysis.. A team with expertise in engineering, maintenance, and safety evaluated the existing refrigeration system in depth and developed recommendations to improve the safety and operability of the system. The PHA is updated and revalidated every five years. * Standard operating procedures (SOPs) are used to provide the basis for proper and safe operation of the ammonia refrigeration system. The SOPs include procedures for normal operations, startup, shutdown, emergency operations, and emergency shutdown. They also describe safe operating limits for temperature and pressure, the consequences of operating outside these safe operating limits, and a description of safety systems and how they operate. * Refrigeration system maintenance personnel receive refresher training at least every three years. The training content is based on the process safety information and operating procedures. * Contractors that are hired to work on, or adjacent to, the refrigeration system are "pre-qualified" based on their knowledge of ammonia refrigeration, understanding of applicable codes and standards, and their demonstrated ability to work safely. In addition, these contractors are periodically evaluated to ensure that they continue to work safely. * A formal preventative maintenance program is in the process of being fully developed and deployed at the C Street facility. This will include regular inspection of major powered equipment, including compressors, pumps and large fans, bearings, couplings, shaft seals, mountings, etc., for vibration or incipient mecha nical failure, and regular inspection and calibration of liquid level sensors, temperature and pressure instruments, switches and shutdown devices that have safety implications. * Formal authorization systems (i.e., management of change procedure, pre-startup safety review) are in place to ensure that system changes or expansions are as safe as the original design and that an independent recheck confirms that the changes are consistent with the engineering design and in a condition to be safely operated prior to startup. * Events that might cause an accidental or unexpected release of ammonia are subjected to a formal investigation. The objective of the investigation is to correct deficiencies in such a way as to prevent recurrence. * Prior to the performance of any hot work (i.e., spark or flame producing operations such as welding, cutting, brazing, grinding), management must approve the work by executing a written hot work authorization permit to verify that precautions to prevent fire have been implemented. * Planning with the local fire department occurs often to ensure a rapid response to potential incidents with the system or external events, such as floods or tornadoes. * Prevention program compliance audits are performed every three years to verify that the appropriate management systems are in place and are being properly implemented. Any deficiency found in an audit is corrected. 4.0 ACCIDENT HISTORY There have been no accidental releases of ammonia at the facility in the last five years that have resulted in death, injury, or significant property damage on site or off-site death, injury, evacuation, sheltering in place, property damage, or environmental damage. 5.0 EMERGENCY RESPONSE PROGRAM The C Street facility has implemented a detailed written Emergency Response Plan (ERP). The ERP is intended to address all emergencies at the facility, in addition to incidents related to a release of ammonia. |