Grand River Dam Authority Coal Fired Complex - Executive Summary

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EXECUTIVE SUMMARY 
 
 
Facility Description 
    
The Coal-Fired Complex is an electrical production power plant operated by the Grand River Dam Authority (GRDA).  The facility is located three miles east of Chouteau, Oklahoma on State Highway 412.  The power plant contains two primary electric generators, referred to as Unit 1 and Unit 2.  Unit 1 was placed in commercial operation in 1981, and Unit 2 in 1986.  Each unit consists primarily of a coal combustion boiler, a steam turbine, an electric generator, pollution control equipment, and auxiliary support equipment.  Total maximum facility generating capacity is 1010 megawatts. 
Coal is transported to the facility using rail cars and trucks.  The coal is burned in a steam-generating boiler.  Steam produced in the boiler flows to a steam turbine.  The steam turbine then drives an electric generator. 
Combustion gases from each boiler contain ash, which is the mineral portion of coal not combusted to a gas.  Unit 1 has an electrostatic precip 
itator to remove ash before combustion gases exit a chimney.  Unit 2 has a sulfur dioxide removal system that injects lime slurry into combustion gases.  This slurry reacts with sulfur dioxide gas to form a solid.  This composite ash is then removed in an electrostatic precipitator, similar to Unit 1.  Some of the collected ash is placed in the ash storage area south of the two units, and some of the ash is sold for beneficial purposes. 
Water for the plant is pumped from the Grand Neosho River, located ? mile east of the facility.  The water is used primarily in two cooling towers, which remove waste heat from the two steam turbines.  Water is also used in various plant process equipment, again primarily for cooling or steam production in the boiler.  Sewage water from bathrooms and personnel showers flows to a total retention treatment lagoon.  After use, process water flows into settling ponds for removal of suspended solids.  Two oil/water separators are also used to insure any spil 
led oil does not enter settling ponds. 
 
    
Accidental Release Prevention & Emergency Response Policies 
 
The GRDA Coal-Fired Complex is strongly committed to chemical safety, prevention of accidents and protection of the public.  The implementation of this has been accomplished in a multi-layered manner using equipment system design, management oversight, extensive written procedures, and training of competent and responsible personnel.  The safety measures include the following: 
 
The Coal-Fired Complex plant site is surrounded by an 8-foot high security (chain link) fence.  Access to the site is permitted through a gate controlled by dedicated security personnel.  Security personnel are on duty 24 hours per day, every day.  Security officers make frequent patrols, searching for unusual circumstances, including fire, spills, and alarms.  The entire power plant is completely lighted at night.  Lighting is controlled by photoelectric cells to ensure that the site is illuminated during peri 
ods of darkness.  A shift supervisor is on duty 24 hours per day, every day.  The shift supervisor has the training and full authority to direct personnel and resources to contain a chemical problem or emergency.  Operations personnel are qualified for their responsibilities using detailed checksheets.  Operators must complete an extensive set of workbooks covering fundamental science and principles of proper power plant operation.  Operators must learn extensive written operating procedures and are then evaluated by experienced supervision.  Hazardous chemicals are normally handled or managed by Results Technicians who have specialized training on the chemicals involved.  A computerized maintenance management program is used to help assure that equipment is regularly inspected and properly maintained.  Employees have been trained over accident prevention concepts and philosophy using formal programs developed by the Dupont Chemical Company.  These programs stress following procedure,  
wearing correct personnel protective equipment, maintaining good communications, and careful observation of safety conditions. 
 
Chemical Description 
 
Two chemicals used for water treatment at the facility and present in amounts greater than the respective threshold planning quantities are aqua ammonia (29.3% NH3) and liquid chlorine.  The maximum quantities stored on-site are  
1)     aqua ammonia - 43,010 pounds of solution at maximum tank capacity of 5,750 gallons 
                             (12,602 pounds as NH3) 
2)     chlorine -  8,000 pounds in one-ton cylinders 
 
Worst Case Release 
 
EPA's RMP* Comp was the model used to estimate the worst case release scenarios for aqua ammonia and for chlorine.  Two scenarios, a sudden catastrophic containment failure and a slower leak-related situation, were modeled for each chemical: 
 
Aqua Ammonia -   (1)    a failure of the ammonia storage tank, located within a concrete containment dike, would result in the loss of approximately 80% (34,000 lbs.) of the tota 
l tank capacity to the containment area.  This assumes the tank was filled to capacity and the release was allowed to proceed until the liquid levels in the tank and the containment area were equalized. 
(2)    The alternative scenario (e.g. - vessel, valve, or fitting leak) demonstrated the effect of release of 1,190 pounds of chemical over a period of sixty (60) minutes. 
 
The conclusion of the modeling, for both aqua ammonia release scenarios, is that no offsite impact is to be anticipated. 
 
Chlorine -         (1)    A chlorine release, resulting in the emptying to the atmosphere of the total contents of one 2,000 pound cylinder in ten minutes, was the worst case scenario.  This assumed the total failure of the vessel and built-in safeguards. (i.e. fuse plug) 
(2)    The alternative scenario assumed the loss of a fuse plug (i.e. a ?-inch to 1-inch hole in the cylinder) from the chlorine cylinder. (the fuse plug is designed to prevent overpressure from occurring in the cylinder.)  This scenario would  
also represents the maximum amount of chlorine anticipated to be released should a value or fitting failure occur. 
 
Chlorine scenario (2) indicated no offsite impact is to be anticipated.  Chlorine scenario (1) indicated an endpoint (i.e. distance to extremity of the area potentially damaged by the release) of 1.3 miles.  This includes offsite areas. 
 
Mitigation 
 
The chlorine cylinders are stored in a totally enclosed building.  Chlorine sensors within the building detect any leak and trigger a visual alarm on the roof.   
The visual alarm is within direct line-of-sight of the security guard shelter.  This shelter is staffed 24 hours per day, 365 days per year.  In addition, plant-operating personnel check the building once every four hours on the back shifts.  During the day shift, plant personnel make chlorine equipment and storage checks in the building.  Once every three months the system is checked by a manufacturer's representative and rebuilding and replacement is accomplished as 
necessary. 
A chlorine repair kit for field repair of cylinder leaks is maintained on-site.  Nine individuals are trained in the proper use of the kit.  In addition, these nine individuals receive training on the safe and proper use of self-contained breathing apparatus and chlorine safety which would allow them to enter the storage building during a chlorine leak. 
A team of 25 facility personnel, the site rescue team, receive training on the entry of confined spaces while using self-contained breathing apparatus.  These individuals are in addition to the nine previously mentioned.  
Specific safety procedures for the unloading of aqua ammonia from a tank truck and the loading and unloading of chlorine cylinders from the delivering truck are provided to all personnel engaged in these activities. These procedures are intended to provide the personnel involved with procedures that will maximize personal safety and minimize the possibility of leaks, overfilling, and cylinder damage.  Addit 
ional procedures are provided to the personnel directly responsible for chemical loading and unloading, and for plant chlorine response. 
 
Emergency Response Program 
 
The GRDA, in compliance with the SARA Community Right-to-Know requirements, has provided all pertinent information to the Local Emergency Planning Commission (LEPC), including the local fire departments and Mayes County Civil Defense. 
A plant directive addressing the plant emergency response plan has been distributed to facility personnel.  Regular drills of the prescribed procedures are conducted.   
Coordination of emergency response actions is the responsibility of the AGM of Thermal Generation.    
Five Year Accident History 
 
During the last five years, no RMP incidents have occurred at the GRDA Coal-Fired Complex. 
 
Prevention Program 
 
The facility has in place plant directives and chemical unloading procedures pertinent to the handling and storage of chlorine and aqua ammonia.  Additional directives are applicable to th 
e entry of an area affected by toxic gases and vapors.  All plant management is responsible for making sure that each employee in their area of responsibility understands and follows the applicable procedures. 
A facility safety committee consisting of six members plus senior plant management meets once per month to address various safety issues.  This provides a forum for discussion and resolution of any issues relating to chemical safety. 
 
Planned Changes to Safety 
 
The management at the Coal-Fired Complex is committed to existing safety programs and will continue to strive for improvement concerning the safety of our employees and equipment.
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