TXU Processing Springtown Plant - Executive Summary
ACCIDENTAL RELEASE PREVENTION AND RESPONSE |
The Springtown gas plant has a long-standing commitment to employee and public safety. This
commitment is demonstrated by the resources invested in accident prevention, such as training of
personnel and considering safety in the design, installation, operation, and maintenance of our
processes. Our standing practice is to implement reasonable controls to prevent foreseeable
releases of regulated flammable substances. However, if a release does occur, trained gas plant
personnel will take appropriate action to control/mitigate the release.
A DESCRIPTION OF THE STATIONARY SOURCE AND REGULATED SUBSTANCES
The Springtown gas plant, located in Springtown, Texas, operates a variety of processes to
recover petroleum products (e.g., natural gas, propane, butane, condensate) from field gas. The
gas plant also recovers the regulated flammables, pentane and ethane. There are no threshold
quantities of toxic substances present.
SEQUENCE ANALYSIS RESULTS
The worst-case scenario (WCS) associated with a release of flammable substances in Program 3
processes at the gas plant is a vapor cloud explosion (VCE) involving the full inventory of the
storage tank containing 84,000 lb of natural gas liquids (NGL). The maximum tank capacity is
assumed to release and ignite. The maximum distance to the 1-psi endpoint for this WCS is 0.4
mile. Although we have a number of controls to prevent such releases, no credit for mitigation
measures were taken into account in evaluating this WCS.
The alternative release scenario (ARS) for flammable substances at the gas plant is a vapor cloud
fire (VCF) involving the storage tank containing 125,100 lb of propane. The maximum distance
to the 1-psi endpoint for this ARS is 0.1 mile. No credit for mitigation measures were taken into
account in evaluating this ARS.
GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM
The following is a summary of the accident prevention program in place
at the plant. Because
processes at the gas plant that are regulated by the Environmental Protection Agency's (EPA's)
risk management program (RMP) regulation are also subject to the Occupational Safety and
Health Administration's (OSHA's) process safety management (PSM) standard, this summary
addresses each of the OSHA PSM elements and describes the management system in place to
implement the accident prevention program.
The Springtown gas plant encourages employees to participate in all facets of process safety
management and accident prevention. Examples of employee participation range from updating
and compiling technical documents and chemical information to participating as a member of a
process hazard analysis (PHA) team. Employees have access to all information created as part of
the gas plant accident prevention program. Specific ways that employees can be involved in the
accident prevention program are documented in an employee participation pla
n that is
maintained at the gas plant and addresses each accident prevention program element. In
addition, the gas plant has a number of initiatives in place that address process safety and
employee safety issues.
Process Safety Information
The Springtown gas plant keeps a variety of technical documents that are used to help maintain
safe operation of the processes. These documents address chemical properties and associated
hazards, limits for key process parameters and specific chemical inventories, and equipment
design basis/configuration information. Specific departments within the gas plant are assigned
responsibility for maintaining up-to-date process safety information. The reference documents
and their location is readily available as part of the written employee participation plan to help
employees locate any necessary process safety information.
Chemical-specific information, including exposure hazards and emergency response/exposure
treatment considerations, is provide
d in material safety data sheets (MSDSs). This information is
supplemented by documents that specifically address known corrosion concerns and any known
hazards associated with the inadvertent mixing of chemicals. For specific process areas, the gas
plant has documented safety-related limits for specific process parameters (e.g., temperature,
level, composition). The gas plant ensures that the process is maintained within these limits
using process controls and monitoring instruments, highly trained personnel, and protective
instrument systems (e.g., automated shutdown systems).
The gas plant also maintains numerous technical documents that provide information about the
design and construction of process equipment. This information includes materials of
construction, design pressure and temperature ratings, and electrical rating of equipment. This
information provides a basis for establishing inspection and maintenance activities, as well as
evaluating proposed changes to ensure
that safety features in the process are not compromised.
Process Hazard Analysis (PHA)
The Springtown gas plant has a comprehensive program to help ensure that hazards associated
with the various processes are identified and controlled. Within this program, each process is
systematically examined to identify hazards and ensure that adequate controls are in place to
manage these hazards.
The gas plant primarily uses the What If analysis technique to perform these evaluations. The
analyses are conducted using a team of people who have operating and maintenance experience
as well as engineering expertise. The team identifies and evaluates hazards of the process as well
as accident prevention and mitigation measures, and the team makes suggestions for additional
prevention and/or mitigation measures when the team believes such measures are necessary.
The PHA team findings are sent to local and corporate management for resolution.
Implementation of mitigation options in response to
PHA findings is guided by a relative risk
ranking assigned by the PHA team. All approved mitigation options in response to PHA team
findings are tracked until they are completed. The final resolution of each finding is documented
To help ensure that the process controls and/or process hazards do not eventually deviate
significantly from the original design safety features, the plant periodically updates and
revalidates the hazard analysis results. These periodic reviews are conducted at least every five
years and will be conducted at this frequency until the process is no longer operating. The results
and findings from these updates are documented and retained. Once again, the team findings are
forwarded to management for consideration, and the final resolution of the findings is
documented and retained.
The Springtown gas plant maintains written procedures that address various modes of process
operations, such as (1) unit startup, (2) normal
operations, (3) temporary operations, (4)
emergency shutdown, (5) normal shutdown, and (6) initial startup of a new process. These
procedures can be used as a reference by experienced operators and provide a basis for consistent
training of new operators. These procedures are periodically reviewed and annually certified as
current and accurate. The procedures are kept current and accurate by revising them as necessary
to reflect changes made through the management of change process. These procedures are
readily available in the process unit for operators and other personnel to use as necessary to
safely perform their job task.
To complement the written procedures for process operations, the Springtown gas plant has
implemented a comprehensive training program for all employees involved in operating a
process. New employees receive basic training in gas plant operations if they are not already
familiar with such operations. After successfully completing this training, a
new operator is
paired with a senior operator to learn process-specific duties and tasks. After operators
demonstrate (e.g., through tests, skills demonstration) having adequate knowledge to perform the
duties and tasks in a safe manner on their own, they can work independently. In addition, all
operators periodically receive refresher training on the operating procedures to ensure that their
skills and knowledge are maintained at an acceptable level. This refresher training is conducted
at least every three years. This training is documented for each operator, including the means
used to verify that the operator understood the training.
The Springtown gas plant uses contractors to supplement its work force during periods of
increased maintenance or construction activities. Because some contractors work on or near
process equipment, the gas plant has procedures in place to ensure that contractors (1) perform
their work in a safe manner, (2) have the appropriate know
ledge and skills, (3) are aware of the
hazards in their workplace, (4) understand what they should do in the event of an emergency, (5)
understand and follow plant safety rules, and (6) inform gas plant personnel of any hazards that
they find during their work. This is accomplished by providing contractors with (1) a process
overview, (2) information about safety and health hazards, (3) emergency response plan
requirements, and (4) safe work practices prior to their beginning work. In addition, the
Springtown gas plant evaluates contractor safety programs and performance during the selection
of a contractor. Gas plant personnel periodically monitor contractor performance to ensure that
contractors are fulfilling their safety obligations.
Pre-startup Safety Reviews (PSSRs)
The Springtown gas plant conducts a PSSR for any new facility or process modification that
requires a change in the process safety information. The purpose of the PSSR is to ensure that
safety features, procedur
es, personnel, and equipment are appropriately prepared for startup prior
to placing the equipment into service. This review provides an additional check to make sure
construction is in accordance with the design specifications and that all supporting systems are
operationally ready. The PSSR team uses checklist(s) to verify startup readiness. A PSSR
involves field verification of the construction and serves a quality assurance function by
requiring verification that accident prevention program requirements are properly implemented.
The Springtown gas plant has well-established practices and procedures to maintain pressure
vessels, piping systems, relief valves, controls, pumps and compressors, and emergency
shutdown systems in a safe operating condition. The basic aspects of this program include: (1)
conducting training, (2) scheduled preventive maintenance, (3) performing inspections and tests,
(4) correcting identified deficiencies, and (5) applying quali
ty assurance measures. In
combination, these activities form a system that maintains the mechanical integrity of the
Maintenance personnel receive training on (1) an overview of the process, (2) safety and health
hazards, (3) applicable maintenance procedures, (4) emergency action plan, and (5) applicable
safe work practices to help ensure that they perform their jobs in a safe manner. Scheduled
preventive maintenance helps ensure that work is performed in a timely and consistent manner.
Inspections and tests are performed to help ensure that equipment functions as intended and to
verify that equipment is within acceptable limits (e.g., adequate wall thickness for pressure
vessels). If a deficiency is identified, employees will correct the deficiency before placing the
equipment back into service (if possible), or plant management will review the use of the
equipment and determine what actions are necessary to ensure the safe operation of the
part of the mechanical integrity program is quality assurance. The Springtown
gas plant incorporates quality assurance measures into equipment purchases and repairs. This
helps ensure that new equipment is suitable for its intended use and that proper materials and
spare parts are used when repairs are made.
Safe Work Practices
The Springtown gas plant has long-standing safe work practices in place to help ensure worker
and process safety. Examples of these include (1) control of the entry/presence/exit of support
personnel, (2) a lockout/tagout procedure to ensure isolation of energy sources for equipment
undergoing maintenance, (3) a procedure for safe removal of hazardous substances before
process piping or equipment is opened, (4) a permit and procedure to control spark-producing
activities (i.e., hot work), and (5) a permit and procedure to ensure that adequate precautions are
in place before entry into a confined space. These procedures (and others), along with training of
affected personnel, form a system to help ensure that operations and maintenance activities are
Management of Change
The Springtown gas plant has a comprehensive system to manage changes to all covered
processes. This system requires that changes to items such as process equipment, chemicals,
technology (including process operating conditions), procedures, and other facility changes be
properly reviewed and authorized before being implemented. Changes are reviewed to (1) ensure
that adequate controls are in place to manage any new hazards and (2) verify that existing
controls have not been compromised by the change. Chemical hazard information, process
operating limits, and equipment information, as well as procedures, are updated to incorporate
these changes. In addition, operating and maintenance personnel are provided any necessary
training on the change.
The Springtown gas plant promptly investigates all incidents that resulted in, o
r reasonably could
have resulted in, a fire/explosion, major property damage, environmental loss, or personal injury.
The goal of each investigation is to determine the facts and develop corrective actions to prevent
a recurrence of the incident or a similar incident. The investigation team documents its findings,
develops recommendations to prevent a recurrence, and forwards these results to plant
management for resolution. Corrective actions taken in response to the investigation team's
findings and recommendations are tracked until completed. The final resolution of each finding
or recommendation is documented, and the investigation results are reviewed with all employees
(including contractors) who could be affected by the findings. Incident investigation reports are
retained for at least five years so that the reports can be reviewed during future PHAs and PHA
To help ensure that the accident prevention program is functioning properly, the S
plant periodically conducts an audit to determine whether the procedures and practices required
by the accident prevention program are being implemented. Compliance audits are conducted at
least every three years. Both hourly and staff personnel may participate as audit team members.
The audit team findings are forwarded to plant management for resolution. Corrective actions
taken in response to the audit team's findings are tracked until completion. The final resolution
of each finding is documented, and the two most recent audit reports are retained.
CHEMICAL-SPECIFIC PREVENTION STEPS
The processes at the Springtown gas plant have hazards that must be managed to ensure
continued safe operation. The following is a description of existing safety features applicable to
prevention of accidental releases of regulated substances in the facility.
Universal Prevention Activities
The accident prevention program summarized above is applied to all RMP covered processes a
the Springtown gas plant. Collectively, these prevention program activities help prevent
potential accidents that could be caused by equipment failures and human errors.
Specialized Safety Features
The Springtown gas plant has safety features to help (1) contain/control a release, (2) quickly
detect a release, and (3) reduce the consequences of (mitigate) a release. The following types of
safety features are used in the covered processes:
7 Hydrocarbon detectors with alarms
7 Process relief valves that discharge to a vent stack
7 Valves to permit isolation of the process (manual or automated)
7 Automated shutdown systems for specific process parameters (e.g., high temperature)
7 Curbing or diking to contain liquid releases
7 Redundant equipment and instrumentation (e.g., uninterruptible power supply for process
control system, backup pumps)
7 Atmospheric relief devices
7 Fire extinguishers
7 Trained personnel
7 Personal protective equipment
FIVE-YEAR ACCIDENT HISTORY
The Springtown gas plant has an excellent record of accident prevention over the past five years.
There have been no releases of regulated substances that resulted in deaths, injuries, property or
environmental damage, evacuations, or sheltering in place. Also, there has been a decreasing
trend in the frequency of incidental releases.
EMERGENCY ACTION PLAN INFORMATION
The Springtown gas plant maintains a written emergency action plan, which is in place to protect
the safety of workers and the public, as well as the environment. There are no 112(r) threshold
toxic substances on the plant site. For a non-incidental release of a flammable substance,
including the possibility of a fire, response actions have been coordinated with the local fire
department, and mechanisms for notification are in place. Employees receive training as
necessary to perform their specific emergency actions. The emergency action plan is updated
when necessary, and affected personnel are informed and/or trained in the changes.
The gas plant has around-the-clock communications capability with appropriate officials and
emergency response organizations (e.g., fire department). This provides a means of notifying the
public of an incident if necessary, as well as facilitating quick response to an incident.
PLANNED CHANGES TO IMPROVE SAFETY
The Springtown gas plant resolves all findings from PHAs, some of which result in
modifications to the process. No changes are currently planned.