DUPONT WURTLAND PLANT - Executive Summary |
|
Accidental Release Prevention and Response Policies DuPont's Wurtland Plant has a long-standing commitment to worker and public safety. This commitment is demonstrated by the resources invested in accident prevention, such as training personnel and considering safety in the design, installation, operation, and maintenance of our processes. Our policy is to implement reasonable controls to prevent foreseeable releases of substances. However, if a release does occur, trained personnel will respond to control and contain the release. Description of the Stationary Source and Regulated Substances The Wurtland Plant manufactures and processes sulfuric acid in Greenup County Kentucky. Raw material, intermediate and process storage tanks are in use at the site. The Wurtland Plant was evaluated to determine if any regulated flammable or toxic substances exceeded the threshold quantity. Based on process knowledge, DuPont identified the regulated substances and quantities kept on site. The facility uses three regulated substances in the sulfuric acid process, oleum, sulfur trioxide, and anhydrous hydrogen chloride (Process 1). In addition, railcars containing oleum and anhydrous hydrogen chloride are occassionally on-site for a short period of time prior to shipping without active shipping papers (Process 2). Based on worst-case analyses, the distances to endpoints [i.e. Emergency Response Planning Guideline Level 2 (ERPG-2) developed for each substance by the American Industrial Hygiene Association] exceed the distances to public receptors (i.e., off-site residences, institutions, industrial and commercial office buildings, parks, or recreational areas inhabited or occupied by the public). In addition, DuPont is subject to Occupational Safety and Health Administration (OSHA) Process Safety Management (PSM) and is classified under a listed SIC Code 2819. Therefore, the sulfuric acid process and the railcar storage area are classified as Program 3 under the Accident al Release Prevention (ARP) Program. Off-Site Consequence Analysis Results Worst-Case Releases Flammable Substances The endpoint for the worst-case release of a flammable substance is 1 psi overpressure (i.e. 15.7 psia) for vapor cloud explosions. DuPont Wurtland Plant does not store any flammable substances listed in the rule in the threshold quantities required by the regulation; therefore, DuPont does not have a worst-case scenario for flammable substances. Toxic Substances Endpoints for toxic substances are based on the ERPG-2. Toxic endpoints are listed in Appendix A to 40 CFR Part 68 (Table of Toxic Endpoints). Each of the regulated toxic substances at the Wurtland Plant was reviewed to determine the substance with the greatest distance to an endpoint. For the oleum storage vessel, administrative controls exist in which the tank is only filled to 90% capacity. Alarms are in place to ensure that the tank is never filled over 90% of the capacity. The distance to the toxi c endpoint resulting from the instantaneous release of the contents of the oleum tank and an anhydrous hydrogen chloride railcar would have an off-site impact. The distance to the toxic endpoint was calculated based on the U.S. EPA lookup tables contained in the OCA Guidance Document. Endpoints for toxic substances are based on the ERPG-2. Toxic endpoints are listed in Appendix A to 40 CFR Part 68 (Table of Toxic Endpoints). Each of the regulated toxic substances at the Wurtland Plant was reviewed to determine the substance with the greatest distance to an endpoint. Alternative Releases Alternative release scenarios are those that are more likely to occur than the worst-case release scenario. Toxic Substances One alternative release scenario for each toxic substance is required under the ARP program. A hypothetical release scenario has been identified for the regulated toxic substances, oleum, sulfur trioxide, and anhydrous hydrogen chloride at the Wurtland Plant. For ole um, it was assumed that a 4-inch nozzle valve line fails. This area is not diked, but the pump can be shutdown and flow stopped within a maximum time period of 10 minutes. This release has an off-site impact, and has off-site impact on the residential population, as determined by the OCA Guidance and the "Landview" program census data. For sulfur trioxide, it was assumed that a 2-inch loading hose breaks. This area is not diked, but the maximum response time is 2 minutes to shutdown the flow. This release has an off-site impact, and has off-site impact on the residential population, as determined by the OCA Guidance and the "Landview" program census data. For anhydrous hydrogen chloride, it was assumed that a 1-inch unloading hose ruptures. This area is not diked, but the maximum response time would be 15 minutes to shutdown the flow. This release has an off-site impact on the residential population, as determined by the OCA Guidance and the "Landview" program census data. Hypothetical release scenarios have also been identified for the regulated toxic substances, oleum and anhydrous hydrogen chloride stored in railcars prior to shipping. For both chemicals, it was assumed that the railcar leaks. The storage area is not diked, so no active mitigation was assumed, but foam would be applied to contain and neutralize the spilll. Both hypothetical releases would have off-site impact on a small residential population, as determined by the use of the OCA Guidance and the "Landview" program census data. General Accidental Release Prevention Program The following is a summary of the accident prevention program in place at DuPont's Wurtland P lant. Because processes at the plant that are regulated by the EPA's risk management program (RMP) regulation are also subject to the OSHA's PSM standard, this summary addresses each of the OSHA PSM elements and describes the management system in place to implement the accident prevention program. Employee Participation DuPont encourages employees to participate in all facets of process safety management and accident prevention. Examples of employee participation range from updating and compiling technical documents and chemical information to participating as a member of a process hazard analysis (PHA) team. Employees have access to all information created as part of the Wurtland Plant's accident prevention program. One way that employees can be involved in the accident prevention program is our Safety, Health, and Environmental (SHE) Committee. In addition, Wurtland has a number of initiatives under way that address process safety and employee safety issues. These initiativ es include forming teams to promote both process and personal safety. The teams have members from all areas of the plant, including operations, maintenance, engineering, and plant management. Process Safety Information The Wurtland Plant keeps a variety of technical documents that are used to help maintain safe operation of the processes. These documents address chemical properties and associated hazards, limits for key process parameters and specific chemical inventories, and equipment design basis/configuration information. Specific departments within the plant are assigned responsibility for maintaining up-to-date process safety information. A table summarizing the reference documents and their location is readily available as part of the written employee participation plan to help employees locate any necessary process safety information. Chemical-specific information, including exposure hazards and emergency response/ exposure treatment considerations, is provided in material safety data sheets (MSDSs). This information is supplemented by documents that specifically address known corrosion concerns and any known hazards associated with the inadvertent mixing of chemicals. For the sulfuric acid process area, Wurtland has documented safety-related limits for specific process parameters (e.g., temperature level, composition) in a Standard Conditions Manual. The plant ensures that the process is maintained within these limits using state-of-the-art process controls and monitoring instruments, emergency relief systems with flare, redundant power supply and safety systems, highly trained personnel, and protective instrument systems (e.g., automated shutdown systems). The plant also maintains numerous technical documents that provide information about the design and construction of process equipment. This information includes materials of construction, design pressure and temperature ratings, and electrical rating of equipment. This information, in combinat ion with written procedures and trained personnel, provides a basis for establishing inspection and maintenance activities, as well as for evaluating proposed process and facility changes to ensure that safety features in the process are not compromised. Process Hazard Analysis (PHA) Wurtland has a comprehensive program to help ensure that hazards associated with the various processes are identified and controlled. Within this program, each process is systematically examined to identify hazards and ensure the adequate controls are in place to manage these hazards. Wurtland primarily uses the hazard and operability (HAZOP) analysis technique to perform these evaluations. HAZOP analysis is recognized as one of the most systematic and thorough hazard evaluation techniques. The analyses are conducted using a team of people who have operating and maintenance experience as well as engineering expertise. This team identifies and evaluates hazards of the process as well as accident p revention and mitigation measures, and the team makes suggestions for additional prevention and/or mitigation measures when the team believes such measures are necessary. The PHA team findings are forwarded to local and corporate management for resolution. Implementation of mitigation options in response to PHA findings is based on a relative risk ranking assigned by the PHA team. This ranking helps ensure that potential accident scenarios assigned the highest risk receive immediate attention. All approved mitigation options in response to PHA team findings are tracked until they are completed. The final resolution of each finding is documented and retained. To help ensure that the process controls and/or process hazards do not eventually deviate significantly from the original design safety features, Wurtland periodically updates and revalidates the hazard analysis results. These periodic reviews are conducted at least every 5 years and will be conducted at this frequency unti l the process is no longer operating. The results and findings from these updates are documented and retained. Once again, the team findings are forwarded to management for consideration, and the final resolution of the findings is documented and retained. Operating Procedures Wurtland maintains written procedures that address various modes of process operations, such as (1) unit startup, (2) normal operations, (3) temporary operations, (4) emergency shutdown, (5) normal shutdown, and (6) initial startup of a new process. These procedures can be used as a reference by experienced operators and provide a basis for consistent training of new operators. These procedures are periodically reviewed and annually certified as current and accurate. The procedures are kept current and accurate by revising them as necessary to reflect changes made through the management of change process. This information is readily available to operators in the process unit and for other personnel to us e as necessary to safely perform their job tasks. Training To complement the written procedures for process operations, Wurtland has implemented a comprehensive training program for all employees involved in operating a process. New employees receive basic training in plant operations if they are not already familiar with such operations. After successfully completing this training, a new operator is paired with a senior operator to learn process-specific duties and tasks. After operators demonstrate (e.g., through tests, skills demonstration) having adequate knowledge to perform the duties and tasks in a safe manner on their own, they can work independently. In addition, all operators periodically receive refresher training on the operating procedures to ensure that their skills and knowledge are maintained at an acceptable level. This refresher training is conducted at least every 3 years. All of this training is documented for each operator, including the means used to VERI FY that the operator understood the training. Contractors Wurtland uses contractors to supplement its workforce. Because some contractors work on or near process equipment, the plant has procedures in place to ensure that contractors (1) perform their work in a safe manner, (2) have the appropriate knowledge and skills, (3) are aware of the hazards in their workplace, (4) understand what they should do in the event of an emergency, (5) understand and follow site safety rules, and (6) inform plant personnel of any hazards that they find during their work. This is accomplished by providing contractors with (1) a process overview, (2) information about safety and health hazards, (3) emergency response plan requirements, and (4) safe work practices prior to their beginning work. In addition, Wurtland evaluates contractor safety programs and performance during the selection of a contractor. Plant personnel periodically monitor contractor performance to ensure that contractors are fu lfilling their safety obligations. Pre-startup Safety Reviews (PSSRs) Wurtland conducts a PSSR for any facility modification that requires a change in the process safety information. The purpose of the PSSR is to ensure that safety features, procedures, personnel, and equipment are appropriately prepared for startup prior to placing the equipment into service. This review provides one additional check to make sure construction is in accordance with the design specifications and that all supporting systems are operationally ready. The PSSR review team uses checklists to verify all aspects of readiness. A PSSR involves field verification of the construction and serves a quality assurance function by requiring verification that accident prevention program requirements are properly implemented. Mechanical Integrity Wurtland has well-established practices and procedures to maintain pressure vessels, piping systems, relief and vent systems, controls, pumps and compressors, and emer gency shutdown systems in a safe operating condition. The basic aspects of this program include: (1) conducting training, (2) developing written procedures, (3) performing inspections and tests, (4) correcting identified deficiencies, and (5) applying quality assurance measures. In combination, these activities form a system that maintains the mechanical integrity of the process. Maintenance personnel receive training on (1) an overview of the process, (2) safety and health hazards, (3) applicable maintenance procedures, (4) emergency response plans, and (5) applicable safe work practices to help ensure that they can perform their jobs in a safe manner. Written procedures help ensure that work is performed in a consistent manner and provide a basis for training. Inspections and tests are performed to help ensure that equipment functions as intended and to verify that equipment is within acceptable limits (e.g., adequate wall thickness for pressure vessels). If a deficiency is ident ified, employees will correct the deficiency before placing the equipment back into service (if possible), or a management of change team will review the use of the equipment and determine what actions are necessary to ensure the safe operation of the equipment. Another integral part of the mechanical integrity program is quality assurance. Wurtland incorporates quality assurance measures into equipment purchases and repairs. This helps ensure that new equipment is suitable for its intended use and that proper materials and spare parts are used when repairs are made. Safe Work Practices Wurtland has long-standing safe work practices in place to help ensure worker and process safety. Examples of these include (1) control of the entry/presence/exit of support personnel, (2) a lockout/tagout procedure to ensure isolation of energy sources for equipment undergoing maintenance, (3) a procedure for safe removal of hazardous substances before process piping or equipment is opened, (4) a permit and procedure to control spark-producing activities (i.e., hot work), (5) a permit and procedure to ensure that adequate precautions are in place before entry into a confined space, and (6) a pre-start-up safety review on each unit. These procedures (and others), along with training of affected personnel, form a system to help ensure that operations and maintenance activities are performed safely. Management of Change Wurtland has a comprehensive system to manage changes to all covered processes. This system requires that changes to items such as process equipment, chemicals, technology (including process operating conditions), procedures, and other facility changes be properly reviewed and authorized before being implemented. Changes are reviewed to (1) ensure that adequate controls are in place to manage any new hazards and (2) verify that existing controls have not been compromised by the change. Affected chemical hazard information, process operating lim its, and equipment information, as well as procedures, are updated to incorporate these changes. In addition, operating and maintenance personnel are provided any necessary training on the change. Incident Investigation Wurtland will promptly investigate all incidents that result in, or reasonably could have resulted in, a fire/explosion, toxic gas release, major property damage, environmental loss, or personal injury. The goal of each investigation is to determine the facts and develop corrective actions to prevent a recurrence of the incident or a similar incident. The investigation team documents its findings, develops recommendations to prevent a recurrence, and forwards these results to plant management for resolution. Corrective actions taken in response to the investigation team's findings and recommendations are tracked until they are complete. The final resolution of each finding or recommendation is documented, and the investigation results are reviewed with all emplo yees (including contractors) who could be affected by the findings. Incident investigation reports are retained for at least 5 years so that the reports can be reviewed during future PHAs and PHA revalidations. Compliance Audits To help ensure that the accident prevention program is functioning properly, Wurtland periodically conducts an audit to determine whether the procedures and practices required by the accident prevention program are being implemented. Compliance audits are conducted at least every 3 years. Both hourly and staff personnel participate as audit team members. The audit team develops findings that are forwarded to plant management for resolution. Corrective actions taken in response to the audit team's findings are tracked until they are complete. The final resolution of each finding is documented, and the two most recent audit reports are retained. Chemical-Specific Prevention Steps The process at Wurtland has hazards that must be managed to ensure continu ed safe operation. The following is a description of existing safety features applicable to prevention of accidental releases of regulated substances in the facility. Universal Prevention Activities The accident prevention program summarized previously is applied to all RMP-covered processes at Wurtland. Collectively, these prevention program activities help prevent potential accident scenarios that could be caused by equipment failures and human errors. Specialized Safety Features Wurtland has safety features on units to help (1) contain/control a release, (2) quickly detect a release, and (3) reduce the consequences of (mitigate) a release. The following types of safety features are used in the covered process: Release Containment/Control Automatic shut-off devices and relief valves Curbing or diking to contain liquid releases Redundant equipment and instrumentation (e.g., uninterruptible power supply for process control system, backup firewater pump) Administrative contro ls to minimize toxic chemical inventories. Release Mitigation Trained emergency response personnel Personal protective equipment (e.g., chemical protective clothing, self-contained breathing apparatus) Continuous pressure monitoring of vessels and pipes Audible warning alarms Five-Year Accident History DuPont Wurtland Plant has had one accidental releases during the past five years which meets the criteria for an accidental release per 40 CFR 68.42. Emergency Response Program Information Wurtland maintains a written incident response plan, which is in place to protect worker and public safety as well as the environment during an emergency. The plan consists of procedures for responding to a release of a regulated substance. The procedures address all aspects of emergency response, including proper first aid and medical treatment for exposures, evacuation plans and accounting for personnel after an evacuation, notification of local emergency response agencies and the public if a release occurs, and post-incident cleanup and decontamination requirements. In addition, the plant has procedures that address maintenance, inspection, and testing of emergency response equipment, as well as instructions that address the use of emergency response equipment. Employees receive training in these procedures as necessary to perform their specific emergency response duties. The incident response plan is updated when necessary based on modifications made to plant processes. The overall emergency response program for Wurtland is coordinated with the Wurtland Fire Department. This coordination includes periodic meetings of the Wurtland Plant personnel and the Wurtland Fire Chief to discuss needs and concerns in the event of an incident at the plant. Wurtland has around-the-clock communications capability with the Fire Department who have the ability to communicate to all state, federal and county agencies as to needed equipment (i.e., firefighting equipment, manpower, ambulances, hospitals, law enforcement, and HAZMAT operations). This provides a means of notifying the public of an incident, if necessary, as well as facilitating quick response to an incident. In addition to periodic meetings with the Fire Chief, Wurtland conducts periodic emergency drills that involve the Fire Department and emergency response organizations, and the plant provides annual refresher training to local emergency responders regarding the hazards of regulated substances in the plant. Planned Changes to Improve Safety Wurtland has several elements of the management system of the accident prevention program in place to improve safety throughout the facility. These elements are part of an overall ongoing safety improvement process. |