Dan Tudor & Sons Cold Storage #2 - Executive Summary |
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EXECUTIVE SUMMARY Accidental Release Prevention and Emergency Response Policies Dan Tudor & Sons utilizes anhydrous ammonia as the refrigerant in their Woollomes Avenue cold storage facility near Delano, California. As it is Dan Tudor & Sons' policy to comply with all applicable governmental regulations, the cold storage facility was designed and constructed during 1995 to the 1991 Uniform Building Code/Uniform Mechanical Code. Personnel from Dan Tudor & Sons monitor the daily operation of the refrigeration system. All service, maintenance, and repairs to the ammonia refrigeration system are contracted to a qualified licensed refrigeration contractor specializing in ammonia refrigeration. Utilizing an experienced qualified contractor to perform routine service, maintenance, and repairs ensures that the equipment is in excellent operating condition. While it is Dan Tudor & Sons' objective to be a responsible citizen of the community in all of its business activities, the limited staff at the cold storage facility precludes emergency response operations. As such, an emergency action plan has been prepared for Dan Tudor & Sons and a chain of command to respond to emergencies has been established. Description of the Stationary Source and Regulated Substances Dan Tudor & Sons owns and operates a cold storage facility located at 33398 Woollomes Avenue. Delano is the closest city to the Dan Tudor & Sons cold storage facility. The rural plant was constructed during 1995 utilizing all new equipment at the time of construction. Anhydrous ammonia is used as the refrigerant that provides process cooling for the Dan Tudor & Sons cold storage facility. The refrigeration system consists of a suction accumulator with a liquid transfer system, three compressors, an evaporative condenser, a high pressure receiver, and several flooded evaporators. During normal operation, the anhydrous ammonia is distributed throughout the refrigeration syste m. However, during major maintenance activities, the entire refrigeration system can be "pumped down" to evacuate the ammonia from the system and store it in the high pressure receiver. The maximum quantity of ammonia that can be stored in the high pressure receiver is 15,390 pounds. For purposes of the offsite consequence analyses, the RMP regulations define the toxic endpoint for anhydrous ammonia as 0.14 mg/l (200 ppm). This concentration has been established by the American Industrial Hygiene Association as the Emergency Response Planning Guideline Level 2 (ERPG-2). ERPG-2 is the maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to one hour without experiencing or developing irreversible or other serious health effects or symptoms which could impair an individual's ability to take protective action. Worst-Case Release Scenario and Alternative Release Scenario Offsite consequence analyses are used as tool s to assist in emergency response planning. The RMP regulations require the owner or operator of a stationary source to analyze the offsite impacts due to an accidental release of a regulated substance. The offsite consequence analysis for a Program 3 process must analyze the worst-case release scenario and an alternative release scenario. Since Dan Tudor & Sons' ammonia-based refrigeration system is considered a Program 3 process, both release scenarios were evaluated in the offsite consequence analysis. The offsite consequence analysis must include an estimate of the residential population within an area potentially affected by the accidental release scenario. This area is defined as a circle with a radius equivalent to the distance the release would travel with concentrations at or above the toxic endpoint. The circle also defines the area in which potential environmental receptors must be identified. The worst case release is defined by the U.S. EPA as the total release of the contents of the single largest vessel or pipe within 10 minutes. For liquefied gases stored under pressure, the entire contents of the vessel or pipe are assumed to be released as a vapor. A total vapor release is highly unlikely. However, this standardized worst case scenario was developed for emergency response agencies to use for planning purposes. An alternative release scenario is a release that is more likely to occur than the worst-case release scenario. For Dan Tudor & Sons, the alternative release scenario was selected based on the results of the Process Hazard Analysis (PHA) for the ammonia-based refrigeration system. A credible release event with a high discharge rate would potentially have the greatest offsite impact. Although not likely to occur, a release from a pressure relief valve was chosen as the alternative release scenario. Dan Tudor & Sons has analyzed the offsite consequences of the worst-case and alternative release scenari os. For the worst-case release scenario, the release of 15,390 lbs. of ammonia over a 10 minute period outside of the engine room, the plume would travel 1.5 miles at concentrations at or above the endpoint. Using 1990 Census data, the population potentially affected within the worst- case release scenario circle is 64 persons. Due to the rural location of this facility, the population potentially affected by this worst case release is substantially overstated by the 1990 Census data. The public receptors included a couple of residences. There were no environmental receptors within the worst case release scenario circle. In the alternative release scenario, a release from a pressure relief valve was modeled as ammonia vapor stored under pressure. For a release of 158.7 lb/min of anhydrous ammonia to the atmosphere, the model calculated that the plume would travel 0.1 mile at concentrations at or above the endpoint. No residences are located within the 0.1 mile area a round the Dan Tudor & Sons facility. As such, there would be no population impacts from the alternative release scenario. There were also no public receptors or environmental receptors within the alternative release scenario circle. General Accidental Release Prevention Program and Chemical-Specific Prevention Steps A PSM program, which meets the requirements of the general accidental release prevention program, is being implemented by Dan Tudor & Sons to address the anhydrous ammonia system. The PSM program includes the following chemical- specific prevention steps: ? Written process safety information, including information pertaining to the hazards of ammonia, the technology of the process, and the equipment in the process is being compiled. ? Process Hazard Analyses (PHA) will be updated and revalidated at least every five years. ? Written operating procedures will be reviewed at least annually. ? Safe work practices, such as lockout/tagout, confined space entry, opening process equipment or piping, and control over entrance into the facility are implemented as needed. ? If employees are involved in operating the ammonia system, they will receive initial training and refresher training at least every three years. ? Written mechanical integrity procedures have been established and implemented. ? A Management of Change (MOC) program has been developed and implemented to address all proposed changes to the ammonia system. ? Pre-startup safety reviews will be performed when a modification is made to the ammonia system that is significant enough to require a change in the process safety information. ? Audits will be conducted at least every three years to evaluate compliance with the CalARP regulations. ? Incident investigation procedures have been established. ? A written plan of action regarding the implementation of employee participation has been developed and implemented. ? Hot work permits will be issued for all hot work oper ations conducted on or near the ammonia system, as needed. ? A Contractor Safety Policy has been developed and implemented. To ensure that the general accidental release prevention program and the chemical-specific prevention steps are implemented, Dan Tudor & Sons has assigned overall responsibility for the RMP elements to the General Manager. The General Manager has the overall responsibility for the development, implementation, and integration of the RMP elements. Five-Year Accident History Dan Tudor & Sons has not had any accidental releases from the ammonia-based refrigeration system that have resulted in deaths, injuries, or significant property damage on site, or known offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage in the last five years. Emergency Response Program Dan Tudor & Sons has established an emergency action plan and a chain of command to respond to emergencies and to notify emergency responders when there is a need for a response. However, an emergency response program does not need to be developed for the facility since Dan Tudor & Sons employees will not respond to accidental releases of ammonia, the facility is included in the community emergency response plan, and appropriate mechanisms are in place to notify emergency responders. Planned Changes To Improve Safety Dan Tudor & Sons relies on the expertise of qualified ammonia refrigeration contractors to regularly evaluate the need for any changes to the refrigeration equipment and to improve safety. Currently, Dan Tudor & Sons does not have any changes planned to improve safety associated with the ammonia refrigeration system. |