Kennecott Utah Copper Corp. Smelter and Refinery - Executive Summary |
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Accidental Release Prevention and Emergency Response Policies Kennecott Utah Copper Corporation (KUCC) is committed to providing a safe and healthy work environment. Health, safety and environmental matters are an integral part of our business and a part of our strategic and operational decision-making criteria. KUCC has established and maintains Health, Safety and Environmental Standards and procedures to promote safety awareness and control hazards during operations. The KUCC Spill Prevention Control and Countermeasures Plan prepared in accordance with EPA and State regulations on oil pollution prevention has been expanded to include guidance on all chemical spills. Copies of the plans are located at each facility and requirements for the plan are defined in KUCC Environmental Procedures Standards. Specific operational procedures are established for the Sulfur Dioxide system. Emergency Response Plans have been developed for each of the KUCC plants. These emergency procedures are d esigned to be utilized in an event that requires marshalling of Emergency Response Groups due to serious accidents/injuries, major property damage, or major environmental impact. Stationary Source and Regulated Substances Handled The Kennecott Utah Copper Corporation Smelter smelts copper concentrate to produce copper anodes and sulfuric acid. The sulfuric acid is sold to various customers. The copper anodes are sent to the nearby Kennecott Utah Copper Refinery, which produces copper cathodes, gold, silver, selenium, copper telluride, and lead carbonate and/or lead sulfate from the copper anodes. The plants employ a series of separation steps to produce valuable metals and sulfuric acid from the natural sulfide minerals in copper concentrate. The Precious Metals Plant at the Refinery reacts anhydrous sulfur dioxide (SO2) with a mixture to separate selenium from other elements in the mixture. Anhydrous sulfur dioxide is a regulated substance under EPA's Chemical Accident Preventi on Rule (40 CFR Part 68). Anhydrous sulfur dioxide is stored in a tank, which is equipped with piping to feed the sulfur dioxide into the selenium reduction tank where reactions occur in an acidic solution. The Smelter uses natural gas as its primary fuel, but it stores propane for use as a backup fuel in the event of a curtailment of the supply of natural gas. Propane is a regulated substance under EPA's Chemical Accident Prevention Rule (40 CFR Part 68), because, like all fuels, it is flammable. However, a court order has stayed the requirement to prepare a Risk Management Plan (RMP) for propane until further decisions by the court. Kennecott Utah Copper will revise this RMP as necessary in accordance with the court's decisions. Worst-case Release Scenarios and Alternate Release Scenarios, including Administrative Controls and Mitigation Measures to Limit the Distances for Each Reported Scenario The worst-case scenario selected by EPA is a hypothetical and very unlikely releas e of the entire contents of the SO2 tank over a period of 10 minutes during stagnant atmospheric conditions typical of a temperature inversion. The accidental release prevention steps described below make this scenario very unlikely. The scenario is mitigated by limiting the contents of the tank to 119,000 lb (85% of its nominal capacity, 140,000 lb; 71% of its total capacity, 167,000 lb), through written procedures together with the capacity of the delivery trucks. The distance to the toxic endpoint predicted by the EPA-approved model DEGADIS is 2.24 miles. Based on detailed information on land ownership and use, no one lives within that distance from the tank. (Census data were examined, but they are too imprecise geographically to be used in this case.) There are no schools, residences, hospitals, prisons, National Parks, Forests, Monuments, Wilderness Areas, or officially designated wildlife sanctuaries, preserves, or refuges within that distance. However, there are industri al facilities within that distance owned by Kennecott and by others. The Great Salt Lake State Park (South Shore) and a beachside resort/recreation area are located within that distance. Sections of Interstate 80 and Utah Highways 201 and 202 pass within that distance. The much more realistic alternative release scenario is a release of 4.2 lb/min of SO2 for two hours from process piping caused by failure (due to corrosion) of 1 of 4 bolts at a flange. We selected this scenario based on process hazards analysis and on an actual incident in 1998. It is assumed that SO2 detectors will set off alarms, and that it could take up to one hour to respond to the leak alarms, and one additional hour to repair the leak. The distance to the toxic endpoint predicted by the EPA-approved model DEGADIS is 0.19 miles. Based on detailed information on land ownership and use, no one lives within that distance from the tank. (Census data were examined, but they are too imprecise geographically t o be used in this case.) There are no schools, residences, hospitals, prisons, recreation areas, National or State Parks, Forests, Monuments, Wilderness Areas, or officially designated wildlife sanctuaries, preserves, or refuges within that distance. However, there are industrial facilities within that distance owned by Kennecott. Short sections of Utah Highways 201 and 202 pass within that distance. General Accidental Release Prevention Program and Chemical-specific Prevention Steps KUCC complies with the OSHA PSM program for the SO2 storage process. Process controls include vents, relief valves, check valves, scrubbers, manual and automatic shutoffs, interlocks, alarms and procedures, grounding equipment and rupture disks. Process area detectors, perimeter monitors and video cameras are used to detect releases or other safety problems. Employees are given classroom and on-the-job training, and are tested and observed to ensure competency. The tank is given an ASME bulk stora ge tank integrity test every 5 years, most recently in May of 1999. SO2 sensors are calibrated quarterly by an outside contractor and monthly by KUCC electricians. A Process Hazard Analysis (HAZOP) was done in March 1999; these are done every 5 years. Compliance inspections are conducted by Utah Occupational Safety and Health Agency, most recently in July 1998. Internal compliance audits are also conducted, most recently in March 1999. Five-year Accident History The tank and associated piping for anhydrous sulfur dioxide has been at the Refinery for ten years. Since it was installed in 1989, there have been no accidental releases of sulfur dioxide that resulted in deaths, injuries, or significant property damage on site, or offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage. Emergency Response Program KUCC's plants are included in the Salt Lake County Local Emergency Planning Committee's (LEPC) Emergency Response Plan. In addi tion, KUCC has developed Emergency Response Plans for each of the KUCC plants. These plans are coordinated with the Salt Lake County LEPC. These emergency procedures are designed to be utilized in an event that requires marshalling of Emergency Response Groups due to serious accidents/injuries, major property damage, or major environmental impact. The Plans identify and categorize personnel action procedures for directing response to emergency events. They provide guidance to individuals assigned emergency responsibilities and provide back-up information and data to facilitate management of response and recovery after an event has occurred. The Plans include procedures for informing the public and Salt Lake County LEPC in the event of accidental releases. Emergency Response Groups are trained on a regular basis. The Refinery Emergency Response Plan is supplemented by an Emergency Preparedness procedure contained in the SO2 Process Safety Management Program Manual, which specifical ly addresses a release of sulfur dioxide. The procedure focuses on emergency evacuation and response procedures. Planned Changes to Improve Safety KUCC has a well established safety program with the goal to continuously improve company safety performance. In 1999, a goal of a twenty-five percent (25%) reduction in the number of safety incidents has been adopted company wide. At the Refinery, a SO2-PSM committee routinely meets to discuss issues, review action items, and to identify system improvements to enhance the overall integrity of the SO2 process. The SO2-PSM committee will continue to function proactively for the continued safe handling and operation of the sulfur dioxide system. |