CITGO Corpus Christi Refinery East Plant - Executive Summary |
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EXECUTIVE SUMMARY, CITGO Corpus Christi Refinery, East Plant Accidental Release Prevention and Response Policies: The CITGO Corpus Christi Refinery (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 and/or specially trained out-side responders will respond to control and contain the release. Description of the Stationary Source and Regulated Substances: CITGO Refining and Chemicals Company L.P. is a refiner, transporter and marketer of transportation fuels, lubricants, petrochemicals, refined waxes, asphalt and other industrial products. CITGO Corpus Christi Refinery supplies high octane gasoline, di esel fuels and petrochemicals. The refinery consists of two plants, the East Plant at 1801 Nueces Bay Blvd., and the West Plant at 7350 IH37. The East Plant refinery has several regulated flammable substances, such as hydrogen, methane, ethane, propanes, butanes, pentanes and flammable mixtures. The refinery also uses and/or processes toxic substances, such as hydrogen fluoride (HF), hydrogen sulfide (H2S), ammonia, sulfur dioxide, methyl mercaptan and chlorine. HF, H2S and chlorine are present above threshold quantities. Hazard Assessment Results: The information provided are estimates required by the Environmental Protection Agency (EPA) and are used to illustrate the importance for risk reduction, safety, prevention and emergency preparedness and response. It is not a prediction that a worst case release will occur or any indication that such a release will ever occur. The release scenarios are designed to be exercises which calculate the potential impact on the community ba sed upon extreme conditions defined by the EPA. Given the unrealistic guidelines of a worst-case scenario, more realistic scenarios (alternative release scenarios) were developed to more closely simulate a real world event. The alternative release scenarios may be used by local government and industry to prepare emergency response plans. The potentially affected areas, given the extreme nature of the hypothetical events, are areas that could be exposed at a potentially health-threatening level. The levels of concern have been developed by the government for each chemical. The levels that could be harmful vary significantly by chemical. The worst-case scenario is the complete release of the largest inventory of the chemical over 10 minuets under weather conditions that would allow the chemical to travel as far as possible. The worst-case scenario for toxic substances in the refinery Program Level 3 processes is a catastrophic failure of a HF Acid storage drum. The worst-cse sce nario is an assumed 10-minute release of 150000 pounds of HF gas. Although we have numerous controls to prevent such releases and to manage their consequences, no credit for administrative controls or passive mitigation measures were taken into account in evaluating this scenario, as per EPA mandate. This release scenario has off site impact and the maximum distance to the toxic endpoint of 20 ppm (0.016 mg/liter) for this scenario is 15 miles. The laws of physical science would not result in a complete release of the chemical as mandated by the EPA and some literature references suggest that the mandated combination of "F" stability class and 1.5 m/sec wind speed may not exist and certainly can not exist for more than 12 consecutive hours. The alternative release scenario, a smaller more realistic release, for HF is failure of a pump seal, resulting in a release of 3189 pounds of vapor over a 10-minute period. The 10-minute release duration is the approximated time necessary to r espond to and stop the release. The water curtain mitigation measures were taken into account in evaluating this scenario. An efficiency of 90% was assumed thus reducing the release to 319 pounds. This release scenario has impact slightly offsite. The maximum distance to the toxic endpoint of 20 ppm (0.016 mg/liter) for this scenario is 0.35 miles. A typical Corpus Christi weather condition is used for all alternative release scenarios. The alternative release scenario for H2S is failure of the main acid gas line from the Knock Out Drum resulting in a release of 3180 pounds of H2S over a 10 minute period. The 10-minute release duration is the approximate time necessary to respond to the H2S alarms and to stop the release. No other mitigation measures were taken into account in evaluating this scenario. This release scenario has impact slightly offsite and the maximum distance to the toxic endpoint of 30 ppm (0.042 mg/liter) for this scenario is 0.7 miles. The alternative rel ease scenario for chlorine is failure of the discharge line from a chlorine tank resulting in a release of 1093 pounds of chlorine over a 10-minute period. The 10-minute release duration is the approximate time necessary to respond to and stop the release. No other mitigation measures were taken into account in evaluating this scenario. This release scenario has impact slightly offsite. The maximum distance to the toxic endpoint of 3 ppm (0.0087 mg/liter) for this scenario is 0.7 miles. The worst case scenario associated with a release of flammable substances in the refinery Program Level 3 processes is an assumed vapor cloud explosion (VCE) involving the administratively controlled inventory of the largest storage tank containing a LPG product, iso butane (i-butane), and the full inventory of a smaller storage tank containing the LPG product butane. The tank inventories of 3,829,268 and 3,685,926 pounds respectively are assumed to be released, completely vaporized, and ignited, r esulting in a VCE. Ten percent of the released quantities are assumed to participate in the resulting explosion. This scenario has offsite impact and the maximum distances to the 1 psi endpoint for these scenarios are both 1.0 mile. Although we have numerous controls to prevent such releases and to manage their consequences, no credit passive mitigation measures other than the administrative control were taken into account in evaluating these scenarios, as per EPA mandate. Two scenarios are listed because the second scenario affects receptors not affected by the first scenario. The alternative release scenario for flammable materials at the refinery is a VCE resulting from the release of propylene from a transfer line, 1,000 pounds released over a 10-minute period. The release is expected to be isolated by the operators within 10 minutes (active mitigation). This release scenario has impact slightly offsite and the maximum distance to the 1 psi endpoint for this scenario is 0.07 miles. Passive mitigation measures were not taken into account in evaluating this scenario. General Accidental Release Prevention Program Steps: The following is a summary of the accident prevention program in place at the refinery. Because processes at the refinery that are regulated by the EPA Risk Management Program (RMP) regulation are also subject to the OSHA 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 refinery encourages employees 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 information created as part of the refinery accident prevention program. Specific ways that employees c an 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 that address process safety and employee 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 refinery 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 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, composition) 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 provid e 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 refinery 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 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 e valuation 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 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, the 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 refinery maintains written procedures that address various modes of process operations, such as unit startup, normal operations, temporary operations, emergency shutdown, normal shutdown, and 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 curren t and accurate by revising them as necessary to reflect changes made through the management of change process. The refinery also maintains a Key Process Parameter Document that provides guidance on how to respond to upper or lower limit exceedances for specific process and equipment parameters. This information, along with written operating procedures, is readily available to operators in the process unit and for other personnel to use as necessary to safely perform their job tasks. Training To complement the written procedures for process operations, the 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 tasks. After operators demonstrate (e.g., through tests, shills 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 verify that the operator understood the training. Contractors The refinery uses contractors to supplement its workforce. Because some contractors work on or near process equipment, the refinery has procedures in place to ensure that contractors perform their work in a safe manner, have the appropriate knowledge and skills, are aware of the hazards in their workplace, understand what they should do in the event of an emergency, understand and follow site safety rules, and inform plant personnel of any hazards that they find during their work. This i s accomplished by providing contractors with a process overview, information about safety and health hazards, emergency response plan requirements, and safe work practices prior to their beginning work. In addition, the refinery also 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 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 rev iew 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 were properly implemented. Mechanical Integrity The 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 conducting training, developing written procedures, performing inspections and tests, correcting identified deficiencies, and 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 an overview of the process, safety and health hazards, applicable maintenance procedures, emergency response plans, and applicable saf e 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 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 Pra ctices The refinery has long-standing safe work practices in place to help ensure worker and process safety. Examples of these include control of the entry/presence/exit of support personnel, a lockout/tagout procedure to ensure isolation of energy sources for equipment that is being worked on, a procedure for safe removal of hazardous materials before process piping and equipment is opened, a permit and procedure to control spark-producing activities, and 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 (MOC) The refinery 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, an d other facility changes be properly reviewed and authorized before being implemented. Changes are reviewed to ensure that adequate controls are in place to manage any new hazards and 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 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 of a similar incident. The investigation team documents its findings, develops recommendations to prevent a recurrence, and fo rwards 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 completed. The final resolution of each finding or recommendation is documented, and the investigation results are reviewed with all employees and 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 refinery 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 refinery management for resolution. Corrective actions taken in response to the audit team's findings are tracked until they are completed. 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 refinery have hazards that must be managed to ensure continued safe operation. The accident prevention program summarized previously is applied to the refinery Program 3 processes. Collectively, these prevention program activities help prevent potential accident scenarios that could be caused by equipment failures and human errors. In addition to the accident prevention program activities, the refinery has safety features on many units to help contain/control a release, quickly detect a release, and reduce the consequences of (mitigation) a release. The following types of safety features are used in various processes: Release Detection Hydrocarbon, HF and H2S detectors with alarms. Cameras and monitors. Release C ontainment/Control Process relief valves that discharge to a flare to capture and incinerate episodic releases. Scrubbers to control/neutralize hydrocarbon or chemicals. Valves to permit isolation of the process (manual/automatic) Automated shutdown systems for specific parameters. (e.g., high level, pressure, temperature) Vessels to permit partial removal of process inventory. Curbing or diking to contain liquid releases. Redundant equipment and instruments (e.g., uniterruptible power supply, backup pumps) Relief devices. Release Mitigation Fire suppression and extinguishing systems. Deluge system for specific equipment. Trained emergency response personnel. Personal protective equipment. Blast-resistant buildings to protect control systems. Five Year Accident History: The refinery has a good record of accident prevention over the past 5 years. There have been a total of 7 incidents, 5 incidents involving the release of flammable substances, 1 inciden t involving H2S, 3 incidents involving HF. There have been no incidents involving chlorine. One flammable incident and 1 H2S incident resulted in off site effects. We investigate every incident very carefully to determine ways to prevent similar incidents form occurring. Emergency Response Program Information: The 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, the refinery has procedures that address maintenance, inspection and testing of emergency response equipment, as well as instruction that addresses 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 to based upon modifications made to refinery processes or other refinery facilities. The overall emergency response program for the refinery is coordinated with the Corpus Christi (Nueces County), Texas Local Emergency Planning Committee (LEPC) and Refinery Terminal Fire Company (RTFC). This coordination includes periodic meetings of the committee, which includes local emergency response officials, local government officials, and industry representatives. The refinery has around-the-clock communications capability with appropriate LEPC and RTFC officials and emergency response organizations (e.g., fire department). This provi des a means of notifying the public of an incident, if necessary, as well as facilitating quick response to an incident. Planned Changes to Improve Safety: The refinery resolves all findings from Process Hazard Analyses, some of which result in modifications to the process. The following types of changes may be implemented in response to PHA findings: Decrease in process chemical inventory. New or revised process instrumentation and/or controls. New or revised release detection systems. New or revised release containment systems. New or revised release mitigation systems. New or modified process equipment. Revisions to personnel training programs. New or revised written operating or maintenance procedures. New or revised emergency response resources. New types of process chemicals. |