Cascade System Gas Processing Plant - Executive Summary |
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EXECUTIVE SUMMARY Accidental Release Prevention And Response Policies The NRC Pipeline, LLC Cascade System Gas Production Plant has a standing commitment to worker protection and public safety. This commitment is demonstrated by the resources invested in accident prevention, such as training personnel and considering safety in the design, installation, operation, and maintenance of this facility. Our policy is to implement reasonable controls to prevent foreseeable releases of regulated substances. However, if a release does occur, gas plant trained personnel will respond to control and contain the release. Description of the Stationary Source and Regulated Substances The Cascade System Gas Processing Plant, located near Oilmont, Montana operates a variety of processes to produce petroleum products (e.g. natural gas, propane and condensate) from natural gas. The Cascade System Gas Processing Plant produces and stores propane, a regulated flammable substance. There are no regulated toxic substances at the Cascade System facility. Offsite Consequence Analysis Results The worst-case scenario (WCS) associated with a release of flammable substances in Program Level 1 processes at the facility consists of a vapor cloud explosion (VCE) involving the full inventory of the largest storage tank containing 16,800 gallons (71,232 pounds) of natural gas liquid propane. A written procedure is in place to limit the storage inventory to 90% of the maximum tank capacity; therefore, the reduced inventory is assumed to release and ignite, resulting in a VCE. The maximum distance to the 1-psi endpoint for this WCS is 0.3 miles. Although numerous controls are in place to prevent such releases and to manage their consequences, no credit for passive mitigation measures was taken into account in evaluating this WCS. The hazard assessment results for the flammable WCS event is graphically presented as Figure 1. Con tractors The Cascade System Gas Processing Plant uses contractors to supplement its workforce 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 knowledge 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 site 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. Mechanical Integrity The Cascade System Gas Processing Plant has established practices and procedures to maintain pressure vessels, piping systems, relief and vent systems, controls, pumps and compressors, and emergency shutdown systems in a safe operating condition. The basic aspects of this program include: (1) conducting training, (2) developing procedures, (3) performing inspections and tests, (4) correcting identified deficiencies, and (5) applying quality assurance measures. In combination, these activities form a system that maintains the mechanical integrity of the process. Maintenance personnel sometime receive training on: (1) an overview of the process, (2) safety and health hazards, (3) applicable maintenance procedures, (4) emergency response plans, and (5) applicable safe work practices to help ensure that they can perform their jobs in a safe manner. These procedures help ensure that work is performed in a consistent manner and provide a basis for training. Inspections and tests are performed to help ensure that equipment functions as intended and to verify that equipment is within acceptable limits. If a de ficiency is identified, employees will correct the deficiency before placing the equipment back into service (if possible). Another integral part of the mechanical integrity program is quality assurance. The Cascade System Gas Processing 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 Cascade Systems gas plant has 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 procedure to control spark producing activities (i.e., hot work), and (5) a pr ocedure 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 performed safely. Incident Investigation The Cascade System Gas Processing Plant promptly investigates all incidents that resulted in, or 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. Chemical-Specific Prevention Steps The processes at the Cascade System Gas Processing Plant have hazards that are managed to ensure continued safe operation. 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 pre viously is applied to the RMP-covered processes at the Cascade System Gas Processing Plant. Collectively, these prevention program activities help prevent potential accident scenarios that could be caused by equipment failures and human errors. Specialized Safety Features The Cascade System Gas Processing Plant has safety features such as: (1) contain/control a release and (2) reduce the consequences of (mitigate) a release. The following types of safety features are used in the covered processes. Release Containment Control Process relief valves that discharge to a flare to capture and incinerate episodic releases Valves to permit isolation of the process Curbing or diking to contain liquid releases Release Mitigation Trained emergency response personnel Protective equipment (e.g., chemical protective clothing, self- contained breathing apparatus) Five-Year Accident History The Cascade System Gas Processing Plant has an excellent record of accident prevention over the past five years. There have been no off-site accidents within this time period. Emergency Response Program Information The Cascade System Gas Processing Plant has an emergency response program that is in place to protect worker and public safety, as well as the environment. The program consists of procedures for responding to a release of a regulated substance, including the possibility of a fire or explosion if a flammable substance is accidentally released. 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, notification of local emergency response agencies and the public, if a release occurs, and post incident cleanup and decontamination requirements. In addition, the plant has procedures that address maintenance, inspection, and testing of emergency response equipment, as well as instructions that address the use of emergency response equipment. Employees receive training in these procedures as necessary to perform their specific emergency response duties. When necessary, the emergency response program is updated based on modifications made to gas plant processes or other Cascade Systems gas plant facilities. The overall emergency response program for the Cascade System Gas Processing Plant is coordinated with the Toole County Local Emergency Planning Committee (LEPC). This coordination includes meetings of the committee, which includes local emergency response officials, local government officials, and industry representatives. The Cascade System Gas Processing Plant has around-the-clock communications capability with appropriate LEPC 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. |