OLS Energy-Chino Cogeneration Facility - Executive Summary
Ammonia is widely used for reducing the emissions of nitric oxide from the steam generator heater exhaust. The OLS Energy-Chino Cogeneration Facility (Cogeneration Facility) also uses ammonia for reducing the emissions of nitric oxide from the steam generator exhaust. The Cogeneration Facility's ammonia handling process is subject to the U.S. Environmental Protection Agency (EPA) Risk Management Program and Plan and also to the California Accidental Release Prevention (CalARP) Program. These Programs require the following information in the executive summary of the Risk Management Plan: |
7 Accidental release prevention and emergency response policies.
7 General facility and regulated substances information.
7 Offsite consequence analysis results.
7 Summary of the accidental release prevention program and chemical-specific prevention steps.
7 Five-year accident history summary.
7 Emergency response program summary.
7 Planned changes to improve safety.
The above information for the OL
S Energy-Chino Cogeneration Facility is provided below.
Accidental Release Prevention and Emergency Response Policies
The OLS Energy-Chino Cogeneration Facility accidental release prevention policy involves a unified approach that integrates proven technology, trains staff in operation and maintenance practices, and uses tested and proven management system practices. All applicable procedures of the State of California and EPA's Prevention Program are adhered, including key elements such as training, systems management, and emergency response procedures. The Cogeneration Facility is a non-responding facility, which means that the facility employees will not respond to accidental release. Instead, the facility has coordinated with local response agencies (Chino Fire Valley Fire Department) to respond to any ammonia release that may occur at the facility. Since the Cogeneration facility is a non-responder, the facility has prepared an Emergency Action Plan to handle any potential ac
cidental releases. The Plan is designed to safeguard both on- and off-site people and is in compliance with the EPA and CalARP Emergency Response Program requirements. The Cogeneration Facility has an excellent record in preventing accidents from occurring.
General Facility and Regulated Substance Information
The Cogeneration Facility, operating since 1988, is located at 5601 Eucalyptus Avenue in the City of Chino, in San Bernardino County. Ammonia is used for the reduction of nitric oxide from the steam generator exhaust. Ammonia is stored in a bulk storage tank, which is designed to hold 10,936 gallons of ammonia. However, operating procedures (administrative control) specify that maximum quantity of ammonia in the tank should be 85% of the tank design capacity. This ammonia storage exceeds the listed threshold quantities in the EPA and CalARP RMP rules. It also exceeds the listed threshold quantities in the federal and California Occupational Safety and Health Administratio
n (OSHA) Process Safety Management (PSM) Standards.
Ammonia is brought to the Cogeneration Facility and transferred to the bulk ammonia storage tank. The tank is equipped with an electrically heated vaporizer to maintain adequate vaporization and constant pressure in the storage tank during ammonia withdrawal. Vaporized ammonia is withdrawn from the tank and diluted with ambient air prior to injection into the plant's Heat Recovery Steam Generator (HRSG) Selective Catalytic Reduction (SCR) zone. The ammonia system contains the following instrumentation and controls to ensure safe operation of the system:
Storage Tank Fill and Outlet Lines: Excess flow check valves (EFCV) are installed in the storage tank nozzles for the vapor return line, inlet and outlet lines of the vaporizer, drain line, and vapor supply line. The EFCV closes the line in the event of a break to minimize the escape of ammonia to the atmosphere.
Leak Detectors: Two ammonia detectors are installed near the stora
ge tank. These alarms will activate at ammonia concentration of 200 ppm. A signal is sent to a local audible alarm and remotely to the DCS located in the Control Room.
Storage Tank: The tank is equipped with high pressure and high high-pressure alarms. A water deluge system is available to cool the tank and reduce the pressure. In addition, the tank is provided with a dual pressure relief valve to protect the tank integrity during overpresurization.
Ammonia Vaporizer: High pressure or high temperature will shut down the vaporizer heater. The vaporizer is also provided with a pressure relief valve.
Ammonia Dilution System: To prevent ammonia concentrations in the dilution air stream from reaching explosive limits, power or blower failure will cause a flow control valve to close; thus stopping the ammonia flow from the storage tank.
The Cogeneration Facility is also provided with an emergency generator, which will be operational in 5 to 10 minutes on loss of main source of power
Offsite Consequence Analysis Results
The offsite consequence analysis includes consideration of two ammonia release scenarios, identified as "worst-case release scenario" and "alternative release scenario". The first scenario is defined by EPA, which states that "the owner or operator shall assume that the ... maximum quantity in the largest vessel ... is released as a gas over 10-minutes," due to an unspecified failure. The alternative scenario is defined as "more likely to occur than the worst-case release scenario".
The worst-case release scenario for the Cogeneration Facility involves a failure of the ammonia bulk storage tank containing 9,295 gallons (52,055 pounds) of ammonia to the atmosphere over a 10-minute duration. Only passive or administrative controls are allowed under the worst-case scenario to reduce the off-site impacts. The storage capacity of the ammonia tank is 10,936 gallons, but administrative controls are used to fill the tank to only 9,295 gallons. The
administrative controls include written operating procedures. A secondary containment (dike) is also provided for the bulk ammonia tank. This passive mitigation control was not taken into account for performing the off-site consequence analysis because anhydrous ammonia is not expected to pool and then evaporate slowly from the pool. The ammonia release rate to the atmosphere was estimated at 5,205.5 lbs./min).
The bulk ammonia tank rupture, resulting in ammonia release could be caused by catastrophic events, such as an earthquake. The released liquid ammonia is assumed to form a denser-than-air cloud consisting of ammonia vapor and liquid droplets (aerosols) and then disperse in the atmosphere. The distance to the toxic endpoint was estimated using the EPA and National Oceanic and Atmospheric Administration's ALOHA dense gas dispersion model. The toxic endpoint selected by EPA and CalARP rules for ammonia is 200 ppm, which is the Emergency Response Planning Guideline Level 2 (E
RPG-2). The toxic endpoint was conservatively set by EPA to ensure public notification and that local emergency response planning takes into account the greatest possible impacted area surrounding the release point. In practice, this type of a total failure of a bulk storage tank would be unlikely. EPA-mandated meteorological conditions, namely atmospheric Stability Class F, wind speed of 1.5 meter per second, highest daily maximum temperature (110 deg F), and average relative humidity (65%) were used for the worst-case release scenario analysis. The results of the dispersion modeling analysis indicated that the worst-case release scenario has offsite impacts.
The alternative release scenario is more of a possible release scenario that may occur compared to the worst-case release scenario. Based on the process hazard analysis performed for the ammonia system, an alternative release scenario was selected. Unlike the worst-case scenario, active controls can be applied to minimize
the release rate, total quantity, and impacts. Active controls consist of mechanical, electrical, or human input. The alternative release scenario selected for the analysis involves the release of ammonia gas from a crack in the one-inch flex-hose connecting the ammonia storage tank to the process. The ammonia monitors installed at the facility and response by the emergency response team were considered as active controls, which would reduce the ammonia release duration from the cracked flex hose. No passive mitigation systems were considered for the alternative release scenario analysis. The ammonia vapor release rate was estimated at 2.6 lbs./min. Since the ammonia vapor released from the cracked flex hose would be neutrally buoyant, ALOHA's neutrally buoyant model was used for the dispersion analysis. The meteorological conditions used for the dispersion modeling were Stability Class D, wind speed of 3.0 meter per second, annual average temperature of 62 deg F, and average re
lative humidity of 65%. The results of the dispersion modeling analysis indicated that the alternative release scenario has offsite impacts.
Finally, no ammonia releases that could have caused safety or health hazard (no deaths, injuries, property or environmental damage, evacuations, or sheltering in place) occurred at the OLS Energy-Chino Cogeneration Facility during the last five years. Some minor, incidental releases may have occurred over this period, but they were quickly handled by staff, or posed no safety or health hazards.
Summary of the Accidental Release Prevention Program and Chemical-Specific Prevention Steps
The Cogeneration Facility is in compliance with Federal and State Process Safety Management requirements. The Cogeneration Facility accidental release prevention program is based on the following key elements:
7 Detailed management system and clear levels of responsibilities and team member roles.
7 Comprehensive process safety information that is readily avail
able to staff, emergency responders, and contractors.
7 Comprehensive preventive maintenance program.
7 Performance of process hazard analysis of equipment and procedures with operation and maintenance staff participation and review.
7 Use of state-of-the-art process and safety equipment.
7 Use of accurate and effective operating procedures, written with the participation of the operators.
7 High level of training of the operators and maintenance staff.
7 Implementation of an incident investigation, inspection, and auditing program using qualified staff.
Chemical-specific prevention steps include availability of self-contained breathing apparatus (SCBA), awareness of the hazardous and toxic properties of ammonia, and presence of ammonia detectors and alarms.
Process and Chemical Safety Information
Comprehensive chemical data have been assembled to include regulatory reporting and action thresholds, health hazard, and chemical exposure limitations, as well as detailed physical proper
ties of ammonia. This information includes ammonia background information and MSDS sheets.
Details such as maximum intended inventory; safe upper and lower temperatures; safe upper and lower pressures; and codes and standards used to design, build, and operate the processes are on file at the facility.
Process Hazard Analysis
In 1994, a detailed process hazard analysis (PHA) was conducted using the "Hazard and Operability (HAZOP)" technique. This PHA was updated in April 1999 and will be updated again within a five-year period or whenever there is major change in the process. A list of recommended actions were developed based on the 1999 PHA review and Cogeneration Facility staff is currently working to resolve the recommended actions. Staff will document completion of the recommended action items.
A seismic walkthrough was recently completed based on the 1997 UBC. No recommendations have been made for the Cogeneration Facility.
The Cogeneration Facility
maintains up-to-date, accurate, written operating procedures that provide clear instructions for ammonia process. The Cogeneration Facility ensures effective operating practices by combining them with operating and maintenance training programs. The operating procedures include: (1) ammonia bulk tank loading procedures (performed by the vendor), (2) ammonia system start up procedure, (3) ammonia dilution system operating procedure, (4) ammonia shutdown procedure, and (5) ammonia system emergency shutdown procedure. The Cogeneration Facility updates the procedures periodically to ensure that they reflect safe operating practices and include changes in the handling of ammonia technology, equipment and reconfiguration of the facilities.
The Cogeneration Facility employees presently involved in operating or maintaining the ammonia process are trained in an overview of the process and detailed, applicable operating and maintenance procedures. The Cogeneration Facility ensures
that each employee newly assigned to the process, is trained and tested to be competent in the operating procedures listed pertaining to their duties. The Cogeneration Facility training includes employee documentation files. Each employee has been trained to receive the required knowledge, skills, and abilities to safely carry out the duties and responsibilities, including ammonia emergency response, as provided in the operating procedures.
Refresher training is provided annually to each employee operating the covered process to ensure that the employee understands and adheres to the current operating procedures. In addition, the Cogeneration Facility ensures that operators are trained in any updated or new procedures prior to startup of a process after a major change as indicated in their Management of Change procedures.
The Cogeneration Facility has procedures and policies in place that ensure that only contractors with good safety programs are selected to perfor
m work on and around the ammonia process and that the contractors are properly informed of the hazards, access limitations to these process areas, and emergency response procedures, and prepared to safely complete the work. The contractors are informed, prior to the initiation of the work at the site, of the applicable provisions of the emergency action plan. The Cogeneration Facility holds contractor safety briefings before allowing them near or in the process area, controls access to the process areas, and evaluates the contractor's performance.
Pre-Startup Safety Review and Mechanical Integrity Program
The Cogeneration Facility ensures that a pre-startup safety review is completed for any new covered-by-the-rules process, or for significant modifications to an existing covered process that requires a change in the process safety information. The Cogeneration Facility maintains the mechanical integrity of process equipment to help prevent equipment failures that could endanger w
orkers, the public, or the environment. The Cogeneration Facility mechanical integrity program includes the following:
7 Written procedures for maintaining mechanical integrity through inspection and testing of process equipment, based on instructions of equipment vendors, industry codes, and prior operating experience.
7 Implementation of the written procedures by performing inspections and tests on process equipment at specified intervals.
7 Training of maintenance personnel in procedures for safe work practices such as lockout/tagout, line or equipment opening, and avoidance and correction of unsafe conditions.
The Cogeneration Facility uses a software program that assures inspection, testing, and maintenance of ammonia equipment is performed in accordance with industry practice.
Hot Work Permits and Management of Change
The Cogeneration Facility requires employees and contractors to employ safe work practices when performing "hot work" in, on, or around the covered process. T
he Cogeneration Facility uses a permit program to ensure hot work is conducted safely on or near a process involving ammonia.
The Cogeneration Facility provides a system and approach to maintain and implement any management of change or modifications to equipment, procedures, chemicals, and processing conditions. This system allows Cogeneration Facility staff to identify and review safety hazards or provide additional safety, process, or chemical information to existing data before the proposed change would either compromise system safety or need training to be completed.
Internal Compliance Audits
Internal compliance audits will be conducted every 3 years to verify compliance with the programs and procedures contained in the RMP. The Cogeneration Facility will assemble an audit team that will include personnel knowledgeable in the Risk Management Program rule and in the process. This team will evaluate whether the prevention program satisfies the requirements of the Risk Manageme
nt Program rule and whether the prevention program is sufficient to help ensure safe operation of the process. The results of the audit will be documented, recommendations resolved, and appropriate enhancements to the prevention program will be implemented.
The Cogeneration Facility investigates all incidents that could reasonably have resulted in a catastrophic release (serious injury to personnel, the public, or the environment) so that similar accidents can be prevented. An investigation team is assembled and the investigation is initiated within 48 hours of the incident. The results of the investigation are documented, recommendations are resolved, and appropriate process enhancements are implemented. Information found during the investigation is reviewed by affected staff and added or used to revise operating and maintenance procedures.
Five-year Accident History Summary
No ammonia releases that could have caused safety or health hazard (no deaths, i
njuries, property or environmental damage, evacuations, or sheltering in place) occurred at the Cogeneration Facility during the last five years.
Emergency Response Program Summary
The Cogeneration Facility is a non-responding facility, which means that the facility employees will not respond to ammonia accidental release. Instead, the facility has coordinated with local response agencies to respond to any ammonia release that may occur at the facility. As part of the emergency response program, the Cogeneration Facility has developed and implemented an Emergency Action Plan for the purpose of protecting employee health and the environment.
The facility Emergency Action Plan has been coordinated (reviewed) with the Chino Valley Fire Department. This agency is a member of the Local Emergency Planning Committee (LEPC), and was involved with the development of a community emergency action plan. The main elements of the Emergency Action Plan are: (1) organizational structure (chain
-of-command), responsibilities of various personnel at the Cogeneration Facility, and the personnel who can provide additional information regarding the contents of the Emergency Action Plan, (2) procedures for reporting fire or other emergencies, including procedures for notifying the public and local emergency response agencies of a release, (3) emergency escape procedures and emergency escape routes assignments, including emergency evacuation procedures, routes, and safe assembly points, (4) procedures to be followed by employees who remain to operate critical plant operations before they evacuate, (5) documentation of proper first aid and emergency medical treatment necessary to treat accidental human exposures and the detailed information on emergency health care, and (6) a description of the facility alarm systems and meaning of individual alarm signals, including the evacuation alarm.
Planned Changes to Improve Safety
A number of changes to improve safety (recommended actions
) were previously identified for the ammonia process in 1994 under the State of California Risk Management and Prevention Program (RMPP) Process Hazard Analysis. This PHA was further reviewed in April 1999 under the RMP and CalARP program requirements. Based on this PHA review, three additional recommendations were made to improve the safety of the ammonia process. It is expected that the recommended actions will be evaluated and implemented by July 1999. The implementation of these recommendations will further improve the safety of the ammonia system.