Union Carbide Seadrift Plant - Executive Summary |
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UNION CARBIDE CORPORATION SEADRIFT, TX PLANT RISK MANAGEMENT PLAN EXECUTIVE SUMMARY 1. Accidental Release Prevention and Emergency Response Policies The Union Carbide Seadrift Plant is committed to operating and maintaining all of our processes in a safe and responsible manner. We have implemented a combination of accidental release prevention programs and emergency response planning programs to help ensure the safety of our employees and the public, as well as to protect the environment. These programs include both Union Carbide's Responsible CareR requirements and governmental requirements, such as the Environmental Protection Agency's (EPA) Risk Management Program (RMP) rule and the Occupational Safety and Health Administration's (OSHA) Process Safety Management (PSM) standard. The information from the Risk Management Plan has been shared with plant neighbors, LEPC members, elected officials, and other community members through public meetings. Input on the plan has been rece ived from the Community Advisory Panel and has been incorporated into the plan as well as the public communication sessions. 2. Description of the Facility and Regulated Substances The Union Carbide Seadrift Plant is a manufacturing facility that annually produces approximately 3.6 billion pounds of plastic, rubber, and other chemical products in its various operating units. Most are intermediates used in other Union Carbide processes, or sold to customers who convert them into finished products. The RMP rule requires that if a facility, such as the Seadrift Plant, has a specific amount (threshold) or more of any one of 140 toxic and/or flammable chemicals, the facility must follow the RMP rule requirements for that chemical. The Union Carbide Seadrift Plant has the following RMP-regulated toxic substances in quantities above the threshold: RMP Toxic Chemicals RMP Flammable Chemicals Ethylene Oxide 1,3-Butadiene Ammonia Butene-1 Vinyl Acetate Ethane Titanium Tetrachloride E thylene Isopentane Methane Propane Propylene 3. Key Offsite Consequence Analysis Scenarios EPAs RMP rule requires that we provide information about the worst-case release scenario(s) and alternative release scenario(s) for our facility. The following are brief summaries of these scenarios. Unless otherwise specified, no credit was taken for administrative controls or mitigation measures in evaluating the off-site impact of the scenarios. Steps to prevent these scenarios from occurring, and to mitigate their effects should they occur, appear in Section 4. A) Regulated Toxic Chemicals Worst-Case Release Scenario -- This scenario assumes an over-pressure and rupture of a storage tank, releasing 294,000 pounds of ethylene oxide as a gas to the atmosphere. An administrative control limits the maximum filling capacity of this storage tank to 85 percent (294,000 pounds). According to EPAs Offsite Consequence Analysis (OCA) Guidance Table, this release could impact off-site publ ic receptors. . The following administrative control is used in this analysis: 7 Inventory Restriction: Written operating procedures and a high-level shutdown system limits the maximum filling capacity of this storage tank to 85 percent (294,000 pounds). In addition, specific steps to prevent this scenario from occurring, and to mitigate its effects should they occur, include: 7 Double Wall Tank: The tank has a secondary tank wall which is designed to contain a leak in the primary wall. 7 Secondary Wall Leak Detection: A sensor is designed to detect leaks between the primary and secondary walls of the tank. 7 Enclosed Tanks: The surge tanks are inside concrete containment walls and covered with gravel to minimize the potential for external impact. 7 Secondary Containment Around Tanks: The area around the tanks is diked and curbed to contain spills. 7 Combustible Gas Detectors Interlocked to Sprinkler-Deluge System: This system is designed to detect flammable vapors and to autom atically activate the deluge system (water spray) to suppress flammable vapors. 7 Emergency Shutdown System: A manual emergency shutdown system is designed to shut down the pumps, place transfer valves in fail safe position, and actuate the deluge system. 7 Surveillance: Temperature, pressure, level, and combustible gas detectors are continuously monitored from a remote location. The area is always under surveillance of a remotely operated camera to detect unusual circumstances. 7 Flares: Pressure relief devices are routed to a flare for destruction of ethylene oxide. 7 Fire Water Monitors: In addition to the sprinkler-deluge system, area fire water spray monitors can be used to help suppress ethylene oxide vapors. Alternative Release Scenarios -- Ethylene Oxide: This scenario assumes a pressure relief valve on equipment in the Oxide Unit opens and relieves 3000 pounds of ethylene oxide over a five minute period. According to the OCA Guidance Table, this release could impact off-site public receptors. The following active mitigation measures are used in this analysis: 7 Emergency Shutdown System: A manual emergency shutdown system is designed to shut down the pumps, compressors, and heat transfer equipment and put the valves in a fail-safe position. 7 Surveillance: Unit operating conditions such as temperature, pressure and flow rates are continuously monitored in the control room and upset conditions such as in the scenario are immediately detected. Other specific steps to prevent this scenario from occurring, and to mitigate its effects should they occur, include: 7 Combustible Gas Detectors Interlocked to Sprinkler-Deluge System: This system is designed to detect flammable vapors and to automatically activate the deluge system (water spray) to suppress flammable vapors. 7 Fire Water Monitors: In addition to the sprinkler-deluge system, area fire water spray monitors can be used to help suppress ethylene oxide vapors. Anhydrous Ammonia: This scenario assumes a hose fails while unloading a tank car into a storage tank. The contents of the car (150,000 pounds) is released to the air over a 30 minute period. According to the OCA Guidance Table, this release could impact off-site public receptors. The following active mitigation measure is used in this analysis: 7 Excess Flow Check Valves: The valves are designed to check closed when the flow rate exceeds the designed limit, as would be the case with a hose rupture. The check valve is not positive isolation, but instead it serves to limit the flow rate. The result is a decrease in the downwind concentration of ammonia. Other specific steps to prevent this scenario from occurring, and to mitigate its effects should they occur, include: 7 Leak Detection: Ammonia leak detectors, installed in the unloading area and around the storage tank, sound an alarm in the control room if a leak should occur. They also isolate the pressure source used to unload the car. 7 Deluge system: A water spray system designed to suppress ammonia vapors can be manually actuated, or automatically actuated by heat. 7 Fire Water Spray Monitors: Area fire water spray monitors can be used to help suppress anhydrous ammonia vapors. 7 Surveillance: Operators and maintenance employees monitor the work area while unloading ammonia. Vinyl Acetate: This scenario assumes the vinyl acetate storage tank is overfilled and the 3,300 pound liquid release is contained in the diked area around the tank. According to the OCA Guidance Table, this release could impact off-site public receptors. The following active and passive mitigation measures are used in this analysis: 7 Diking: Tank is diked to be able to contain the entire contents of the tank plus rainfall. 7 Tank Level Monitoring: The tank level is verified prior to transferring material into the tank to ensure adequate space is available. 7 Surveillance: The tank area is monitored frequently for unusual circumstances by employees maki ng routine inspection rounds in the storage area. Particular attention is given during transfers when the risk of overflow is greatest. Other specific steps to prevent this scenario from occurring, and to mitigate its effects should they occur, include: 7 Maximum Level: Procedures require that the tank level does not exceed 85% of its capacity. 7 Spill Response: Fire water monitors and foam trailer are available in the area to reduce emissions. Titanium Tetrachloride: This scenario assumes that an unloading hose attached to the storage cylinder ruptures and releases the entire contents (6,200 pounds) to the air. According to the OCA Guidance Table, this release could impact off-site public receptors. The following active and passive mitigation measures are used in this analysis: 7 Hose Size: The cylinders are unloaded with =" diameter hoses which limits the amount of material that can be released. 7 Cylinder Size: The material is delivered in relatively small quantities and on ly one cylinder is connected at a time. Therefore the amount of material that can be released is limited. Other specific steps to prevent this scenario from occurring, and to mitigate its effects should they occur, include: 7 Pad Drains: Concrete around the cylinder is sloped to a containment sump and is able to contain the entire contents of the cylinder plus rainfall. 7 Leak Detectors: The area contains sensors capable of alarming when a leak is detected. The sensors also automatically activate the deluge system and automatically isolate the supply cylinder from the process when a significant leak is detected. 7 Surveillance: Personnel remain in the area when the cylinders are being unloaded to the tank. Routine operator rounds and inspections provide another means to identify problems. 7 Deluge Systems: Manual and automatic deluge systems are available to suppress a release. 7 Fire Water Monitors: Fire water monitors exist in the area to aid in knocking down and/or dispersi ng a release. B) Regulated Flammable Chemicals Worst-Case Release Scenarios -- 1,3-Butadiene: The worst-case release scenario for a flammable regulated substance assumes catastrophic failure of a storage tank that releases 4,000,000 pounds of 1,3-butadiene as a gas to the atmosphere, leading to a vapor cloud explosion. The tank is in a diked area to contain and minimize evaporation of the 1,3-butadiene. According to the OCA Guidance Table, this release could impact off-site public receptors. The following administrative control was used in this analysis: 7 Inventory Restriction: An administrative control limits the maximum filling capacity of this storage tank to 80 percent (4,000,000 pounds). In addition, specific steps to prevent this scenario from occurring, and to mitigate its effects should they occur, include: 7 Secondary Containment Dike: The dike contains and minimizes 1,3-butadiene evaporation to the atmosphere. 7 Combustible Gas Detectors: This system is designed to detect flammable vapor and to automatically activate the deluge system (water spray) to help suppress flammable vapor. 7 Emergency Shutdown System: The manual emergency shutdown system is designed to isolate the tank and pump, and to actuate the deluge system. 7 Deluge System: A water spray system is designed to help suppress 1,3-butadiene vapors. It is actuated by combustible gas detectors or the emergency shutdown system. A foam trailer is also available in the area for fire fighting. 7 Monitoring and Surveillance: The tank pressure and level are monitored and alarmed. The area is inspected frequently as routine part of operations. Alternate Release Scenario -- 1,3-Butadiene: This scenario assumes a buried pipeline near the company fence line is struck by excavation equipment. This causes the pipeline to fail, releasing 1,3-butadiene as a gas through a 1 inch diameter hole to the atmosphere for 30 minutes, and leads to a vapor cloud explosion. The total amount of chem ical released is 7,100 pounds. According to the OCA Guidance Table, this release could impact off-site public receptors. The following active and passive mitigation measure is used in this analysis: 7 The pump discharge pressure, the line size and distance to excavation site reduce the amount of material that can potentially be released. 7 The duration of release is limited due to the nature and location of the release. The persons who cause the release due to an excavation immediately are aware of the release. This is quickly communicated and source of the material is valved in. Emergency response plans are rapidly initiated. Other specific steps to prevent this scenario from occurring include: Excavation Procedures: A hazardous work permit and excavation permit are required to dig in the vicinity of the 1,3 butadiene line. The excavation is either hand-dug or hand-probed ahead of excavation equipment. Line location is positively identified prior to digging. 4. General Acci dental Release Prevention Program and Chemical-Specific Prevention Steps A) General Program Our general accident prevention program consists of compliance with the EPA RMP rule and OSHA's PSM standard and implementation of Union Carbide's Operational Safety Program and Episodic Risk Management System. Key elements include: Equipment Design: Vessels (including shipping containers) and other process equipment are designed according to recognized industry standards and/or governmental requirements. Process Safety Information: Chemical hazard, process technology, and equipment information is documented, maintained up-to-date, and available to operating personnel. Process Hazard Analysis: Process hazard analyses are conducted every five years to identify major process hazard scenarios and to recommend corrective action(s) needed to prevent their occurrence. Episodic Risk Management: Periodic reviews are conducted to identify hazards which could have significant community impact and to recommend corrective action(s) needed to prevent their occurrence. These reviews utilize advanced quantitative risk assessment techniques. Operational Safety Standards: Design requirements for active and passive mitigation controls used to prevent major process hazards are documented in operational safety standards. Operating Procedures: Operating procedures provide detail on how to safely operate a process and are maintained up-to-date. Operator Training/Certification Program: The plant has a training and testing program which provides operators with the proper skills and knowledge prior to allowing them to independently operate a process. Technical Staff Training and Support: Trained technical staff employees are available 24 hours a day to support operations. Maintenance Procedures: The plant has specific procedures for maintaining process equipment so that it operates safely. Maintenance Training: The plant trains persons who perform routine or complex maintenance tasks on process equipment. Mechanical Integrity Program: Vessels (including shipping containers) and other process equipment are periodically tested and/or inspected to ensure safe operation of process equipment, following recognized industry standards and/or governmental requirements. Management of Change: The plant has a management system to ensure that modified facilities and processes will be safe to operate. Pre-startup Safety Reviews: Reviews are conducted just prior to startup to ensure that modified facilities and processes are safe for operation. Incident Investigation: The plant has a program to ensure that accidents and incidents are properly investigated to determine the cause(s) and to implement corrective action(s) that are needed to prevent the event from reoccurring. Employee Participation: The plant has a program to involve employees in prevention program elements. Hot Work Permit: The plant has a procedure to ensure that welding, cutting and brazing are safely performed in areas where flammable or combustible material may be present. Contractor Safety Program: The plant has a program to ensure that contractors are properly trained and perform their work in compliance with safety requirements. Compliance Audits: Periodic Corporate and plant-led audits are conducted to ensure that process operations comply with governmental and Union Carbide requirements. Operational Safety Program: Union Carbide has a comprehensive program to ensure that all the elements listed above are implemented at every Union Carbide location. This Program includes accountabilities for timely and proper implementation of the program elements. 5. FIVE-YEAR ACCIDENT HISTORY In the last five years there has not been an accident or incident involving an EPA RMP chemical at the Union Carbide Seadrift Plant that resulted in an on-site death, injury, or property damage; or a known off-site death, injury, evacuation, shelter-in-place, property damage or environmental damage. 6. E MERGENCY RESPONSE PROGRAM The Seadrift Plant maintains a written emergency response program to protect worker and public safety, as well as the environment. The program consists of procedures for responding to releases of hazardous substances, including the possibility of a fire or explosion if a flammable substance is accidentally released. The procedures address all aspects of emergency response, including: 7 Proper first-aid and medical treatment for exposures 7 Evacuation and shelter-in-place plans and accounting for personnel after an incident 7 Notification of local emergency response agencies and the public if a release occurs 7 Post-incident cleanup and decontamination requirements, and 7 Inspecting, testing, maintaining, and using emergency response equipment. The emergency response program is updated when necessary based on modifications made to facility processes. The Seadrift Plant maintains a trained emergency squad to handle fires, explosions, toxic vapor releases, spills, and medical emergencies. The plant squad trains and drills with local emergency responders to enhance their skills and tactics for responding to an accidental chemical release. Critiques are held on drills and actual events. In addition to the plant emergency squad, Union Carbide's Hazardous Emergency Leaks Prevention (HELP ) team on the Gulf Coast responds to accidental releases from transportation incidents occurring in the continental U.S. The emergency response program provides the essential planning and training for effectively protecting workers, the public, and the environment during emergency situations. Detailed emergency response plans are developed and coordinated with the Calhoun County Emergency Planning Committee and the community. A Mutual Aid Network has been established with Calhoun County and other local chemical plants to further enhance the ability to respond to an emergency. 7. PLANNED CHANGES TO IMPROVE SAFETY On-going programs, such as process ha zard analysis reevaluations, continually aim to improve process safety. The following is a list of specific improvements that we are planning to implement at the Seadrift Plant to help prevent and/or better respond to accidental chemical releases: 7 A new Corporate program that uses semi-quantitative assessment techniques in process hazard analyses to ensure that controls used for prevention or mitigation of hazards provide adequate protection 7 Conduct periodic process hazard analyses for all processes and implement resulting recommendations for improvements to safety equipment and procedures. 7 A new Corporate program designed to ensure that process safety information is kept up-to-date. 7 All new projects are designed around principles of inherent safety so that process safety is integrated directly into the design. 7 Changes to new or revised systems seek to minimize the quantities of hazardous materials. 7 Union Carbide continues to implement a corporate-wide strategy to avoid computer hardware and software systems operating disruptions due to the year 2000 changeover. The latest information on the company's Y2K efforts can be found on our Internet site -- www.unioncarbide.com. This information will be periodically updated through first quarter 2000. |