SRW Cogeneration Limited Partnership - SRWCLP - Executive Summary
ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES |
The SRWCLP power plant is owned by SRW Cogeneration Limited Partnership ("SRWCLP"). The general partners of SRWCLP are Conoco Global Power Developments - Sabine Inc. and NRG Sabine River Works GP LLC. The limited partners of SRWCLP are Conoco Global Power Assets Sabine Inc. and NRG Sabine River Works LP LLC. The SRWCLP power plant is located within the boundaries of the DuPont Sabine Riverworks Plant. The power plant is operated and maintained by DuPont personnel under contract to the owner, which will require approximately 26 fill-time equivalent employees. On-site management oversight is the responsibility of the power plant Operations Director, who is an employee of SRWCLP. Because DuPont operates the facility, all safety-related activities at the power plant adhere to the corporate policies of the E.I. DuPont De Nemours and Company. These policies can be summarized as follows:
- All safety and environmental inci
dents are preventable.
- The Goal is Zero. Zero injuries and zero incidents.
Corporate policies are embodied in the numerous Safety, Health, Environmental, and Engineering Standards which apply globally. At Sabine River Works, the policies are implemented through the site Safety, Health and Environmental Manual and Process Safety Management Manual.
DESCRIPTION OF THE STATIONARY SOURCE AND REGULATED SUBSTANCES
The SRWCLP Power Plant is situated within the boundaries of the DuPont Sabine River Works Plant, which is located approximately two miles south of the city of Orange in a rural setting on FM 1006. The DuPont plant site is located on 1500 acres evenly divided between manufacturing processes, the employee recreation area, and bio-oxidation ponds. The facility is secured by a chain-link fence, video cameras, controlled entry, and a 24-hour security force.
The power plant is a gas-fired combustion turbine cogeneration plant that produces steam and electricity. As a means of r
educing nitrogen oxide emissions from the gas-fired turbine, aqueous ammonia (28 percent ammonia by weight) is vaporized and injected into the turbine exhaust. The ammonia acts as a reagent in the selective catalytic reduction (SCR) of nitrogen oxides across a solid catalyst bed.
The aqueous ammonia is stored on site in a single storage tank. The total capacity of the ammonia storage and feed system exceeds the threshold quantity for applicability to 40 CFR Part 68, the Risk Management Program (RMP) regulation. There are no other toxic or flammable materials on site that exceed RMP threshold levels.
OFFSITE CONSEQUENCE ANALYSIS RESULTS
The worst case scenario (WCS) associated with a release of a toxic substance is the assumed failure of the aqueous ammonia storage tank. Based on the RMP regulation, the WCS is the immediate release of the entire inventory of liquid aqueous ammonia, forming an evaporating pool. This maximum quantity of 28,012 gallons of solution would be containe
d within a 966 square foot containment system (i.e., a concrete dike) which is designed to act as passive spill release mitigation. Under these conditions, the RMP rule specifies that the scenario be modeled as an evaporating pool contained within this diked area.
The WCS was modeled using the EPA Offsite Consequence Analysis (OCA) Guidance reference tables and equations. According to these methods, the WCS produces a vapor cloud that extends from the release to a distance that encompasses public receptors as defined by EPA. The extent of the vapor cloud is defined by the EPA toxic endpoint for ammonia (200 ppm). Public receptors that could be affected by the WCS include off site residential, recreational, and industrial receptors. These receptors were identified using U.S. Census Bureau data via the Landview program, supplemented by a visual survey.
The alternative release scenario (ARS) for aqueous ammonia involves the assumed failure of a one-inch ammonia line from the bottom
of the storage vessel. The released ammonia solution would be contained within the 966 square foot dike surrounding the storage tank. The ARS was modeled using EPA OCA Guidance reference tables and equations, with the dike acting as passive mitigation. No active release mitigation was credited in the ARS modeling analysis.
The modeled ARS distance to the toxic endpoint exceeds the boundaries of the power plant, and encompasses portions of the surrounding DuPont Sabine River Works Plant. The DuPont plant is a separate stationary source and is therefore an industrial off site receptor according to EPA definitions. No residential, recreational, or other receptors were identified within the modeled ARS impact distance.
GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM
The SRWCLP Power Plant implements management systems and practices that meet or exceed RMP Level 2 Prevention Program requirements. The power plant is not subject to 29 CFR 1910.119, the Process Safety Management (PSM)
Standard because the aqueous ammonia concentration (28 percent by weight) is below the PSM threshold of 44 percent by weight. The facility is classified as NAICS Code 221112, fossil fuel power generation. As described above, the WCS could affect off site receptors. This set of conditions dictates Prevention Program 2 applicability under the RMP regulation.
Prevention Program 2 requirements are defined according to the following elements:
- Safety information;
- Hazard review;
- Operating procedures;
- Compliance audits; and
- Incident investigation.
The requirements of these elements are met or exceeded through implementation of safety procedures developed to comply with the more rigorous PSM standard. DuPont personnel operating the power plant conduct their activities under control of the safety programs of the surrounding DuPont facility, which is subject to the PSM regulation. All activities adhere to the requirements of DuPont Corporate SHE Standa
rd S21A, "Process Safety Management." This Standard includes and embraces the elements of both 29 CFR 1910.119 (PSM) and 40 CFR Part 68 (RMP).
The Power Plant and DuPont Sabine River Works Plant safety programs include:
Designing for Safety...
- A documented process technology system covers hazards of materials, equipment design basis, and process design basis.
- Accident prevention and mitigation systems are strategically located.
- Applicable codes and standards are met or exceeded.
- Materials of construction are chosen to provide mechanical integrity.
Maintaining our Plant...
- Maintenance personnel are trained and experienced.
- Contractors are trained and qualified.
- A work permit system controls hazards.
- Operators are trained and job qualified.
- Technical resources are available and utilized as required.
- Operators follow approved procedures.
Auditing our Operations...
- Routine safety inspections are conducted.
- Corporate, independent and govern
mental audits and reviews are conducted.
- Process Hazards Analyses are conducted.
- Safety critical equipment is subjected to periodic testing and inspection to ensure ongoing mechanical integrity.
- Pre-startup safety reviews are conducted prior to starting any new or modified equipment.
- Quality assurance of critical equipment ensures fabrication in accordance with design specifications.
- All incidents are investigated and actions are taken to prevent recurrence.
Safety is a job requirement for all employees and contractors!
CHEMICAL-SPECIFIC PREVENTION STEPS
As a new facility in 2001, the ammonia system is designed to meet or exceed current design standards for aqueous ammonia storage and handling systems. A detailed hazard and operability study (HAZOP) was conducted to verify design and operational safety, and to identify the potential for safety enhancements. The analysis included the delivery and unloading of ammonia to the storage tank, as well as ammonia storage, pumpin
g, vaporization, and injection. As a result of the HAZOP study, additional process controls were added to further enhance operational safety.
A pre-startup safety review was conducted prior to initial operation to field-verify that equipment was installed as designed. The ammonia system is subjected to preventive maintenance inspections and testing to ensure its ongoing integrity. Future system modifications, if required, will be controlled under a strict management of change program to ensure that appropriate ammonia design standards are applied. Management of change also ensures that proper hazard review is conducted, training is performed, and operating, maintenance, and emergency response procedures are kept up-to-date.
FIVE-YEAR ACCIDENT HISTORY
The SRWCLP Power Plant will begin operations 2001, and as such, has not experienced an accidental release of ammonia. Therefore, no accidents have resulted in either on site or off site effects as defined in 40 CFR Part 68 for five
-year accident history reporting.
EMERGENCY RESPONSE PROGRAM
The facility maintains a written emergency response program which is in place to protect worker health and public safety. The program is coordinated with the community response plan maintained by the Orange County LECP. The facility plan includes procedures for responding to a release of a regulated substance, including the possibility of a release of 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; and notification of local emergency response agencies and the public if a release occurs.
Plant personnel are trained and equipped to respond to releases of the ammonia. The program can be summarized as follows:
Training and Preparation...
- All plant personnel receive emergency response training.
- Plant emergency responders are trained to control releases.
- Emergency respo
nse plans are current.
- The plant participates in emergency drills.
- Critiques are held on drills and actual events.
If a Major Release Occurs...
- The emergency alarm is sounded.
- The plant Emergency Operating Center is activated.
- The plant Incident Commander and emergency squad respond.
- The Community Alert System is sounded.
- Community emergency responders are notified as appropriate.
PLANNED CHANGES TO IMPROVE SAFETY
The SRWCLP Power Plant will begin operations in 2001 with aqueous ammonia systems that meet or exceed the latest in design standards. The detailed HAZOP study conducted during design identified additional process controls that were implemented to further minimize the potential for ammonia-related accidents. Further planned safety enhancements include:
- A continued focus on the "The Goal is Zero" for injuries and incidents.
- Training in "Operational Discipline" for all process-related employees.