TVA - Paradise Fossil Plant - Executive Summary

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EXECUTIVE SUMMARY 
 
I.    Accidental Release Prevention and Emergency Policies 
 
Environmental protection and enhancement are essential elements of TVA's integrated resource management mission. TVA exhibits progressive environmental leadership in managing its unified river and power system for multiple public benefits, including the production of reliable, competitively priced power. TVA is committed to setting the standard for environmental excellence among utilities and federal agencies, and to making the Tennessee Valley a model in sustainable energy, resource, and economic development and management. TVA assures that employees are aware of their environmental responsibilities, use effective environmental processes, and are held accountable for performance.  
 
TVA management and employees will be responsible for maintaining compliance with environmental requirements and striving for environmental excellence in performing their respective duties.  We will assure environmental protection a 
nd reduce risks to our employees and communities in which we operate through proper environmental review of new developments and through safe technologies, operating procedures, and emergency preparedness.  All activities will be conducted in accordance with current environmental and health and safety regulatory requirements. 
 
II.    Stationary Source and Regulated Substances Handled 
 
The affected facility consists an anhydrous ammonia storage facility including two 30,000 gallon storage tanks with supporting unloading equipment, vapor compressors and liquid transfer pumps, piping to convey the liquid ammonia, vaporizers to convert ammonia from a liquid to a gas, and a gas dilution and injection system to inject ammonia into a selective catalytic reduction emission control system. 
 
There is only one regulated substance at the facility - anhydrous ammonia.  With two 30,000 gallon storage tanks, the maximum amount of anhydrous ammonia in the storage facility at any time is 260,220 pounds an 
d the maximum amount contained in the largest single vessel is 130,110 pounds. 
 
III. Summary of Worst Case and Alternative Release Scenarios 
 
The Worst Case Release Scenario and the Alternative Release Scenario(s), including administrative controls and mitigation measures to limit the distances to the end point for each reported scenario were developed.  To perform the required offsite consequence analysis for the facility, the very conservative EPA RMP*Comp model was used.   
 
The worst case release scenario involves the complete rupture of one 30,000 gallon storage tank.  A maximum release of 130,110 pounds of anhydrous ammonia over a 10 minute period was considered.  The released quantity has not been limited by a system of administrative controls.  Under worst case meteorological conditions of Class F stability and 1.5 m/s wind speed, ammonia could travel up to 4.4 miles before reaching the specified toxic end point level of 0.14 mg/L. 
 
The alternative case release scenario with the 
worst credible case offsite impact involves the release of 26,622 pounds of ammonia vapor loss from the failure of a pressure safety valve to reseat or from ruptured vapor piping.  Under typical meteorological conditions of Class D stability and 3 m/s wind speed, ammonia could travel up to 0.3 miles before reaching the specified toxic end point level of 0.14 mg/L. 
 
An alternative case release scenario with the most likely, most sever case involves the release of 100 pounds of liquid ammonia from a failing transfer hose during the unloading of liquid ammonia from a rail or truck tank.  Under typical meteorological conditions of Class D stability and 3 m/s wind speed, ammonia could travel up to 0.1 miles before reaching the specified toxic end point level of 0.14 mg/L. 
 
IV.     Description of Release Prevention Program 
 
Process Safety Information - TVA maintains documentation of safety information concerning chemical hazards, operating parameters, and equipment designs and specifications a 
ssociated with the process. 
 
Process Hazard Analysis - TVA conducted comprehensive analyses of the process to ensure that hazards associated with the process were identified and controlled effectively.  The Hazardous and Operability Study (HAZOP) analysis methodology was used to assess the potential hazards of the process.  The study was conducted by a team of qualified personnel with expertise in engineering, control logics, and process operations.  Findings resulting from the analysis were addressed.  The HAZOP analysis was conducted on August 20-22, 1999 and a pre-startup HAZOP review was conducted on March 22, 2000. 
 
Operating Procedures - TVA has established and maintained procedures for safely conducting activities within our covered process.  The procedures cover various operational phases including initial startup, normal startup, normal shutdown, temporary operations, emergency shutdown, emergency operations, and startup following a turnaround or emergency shutdown.  The infor 
mation is readily available to operators and maintenance personnel involved in the process and the information is periodically reviewed to assure it is current. 
 
Training - TVA's training program is comprehensive and is implemented to ensure that all personnel involved in the operation and maintenance of the process are properly trained in the safe operation and maintenance of the process and knowledgeable of the hazards of the process.  The personnel are provided with refresher training at least every three years or more often if needed. 
 
Mechanical Integrity - TVA conducts well documented maintenance checks on process equipment to ensure safe and reliable operations.  All process equipment routinely checked includes storage tanks and pressure vessels, piping systems, relief and venting systems, controls and pumps, emergency shutdown systems, and monitoring devices.  All maintenance operations conducted on the covered process are performed by qualified personnel who have had proper tr 
aining.  Equipment deficiencies identified by the maintenance checks are corrected promptly and safely. 
 
Management of Change - TVA maintains written procedures to manage changes in the process equipment, procedures and monitoring technology.  Personnel whose job tasks are affected by a modification in the process are promptly apprised of the modification and provided training to address the modification. 
 
Pre-Startup Review - A pre-startup safety review was conducted prior to the startup of the new process.  Established pre-startup safety review procedures will assure that construction, equipment, operating and maintenance procedures are suitable for a safe startup prior to placing equipment into operation. 
 
Compliance Audits - TVA conducts environmental and safety audits on a regular basis and will determine whether the provisions set out under the RMP rule are being implements.  The audits will be conducted at least every 3 years and any corrective actions required as a result of th 
e audits will be promptly and safely implemented. 
 
Incident Investigations - Any incident that results in or could reasonably result in a significant release of a regulated substance is promptly investigated.  Procedures ensure that investigations are undertaken to identify the circumstances leading to the incident as well as any corrective actions to prevent the situation surrounding the release does not reoccur.  All reports will be retained for at least 5 years. 
 
Employee Participation - TVA believes in a team approach to process safety management and accident prevention.  Employees are encouraged to express their views concerning accident prevention issues and to recommend improvements.  In addition, our employees have access to all information developed through implementation of the RMP, including information resulting from process hazard analyses. 
 
Contractors - TVA develops partnerships with contractors to effectively conduct business and operate generation facilities, especiall 
y in maintenance and construction activities.  Prior to selecting a contractor, TVA evaluates the qualifications of the contractor including their safety performance.  Procedures are in place to ensure that contractors are properly informed of known potential hazards related to the contractor's work and the process involved, including the emergency response procedures in the event of an accidental release of a regulated substance. 
 
V.    Five Year Accident History   
 
The ammonia facility is a new facility and thus does not have an accident history. 
 
VI.    Emergency Response Plan 
 
TVA has an emergency response plan in place to respond to accidental releases of hazardous materials.  The plan includes all aspects of emergency response plan requirements including adequate first aid and medical treatment, safe shelter-in-place locations, notification of local emergency response agencies and the public, and qualified contractor responder for post-incident decontamination of affected areas.  The p 
lan will be promptly updated to address any pertinent changes within the process that would require a modification of the emergency response plan.  In addition, periodic emergency response drills are conducted to keep employees, contractors, and local responders familiar with the plan.
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