Circuit Systems of Tennessee, Lp - Executive Summary |
|
A. Circuit Systems of Tennessee accidental release prevention policy involves a unified approach that intergrates technologies, procedures, management practices and training to reduce the risk of a release. B. Circuit Systems of Tennessee makes single sided printed circuit boards based on customer designs and requirements. Chlorine is used as the oxidizing agent in the etching process to remove excess copper from the process panel. Chlorine is drawn under vacuum from a central feed system based on etching requirements. The chlorine room is isolated from the rest of the plant and is maintained at negative pressure by an air scrubbing system. The feed system draws liquid chlorine thorough a vaporizer to feed the vacuum regulator valve. The alarm system is connected to automatic shutoff valves connected directly to the 1 ton cylinders. C. The potential offsite release scenarios analysis considers worst case and alternative scena rio to fulfill EPA's regulations 40CRF68 for offsite consequence analysis. These requirements are part of Risk Management Program of EPA covered under the Clean Air Act section 112(r)(7). Circuit Systems of Tennessee obtained the help of outside consultants to define potential release and potential impact on surrounding community and system improvements. The study concluded that the maximum consequence distance was 2.6 miles might occur for an uncontrolled release under worse case analysis but active mitigation systems reduced the consequence distance to .06 miles for the alternative scenarios. The alternative event may trigger an evacuation of the plant personnel, but ambient concentrations exceeding ERPG-2 value of .0087 mg/L should not occur beyond the plant property. The SLAB method was used to model the worst and alternative scenarios. The SLAB computer model is PC-based model that simulates the atmospheric dispersion of denser-than-air releases. The calibration simulations for the SLAP model was designed to to duplicate the results in the dense gase reference tables, input values were identical to those described in the Offsite Consequence Analysis Guidance (EPA 1996). The reference tables shown in the Guidance were based on the evaporating pool algorithm in the SLAB model and on releases of hydrogen chloride (HCl). A SLAB modeling analysis of dense CAA gases or vapors with different molecular weights revealed that releases of HCl generally provided conservative results under a variety of stability/wind speed combinations, release rates and toxic endpoints. The ten-minute release scenario (EPA defined worst case release) of toxic chemicals was modeled using 10 minute averaging time. For all the dense gas tables, the reference height for wind speed was 10 meters. The relative humidity was 50 percent and the ambient te mperature was 25 C. The source area was the smallest valve that enabled the model to run for all release rates. D. Circuit Systems of Tennessee accidental release program is based on the following key elements: - Training - Preventive maintenance program - Automatic shutoff system - Continuous air scrubbing system - Alarm system - Sound operating procedures - Quality suppliers with sound safety programs and records - Communications with local and state agencies - Environmental Managements System (ISO 14001) Certified BSI, Dec. 1996 E. No accidental releases of chlorine have occurred at this facility in the past five years. F. Circuit Systems of Tennessee emergency response program is cooridnated with local authorities thorough joint traiining and written plans. G. Three major changes were part of the implementation of the RMP program a. The addition of automatic shutoff valves tied to the alarm system and panic buttons b. The ability to provide larger amounts of NaOH to scrubbing system during alram conditions c. Increased offsite training on emergency response for key personnel |