SCA Congeneration Plant - Executive Summary
GE Contractual Services has instituted a Risk Management Program for the SCA Cogeneration Plant, as required by Federal Accidental Release Prevention (ARP) Program regulations at 40 CFR Part 68. The Risk Management Program identifies the equipment, procedures, maintenance, inspection, and training associated with Regulated Substances (RS's) handled at this facility in excess of Federal threshold quantities; describes the structured assessment of hazards which was conducted to assess possible effects on employees and offsite public and environmental receptors; provides the results of an offsite consequences analysis; defines a prevention program, emergency response program, and mitigation measures to reduce the probability and magnitude of accidental releases of RS's; and establishes a schedule and responsibilities for implementation of mitigation measures and auditing of program elements. This Risk Management Plan (RMP) is being filed as required by ARP regulations in order to report |
the elements of the current Risk Management Program and to describe further measures planned to mitigate or prevent accidental releases of RS's.
STATIONARY SOURCE AND REGULATED SUBSTANCES HANDLED
GE Contractual Services is the contract operator of a cogeneration facility, SCA Cogeneration Plant, located at 5000 - 83rd St., Sacramento, CA in Sacramento County, owned by Sacramento Cogeneration Authority. Aqueous ammonia (25% solution) is used for selective catalytic reduction of nitrogen oxides in the gas turbine exhaust. This RS is handled in quantities greater than its Federal threshold quantity. The facility is located in an industrial area in south Sacramento with few residences nearby. There are 16 full-time employees at this site. Aqueous ammonia (25% solution) is received in bulk by truck into an enclosed steel storage tank. The aqueous ammonia solution is pumped from the storage tank at a metered rate into the flowing turbine exhaust gas at the location of a catalyst
within the exhaust duct, and reacts chemically with oxides of nitrogen to form nitrogen gas, thus reducing air pollutant emissions in the stack gas.
ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES
It is the policy of GE Contractual Services that the receipt, storage and handling of aqueous ammonia (25% solution) at the SCA Cogeneration Plant be done in a manner which meets regulatory requirements and minimizes the probability and severity of accidental releases of aqueous ammonia (25% solution) to the atmosphere, in order to protect the health and safety of its workers, the public, and the environment. In order to accomplish this goal, GE Contractual Services has gathered safety information on aqueous ammonia (25% solution) and on the process, equipment and procedures involving aqueous ammonia (25% solution); performed a structured assessment of hazards of the process and external events which might affect the process; performed an offsite consequences analysis of d
efined release scenarios; established a written program for prevention and mitigation of releases; and established a written emergency response program coordinated with emergency response agencies.
WORST CASE RELEASE SCENARIO
A single "worst case" release scenario is required to be considered for each stationary source, resulting in the maximum distance to an endpoint for all toxic RS's contained on site above the threshold quantity.
The worst case release scenario for toxic chemicals is defined in the ARP regulations as the release of the contents of the largest single container of RS (in this case aqueous ammonia (25% solution)) over a period of 10 minutes. The scenario considered the release of the contents of the largest container of aqueous ammonia (25% solution) on site, in this case the contents of the 10,000-gallon storage tank containing 18,750 lb. of ammonia.
ALTERNATIVE CASE RELEASE SCENARIO
An "alternative case" release scenario is required to be considered for each tox
ic RS handled in quantities greater than the threshold quantity at the site.
The "alternative case" scenario is described in the ARP regulations as a likely release resulting in offsite effects, considering administrative controls and mitigation measures in place, and is to be determined by the facility operators as part of the Process Hazard Analysis required to be performed during RMP development. The "alternative case" considered for this facility is the release of aqueous ammonia (25% solution) from process piping due to component failure, with the release secured by operators after 5 minutes.
Administrative controls in effect at GE Contractual Services which were considered to mitigate the severity of the Worst Case and Alternative Case release scenarios include GE Contractual Services's written policies and procedures for training of operators and maintenance personnel, written procedures for control of the inventory of aqueous ammonia (25% solution) a
t the facility, and policies regarding quality level of replacement materials and components for the aqueous ammonia (25% solution) system.
Passive mitigation in the form of a concrete secondary containment structure surrounding the storage tank was considered to limit the severity of the Worst Case scenario. The same passive mitigation measure was considered to limit the severity of the Alternative Case scenario. Active mitigation was considered for the Alternative Case, in the form of response of trained operators in a timely manner to close the valve on the suction side of the transfer pump.
GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAMS
General accidental release prevention programs instituted by GE Contractual Services are categorized as administrative (management) programs; procedures, training, and engineering controls; and emergency response programs.
GE Contractual Services maintains policies and procedures conforming to recognized industry standards
covering the operation and maintenance of its selective catalytic reduction process, including quality standards for materials of construction, and training programs for personnel operating and maintaining equipment. This constitutes the general accidental release prevention program for GE Contractual Services' operations at the SCA Cogeneration Plant. The program and document management procedures included in the PSM Program will be used as the management system for the Risk Management Program.
CHEMICAL-SPECIFIC RELEASE PREVENTION STEPS
Release prevention steps specific to aqueous ammonia (25% solution) have been identified and implemented. These include, among other things, creation of numerous facility-specific operation procedures with check boxes for completion of critical steps.
FIVE YEAR ACCIDENT HISTORY
There have been no accidents involving aqueous ammonia (25% solution) at this facility within the past five years resulting in injuries or offsite consequences.
CY RESPONSE PROGRAM
GE Contractual Services' Emergency Response Program applicable to aqueous ammonia (25% solution) has been coordinated with Sacramento County Environmental Management Department, Hazardous Materials Division, the local agency responsible for hazardous materials inventory reporting and release response coordination. It consists of notification of the public agency assigned responsibility for First Response to hazardous materials release emergencies. First Responders have participated with GE Contractual Services personnel in response drills.
PLANNED CHANGES TO IMPROVE SAFETY
All of the improvements and mitigation measures identified in the process hazard analysis which GE Contractual Services committed to accomplish have been completed or are in progress. Any other measures identified by employees during workplace hazard surveys, or as a result of audit activities, will be thoroughly reviewed and considered for implementation.