Chevron Salt Lake Refinery - Executive Summary |
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ACCIDENTAL RELEASE PREVENTION AND RESPONSE POLICIES The Chevron Salt Lake refinery 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 regulated substances. However, if a release does occur, our trained personnel will respond to control and contain the release. DESCRIPTION OF THE STATIONARY SOURCE AND REGULATED SUBSTANCES The Chevron Salt Lake refinery, located in Salt Lake City, Utah, operates a variety of processes to produce petroleum products (e.g., natural gas, propane, butane, gasoline, diesel, jet fuel) from raw crude oil. The refinery has several regulated flammables, which includes: - Hydrogen - Methane - Ethane - Ethylene - Propane - Propylene - Butane - Butene - Isobutane - Iso butene - 2-butene-cis - 2-butene-trans - 2-Methylpropene - Pentane - Isopentane The only regulated toxic substance that the refinery has above threshold quantities is hydrogen fluoride. HAZARD ASSESSMENT RESULTS The worst case scenario (WCS) associated with a release of a regulated flammable substances in a Program 3 process at the refinery is a vapor cloud explosion (VCE) involving the full inventory of a LPG sphere containing butane. Based on EPA's Offsite Consequence Guidance document, this scenario results in the 1.0 psi blast overpressure going off-site. Although we have numerous controls to prevent such releases and to manage their consequences, no credit for passive mitigation measures was taken into account in evaluating this WCS. The worst case scenario (WCS) associated with a release of a regulated toxic substances in a Program 3 process is a release of hydrogen fluoride from a storage tank in the Alkylation Unit. Based on EPA's Offsite Consequence Guidance document , this scenario results in the endpoint of 20 ppm of hydrogen fluoride going off-site. No credit for passive mitigation measures was taken into account in evaluating this WCS. The alternative release scenario (ARS) for flammable substances at the refinery is a VCE resulting from the release of a flammable mixture from a vessel in the Isomerization unit and results in off-site impacts. However, no residences would be reached by the 1.0 psi overpressure. The alternative release scenario (ARS) for toxic substances at the refinery is a release of hydrogen fluoride in the Alkylation unit. The scenario assumes a 1/4" hole in the piping from the hydrogen fluoride storage tank and last for 10 minutes until the emergency block valves are closed. Even though the refinery has a water spray safety system for hydrogen fluoride releases, this ARS does not take into account the impact of the safety system. However, activation of the water spray system will significantly reduce the distance t hat the hydrogen fluoride travels. FIVE-YEAR ACCIDENT HISTORY The Chevron Salt Lake refinery has an excellent record of accident prevention over the past 5 years. There have not been any incidences with a regulated material that resulted in any on-site or off-site impacts. We investigate every incident very carefully to determine ways to prevent similar incidents from occurring. GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM STEPS The following is a summary of the general accident prevention program in place at the Chevron Salt Lake refinery. Because processes at the refinery that are regulated by the EPA RMP regulation are also subject to the OSHA 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 Chevron Salt Lake refinery encourages employees to participate in all facets of process safety management and accident prevention. Examples of em ployee 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 refinery 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 refinery and addresses each accident prevention program element. In addition, the refinery has a number of initiatives under way that address process safety and employee safety issues. These initiatives include forming teams to promote both process and personal safety. The teams typically have members from various areas of the plant, including operations, maintenance, engineering, and plant management. Process Safety Information The Chevron Salt Lake refinery keeps a variety of technical documents that are used to help maintain safe operation of the processes. Th ese 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 refinery 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 specific process areas, the refinery has documented safety-related limits for specific process parameters (e.g., temperature, level, compo sition) in a Key Process Parameter Document. The refinery 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 refinery 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, electrical rating of equipment, etc. This information, in combination 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 The Chevron Salt Lake refinery has a comprehensive program to help ensure that hazards associated with the various processes are identified and controlle d. Within this program, each process is systematically examined to identify hazards and ensure that adequate controls are in place to manage these hazards. The Chevron Salt Lake refinery 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 prevention and mitigation measures, and 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 ensu re that potential accident scenarios assigned the highest risk receive immediate attention. All approved mitigation options being implemented in response to PHA team findings are tracked until they are complete. 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 Chevron Salt Lake refinery 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 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 documented and retained. Operating Procedures The Chevron Salt Lake refinery maintains written procedures that address various modes of proce ss 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 maintained current and accurate by revising them as necessary to reflect changes made through the management of change process. Training To complement the written procedures for process operations, the Chevron Salt Lake refinery has implemented a comprehensive training program for all employees involved in operating a process. New employees receive basic training in refinery 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 t asks. 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. All of this training is documented for each operator, including the means used to verify that the operator understood the training. Contractors The Chevron Salt Lake refinery uses contractors to supplement its workforce during periods of increased maintenance or construction activities. Because some contractors work on or near process equipment, the refinery 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) unde rstand and follow site safety rules, and (6) inform refinery 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 Chevron Salt Lake refinery evaluates contractor safety programs and performance during the selection of a contractor. Refinery personnel periodically monitor contractor performance to ensure that contractors are fulfilling their safety obligations. Pre-startup Safety Reviews (PSSRs) The Chevron Salt Lake refinery conducts a PSSR for any new facility or 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 the 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 The Chevron Salt Lake refinery has well-established practices and procedures to maintain pressure vessels, piping systems, relief and vent systems, controls, pumps and compressors, and emergency 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 equipment. 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 job 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 identified, employees will correct the deficiency before placing the equipment back into service (if possible), or an MOC 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. The Chevron Salt L ake refinery 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 Chevron Salt Lake refinery 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 materials 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 Chevron Salt Lake refinery has a comprehensive system to manage changes to 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 limits, 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 The Chevron Salt Lake refinery promptly investigates all incidents that resulted 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 refinery 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 employees (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, the Chevron Salt Lake refinery periodi cally 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 management personnel participate as audit team members. The audit team develops findings that are forwarded to refinery 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 processes at the Chevron Salt Lake refinery have hazards that must be managed to ensure continued safe operation. The accident prevention program summarized previously is applied to all Program 3 EPA RMP-covered process at the Chevron Salt Lake refinery. Collectively, these prevention program activities help prevent potential accident scenarios that could be caused by (1) equipment failures and (2) human errors. In addition to the accident prevention program activities, the Chevron Salt Lake refinery has safety features on many 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 various processes: Release Containment/Control 1. Process relief valves that discharge to a flare to contain and incinerate episodic releases 2. Valves to permit isolation of the process (manual or automated) 3. Automated shutdown systems for specific process parameters (e.g., high level, high temperature) 4. Curbing or diking to contain liquid releases 5. Redundant equipment and instrumentation (e.g., uninterruptible power supply for process control system, backup power, backup pumps) 6. Atmospheric relief devices 7. Automatic Interlocking System 8. RATS ( Rapid Acid Transfer System) 9. Surveilance camers monitored by plant operators Rele ase Mitigation 1. Fire extinguishing system 2. Trained emergency response personnel 3. Personal protective equipment (e.g., protective clothing, self-contained breathing apparatus) 4. Water spray systems to mitigate a hydrogen fluoride release. EMERGENCY RESPONSE PROGRAM INFORMATION The Chevron Salt Lake refinery maintains a written emergency response program, which is in place to protect worker and public safety as well as the environment. The program consists of procedures for responding to a release of a regulated substance, including the possibility of a fire or explosion if a flammable substance is accidentally released. 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, t he Chevron Salt Lake refinery 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 emergency response program is updated when necessary based on modifications made to refinery processes or other refinery facilities. The emergency response program changes are administered through the MOC process, which includes informing and/or training affected personnel in the changes. The overall emergency response program for the Chevron Salt Lake refinery is coordinated with the South Davis Fire District and the Salt Lake City Fire Department and the Local Emergency Planning Committee (LEPC) within Davis and Salt Lake Counties. This coordination includes periodic meetings of the committees, which includes local government officials, and industry representatives . The Chevron Salt Lake refinery has around-the-clock communications capability with Davis County Sherriffs offices and emergency response organizations (e.g., local mutual aid organizations). 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 LEPC meetings, the Chevron Salt Lake refinery conducts periodic emergency drills that involve the LEPC and emergency response organizations, and the refinery provides annual refresher training to local emergency responders regarding the hazards of regulated substances in the \ refinery. PLANNED CHANGES TO IMPROVE SAFETY The Chevron Salt Lake refinery resolves all findings from PHAs, some of which result in modifications to the process. The following types of changes are planned: 1. Upgraded Alarm Systems 2. Fire Water Mitigations Systems 3. Upgraded Honeywell Controls 4. Interlock Systems |