TXU Processing Company Pueblo Plant - Executive Summary |
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ACCIDENTAL RELEASE PREVENTION AND RESPONSE PROGRAM The Pueblo gas plant has a long-standing commitment to employee and public safety. This commitment is demonstrated by the resources invested in accident prevention, such as training of personnel and considering safety in the design, installation, operation, and maintenance of our processes. Our standing practice is to implement reasonable controls to prevent foreseeable releases of regulated flammable substances. However, if a release does occur, trained gas plant personnel will take appropriate action to control/mitigate the release. A DESCRIPTION OF THE STATIONARY SOURCE AND REGULATED SUBSTANCES The Pueblo gas plant, located in rural Eastland County, Texas, operates a variety of processes to recover petroleum products (e.g., natural gas, propane, butane, condensate) from field gas. The gas plant also recovers the regulated flammables, pentane and ethane. There are no threshold quantities of toxic substances present. OFFSITE CONSEQUENCE ANALYSIS RESULTS The worst-case scenario (WCS) associated with a release of flammable substances in Program 1 processes at the gas plant is a vapor cloud explosion (VCE) involving the full inventory of the storage tank containing 56,000 lb of natural gas liquids (NGL). The maximum tank capacity is assumed to release and ignite. The maximum distance to the 1-psi endpoint for this WCS is 0.3 mile. Although we have a number of controls to prevent such releases, no credit for mitigation measures were taken into account in evaluating this WCS. A second evaluated WCS associated with a release of flammable substances in Program 1 processes at the gas plant is a vapor cloud explosion (VCE) involving the full inventory of the storage tank containing 125,100 lb of propane. The maximum tank capacity is assumed to release and ignite. The maximum distance to the 1-psi endpoint for this WCS is 0.4 mile. Although we have a number of controls to prevent such releases, no credit for mitigation measures were taken into account in evaluating this WCS. GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM The following is a summary of the accident prevention program in place at the Pueblo gas plant. Because processes at the gas plant that are regulated by the Environmental Protection Agency's (EPA's) risk management program (RMP) regulation are also subject to the Occupational Safety and Health Administration's (OSHA's) process safety management (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 The Pueblo gas plant 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 informat ion created as part of the gas plant accident prevention program. Specific ways that employees can be involved in the accident prevention program are documented in an employee participation plan that is maintained at the gas plant and addresses each accident prevention program element. In addition, the gas plant has a number of initiatives in place that address process safety and employee safety issues. Process Safety Information The Pueblo gas 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 gas plant are assigned responsibility for maintaining up-to-date process safety information. The reference documents and their location is readily available as part of the written employee participation plan to h elp 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 specific process areas, the gas plant has documented safety-related limits for specific process parameters (e.g., temperature, level, composition). The gas plant ensures that the process is maintained within these limits using process controls and monitoring instruments, highly trained personnel, and protective instrument systems (e.g., automated shutdown systems). The gas 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 tempera ture ratings, and electrical rating of equipment. This information provides a basis for establishing inspection and maintenance activities, as well as evaluating proposed changes to ensure that safety features in the process are not compromised. Process Hazard Analysis (PHA) The Pueblo gas plant 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 that adequate controls are in place to manage these hazards. The gas plant primarily uses the What If analysis technique to perform these evaluations. The analyses are conducted using a team of people who have operating and maintenance experience as well as engineering expertise. The team identifies and evaluates hazards of the process as well as accident prevention and mitigation measures, and the team makes suggestions for additional prevention and/or mitigation measures w hen the team believes such measures are necessary. The PHA team findings are sent to local and corporate management for resolution. Implementation of mitigation options in response to PHA findings is guided by a relative risk ranking assigned by the PHA team. 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, the plant periodically updates and revalidates the hazard analysis results. These periodic reviews are conducted at least every five years and will be conducted at this frequency until 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 doc umented and retained. Operating Procedures The Pueblo gas plant 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. These procedures are readily available in the process unit for operators and other personnel to use as necessary to safely perform their job task. Training To complement the written procedures for process operations, the Pueblo gas plant has implemented a comprehensive training program for all employees involved in operati ng a process. New employees receive basic training in gas 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 three years. This training is documented for each operator, including the means used to verify that the operator understood the training. Contractors The Pueblo gas plant uses contractors to supplement its work force during periods of increased maintenance or construction activities. Because some contract ors work on or near process equipment, the gas 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 plant safety rules, and (6) inform gas 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, the Pueblo gas plant evaluates contractor safety programs and performance during the selection of a contractor. Gas plant personnel periodically monitor contractor performance to ensure that contractors are fulfilling their safety obligations. Pre-startup Safety Reviews (PSSRs) The Pueblo gas plant conducts a PSSR for a ny new facility or process 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 an additional check to make sure construction is in accordance with the design specifications and that all supporting systems are operationally ready. The PSSR team uses checklist(s) to verify startup 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 The Pueblo gas plant has well-established practices and procedures to maintain pressure vessels, piping systems, relief valves, controls, pumps and compressors, and emergency shutdown systems in a safe operating condition. The basic aspects of this program include: ( 1) conducting training, (2) scheduled preventive maintenance, (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 action plan, and (5) applicable safe work practices to help ensure that they perform their jobs in a safe manner. Scheduled preventive maintenance helps ensure that work is performed in a timely and consistent manner. 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 identified, employees will correct the deficiency before placing the equipment back into service (if possible), o r plant management 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. The Pueblo gas plant 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 The Pueblo gas plant 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), and (5) a permit and procedure to ensure that adequate precautions are in place before entry into a confined space. 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 The Pueblo gas plant 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. Chemical hazard information, process operating limits, and equipment information, as well as procedures, are updated to incorporate these changes. In addition, operating and maintenance personnel are pr ovided any necessary training on the change. Incident Investigation The Pueblo gas plant promptly investigates all incidents that resulted in, or reasonably could have resulted in, a fire/explosion, 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 completed. The final resolution of each finding or recommendation is documented, and the investigation results are reviewed with all employees (including contractors) who could be affected by the findings. Incident investigation reports are retained for at least five years so that the reports can be reviewe d during future PHAs and PHA revalidations. Compliance Audits To help ensure that the accident prevention program is functioning properly, the Pueblo gas plant 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 three years. Both hourly and staff personnel may participate as audit team members. The audit team findings are forwarded to plant management for resolution. Corrective actions taken in response to the audit team's findings are tracked until completion. The final resolution of each finding is documented, and the two most recent audit reports are retained. CHEMICAL-SPECIFIC PREVENTION STEPS The processes at the Pueblo gas plant have hazards that must be managed to ensure continued 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 above is applied to all RMP covered processes at the Pueblo gas plant. Collectively, these prevention program activities help prevent potential accidents that could be caused by equipment failures and human errors. Specialized Safety Features The Pueblo gas plant has safety features 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 processes: Release Detection 7 Excess and low flow shutdowns and alarms Release Containment/Control 7 Process relief valves that discharge to a vent stack 7 Valves to permit isolation of the process (manual or automated) 7 Automated shutdown systems for specific process parameters (e.g., high temperature) 7 Curbing or diking to contain liquid releases 7 Redundant equipment and instrumentation (e.g., uninterruptible power sup ply for process control system, backup pumps) 7 Atmospheric relief devices Release Mitigation 7 Fire extinguishers 7 Trained personnel 7 Personal protective equipment FIVE-YEAR ACCIDENT HISTORY The Pueblo gas plant has an excellent record of accident prevention over the past five years. There have been no releases of regulated substances that resulted in deaths, injuries, property or environmental damage, evacuations, or sheltering in place. Also, there has been a decreasing trend in the frequency of incidental releases. EMERGENCY ACTION PLAN INFORMATION The Pueblo gas plant maintains a written emergency action plan, which is in place to protect the safety of workers and the public, as well as the environment. There are no 112(r) threshold toxic substances on the plant site. For a non-incidental release of a flammable substance, including the possibility of a fire, response actions have been coordinated with the local fire department, and mechanisms for notification are in pl ace. Employees receive training as necessary to perform their specific emergency actions. The emergency action plan is updated when necessary, and affected personnel are informed and/or trained in the changes. The gas plant has around-the-clock communications capability with appropriate officials and emergency response organizations (e.g., fire department). This provides a means of notification of an incident if necessary, as well as facilitating quick response to an incident. PLANNED CHANGES TO IMPROVE SAFETY The Pueblo gas plant resolves all findings from PHAs, some of which result in modifications to the process. Changes currently planned by December 31, 1999 are upgrade to the truck loading station and installation of gas detection in the compressor building. |