Oremet-Wah Chang South Campus - Executive Summary |
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Source Oremet Wah-Chang (OWC) produces a number of specialty metals for aerospace, nuclear, industrial, and commercial applications. Titanium is the principle product of OWC's South Campus facility located at 530 34th Avenue in Albany, Oregon. Titanium is produced by reacting titanium tetrachloride TiCl4 with magnesium metal to produce titanium metal sponge and magnesium chloride. The titanium sponge is further processed into various alloys and a number of different shapes. The magnesium chloride is further processed to recover magnesium metal for reuse and chlorine (Cl2) as a by-product. TiCl4 and Cl2 are the only toxic chemicals regulated by the Risk Management Program (RMP) that are present at the South Campus. These chemicals are closely monitored and controlled to prevent accidental releases to the environment. It is OWC's policy to manage these chemicals and processes "using the highest standards for the protection of our people, our customers, the community, and the envi ronment in order to ensure a safe, productive and competitive facility". Regulated Chemicals OWC's South Campus uses titanium tetrachloride (TiCl4) as a raw material in the titanium metal manufacturing process. TiCl4, a liquid at ambient temperatures, is delivered to OWC in 90-ton rail cars and unloaded into storage tanks ranging in size from 10,000 to 20,000 gallons. The storage tanks are surrounded with concrete curbs designed to contain any accidental leaks or spills from the storage system into a large below-ground containment sump. From the storage area, the TiCl4 is pumped at about 35 gallons per minute to the sponge plant where it is reduced to titanium metal. In the unlikely event of an accidental release, the TiCl4 would be collected in the containment system or flow onto the ground and slowly evaporate. The TiCl4 vapors would react with the humidity in the air to form titanium dioxide, an inert nonhazardous solid, and hydrochloric acid (HCl). The health effect of HCl vapor is primarily an irritant of mucous membranes, the eyes, and the respiratory tract. The HCl vapors would migrate downwind and quickly disperse to below health affect concentrations. Currently, liquid chlorine is produced and sent directly from the process to 90-ton railcars. When a car has been filled, a 200-ton storage tank is used in the interim until the full car can be removed and an empty 90-ton car can be placed in the loading position. OWC has developed a plan to decommission both of the 200-ton tanks and remove them from liquid chlorine service. This plan has two elements. The first element is to limit each of the 200-ton tanks to 90-ton capacity by June, 1999 using engineering and administrative controls. The second element is to completely eliminate their use for liquid chlorine by September 1999. In the unlikely event of an accidental Cl2 release, it would either be released directly into the air as a gas or evaporate into the air from liquid pools formed in l ow spots on the ground. The health affect of Cl2 gas is primarily a respiratory irritant. In sufficient concentrations, the toxic gas irritates the mucous membranes, the respiratory tract and the eyes. The Cl2 gas will migrate downwind and disperse to below health effect concentrations. Accidental Release Prevention and Emergency Response The toxicity of Cl2 and TiCl4 at high concentrations make it necessary for OWC to observe certain safety precautions to prevent unnecessary human exposure, and reduce the threat to the personal health of our employees as well as nearby members of the community. It is OWC's policy to adhere to all applicable federal and state rules and regulations. Safety depends upon the manner in which we handle toxic chemicals including equipment design and safe handling procedures used to operate the equipment. OWC's release prevention program is based on four principles; inherently safe design, effective written procedures, training, and the goal of conti nuous improvement. Our chemical storage and handling equipment meets or exceeds design codes and standards as well as incorporating good engineering practices recommended by industry groups, such as The Chlorine Institute. As a result, OWC's equipment incorporates inherently safe designs. Written operating and maintenance procedures are prepared and reviewed annually for accuracy and safety. Operating and maintenance personnel are thoroughly trained on proper procedures and safety hazards, and are provided with regular refresher training. Equipment and procedures are frequently evaluated and updated with the goal of continuous improvement in both operation and safety. OWC's emergency response program integrates OSHA's and EPA's preparedness planning response and training requirements. In the event of an accidental release, the emergency response plan includes notifying 911 dispatch, who will notify local responders. Plant personnel will notify neighboring industries, DEQ, and O SHA, as necessary. Plant personnel receive classroom training on implementation of the response plan in addition to participating in training exercises. Worst-case and Alternative Release Scenarios The worst-case release scenario at OWC's South Campus facility involves the catastrophic failure and release of the entire contents of a 90-ton liquid Cl2 storage tank. Using EPA's dispersion modeling program, RMP*Comp, the maximum distance downwind from the storage tank to an endpoint concentration of 3 ppm Cl2 is 14 miles. This worst-case impact distance is calculated using EPA mandated assumptions which are conservative. For example, EPA requires the assumption that all of the liquid Cl2 is released as a gas within 10 minutes. Actually, only about a third of the liquid Cl2 will flash off as gas while the remaining two thirds either remains in the tank or spills on the ground and evaporates over a much longer time period. The worst-case analysis also requires the unrealistic a ssumption that the wind blows constantly at a high speed in the same direction for several hours in order for the Cl2 to migrate several miles downwind. OWC believes that these calculated worst-case distances overstate the distances that harmful impacts could occur. The alternative release scenarios are considered by EPA to be more representative of actual impacts attributable to an accidental release. Alternative release scenarios were developed for both Cl2 and TiCl4. Both alternative release scenarios were developed during detailed Process Hazard Analyses involving operating, maintenance, and engineering personnel, and outside experts. The alternative release scenario is intended to represent the largest release, that could reasonably be expected to occur. For Cl2, the alternative release is based on a liquid Cl2 separator overflow that could release 500 pounds of Cl2 gas to the tailgas burners in ten minutes before it is shut off. Using EPA's RMP*Comp model, it is calculate d that this release could exceed 3 ppm Cl2 up to 0.1 miles downwind. For TiCl4, the alternative release scenario is based on a two-inch transfer pipeline failure which would release the contents of the pipeline (700 pounds) plus the pumped volume of 30 gpm for 10 minutes until the pump is turned off. The total release would be about 4,300 pounds of TiCl4. The maximum calculated downwind distance to the endpoint is 0.2 miles. These alternative release scenarios are more realistic than the worst-case releases. Five Year Accident History During the five year period between May 1994 and June 1999, the South Campus has had two documented reportable releases of chlorine and no documented reportable releases of TiCl4. One release occurred on December 23, 1998 and involved the discharge of less than ten pounds of chlorine gas from the hydrochloric acid burner vent. The release resulted in a minor, short-term inhalation injury to one OWC employee with no off-site impacts. The second re lease occurred on March 24, 1999 and involved the release of a small but unknown amount of chlorine gas from a line transporting Cl2 from a Mag Cell to the Cl2 cleaning, drying, and liquefying system. The Cl2 line was being rodded out when a small chlorine release exposed the person rodding out the line who was wearing a half facemask respirator at the time. The person was hospitalized for one day for observation of a minor Cl2 inhalation injury. |