Kaiser Aluminum and Chemical Corporation - Executive Summary |
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The executive summary is to provide an overview of the regulated substance (chlorine), regulated processes, the potential effects of a release or emergency episode and the safety measures that Kaiser Aluminum and Chemical Corporation in Heath, Ohio has done to minimize the risks involved. Kaiser Aluminum will observe certain safety precautions to prevent unnecessary human exposure, to reduce the threat to the employees and to nearby members of the community. It is Kaiser's policy to adhere to all applicable Federal and state rules and regulations. Access to the site is strictly enforced by security and is restricted to facility employees, authorized management personnel and authorized contractors. Safety at the site depends upon the manner in which Kaiser handles chlorine, the safety devices inherent in the design of this facility and the training of the Kaiser personnel that operate and maintain the system. The emergency response program developed and employed by Kaiser includes procedures for notification of the local fire authority (Heath), the local emergency planning commission (Licking County Emergency Management) and notification of any potentially affected neighbors. This plan corresponds with the emergency response procedures outlined in the Chlorine Institute's Pamphlet 64, Emergency Response Plans for Chlorine Facilities. The process covered in this Risk Management Program at Kaiser is the storage, handling and use of chlorine. Kaiser uses chlorine as a fluxing agent in the aluminum melting furnaces. Chlorine gas is bubbled through the molten aluminum and helps bind onto and float impurities to the top. Once on top, the impurities can be skimmed off as waste product (dross). A description of each phase of the process as well as the worst-case and alternative release scenarios is included below. Chlorine Unloading and Storage Chlorine is received at the facility in one (1) ton storage containers which contain chlorine under pressure at ambient conditions. The containers arrive on a truck and unloaded via an overhead crane directly into the chlorine storage area along the north central side of the facility. The dock unloading area is designed to minimize handling of the cylinders and the cylinders are only raised approximately 2 feet off of the truck or loading dock at any time. The cylinders are moved into the building and placed in-line. Full containers are placed with the valves facing north (the correct position to be connected to the chlorine system). Empty container valves are placed facing south, to avoid connection to the vaporizer. Administrative measures have been employed during the purchasing and inventory process to insure that no more than four (4) tons of chlorine are purchased and that a maximum of six (6) tons of chlorine are located on-site. Additionally, all incoming containers are thoroughly inspected to insure that damaged containers are not received on-site. Automatic chlorine leak detection as w ell as emergency "B" kits to repair valves and lines on one (1) ton containers are located in the storage area. The presence of these devices provides Kaiser with a rapid detection system in the most crucial area for preventing a large release of chlorine. This detection allows small leaks to be detected and repaired before they can become worse. The storage area, which contains the one (1) ton cylinders and the evaporator equipment, is located in an isolated area of the building away from processes and easily accessible in emergency situations. The storage area is protected with barriers to prevent the possibility of damage by and the appropriate warning signs. Chlorine Vaporization (Evaporation from Liquid to Gas) Chlorine containers are connected to the vaporizing system, which is merely a heating system to evaporate the chlorine liquid. When ambient temperatures are warmer it is common practice to withdraw vapor directly from the ton container. When vaporizing chlorine from a one (1) ton container liquid chlorine is transferred to the heat exchanger where it is caused to boil (vaporize) by the controlled application of heat. Chlorine gas is withdrawn from above the pool of boiling liquid and delivered to the point of use. The evaporator contains many features (ie. Pressure relief valves, shut off valves) that help insure its safe use and prevention of large chlorine release. The design of the evaporator unit conforms to ASME and the Chlorine Institutes recommendations. The steel gas-pressure cylinder (heating chamber) and all of the pressure relief valves on the unit conform to ASME Code, Section VIII, Division 1 for pressure vessels. Chlorine Gas Transfer Once the chlorine is processed in the evaporator it is transferred via overhead piping to the distribution points (gas panels) at the melting furnaces. Manual shut-off valves and chlorine detection alarms are located near the gas panels. At the gas panels chlorine is combined with the appropr iate mixture of argon and nitrogen and is distributed to the aluminum melting reservoirs. The amount of chlorine applied to a charge of aluminum varies depending on the alloy being melted. Worst-Case Release Scenario (WCS) The criteria to be used for evaluation of the worst-case release scenario is given in 40CFR'68.25 The USEPA has defined the worst-case scenario as the release of the largest quantity of a regulated substance from a single vessel or process line failure that results in the greatest distance to a toxic endpoint. WCS Parameters - The toxic endpoint for Chlorine is 0.0087 mg/l (3 ppm). The release rate was 200 lbs/min over a 10 min. period for a total release of 2,000 lbs or the contents of a single storage container. The wind speed for the analysis shall be 1.5 meters per second with an F stability class. The ambient temperature and humidity shall be assumed to be 25EC and 50 percent humidity based on usage of the RMP Offsite Consequence Analysis Guidance. Th e WCS of a regulated toxic substance was assumed to have a ground level release, i.e. 0 feet. Rural roughness was assumed for the release topography due the fact that less than 50% of the area surrounding the facility would be considered urban or developed. The maximum distance to the toxic endpoint considering the release scenario described above was determined to be 3.0 miles, using USEPA Guidance Document on RMP for Wastewater Treatment Plants (October 1998) using tables generated by the modeling program RMP Comp TM. Alternative Release Scenario (ARS) ARS Parameters - At least one alternative release scenario has to be determined for each toxic substance applicable to the RMP requirements. The alternative release should impact off-site and should be an event that would be more probable than the worst-case release. The alternative release scenario was determined to be a transfer hose failure and was determined during the process hazard analysis. The guidance indicated above uses "average" weather conditions, which consist of a wind speed of 3 m/s and D stability class. The ambient temperature and humidity shall be assumed to be 25EC and 50 percent humidity based on usage of the RMP Offsite Consequence Analysis Guidance. The release rate was 87 lbs/min over a 10 min. period for a total release of 870 lbs. The ARS of a regulated toxic substance was assumed to have a ground level release, i.e. 0 feet. Rural roughness was assumed for the release topography due the fact that less than 50% of the area surrounding the facility would be considered urban or developed. The maximum distance to the toxic endpoint considering the release scenario described above was determined to be 0.4 miles, using USEPA Guidance Document on RMP for Wastewater Treatment Plants (October 1998) using tables generated by the modeling program RMP Comp TM. |