Wisconsin Electric Power Company Concord Generati - Executive Summary |
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ACCIDENTAL RELEASE PREVENTION PROGRAM: In this electric generating facility, anhydrous ammonia is handled as adjunct to the manufacturing process. Both the EPA and OSHA consider this chemical hazardous. Anhydrous ammonia is used to alter specific temperature and other related physical properties from ambient air for the efficient generation of electricity. As this is a new facility, every effort has been taken to adhere to current regulations regarding anhydrous ammonia use. The Concord facility has completed an exhaustive safety and design review under the OSHA Process Safety Management law, 2 CFR 1910.119. This law requires a complete analysis of the anhydrous ammonia process from a catastrophic release and safety perspective prior to its being put on-line. This document can be reviewed by contacting the WEPCO offices. It is WEPCO's policy to not only adhere to the Federal and State laws governing the use of this cemical but to extend safety, health, and environmental efforts beyond that of government requirements. In that vein WEPCO and its employees are committed to the safety and health of the employees and the well being of our community. The Concord facility finds support from the internal corporate safety, health, and environmental staff as well as a number of outside professional consultants. WEPCO's emergency response planning program is based on the OSHA, EPA, and Coast Guard models for Hazardous Waste Operations and Emergency Response guidelines. Concord Station has an interactive HAZMAT structure within the facility. The system consists of WEPCO employees working with the Jefferson County LEPC and its emergency Director exclusidely and is active twenty-four hours a day to deal with any emergency related to the application of highly hazardous chemicals, namely anhydrous ammonia. The Emergency Response Plan details the procedural aspects of the HAZMAT effort in the facility and the interaction between its members, the employees, local commun ity, and its emergency personnel. THE STATIONARY SOURCES AND REGULATED SUBSTANCES HANDLED: The Concord Generating Station uses anhydrous ammonia within the facility. As stated previously the anhydrous ammonia is utilized as a refrigerant to temper the ambient air before it is introduced into the turbine mechanism. The anhydrous ammonia is kept within a closed loop system and is transferred through the system via compressors, pumps, etc. The low pressure receiver will hold the largest amount of anhydrous ammonia at any one time. The low pressure receiver will have a maximum capacity of 3,400 gallons or 10,299 pounds of anhydrous ammonia. this being 54% of the total capacity of the vessel itself. the system can be 'topped off' at year's end to allow for any minor losses within the system. Technical grade or better of anhydrous ammonia is utilized to minimize the introduction of contaminants such as water into the system. Written Standard Operating Procedures are followed for al l system operations including the transfer of anhydrous ammonia to the system. System components are accounted for on a dedicated parts inventory system and managed through an in-house maintenance schedule established in cooperation with the component manufacturers. THE WORST-CASE AND ALTERNATE RELEASE SCENARIOS: AMMONIA WORST CASE F CLASS: Failure of a single low pressure receiver with a capacity of 10,299 pounds of anhydrous ammonia. Considering an opening 3 inches in length and .55 inches in width. This would result in the release of all of the anhydrous ammonia in the low pressure receiver in roughly 10 minutes. The atmospheric conditions are dictated by the Environmental Protection Agency for this case. The wind direction should be considered on a case by case basis. The footprint (see case printouts) has included an outside zone which can be used to derive a safety zone outside the direct area or level of concern area. The maximum threat zone is 1.7 miles down range for the lethal concentration utilizing the F atmospheric class required by the EPA. The estimated threat zone perpendicular to the flow is roughly 0.90 miles on either side of perpendicular. AMMONIA WORST CASE B CLASS: All information for this model is identical with the above scenarios with the exception of the atmospheric conditions. B class atmospherics were used instead of the prescribed EPA F class. The maximum threat zone is 1.2 miles down range for the lethal concentration with a perpendicular threat zone of 1.2 miles. AMMONIA ALTERNATE CASE F CLASS: The alternate case release scenario consisted of a pressure release from the top of the low pressure receiver through the pressure relief valve at that location. The pressure relief valve has a diameter of 0.5 inches. The release rate of 5.38 pounds per minute accounted for 283 pounds of released ammonia over a one-hour period. (a model with a release longer than one hour is considered inaccurate due to variability of atmospheric s for the time period). The maximum threat zone down range is 62 yeards. This extremely short distance does not allow for a footprint computer generation. AMMONIA ALTERNATE CASE B CLASS: The alternate case release scenario is the same as the F class. The maximum threat zone is 359 yards down range with a perpendicular maximum threat zone of 180 yeards. THE GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM AND THE SPECIFIC PREVENTION STEPS: The facility complies with the OSHA Process Safety Management Standard for the highly hazardous chemical anhydrous ammonia. As part of the requirements a process hazard analysis (PHA) was performed in the form of a Hazard and Operability Study (HAZOP) including a review of mechanical integrity. As a result of this, the process and instrument diagrams (P&ID's) have been reviewed as part of the accident prevention program. All valves, gangs, and headers have been placed on the roof where possible to reduce potential exposure of employees. this al so reduces the potential from strike damage. Component parts are also being replaced based upon a specific schedule as established under mechanical integrity. The system is also being evvaluated for leaks via a real-time ammonia analyzer. All workers involved with the system have been trained regarding system safety and operation. All operations are supported by written operating instructions. WEPCO has also retained technical consultants, Caldwell Energy and Environmental Inc. and an environmental/occupational health consultant, TriStar Associates Inc. Both of these firms are active participants in any decisions related to issues regarding the process safety of the ammonia system. FIVE YEAR ACCIDENT HISTORY: ANHYDROUS AMMONIA: No history is available since this is a new process. |