Pasadena Power Plant - Executive Summary
ACCIDENTAL RELEASE PREVENTION AND RESPONSE POLICIES |
Calpine 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. It is the policy of Calpine to implement reasonable controls to prevent foreseeable releases of regulated substances.
DESCRIPTION OF THE STATIONARY SOURCE AND REGULATED SUBSTANCES
The Pasadena power plant, located in Harris County, Texas, is a gas-fired combustion turbine cogeneration plant that produces stream and electricity. The steam is consumed by local a industrial user. Electricity is also sold to local industry with the remaining output being placed on the grid for general consumption. As a means of reducing nitrogen oxide emissions from the single gas-fired combustion turbine, anhydrous ammonia is injected into the turbine exhaust stream. The anhydrou
s ammonia is stored on-site in a single storage tank. The total storage capacity of this toxic material exceeds the threshold level for RMP applicability. There are no other toxic or flammable materials on-site which exceed RMP levels.
OFFSITE CONSEQUENCE ANALYSIS RESULTS
The worst case scenario (WCS) associated with a release of a toxic substance at the plant is a release involving the anhydrous ammonia storage tank. Based on guidance from the EPA, the WCS involves the complete inventory in the storage tank released over a 10-minute period. The 14,200-gallon anhydrous ammonia tank is limited to 85% storage capacity by administrative controls. Assuming a specific gravity of 0.6386 for liquid anhydrous ammonia, the maximum storage tank capacity is 64,284 lbs. The WCS is modeled based on a release rate of 6,428 lbs/min. The EPA's RMP*Comp model indicates that the endpoint for this type of release is 2.8 miles. There are public receptors within this distance. Therefore, a Program
3 RMP is required for the anhydrous ammonia process.
Alternative scenarios were addressed as required by rule. Based on EPA guidance, alternative release scenarios of anhydrous ammonia most likely involve flashing liquid releases. The anhydrous ammonia system is designed such that all piping downstream of the storage tank is laid beneath concrete. The storage tank sets in a reinforced concrete containment area which would contain any spills and also provides protection from any blast effects. The truck loading point is surrounded by traffic posts and is equipped with pull-away valves and a breakaway hose. There is a water deluge system over the storage tank which is triggered by an atmospheric concentration of 200 ppmv. Anhydrous ammonia is water soluble. If the deluge system is activated, the released anhydrous ammonia is flushed from the atmopshere. The water/ammonia mixture enters the plant drainage system. All piping and vessels have a pressure rating that is greater than
normal operating pressures. The system is equipped with redundant control systems including shutoff valves, pressure relief valves, pressure indicators, etc. Alternative release scenarios were identified as: (1) tank leak due to external impact and, (2) tank truck pull-away. The alternative scenarios involving a tank leak impacts public receptors.
GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM
The following is a summary of the accident prevention program in place at the plant. Because processes at the 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.
Calpine actively encourages employees to participate in all facets of process safety m
anagement and accident prevention. Each employee is urged to participate in the continual upgrading and maintaining of all health and safety programs. Employee involvement is achieved through direct participation on a voluntary basis, active consultation with affected employees, and participation in the process hazard analysis (PHA) team. Employees have access to the PHA and all other information required to be developed under the process safety management standard.
Process Safety Information
Calpine maintains a variety of technical documents that are used to help maintain safe operations of the plant with regards to the anhydrous ammonia system. These documents address chemical properties and associated hazards, limits for key process parameters and specific chemical inventories, and equipment design basis/configuration information. Specific personnel within Calpine are assigned responsibility for maintaining up-to-date process safety information.
Chemical-specific information, i
ncluding 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 plant has documented safety-related limits for specific process parameters (e.g., temperature, level, composition). The 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 plant also maintains numerous technical documents that provide information about the design and construction of process equipment. This information includes materials of construction, design pressure and temperature ratings, and electrical rating of equipment. This information, in 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 (PHA)
The Calpine Pasadena Power 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 Calpine Pasadena Power Plant 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 the team makes suggestions for additional prevention and/or mitigation measures when the team believes such measures are necessary.
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 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.
The Calpine Pasadena Power 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, (6) startup after an emergency shutdown, (7) operating limits, and (8) safety and health considerations. These procedures
can be used as a reference by experienced operators and provide a basis for consistent training of new operators. The procedures are kept current and accurate by revising them as necessary.
To complement the written procedures for process operations, Calpine has a comprehensive training program for all employees involved in operating the anhydrous ammonia process. New employees receive basic training in plant operations if they are not already familiar with such operations. After successfully completing this training, a new operator is paired with a senior operator to learn process-specific duties and tasks. After operators demonstrate (e.g., through tests, skills demonstration) having adequate knowledge to perform the duties and tasks in a safe manner on their own, they can work independently. In addition, all operators receive refresher training at least once every three years on the operating procedures to ensure that their skills and knowledge are maintained at an acc
eptable level. All training is documented for each operator, including the means used to verify that the operator understood the training.
Calpine uses contractors to supplement its workforce during periods of increased maintenance or construction activities. Because some contractors work on or near process equipment, the plant has procedures in place to ensure that contractors (1) perform their work in a safe manner, (2) have the appropriate knowledge and skills, (3) are aware of the hazards in their workplace, (4) understand what they should do in the event of an emergency, (5) understand and follow site safety rules, and (6) inform plant personnel of any hazards that they find during their work. This is accomplished by providing contractors with (1) a process overview, (2) information about safety and health hazards, (3) emergency response plan requirements, and (4) safe work practices prior to their beginning work. In addition, Calpine evaluates contractor safety pr
ograms and performance during the selection of a contractor. Plant personnel periodically monitor contractor performance to ensure that contractors are fulfilling their safety obligations.
Pre-startup Safety Reviews (PSSRs)
Calpine 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 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.
pine 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) performing and documenting inspections and results, (2) conducting maintenance training, (3) developing written procedures, (4) correcting identified deficiencies, and (5) applying quality assurance measures. In combination, these activities form a system that maintains the mechanical integrity of the process.
Maintenance personnel receive training on (1) an overview of the process, (2) safety and health hazards, (3) applicable maintenance procedures, (4) emergency response plans, and (5) applicable safe work practices to help ensure that they can perform their jobs in a safe manner. Written procedures help ensure that work is performed in a consistent manner and provide a basis for training. Inspections and tests are perf
ormed to help ensure that equipment functions as intended and to verify that equipment is within acceptable limits. If a deficiency is identified, employees will correct the deficiency before placing the equipment back into service (if possible), or 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. Calpine 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.
Hot Work Permit
The Calpine Pasadena Power Plant has a hot work program in place to help ensure worker and process safety. The hot work permit and procedures are designed to control spark-producing activities and to ensure that adequate precautions are in place before work begins in the hazardous ar
ea. 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
Calpine has a comprehensive system to manage changes to the anhydrous ammonia system. 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.
Calpine promptly investiga
tes all incidents that results in, or reasonably could have resulted in, a fire/explosion, toxic gas release, major property damage, environmental loss, or personal injury. The goal of each investigation is to determine the facts and develop corrective actions to prevent a recurrence of the incident or a similar incident. The investigation team documents its findings, develops recommendations to prevent a recurrence, and forwards these results to plant management for resolution. Corrective actions taken in response to the investigation team's findings and recommendations are tracked until they are complete. The final resolution of each finding or recommendation is documented, and the investigation results are reviewed with all employees (including contractors) who could be affected by the findings. Incident investigation reports are retained for a minimum of 5-years so that the reports can be reviewed during future PHAs and PHA re-validations.
Emergency Planning and Response
ne has a written emergency action plan that describes the safety and emergency procedures and tools recommended to be used to handle and control accidental spills and/or fires in the anhydrous ammonia storage and processing area. All personnel are trained in standard first aid and CPR training. In the event of an emergency plant personnel can contact the Pasadena Fire Department. Calpine personnel can also contact the Phillips Chemical Complex via two-way emergency radio.
The anhydrous ammonia storage tank is equipped with a detector alarm that triggers at an atmospheric concentration of 200 ppmv. In the event of an alarm, plant personnel assess the situation. If it is determined that a major ammonia spill has occurred, plant personnel will contact the local fire department, the LEPC, the Pasadena police and county sheriff, and the Phillips Chemical Complex. Personnel will evacuate the plant and meet emergency response teams at the designated meeting point and accompany them to
the proximity of the emergency. Plant personnel are not trained nor equipped to respond to a worst-case release event in the anhydrous ammonia system.
To help ensure that the accident prevention program is functioning properly, Calpine periodically conducts an audit to determine whether the procedures and practices required by the accident prevention program are being implemented. Calpine management will certify that the PSM has been evaluated at least every three years. The audit team develops findings that are forwarded to plant personnel 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 anhydrous ammonia process at the Pasadena power plant has hazards that must be managed to ensure continued safe operation. The following is a description of existing s
afety features applicable to prevention of accidental releases of regulated substances in the facility.
Universal Prevention Activities
The accident prevention program summarized previously is applied to the RMP- covered process at the power plant. Collectively, these prevention program activities help prevent potential accident scenarios that could be caused by equipment failures and human errors.
Specialized Safety Features
The Pasadena power plant 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 the covered processes:
7 Ammonia detectors (200 ppmv trigger) with audible alarms
7 Valves to permit isolation of the process (manual or automated)
7 Automated shutdown systems for specific process parameters (e.g., temperature/pressure/flow rates)
7 Redundant equipment and instrume
7 Atmospheric relief devices
7 Anhydrous ammonia storage tank water deluge system
7 Reinforced concrete containment basin
FIVE-YEAR ACCIDENT HISTORY
The Pasadena Power Plant came on line in 1998 and has an excellent record of accident prevention. To date there have been no accidents that have occurred at the plant which resulted in offsite effects as defined in 40 CFR 68. The following table is a summary of the number of accidents that have occurred during the past 5 years which resulted in;
7 on-site deaths, injuries, or significant property damage
7 offsite deaths, injuries, property damage, evacuations, sheltering in place, or environmental damage
1995 1996 1997 1998 1999
Number of RMP Events with Onsite Effects N/A N/A N/A 0 0
Number of RMP Events with Offsite Efffects N/A N/A N/A 0 0
EMERGENCY RESPONSE PROGRAM INFORMATION
The Calpine Pasadena Power Plant maintains a written emergency response program, which is in place to protect worker and public safety. The program
consists of procedures for responding to a release of a regulated substance, including the possibility for a release of anhydrous ammonia. 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.
Plant employees are trained to handle small emergencies only. Employees are not trained to respond to RMP releases. In the event of an RMP release, employees will activate shutdown procedures, evacuate the plant, and notify local emergency response teams. The emergency response program is updated when necessary based on modifications made to the plant processes.
The overall emergency response program for the Pasadena Power Plant is coordinated with the Pasadena Local Emergency Planning Committee (LEPC). This coordination includes attendance at periodic LEPC meetings. Cal
pine has around-the-clock communications capability with appropriate LEPC officials and emergency response organizations (e.g., fire department). This provides a means of notifying the public of an incident, if necessary, as well as facilitating quick response to an incident.