Trout/Blue Chelan - Executive Summary |
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A.Accidental Release Prevention and Emergency Response Trout/Blue Chelan, Inc. (hereafter referred to as Trout/Blue Chelan) accidental release prevention policy involves a unified approach that integrates technologies, procedures, and management practices. It is the policy of Trout/Blue Chelan to adhere to all applicable federal and state safety and environmental regulations. Trout/Blue Chelan refrigeration personnel do respond to ammonia releases and have received training in accordance with 29 CFR 1910.120, in addition to training specifically for ammonia. An emergency plan has been developed covering notification to public safety agencies and the public. An evacuation plan for the plant has also been developed and all employees receive training on this plan. At Trout/Blue Chelan anhydrous ammonia is used on-site. Ammonia is considered hazardous by EPA and is listed on the Extremely Hazardous Substance (EHS) list. Chemical properties of ammonia make it necessary to observe cer tain safety precautions in handling ammonia in order to: 7 Prevent unnecessary human exposure 7 Reduce the threat to our personnel 7 Reduce the threat to the community B.Facility and Regulated Substance Handled Trout/Blue Chelan is a fruit processing and cold storage facility, located near the city of Chelan, county of Chelan, state of Washington. The regulated substance used at Trout/Blue Chelan is anhydrous ammonia (CAS# 7664-41-7). The anhydrous ammonia is used as a refrigerant. There is 28,000 pounds of anhydrous ammonia in the system. Trout/Blue Chelan uses other hazardous substances on-site, however they do not meet or exceed the threshold limits established in 40 CFR 68.130. However, Trout/Blue Chelan believes in the concept set forth in the "General Duty Clause" of the Clean Air Act. To this effect, Trout/Blue Chelan has established policies, procedures and training to reduce the risk of an accidental hazardous substance release for the safety of its employees and surro unding areas. C.Worst-Case and Alternative Scenarios The off-site consequence analysis considers two ammonia release scenarios identified as "worst case" and "alternative" scenarios. The worst case scenario is defined by the Environmental Protection Agency (EPA), which states that "the owner or operator shall assume that the maximum quantity in the largest vessel is released ". The alternative scenario is defined as "more likely to occur than the worst case scenario". Worst-Case Scenario - Failure of the largest vessel would release 12,000 pounds of anhydrous ammonia. The release would occur inside the compressor room; its walls are in direct contact with the outside, however the effects of building mitigation were not considered. The distance to the toxic end-point of 0.14 mg/L is 1.8 mile. The "risk radius" extends past the boundaries of the plant, into public receptor areas. Distance was determined by use of RMP-COMP. Alternative Release Scenario - Several alternative s cenarios were modeled, using ALOHA, version 5.2.1, however a release from the bottom (liquid space) of the receiver, under normal operating conditions, was chosen. This alternative scenario provided the greatest risk radius of 1,100 yards. There was no building mitigation used for this scenario. It was, however, assumed that the safeties and computer control would limit the release to the amount in the receiver. Both the "worst-case" and "alternative" scenarios are unlikely due to the safeties on the system such as temperature and pressure cutouts, computer controls and pressure relief valves to prevent an overpressure situation. A more realistic scenario would be that of a pressure relief valve lifting, discharging ammonia vapor from vents on top of the building, approximately 40 feet above the ground. In scenarios modeled for this type of an event, the risk radius was reduced to approximately 250 yards. D.General Accidental Release Prevention Program Trout/Blue Chelan's acci dental release prevent program is based on the following key elements: 7 Training of personnel 7 Preventative maintenance program 7 Use of safety equipment 7 Use of accurate and effective written operating procedures Trout/Blue Chelan complies with: 7 OSHA's and Washington State's process safety management rule. 7 Washington State's safety regulations. 7 IIAR (International Institute of Ammonia Refrigeration) standards for good work practices. The ammonia refrigeration system was installed to standards and local codes at the time of installation. Piping and equipment is secured and protected; compressor (engine) room doors are tight fitting and open outwards. Other safety systems Trout/Blue Chelan utilizes include: 7 Computerized controls, which can be operated remotely 7 Suction trap hi-level float 7 High discharge pressure shut down 7 Low suction pressure shut down 7 High discharge temperature shut down 7 Oil pressure failure shut down 7 High amperes shut down 7 Automatic timer to prevent short cycling 7 Oil filters plugged shut down 7 250 psi relief valves on high pressure side, to prevent overpressure situations 7 150 psi relief valves on low pressure side, to prevent overpressure situations Operating Procedures and checklists have been prepared by Trout/Blue Chelan to be used by employees performing operational functions. Procedures are kept in the refrigeration office. These procedures include: 7 Pre-start up procedures 7 Routine operations 7 Maintenance 7 Response to major and minor releases 7 emergency action plan E.Five-Year Accident History Trout/Blue Chelan has had one accident involving ammonia in the last five years. This involved the lifting of a pressure relief valve to prevent an overpressure situation. The cause that led up to the event was due to human error. There w ere no injuries due to this event and approximately 40 pounds of ammonia was release. F.Emergency Response Program In addition to the operating procedures, Trout/Blue Chelan has established Emergency Response Guidelines for releases involving ammonia. These procedures are part of the ongoing training. Trout/Blue Chelan coordinates its response efforts with Chelan County Fire District 7, which is the local fire department. G. Planned Safety Improvements Trout/Blue Chelan plans to install ammonia monitors/detectors in the engine room. The engine room ventilation fan will be connected to an ammonia monitor so that the fan will activate upon reaching a threshold less than 40,000 parts per million, which is < of ammonia's lower explosive limit (LEL). The actual threshold will be at, or less than, 1,000 ppm and the monitor will be connected to the auto dialer, to alarm refrigeration personnel of a potential ammonia release. Other planned improvements to safety are to increase traini ng to personnel (both refrigeration and fork lift operators), review and update the emergency plan, and provide training in the emergency (evacuation) plan to all plant personnel. |