Tomen Agro, Inc. - Executive Summary |
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Plant Description Tomen Agros facility in Perry, Ohio has produced a fungicide, Captan, at its current location for 45 years. The facility is located on 77 acres in eastern Lake County in a generally rural area. The facility handles several chemicals in the manufacture of Captan, five of which are addressed by the RMP rule: 4-four toxics (chlorine, anhydrous ammonia, carbon disulfide and perchloromethyl mercaptan) and 1-one flammable (1,3-butadiene). RMP Summary The RMP rule requires the reporting of a worst case scenario for one toxic and one flammable chemical. In addition, an alternative scenario for each toxic and one flammable chemical must be evaluated. Below are the plants scenarios. The worst case scenarios are defined in the RMP rule as the hypothetical release of the largest quantity of the material in 10 minutes from its container. Only passive mitigation efforts such as those controls in place that do not require action by an employee to initiate are allow ed to be considered (such as a dike or enclosure in a building). The alternative release scenarios were determined using assumptions based on past experiences by experienced plant personnel. These alternative release scenarios are more credible to real-world potential incidents. For alternative release scenarios, facilities are allowed to include active mitigation which includes procedures and equipment that contain or minimize the impact of an accidental release. Worst Case Scenarios The worst case scenario for toxics is a chlorine release from a 90 ton rail car that by regulation is assumed to be emptied in 10 minutes. Under worst-case weather conditions, chlorine could travel 14 miles before reaching the toxic endpoint from the RMP regulation. It is noted that this scenario assumes meteorological conditions that are uncommon to the area, specifically a wind speed of 1.5 mph that is far less than historical averages. Average wind speed in this area as determined by the Natio nal Oceanic and Atmospheric Administration is 10 mph. This scenario is highly unlikely and would require an extraordinary event to cause the release rate required by rule to occur. Chlorine rail cars are fabricated, tested and inspected regularly by the chlorine car owner per Department of Transportation regulations. If this scenario actually occurred, the plants fire protection system would be utilized via fire monitors which circle the plant to reduce the vapors generated from the spill; therefore, the theoretical distance a toxic cloud would travel is reduced. The plant also has emergency equipment on site and personnel trained in its use to mitigate leaks from a chlorine rail car (for example, Chlorine Institutes C-Kit). The worst case scenario for a flammable is a 1,3 butadiene release from a 35,000 gallon storage tank. Given the constraints of the RMP rule, the estimated distance to the endpoint is 0.5 miles. At this distance the effect would likely be limited to minor structural damage such as broken glass (1 psig overpressurization). It is noted that a vapor explosion can only occur if the butadiene vapors come in contact with an ignition source. By design, the area in the vicinity of the storage tank is void of such ignition sources by utilizing explosion-proof fixtures and equipment. The same likelihood as the chlorine rail car applies to this scenario. The storage tank is designed, constructed and tested per American Society of Mechanical Engineers (ASME) specifications. The tank is protected against accidental vehicle damage by its location within a concrete dike and is not located in an area likely to be subject to damage from maintenance activities or overhead work. The other possible cause of this scenario is due to tank failure due to over-pressurization. The tank is protected by dual relief valves and rupture disk combinations that are annually tested and are designed to relieve tank pressure prior to causing any damage to the tanks structural integrity. Also, two independent deluge systems exist that, when activated (one automatic activation and one manual), would cover the tank with more than a thousand gallons per minute of water reducing the amount of butadiene that would vaporize. This reduces the likelihood of a vapor cloud explosion. There are also 4 fire monitors that can be directed on the tank to flood the tank with significant amounts of water. Similar to the chlorine scenario, meteorological assumptions are not indicative of the regions historical averages that would increase the dispersion and dilution of the vapors generated and significantly reduce the likelihood, severity and radius of damage from this hypothetical event Alternative Release Scenarios The alternative release scenario for chlorine is a leak of a "barco joint" on the unloading line used to transfer chlorine from the rail cars to the process reactors. This scenario assumes that the 1 inch joint leaks for 5 minutes under worst c ase weather conditions. The estimated distance to the endpoint for this scenario is 0.4 miles. The mitigating circumstances that would reduce the likelihood of this event include the presence of surveillance cameras continuously monitored by plant personnel, chlorine detectors on the unloading dock to detect leaks, emergency shutoff valves on the chlorine cars that can be actuated remotely and excess flow valves built into the rail cars that are designed and constructed to Chlorine Institute standards. In addition, the barco joints are inspected annually to insure their integrity. The alternative release scenario for1,3 butadiene is a quarter inch hole in the liquid unloading hose used to off-load butadiene from the rail cars to the storage tanks. This scenario assumes an off-loading rate of 300 pounds per minute under the same worst case weather conditions as the chlorine alternative release scenario. It is assumed that the release would require 10 minutes to stop. The resul ting effects of a potential vapor cloud explosion would extend beyond the plants fence line but not to any EPA defined public receptors. The same conditions for the 1,3 butadiene worst case scenario apply to this event concerning lack of ignition sources, deluge water protection and conservative weather assumptions. In addition, there is an emergency shutoff valve on the rail car that can be actuated remotely in the event of a leak and the unloading operation is continuously monitored by plant personnel. Also, the unloading hose is tested annually to assure its mechanical integrity. The alternative scenario for carbon disulfide is a gasket leak in the 2 inch unloading hose utilized for the off-loading of carbon disulfide from rail cars to the storage tanks. An off-loading rate of 41 gallons per minute is assumed at 30 psig (pressure utilized to off-load the chemical). An earthen dike under the rail car aids in the mitigation of the event and the resulting release goes off-site less than half a mile. This event is also mitigated by several measures including a fire monitor in the vicinity, constant monitoring of the area during the unloading operation by plant personnel and automatic shutoff valve on the car that can be actuated by several switches throughout the plant. The corresponding scenario for anhydrous ammonia is the lifting of a 3/4 inch relief valve in the refrigeration system due to pressure buildup in the system. The capacity of the relief valve over a 10 minute duration results in an event that extends less than half a mile from the source. After the systems pressure drops below the 250 psig set point, the relief valve reseats and the leak stops. The plant regularly tests these relief valves per International Institute of Ammonia Refrigeration recommendations and the entire refrigeration system is maintained, tested and inspected by industry specialists who are authorized by the refrigeration equipment manufacturer. The alternative re lease scenario for the final toxic chemical is for perchloromethyl mercaptan (PMM). This event is the failure of the loading hose utilized for the transfer of the chemical from the storage tank to an ISO container for shipment of PMM to an external customer. This 1-1/2 inch hose failure is assumed to last for 5 minutes with no mitigation. Distance to the endpoint for this scenario is less than half a mile from the source. Plant personnel are present in the area during the entire loading procedure to monitor the transfer who can stop the transfer pump in the event of a leak to help mitigate this event. Also, the loading hose is tested annually to insure its integrity. In all these alternative release scenarios, the same meteorological assumptions apply that are not indicative of actual area norms. The use of actual averages would significantly reduce the exposures and concentrations detected at the toxic endpoints. 5-Year Accident History During the past five years, there h as been one accident meeting the reporting requirements of the RMP rule. In November of 1996 a vessel failure and fire occurred in the THPI manufacturing area. This incident caused equipment damage but did not result in any injuries or chemical release. Operator error combined with contaminated raw materials caused the overpressurization. The entire process area was redesigned and rebuilt to prevent a reoccurrence through the use of numerous redundancies, computer interlocks and safety equipment. The accident was responded to by the local fire department and the plants emergency response team and did not result in any off-site impacts. Accidental Release Prevention Program and Emergency Response Tomen Agro complies with the requirements of the Occupational Safety and Health Administrations (OSHA) Process Safety Management (PSM) standard in addition to this Risk Management Program. Compliance with these two regulations ensures the site's commitment to the protection and safe ty of its employees, community and the environment. The plant incorporates several methods to safeguard these populations: A. Plant layout features such as: open-air process equipment structures; slope and drainage to handle any potential spills; buffer areas between plant operations and populated communities; control over plant access through use of 24 hour/365 day security guard presence. B. Protective systems such as: fire protection systems; fire and fume ADT alarm system; ventilation to remove corrosive or flammable vapors; instruments for remote monitoring and control; containment and recovery facilities; closed circuit television cameras/monitors throughout the plant; several emergency manual and automatic shutdown circuits. Fume and fire alarms automatically inform the local fire department through ADT whether they are activated by manual trip switches located throughout the plant or by temperature sensors in various deluge sprinkler systems. Testing of the plants emergency procedures, such as evacuation efficiency, internal/external alert systems, and community coordination, enhances response time and demonstrates whether the procedures are viable in an emergency. C. Operating practices such as: work permit system for hazardous work;hot work permits for burning, welding and cutting; special training for operating and maintenance personnel; written instructions in plant operations that reflect approved methods of control and operating the process in a safe manner; procedures defining inspections and repairs to plant equipment. D. Comprehensive facility emergency planning is a crucial element in effective and rapid response to accidents. The plants emergency response program has prepared the facility to respond to and mitigate accidental releases, thereby limiting the severity of such releases and their impact on public health and the environment. Emergency response measures such as: An on-site response team trained to handle a wide variety of po tential emergencies; wide assortment of equipment to mitigate chemical and fire emergencies; close proximity to local township fire department; close working relationship with fire department and LAEPC (Local Area Emergency Planning Commission); periodic emergency drills to determine adequacy of response to various scenarios; training in first-aid, fire fighting, spill response, and hazard identification. The plant has a mutual aid agreement with nearby chemical facilities to share equipment in the event of an emergency. E. Engineering Safeguards 1. Comprehensive mechanical integrity testing program involving; regularly tested safety valves; testing and inspection program of critical piping, vessels and instruments to detect problems before failure and ensure reliability when needed. All pumps, piping and process equipment are designed to meet all required codes designed for hazardous/severe service (for example, ASME, API [American Petroleum Institute]) and utilize special material s of construction and linings (for example, glass, nickel, Teflon) to resist wear and corrosion. 2. Means to protect people and property against harmful consequences of possible piping failure such as: limiting the quantity of liquid escaping by automatic shut-off or excess flow valves; additional block valves; flow-limiting orifices and automatic shutdown of systems; limiting the quantity of chemicals where feasible. 3. An emergency generator is on site (and tested weekly) that provides power to critical plant equipment in the event of a power failure. There are also several UPSs (Uninterruptable Power Supplies) that also provide backup power. These backups power critical pumps, blowers, instrumentation, agitators, computers and lighting. 4. Incident investigations are conducted for any event which resulted or could have resulted in a release of a hazardous chemical to implement safeguards against repeating the scenario. 5. Studies conducted by experienced technical and operat ions personnel with engineering and/or process backgrounds are held to identify and discuss potential hazard and operability problems. These studies result in recommended changes that are implemented to eliminate or mitigate potential chemical releases. Summary In conclusion, the plants commitment to safety of its employees, neighbors and the environment is the top priority of the operation. Significant financial commitments are made annually in this area along with all the necessary personnel to implement safety policies and procedures necessary to foster this commitment. Tomen Agros goals are to provide the training and equipment necessary so that employees will be able to perform their jobs in a safe environment; to constantly evaluate, and change if necessary, work conditions and equipment to ensure that the plant is operated in a safe and environmentally friendly manner. |