Uniqema - Executive Summary |
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Uniqema Atlas Point Site Risk Management Program 1. Accidental Release Prevention and Emergency Response Policies The Uniqema Atlas Point site uses ethylene oxide and propylene oxide as raw materials in the manufacture of various surface active agents (surfactants). Surfactants are used in household, personal care and industrial applications. It is Uniqema's policy to comply with all applicable state and federal regulations. Uniqema is in compliance with the Environmental Protection Agency (EPA) Risk Management Program, 40 CFR Part 68. The Uniqema Atlas Point site conducts hazard analysis reviews prior to the design, construction and operation of any process unit. Records are kept of each hazard review and the actions implemented as an outcome of the review are documented. Detailed information relating to Uniqema's accidental release prevention program is provided in the Accidental Release Prevention Program section. The Uniqema site maintains an Integrated Contingency Plan ( ICP) that describes the emergency response program. It is Uniqema's policy to respond in an efficient and effective manner to any emergency that occurs at the Uniqema Atlas Point site. Uniqema personnel regularly prepare for emergencies by conducting emergency drills that have included the local fire department. A group of Uniqema employees have been trained to act as emergency responders, incident commanders and duty managers. Uniqema emergency personnel can be reached 24 hours a day in the event of an emergency. 2. Stationary Source and Regulated Substances Handled The Uniqema Atlas Point site stores ethylene oxide and propylene oxide in quantities that exceed threshold quantities of 10,000 pounds, as defined in 40 CFR 68.115. Both ethylene oxide and propylene oxide are listed as toxic substances under 40 CFR 68.130. The Uniqema site does not store any additional substances in quantities greater than those specified under 40 CFR 68.130. The worst case release scenario deter mined by Uniqema include the on-site storage of ethylene oxide stored in an aboveground tank. The alternative release scenarios reviewed by Uniqema include the transfer and unloading of ethylene oxide and propylene oxide from a railcar to the onsite aboveground tanks. The largest quantities of ethylene oxide and propylene oxide that are stored at the Uniqema site are in the respective storage tanks. Written procedures limit the quantity stored in the on-site tanks and both storage tanks are located outside in a diked area. An emergency spill retention area, or spill sump, is located south of the tanks and was designed to capture releases from a full railcar and both the ethylene oxide and propylene oxide storage tanks. The Uniqema site has chosen to utilize EPA's Offsite Consequence Analysis Guidance and the RMP Comp program for obtaining the worst case release scenario. Due to the complex nature of the properties of ethylene oxide and propylene oxide, Uniqema utilized EPA's Offs ite Consequence Analysis Guidance, the RMP Comp program and the National Atmospheric Organization's ALOHA model for the alternative release scenarios for ethylene oxide and propylene oxide. Uniqema obtained public and environmental receptor data through Landview III, a desktop mapping program sponsored by the EPA, US Bureau of Census, US Geological Society, Nuclear Regulatory Commission, Department of Transportation and Federal Emergency Management Agency. 3. Worst-Case Release Scenario and Alternative Release Scenarios 3.a. Worst Case Release Scenario: The worst case release scenario is defined by EPA under 40 CFR 68.3 as the release of the largest quantity of a regulated substance from a vessel or process line failure that results in the greatest distance to a toxic or flammable endpoint. The worst case scenario utilizes a wind speed of 1.5 meters/second and an F stability class as well as other applicable parameters. In addition, EPA has specific provisions for toxic gase s that are handled as refrigerated liquids and for passive mitigation systems, such as a spill sump, that are in place. The worst case release scenario determined by Uniqema is the ethylene oxide storage tank. The ethylene oxide tank, with administrative controls considered, stores a maximum of 51,000 gallons or 357,000 pounds of ethylene oxide. Uniqema refrigerates ethylene oxide to 50 degrees Fahrenheit to insure that the ethylene oxide is maintained in the liquid state. Passive mitigation systems are in place at the ethylene oxide storage area and include a diked area approximately 65 feet long and 24 feet wide with drainage to an emergency retention area or spill sump located south of the storage tank area. The spill sump was designed to contain releases from a railcar and both the ethylene oxide and propylene oxide storage tanks. The size of the spill sump is approximately 25 feet by 60 feet, or 1500 square feet, with a depth of 12.5 feet, for a total volume of 18,750 cubi c feet. The topography surrounding the Uniqema Atlas Point site is urban, with obstacles in the immediate area. The worst-case release scenario was computed by Uniqema using EPA's Offsite Consequence Analysis Guidance and the RMP Comp program. The release rate determined by RMP Comp was 252 pounds per minute with an estimated distance to the toxic endpoint at 2.4 miles. The toxic endpoint concentration for ethylene oxide, as specified by EPA, is 0.09 mg/l or 50 parts per million (ppm). 3.b. Alternative Release Scenarios: The alternative release scenario is defined by EPA under 40 CFR 68.28 as the scenario that is more likely to occur and one where the toxic endpoint concentration will reach off-site. In addition, on-site safety systems can be taken into consideration for the alternative release scenario. EPA requires that facilities must submit an alternative release scenario for each toxic substance in quantities greater than those specified in 40 CFR 68.130. The alternat ive release scenarios determined by Uniqema include the ethylene oxide storage tank and the propylene oxide storage tank. As described in the worst case scenario, passive mitigation systems are in place at the ethylene oxide and propylene oxide storage area and include a diked area approximately 65 feet long and 24 feet wide and an emergency retention area or spill sump approximately 25 feet by 60 feet, or 1500 square feet, with a depth of 12.5 feet, located south of the storage tank area. The spill sump was designed to contain releases from a railcar and both the ethylene oxide and propylene oxide storage tanks. As described in the worst case scenario, the topography is urban, with obstacles in the immediate area. The alternative release scenarios reviewed by Uniqema include scenarios that are most likely to occur and where the toxic endpoint concentration will reach off-site. As specified by EPA, the toxic endpoint concentration for ethylene oxide is 0.09 mg/l (50 parts per mill ion) and the toxic endpoint concentration for propylene oxide is 0.59 mg/l (250 parts per million). The alternative release scenarios considered are based on reviews of the process hazards analyses conducted on the ethylene oxide and propylene oxide storage tanks and reviews of actual events. The alternative scenarios considered for the ethylene oxide and propylene oxide storage tanks are the same for both: a 1/2-inch failure in the hose line between the railcar unloading station and the storage tank occurs during the unloading process. While the failure of the hose line could potentially occur, Uniqema believes this scenario is unlikely due to the design and stainless steel construction of the hose. During the unloading of ethylene oxide and propylene oxide from a railcar to the storage tanks, the vessels are pressurized. Both ethylene oxide and propylene oxide are unloaded from the top of the railcars and exist as pressurized liquid. A 15-minute release for the alternative s cenario was utilized in the alternative release scenario since emergency alarms would alert on-site personnel to the situation and on-site response would occur immediately. In addition, EPA requires that the alternative scenario include concentrations above the toxic endpoint beyond the facility's fenceline. Both alternative release scenarios were computed by Uniqema using EPA's Offsite Consequence Analysis Guidance and the RMP Comp program. The alternative case scenario determined by RMP Comp utilizes a wind speed of 6.7 miles/hour and a D stability class for meteorological parameters. In addition, EPA has specific provisions in place for toxic gases that act as a liquid and where a passive mitigation system, such as an emergency spill sump, is in place. Uniqema utilized another model, known as the Areal Locations of Hazardous Atmospheres (ALOHA), to confirm EPA's RMP Comp model results for the ethylene oxide and propylene oxide calculations. ALOHA is a model sponsored by the EPA and the National Oceanic and Atmospheric Administration (NOAA). Uniqema utilized the ALOHA model since the RMP Comp program does not accurately model a pressurized liquid, such as ethylene oxide when stored in a railcar. If ethylene oxide were released when it is stored as a pressurized liquid, it would closely resemble a liquid release. The ALOHA model calculated accurate release rates for both ethylene oxide and propylene oxide and confirmed the results shown by the RMP Comp model and indicated similar off-site distances. For propylene oxide, RMP Comp and ALOHA modeling results indicated that the maximum computed release rate would be 12.5 pounds per minute and that the off-site distance would be approximately 0.1 miles or 528 feet. The toxic endpoint concentration for propylene oxide, as specified by EPA, is 0.59 mg/l or 250 ppm. For ethylene oxide, RMP Comp and ALOHA modeling results indicated that the maximum computed release rate would be 40 pounds/minute and that the off-site distance would be approximately 0.2 miles or 1060 feet. The toxic endpoint concentration for ethylene oxide, as specified by EPA, is 0.09 mg/l or 50 ppm. 4. Accidental Release Prevention Program and Chemical-Specific Prevention Steps The Uniqema accidental release prevention program includes the components of EPA's RMP Prevention Program 3 specified in 40 CFR 68.65 to 68.87. The components include process safety information, process hazard analysis, operating procedures, training, mechanical integrity, management of change, pre-startup review, compliance audits, incident investigation, employee participation, hot work permit, and contractor work. Between 1993 and 1997, Uniqema upgraded the ethylene oxide and propylene oxide storage and handling system. Some of the safety features of the system, also known as active mitigation systems, include the following: - A remote emergency retention area or spill sump is located south of the storage tank area. The spill sump wa s designed to contain releases from a railcar and both the ethylene oxide and propylene oxide storage tanks. The size of the spill sump is approximately 25 feet by 60 feet, or 1500 square feet, with a depth of 12.5 feet, for a total volume of 18,750 cubic feet. - A diked area surrounds the storage tank area and is approximately 65 feet long by 24 feet wide. - A water deluge system was designed and installed based upon the National Fire Protection (NFPA) standards. - A Programmable Logic Controller (PLC) was installed to improve system monitoring and control. This system monitors key parameters such as temperature and pressure and will automatically set the system to a safe state should an upset occur. A hardwired interlock system is in place to monitor and set to a safe state for critical conditions that are immediately threatening to human health. - Alarms are wired and controlled through the PLC and sound an audible alarm as well as a visual flag. Alarms are used for o nly conditions that are not immediately threatening to human health. - Emergency backup power for storage tank area lighting system and control components. - A packed column scrubber was installed for emissions vented during unloading operations. The scrubber was sized to remove emissions at a much higher than normal concentration and rate to insure that a potential upset condition would be controlled. - A dispersion stack for the relief valve outlet was included to disperse emissions during an emergency release. The stack insures that the concentrations at the ground level would be below OSHA's Immediately Dangerous to Life and Health (IDLH) levels. The modeling used to design the stack included scenarios provided by DNREC and incorporated worst case scenario features. 5. Five Year Accident History The Uniqema Atlas Point facility has had no accidental releases from the covered processes in the last five (5) years. 6. Emergency Response Program The Uniqema accidental release prevention program includes the components of EPA's RMP Emergency Response section, specified in 40 CFR 68.90 to 68.95. Uniqema maintains an Integrated Contingency Plan (ICP) that describes the site's emergency response program. The local community emergency response organization, Hollaway Terrace Fire Department, has received a copy of the ICP and has included it in the community emergency response plan. The ICP includes the following elements: - Procedures for informing the public and local emergency response agencies about accidental releases - Documentation of proper first-aid and emergency medical treatment necessary to treat accidental human exposures - Procedures and measures for emergency response after an accidental release of a regulated substance. In addition, the site's emergency response program, as included in the ICP, includes procedures for the use of the site's emergency response equipment and for its inspection, testing and maintenance. The emergency response plan includes procedures to review and update the ICP to reflect changes at the ethylene oxide and propylene oxide storage tanks. Uniqema trains all employees in the applicable procedures and informs them of changes at the ethylene oxide and propylene oxide storage tanks. 7. Planned Changes to Improve Safety Since the ethylene oxide and propylene oxide storage and handling system were recently upgraded and many safety improvements were incorporated in the upgrade, no plans are in place to improve any of the current safety systems of the ethylene oxide and propylene oxide storage and handling system. However, Uniqema is continually improving safety systems throughout the site on an ongoing basis. |