Power Resources, Inc. - Highland Uranium Project - Executive Summary |
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(a) Accidental Release Prevention and Emergency Response Policies - Power Resources, Inc. (PRI's) accidental release prevention policy for the Highland Uranium Project includes a committment to protect residents and the natural environment near its operations from any adverse affects from those operations. PRI's committent to this policy is carried out by ensuring that processes are designed and operated in accordance with recognized and generally accepted good engineering practices, in addition to complying with all applicable federal, state, and local laws. In the event that an accidental release occurs, it is PRI's policy to respond to an emergency situation with an on-site response team and coordinate these efforts with local responders as they arrive on the scene. (b) Stationary Source and Regulated Substances - The Highland Uranium Project produces uranium oxide (yellowcake) using in-situ leach (ISL) technologies. The Project has one regulated substance/process; an anhydrous ammonia storage and distribution system. Anhydrous ammonia is added to the precipitation circuit at the Central Plant for pH control during yellowcake processing. The system operates on demand and consists of an 18,000 gallon (water capacity) storage vessel, a vaporizer, piping, and all ancillary equipment, including valves, gauges, etc. (c) Worst-Case and Alternative Release Scenarios - Administrative controls limit the maximum capacity of the anhydrous ammonia storage vessel to approximately 90,000 lbs. Most of the piping in the distribution system is nominal one inch, with vapor phase flow. Thus, the inventory in piping is minimal compared to the liquid storage of the vessel. The worst-case scenario consists of an unmitigated release of the entire contents of the vessel, at maximum capacity, over a ten-minute period. According to EPA's RMP*Comp computer program, the distance to toxic endpoint for the worst-case scenario is 5.4 miles. The alternative release scenario consists of the failure of a 1/2-inch nipple connected to a pressure gauge on the liquid end of the vaporizer circuit. Shearing off the nipple would create a hole approximately 0.31 square inches in diameter. Using the EPA's RMP Offsite Consequence Analysis Guidance, the release rate was estimated to be 741 lbs/minute over a period of 10 minutes. According to EPA's RMP*Comp computer program, the distance to toxic endpoint for the alternative scenario is 0.5 miles. (d) General Accidental Release Prevention Program and Chemical-Specific Prevention Steps - PRI's general accidental release prevention program is based on the design and use of equipment in accordance with recognized and generally accepted good engineering practices, proper training of operators and maintenance personnel in the effective use of operating procedures, and the completion of hazard reviews. Chemical-specific prevention steps include availability of personal protective equipment (PPE), including full-face ca rtridge respirators and/or self-contained breathing appartus (SCBA), that is worn by operators and maintenance personnel whenever an ammonia line is opened, and employee awareness of the hazardous properties of ammonia. (e) Five-Year Accident History - No accidental releases of anhydrous ammonia have occurred at the Highland Uranium Project within the last five years. (f) Emergency Response Program - Based upon the relatively remote location of the Highland Uranium Project and the amount of time needed by local responders to address an emergency situation, PRI has established a Chemical Emergency Team (CET) and implemented an Emergency Response Plan (ERP) for on-site personnel. The ERP consists of evacuation and response procedures based on the type, location, and magnitude of a release, procedures for notification of local responders and the public, and documentation of emergency medical treatment for accidental exposures to ammonia. The ERP has been coordinated with the Local Eme rgency Planning Committee (LEPC) of Converse County, Wyoming, and incorporated into the Community Emergency Response Plan (CERP). (g) Planned Changes to Improve Safety - Twelve recommendations to improve safety were proposed during a process hazard review of the anhydrous ammonia storage and distribution system in May 1999. These recommendations are being evaluated and will be implemented as required. |