The Testor Corporation - Buckbee Street - Executive Summary |
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THE TESTOR CORPORATION BUCKBEE STREET FACILITY ROCKFORD, ILLINOIS 1.0 SOURCE AND PROCESS DESCRIPTION 1.1 SOURCE The Testor Corporation (Testor) Buckbee Street facility located in Rockford Illinois is subject to the United States Environmental Protection Agency's (USEPA's) Risk Management Program (RMP) for Accidental Chemical Release regulation (40 CFR 68) because it has a process on site which contains a mixture of propane [Chemical Abstract System (CAS) number 74-98-6) and isobutane (CAS number 75-28-5) in quantities exceeding 10,000 pounds. The mixture is used as a propellant in the filling of aerosol paint cans. The propellant is a gas at ambient temperature and pressure and is stored in a 12,000 gallon storage tank at a nominal pressure of 85 pounds per square inch gauge (psig) at 70 F. Due to administrative controls in place at the facility, including written loading procedures, the tank is never filled more than 80% capacity for a maximum on-site quantity of 42,274 pounds. The storage tank and transfer piping are located outdoors. The propellant is a flammable and potentially explosive gas. The propellant is not inherently toxic. 1.2 PROCESS DESCRIPTION The Testor propellant filling system consists of the single storage tank, piping from the storage tank to a small propellant fill building, and an aerosol can filling machine. A Corken centrifugal transfer pump is used to transfer the propellant from the storage tank into the propellant fill building. The filling machine regulates the incoming pressure of the propellant and injects the propellant into 3-ounce aerosol cans. All of the above-described components and interconnecting piping compose a closed system with minimal possibility for a large release. The propellant filling system is protected by specific safety systems and hardware which include safety relief valves, excess flow control valves, and safety interlocks and alarms. Safety relief valves protect the storage tank, the tank fill and return lines, and the piping to the propellant filling machine. Excess flow control valves are located at all openings to the storage tank (excepting the openings for the relief valves) and within the propellant fill building. Gas detectors and alarms within the filling room monitor the ambient air to ensure proper operation of the system. Detected concentrations of propellant within the propellant fill building will actuate exhaust equipment within the fill building and, if levels continue to rise, shut down the process. 2.0 POTENTIAL RELEASE SCENARIOS The propellant filling system is a closed system. Historical releases of propane have included only small volumes primarily inside the propellant fill house from the filling machine. While these incidents can impact employees, they have not historically lead to a release that would result in a potential off-site impact. Consistent with the RMP rule requirements, two specifically defined release scenarios, a worst case relea se and an alternative release, were analyzed to determine the maximum distance to predetermined endpoints. The release scenarios analyzed and the endpoints evaluated are based on the guidance contained in the USEPA's Risk Management Program Guidance for Propane Storage Facilities (the "Propane Guidance"), dated October 1998, and the USEPA's Offsite Consequence Analysis Guidance ("OCAG"), dated April 1999. 2.1 WORST-CASE SCENARIO The worst-case scenario assumes that a failure of the propellant storage tank results in a release of the largest quantity of propellant potentially stored at the facility. Administrative controls limit this maximum quantity to 9,600 gallons (80% of the tank's total volume). In the worst-case scenario, the released material is assumed to form a vapor cloud which comes into contact with an ignition source and detonates. The endpoint for this release is defined as an overpressure of 1 psi caused by the explosion and is considered the threshold for potential serious injuries to people as a result of property damage caused by an explosion. The distance to the endpoint for the worst-case scenario extends beyond the facility boundary. Although the worst-case consequence analysis is required by the RMP rule, a worst-case occurrence is a highly unlikely event. The likelihood of a catastrophic failure of the storage tank is extremely remote because of the following:(1) the storage tank is designed and constructed in accordance with the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (Section VIII); (2) access to the tank by non-Testor personnel is prevented through fencing, and the tank is guarded by concrete stantions; (3) the appearance of the external surface of the storage tank is visually inspected on a routine basis and repairs are arranged when necessary. The tank is operated well below the design pressure (i.e. maximum allowable working pressure) of 250 psig, and because of the safety factors built into the ASME code, significantly higher pressure would be required to cause catastrophic failure of the tank. Such pressures could not be generated internally. High pressure caused by flame impingement or surface radiation from a high challenge fire near the tank is unlikely due to the location of the storage tank away from other structures or buildings. Safety relief valves located on the tank would also actuate to reduce pressure below catastrophic levels. Rupture of the tank from the outside as a result of inadvertent contact (e.g vehicular) is unlikely since the unit has substantial barrier protection to preclude this occurrence. 2.2 ALTERNATIVE RELEASE SCENARIO USEPA specifies that an alternative release scenario be evaluated that is "more likely" to occur than the worst-case scenario and is significant enough to impact off-site areas (i.e., the endpoint must be located beyond the facility boundary). Because the Buckbee Street facility has not experienced a propane release to use as an alternative scenario, the scenarios discussed in the USEPA's OCAG and Propane Guidance documents were considered the most appropriate resource for use in defining the alternate release scenario. The release scenario chosen assumes that damage to the pipe between the pump and the propane fill building creates a crack or hole equivalent to a 1/4-inch diameter hole. This scenario assumes that the release is unmitigated for 60 minutes. The resulting vapor cloud is assumed to contact an ignition source and a vapor cloud fire results. No active or passive mitigation is assumed for this scenario. The endpoint for this release, the lower flammable limit (LFL), is considered to represent the furthest distance from the tank at which radiant heat effects from the fire might have serious injury consequences. The LFL for propane was used because it was lower than that for isobutane. The distance to the endpoint for the alternate release scenario extends beyond the facility boundary . Although an alternative release consequence analysis is required by the RMP rule, a release that is large enough to reach an endpoint beyond the facility boundary is not likely to occur because the facility has a training program designed to ensure that the system is operated by qualified personnel. In addition:(1) the storage tank is designed and constructed in accordance with the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (Section VIII); (2) access to the tank by non-Testor personnel is prevented through fencing, and the tank is guarded by concrete stantions; and (3) the appearance of the external surface of the storage tank and propellant delivery system is visually inspected on a routine basis and repairs are arranged when necessary. 3.0 ACCIDENT HISTORY There have been no accidental releases of propellant at the Testor Buckbee Street facility in the last five years that have resulted in death, injury, or significant property damage on site, or death, injury, property damage, evacuation, sheltering in place, or environmental damage off site. 4.0 PREVENTION PROGRAM Testor has carefully considered the potential for accidental releases of propellant, such as the aforementioned occurrences of the worst-case and alternative-release scenarios. To help minimize the probability and severity of a propellant release, a prevention program that satisfies the OSHA PSM of Highly Hazardous Chemicals standard (29 CFR 1910.119) has been implemented at the Buckbee Street facility. The major objective of this prevention program is to implement a management system that prevents releases of propellant, especially in situations that could expose employees and others to serious hazards. The program employs a systematic approach to evaluating the whole process including process design, process technology, process changes, operational and maintenance activities and procedures, non-routine activities and procedures, emergency preparedness and pr ocedures, training programs, and other interrelated elements that effect the propellant system. The key components of the prevention program are summarized below: 7 Process safety information regarding the propellant system has been developed, documented, and made available to facility operators. This information is used to fully understand and safely operate the propellant system. 7 A formal process hazard analysis (PHA) was last performed on the propellant system on February 3, 1999, and the PHA is updated and revalidated every 5 years. A "What-if" creative brainstorming approach is used. A team with expertise in engineering, operations, maintenance, and safety evaluates the existing system in depth and developed recommendations to improve the safety and operability of the propellant system. The PHA addresses: (1) process hazards; (2) previous incidents; (3) engineering and administrative controls applicable to the hazards; (4) the consequence of control failure; (5) facilit y siting; (6) human factors; and (7) a qualitative evaluation of possible safety and health effects of control system failures. The PHA leads to procedural and/or hardware recommendations to improve the safety and operation of the system 7 Written standard operating procedures (SOPs) are used to provide the basis for proper and safe operation of the propellant system. The SOPs include procedures for normal operation, startup, shutdown, emergency operation, and emergency shutdown. 7 Formal authorization systems 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 can be safely operated prior to startup. 7 Operators and mechanics working in the propellant fill building or who are responsible for unloading propellant from tank cars receive training on the process hazards, process safety information, SOPs and emergency response actions related to the propellant system. The training program ensures that the operators understand the nature and causes of problems arising from system operations and serves to increase awareness of the hazards particular to the propellant system. 7 A mechanical integrity program has been implemented as part of PSM. This program includes: (1) routine system inspections to identify unusual or increasing vibration, incipient leaks, or other indications of potential upsets or failures; (2) replacement or testing of pressure relief valves on the storage tank every 10 years; and (3) periodic testing of gauges, monitoring devices, and safety interlocks. 7 Prior to the performance of any hot work (i.e. spark or flame producing operations such as welding, cutting, brazing, grinding), the work must be approved by executing a written hot work permit to verify precautions have been implemented to prevent fire. 7 Contractors that are hired to work on, or adjacent to, the propellant system are "pre-quali fied" based on their knowledge of propane and/or butane systems and their demonstrated ability to work safely. 7 All incidents that cause or might have caused an accidental or unexpected release of propellant are subject to a formal investigation. 7 A compliance audit of the prevention program is completed every 3 years to verify that the appropriate management systems are in place and are being properly implemented. 7 The prevention program includes an extensive employee participation program involving Testor employees from all levels of the organization and from all areas within the plant (i.e., production and maintenance). This program considers that employees who work on the propellant system are the most knowledgeable about it and are able to easily, effectively, and regularly recommend changes or improvements which enhance safety. 5.0 EMERGENCY RESPONSE PROGRAM The Testor Buckbee Street facility has implemented a detailed written Emergency Action Plan (EAP). The EAP is in tended to address all emergencies at the facility, including incidents related to a release of propellant. The EAP includes awareness and response training for plant employees, coordination with the local fire department, and evacuation of personnel in the facility. The EAP identifies specific individuals and their responsibilities, and identifies procedures for emergency medical care. . |