Texaco South East Kern River Cogeneration Facility - Executive Summary
Risk Management Plan |
South East Kern River Cogen
A. Accidental Release Prevention and Response Policies
Texaco has a long-standing commitment to worker and public safety. This commitment is demonstrated by our efforts in accident prevention, such as training personnel and considering safety in the design, installation, operation, and maintenance of our facilities. Our policy is to implement reasonable controls to prevent foreseeable releases of regulated substances. However, if a release does occur, facility trained personnel will evaluate the situation, take actions within the capabilities of the facility, and/or notify the necessary outside agencies.
B. Description of the Stationary Source and Regulated Substances
The South East Kern River Cogen (SEKR Cogen) is located at 3500 Alfred Harrell Highway, north east of the town of Bakersfield, California within the South East Kern River oilfield. The facility was designed and constructed by Shell Oil in 1988,
and operated by Shell and its affiliates until purchased by Texaco in April of 1999.
The SEKR Cogen consists of three gas turbines, which drive electric generators rated to produce 27 megawatts of electric power. Heat recovery steam generators are connected to the turbines. In the steam generators, waste heat from the turbine exhaust is exchanged with water producing about 10,000 barrels of steam per day. The electric power generated by the facility is used to supply internal load requirements for Texaco and neighboring properties. Excess power is sold to the utility grid. The steam generated by the facility is used for enhanced oil recovery projects.
As part of the air permit issued by the San Joaquin Valley Unified Air Pollution Control District, the LM2500 turbine has a two step process to limit NOx emissions. In the first step, demineralized water is injected into the combustion chamber of the turbine, reducing combustion temperatures and NOx formation. In the second step
, a small concentration of ammonia is mixed into the turbine exhaust gas which then flows across a selective catalytic reduction (SCR) catalyst where NOx and ammonia chemically react to form nitrogen and water vapor. The amount of ammonia used is maintained by a computer control system based upon a preset ammonia feed rate.
Anhydrous ammonia is stored in a 12,000 gallon pressurized storage tank with an inventory limit of 10,200 gallons. The storage tank is operated at about 50 psig but is designed to withstand a pressure of 300 psig. The 300 psig design condition is well in excess of that which can be caused by atmospheric heating. The storage tank is protected by two 300 psig relief valves, one of which is always in service. Ammonia vapor is withdrawn from the top of the storage tank and fed to an intermediate accumulator where the pressure is held at about 30 psig. The pressure in the storage tank is prevented from falling below the minimum pressure set point by two liquid a
mmonia evaporators. The ammonia is fed from the accumulator, diluted with air to a concentration of less than two percent by volume, and is then injected into the turbine exhaust.
The storage tank is refilled three or four times a year. At that time, a tank truck of ammonia is connected to the storage tank's liquid loading and vapor return lines. The lines are protected by pull-away valves and excess flow check valves. In addition, the liquid loading line has a check valve to prevent reverse flow from the storage tank to the tank truck.
C. Offsite Consequence Analysis Results
The worst-case scenario (WCS) associated with a release of ammonia at the SEKR Cogen, based on EPA directive, is a catastrophic release of the total volume of the 10,200 gallon storage tank over a ten minutes period. Although we have numerous controls to prevent such releases and to manage their consequences, no credit for administrative controls or passive mitigation measures were allowed to be taken
into account in evaluating this scenario. Although this facility is located in a relatively rural area, the modeled worst case circle overlaps the populated community. Therefore the toxic cloud formed by the evaporating ammonia in the worst case scenario would reach offsite endpoints and nearby public receptors.
The alternative release scenario (ARS) associated with the ammonia operations at the SEKR Cogen is a based on the most likely event with an endpoint beyond the boundaries of the facility. This release was determined to be a hose rupture while transferring ammonia from the tanker truck to the storage vessel [40CFRpart 68.28(b)(2)(I)]. This event would result in the release of just under 70 pounds of ammonia in a few seconds, with very little offsite consequences as the facility is located in a relatively remote area. The probability of this event happening is extremely low because of precautions taken by the ammonia supplier to ensure the integrity of the hose and precaution
s taken by Texaco to ensure proper hookup including:
7 Utilizing a hose rated at 2000 psi as compared to a system pressure of 100 psi.
7 Daily inspection of the hose by the ammonia supplier
7 Double checking the hose connection made in the field by the truck driver and Texaco to ensure a proper connection, and
7 Use of the hose for only five years instead of the allowed seven years.
D. General Accidental Release Prevention Program
The following is a summary of the accident prevention program in place at the SEKR Cogen. Because the ammonia process at the facility is 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 SEKR Cogen encourages employees and affected contractors to participate in all facets of process safety management and accident prev
ention. 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 facility's accident prevention program. Specific ways that employees can be involved in the accident prevention program are documented in the Employee Participation Plan - Element 1 of the facility Process Safety Management Plan. The Employee Participation Plan is reviewed and adopted by the facility employees. The plan addresses each accident prevention program element. In addition, the facility has a number of initiatives under way to address process safety and employee safety issues. These initiatives include forming teams to promote both process and personal safety.
Process Safety Information: The SEKR Cogen keeps a variety of technical documents that are used to help maintain safe operation of the ammonia process. Thes
e documents address chemical properties and associated hazards, the process, and equipment design information. This information is reviewed in the Process Safety information - Element 2, of the facility Process Safety Management Plan. This document also includes a table summarizing the reference documents and manuals available within the control room and readily available to employees including: Facility Design and Equipment Specification Manuals and Drawings; Operating and Maintenance Manuals; Electrical Specifications; Programming Documentation and Software Support Manuals; Operators Manuals; Procedure Manuals; Safety and Environmental Protection Manuals; and Company Standard Operating Procedures.
The Process Safety information - Element 2, of the facility Process Safety Management Plan contains information on Ammonia, including exposure hazards and emergency response / exposure treatment considerations. The material safety data sheet (MSDS) is also provided. The facility has
documented safety-related limits for specific process parameters (e.g., temperature, pressure, rates and levels) in operational procedures, within Operating Procedures - Element 4 of the facility Process Safety Management Plan. The facility maintains the process within these limits by using process controls and monitoring instruments, trained personnel, and protective instrument systems (e.g., automated shutdown systems).
The facility has technical documents that provide information about the design and construction of process equipment. This information includes materials of construction, and design pressure and temperature ratings of the equipment. Operating history provides a basis for inspection and maintenance activities, as well as for evaluating proposed process and facility changes so safety features in the process are not compromised.
Process Hazard Analysis (PHA): The SEKR Cogen has a comprehensive program to identify and control hazards associated with the identified pr
ocess. Process Hazard Analyses - Element 3 of the facility Process Safety Management Plan establishes a program to systematically examine and identify potential hazards, controls in place to manage these hazards, and recommend additional controls, as appropriate.
The SEKR Cogen has used both a fault-tree and the HAZOP system for evaluating the hazards of the process, or performing Process Hazard Assessments (PHAs). The analyses were conducted using a team of people who had operating and maintenance experience as well as engineering and environmental health and safety expertise. The teams identified and evaluated potential hazards of the process as well as accident prevention and mitigation measures. All resulting suggestions for additional prevention and/or mitigation measures were implemented.
The PHA team findings were forwarded to local management for resolution. Implementation of mitigation options in response to PHA findings was based on a relative risk ranking assigned by
the PHA team. The approved mitigation options in response to PHA team findings were tracked until they were completed. The final resolution of each finding was documented and retained.
The facility 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 SEKR Cogen maintains written procedures that address various modes of process operations. These procedures are collected within Operating Procedures - Element 4 of the facility Process Safety Management Plan. Procedures exist for (1) cold startup, (2) performing rounds, (3) emergency shutdown, (4) normal operations, (5) normal shutd
own, (6) startup following an emergency shutdown, (7) startup following turbine startup, and (8) monitoring of ammonia offloading. In addition, a procedure is also in place for performing regular maintenance and surveillance of the 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 certified as current and accurate. The procedures are kept current and accurate by revising them as necessary to reflect changes. In addition, the SEKR Cogen maintains information on how to respond to upper or lower limit exceedances for specific process or 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 SEKR Cogen has implement
ed a comprehensive training program for all employees involved in operating a process. The program is outlined within Training - Element 5 of the facility Process Safety Management Plan. New employees receive basic training in process 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 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, or more frequently upon request. All of this training is documented for each operator, including the means used to verify and that the operator understood the training.
: The SEKR Cogen uses contractors to supplement its workforce during periods of increased maintenance or construction activities. Because some contractors work on or near process equipment, the facility 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 facility 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. These activities are outlined and described within Contractors- Element 6 of the facility Process Safety Management Plan. In addition, the SEKR Cogen evaluates contractor safety programs
and performance during the selection of a contractor. Facility personnel periodically monitor contractor performance with regard to their safety obligations by performing "observations." These observations are documented and any observed problems are discussed with the contractor and resolved.
Pre-startup Safety Reviews (PSSRs): The SEKR Cogen is operated as it was constructed in 1988. No Pre-Startup Safety Reviews PSSRs have been required to date. Element 7 - Pre-startup Safety Review of the facility Process Safety Management Plan includes a Pre-Startup Safety Review Procedure that would be implemented 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 equipment are appropriately prepared for startup prior to placing the equipment into service. This review provides one additional check that construction is in accordance with the design spe
cifications and that all supporting systems are operationally ready. 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 SEKR Cogen has established practices and procedures to maintain pressure vessels, piping systems, relief and vent systems, controls, and emergency shutdown systems in a safe operating condition. The basic aspects of this program are outlined in Mechanical Integrity - Element 8 of the facility Process Safety Management Plan and 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) safe
ty 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 provide that work is performed in a consistent manner and serve as basis for training. Inspections and tests are performed to help verify that all equipment functions as intended and 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 situation presents an immediate safety concern), or a management of change team will review the use of the equipment and determine what actions are necessary.
Another integral part of the mechanical integrity program is quality assurance. The SEKR Cogen incorporates quality assurance measures into equipment purchases and repairs. This helps determine that new equipment is sui
table for its intended use and proper materials and spare parts are used when repairs are made.
Safe Work Practices: The SEKR Cogen has long-standing safe work practices in place to help provide worker and process safety. Examples of these include (1) control of the entry/presence/exit of support personnel; (2) a lockout/tagout procedure to isolate 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 verify 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 perform operations and maintenance activities safely.
Management of Change: The SEKR Cogen has a comprehensive system to manage changes to the process. This system, described in Management of
Change - Element 10 of the facility Process Management Safety Program, 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) determine 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 SEKR Cogen promptly investigates all incidents related to a covered process that resulted in, or reasonably could have resulted in, a fire/explosion, toxic gas release, major property damage, environmental loss, or personal injury. SEKR C
ogen's program for investigating incidents is described in Incident Investigation - Element 11 of the facility Process Management Safety Program. 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 facility 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 determine that the accident preventio
n program is functioning properly, the SEKR Cogen is periodically audited to determine whether the procedures and practices required by the accident prevention program are being implemented. SEKR Cogen's audit program is detailed in Compliance Audits - Element 13 of the facility Process Management Safety Program. Compliance audits are conducted at least every 3 years. Both hourly and staff personnel participate in these audits. The audit team develops findings that are forwarded to facility 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 ammonia process at the SEKR Cogen presents hazards that must be managed for continued safe operation. The following is a description of the existing safety features applicable to prevention of accidental releases of ammon
ia from the facility.
Universal Prevention Activities: The accident prevention program summarized previously is applied to the ammonia process at the SEKR Cogen. Collectively, these prevention program activities help prevent potential accident scenarios that could be caused by equipment failures and human errors.
Preventive Maintenance: Maintenance and testing of the ammonia system components assures safety for the plant personnel and the public. Maintenance and testing of equipment in the ammonia system is in accordance with the SEKR Cogen ammonia system maintenance procedures. The procedures involve scheduled inspections and testing for the storage vessel, the relief and excess flow valves, the sensing switches, and all associated safety equipment.
Design and Construction Features: The system design philosophy for the SEKR Cogen focused on minimizing the risk of an ammonia release by assuring conservative design of the system components. Only new, first quality equipment a
nd materials were used. They were assembled in accordance with local, state and federal regulations, and applicable industry fabrication standards and codes.
The design features that assure the safety of the system include:
7 The installation of relief and backup relief valves, rupture disks, and excess flow valves.
7 Design of the ammonia storage vessel to withstand pressures 10% higher than required by code
7 Welded and flanged construction, with upgraded corrosion allowances, and heavy-duty schedule
7 Design of the system to meet and exceed earthquake, wind and flood standards
7 Emergency alarms and shutdowns
7 Site security including enclosure fencing and controlled access gates to prevent unauthorized personnel entry and vandalism
7 Emergency beacons and windsocks to alert technicians and plant visitors to the development of a hazardous condition.
Operational Procedures: The plant has a series of operational procedures to handle ongoing operations, repairs and maintenance
. A very detailed and comprehensive procedure is in place and followed for the off-loading of Ammonia, as a leak or accident during off-loading activities is considered the most likely type of incident the facility could encounter.
Monitors and Alarms: The ammonia system is monitored and controlled by a digital computer based control system. The control system responds to changes in temperature, pressure, level and flow to maintain these process variables within predetermined limits. The computer initiates alarms when conditions are not at or beyond process limits to alert the operator. The computer also initiates corrective actions or equipment shutdown. The operator may assume manual control of the process at any time. Manual control by the operator does not bypass any safe operating shutdowns.
E. Five-Year Accident History
To Texaco's knowledge, the SEKR Cogen has a spotless record of accident prevention over the past 5 years, as no accidents or releases of ammonia hav
e occurred from the facility. Texaco will investigate any future incidents very carefully to determine ways to prevent similar incidents from recurring.
F. Emergency Response Planning
The SEKR Cogen maintains a written emergency action plan, which is in place to help protect worker and public safety as well as the environment. The plan identifies steps to be taken in case of an accidental release 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. Employees receive training in these procedures as necessary to perform their specific emergency duties.
The emergency action plan is updated when necessary based on modifications made to the process or management. The emergency action plan changes are administered through the MOC process, which includes infor
ming and/or training affected personnel of the changes.
Emergency response for the SEKR Cogen has been coordinated with the Kern County and City of Bakersfield Fire Departments and the Region 5 Inland South Local Emergency Planning Committee (LEPC). The SEKR Cogen has around-the-clock communications capability with appropriate emergency response organizations (e.g., fire department, Police or Sheriff office). This interface provides the means of notifying the public of an incident, if necessary, as well as facilitating quick response to an incident.
The SEKR Cogen, as part of Texaco's Kern River Operations, conducts periodic emergency drills in conjunction with local emergency response organizations. The drills provide refresher training for employees and responders.
G. Planned Changes to Improve Safety
The SEKR Cogen resolves findings from PHAs, some of which result in modifications to the process. At present, no changes are warranted in response to PHA, safety audit,
or incident investigation findings.