Stockton Cogen Company, Inc. - Executive Summary
Executive Summary |
Air Products and Chemicals, Inc.
Stockton, California Cogeneration Facility
1. Accidental release prevention and emergency response policies:
At this facility we produce steam and electricity. During the manufacturing process we use anhydrous ammonia to reduce our NOx emissions, Chlorine to control micro biological levels in our cooling tower water. Anhydrous ammonia and Chlorine in the amounts handled, are considered Acutely Hazardous Materials (AHMs) by the EPA. It is our policy to adhere to all federal and state rules and regulations. Safety depends upon the manner in which we handle these products combined with the safety devices inherent in the design of the facility. Safe work practices and training of our personnel supplement the inherent safe design of the plant.
Our emergency response program is based upon OSHAs HAZWOPPER regulation (CFR 1910.120). The emergency response plan includes procedures for the notification of the local fire authority a
nd Hazardous Materials Unit so that appropriate measures can be taken by local emergency responders to control accidental releases.
This document has been prepared in accordance with the EPA's Risk Management Program regulation (40 CFR, Part 68). The substances and processes considered during the preparation of this Risk Management Plan (RMP) and the scenarios described were selected based on the criteria established in the regulation.
2. The stationary source and regulated substances handled:
The primary purpose of this facility is cogeneration of steam and electricity. We operate a circulating fluidized bed boiler to produce high pressure steam by the combustion of coal, petroleum coke, and tire derived fuel (TDF). The steam from the boiler is used to turn a turbine generator thereby creating electricity. The steam is condensed in a condens
er by cooling water. We control the microbiological levels in the cooling water with Chlorine.
Nitrogen Oxides (NOx) are a by-product of combustion and are considered an atmospheric pollutant. It is removed from our process by injecting anhydrous ammonia into our boiler. The ammonia reacts with the NOx creating molecules of nitrogen and water vapor, naturally occurring atmospheric gases. This process reduces the plants NOx emissions by approx. 85 % - 90 %.
The regulated substances handled at this facility are anhydrous ammonia and chlorine. The maximum amount of these substances at this facility are 95,000 pounds of anhydrous ammonia stored in a main storage tank and associated process equipment, and 4,000 lbs of chlorine stored in two one ton chlorine containers.
3. The worst case release scenarios and the alternative release scenarios, including administrative controls and mitigation measures to limit the distance for each reported scenario:
The worst case scenario as de
fined by the EPA, associated with a release of anhydrous ammonia at the facility is a catastrophic failure of the ammonia storage tank. A maximum inventory of 95,000 pounds is assumed to be released into a containment dike and vaporizes within ten minutes. A maximum distance to the 0.14 mg/l concentration of ammonia reaches receptors off-site. Although we have numerous controls to prevent such a release and to manage their consequences, no credit for active mitigation measures was taken into account in evaluating the worst case scenario.
Two alternate case scenarios were used for anhydrous ammonia. The first case is the assumed failure of a 2 " vapor line during a filling operation. The second alternate case is the assumed failure of a 3/8 " vapor line at the injection into the boiler. A maximum distance for both scenarios to the 0.14 mg/l concentration toxic endpoint reaches receptors off-site.
The worst case scenario as defined by the EPA, associated with chlorine at the
facility is a catastrophic failure of a 1 ton cylinders. A maximum inventory of 2,000 pounds is assumed to be released in ten minutes. A maximum distance to the 0.0087 mg/l concentration of chlorine reaches receptors off-site. Although we have numerous controls to prevent such a release and to manage their consequences, no credit for active mitigation measures was taken into account in evaluating the worst case scenario.
The alternate case scenario for chlorine is the assumed failure of a 3/8 inch vapor line and the subsequent failure of the vacuum demand regulator. This results in a 3/8" hole in the system. A maximum distance to the 0.0087 mg/l concentration of chlorine reaches receptors off-site.
4. The general accident release prevention program and specific prevention steps:
The facility developed prevention program elements based on the Federal EPAs Accidental release prevention plan, the California Accidental Release Prevention Program (CalARP), and OSHAs Process Saf
ety Management Regulation. The design and construction of the facility comply with applicable state and industry codes.
5. Five year accident history:
This facility was built in 1987. During the past five years there have been no accidents involving or accidental releases of toxic gas that resulted in any deaths, injuries, or significant property damage on site, or known off-site deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage.
6. The emergency response program:
The facilitys emergency response program is based upon OSHAs HAZWOPPER standard. At this site, employees are trained to respond to releases or potential releases of hazardous materials for the purpose of protecting nearby persons, the environment, or property from the effects of the release. They have been trained to OSHAs First Responder Operations Level. The employees receive annual refresher training in their role in the emergency plan. Emergency response activit
ies have also been coordinated with the Stockton Fire Department and the State Office of Emergency Services. Periodic drills are conducted with the Stockton Fire Department to review the effectiveness of our emergency procedures.
7. Planned changes to improve safety:
The facility resolves recommendations from PHAs and Incident Investigations, some of which may result in modifications to the plant design & operating procedures.