AFG Industries, Inc. - Greenland - Executive Summary |
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AFG Industries, Inc. - Greenland Executive Summary a. AFG Industries Inc. - Greenland Plant's accidental release prevention policy involves a unified approach that integrates technologies, procedures, and management practices. All applicable procedures of the U.S. Environmental Protection Agency (EPA) Prevention Program are adhered to. The AFG emergency response policy involves the preparation of a response plan which is tailored to the facility and to the emergency response services available in the community, and is in compliance with the EPA Emergency Response Program requirements. b. The sulfur dioxide storage, transfer, and injection process is used in the float glass manufacturing process. Sulfur dioxide is applied to the underside of the flat glass as it enters the annealing lehr to prevent stress cracking and as a lubricant for the glass. Sulfur dioxide is stored in the basement of the facility, under Float Line 2. There are a maximum of eight one-ton (2000 pounds) s ulfur dioxide tanks located in the basement of the facility. A maximum of four sulfur dioxide tanks are connected to a regulator, and the remaining four tanks are located in storage in the same area. Of the four cylinders which are connected to the regulator, only one cylinder is valved into the system and supplies sulfur dioxide to both float lines. c. The off-site consequence analysis includes consideration of two sulfur dioxide release scenarios, identified as "worst-case release" and "alternative release". The first scenario is defined by EPA, which states that "the owner or operator shall assume that the ... maximum quantity in the largest vessel ... is released as a gas over 10 minutes," due to an unspecified failure. The alternative release scenario is defined as "more likely to occur than the worst-case release scenario". The RMP*Comp modeling program (v1.06), developed jointly by CAMEO, NOAA, and the EPA, was used to determine the off-site consequences analysis for this RMP. RMP*Comp was designed to handle the various regulated substances and handling conditions for the RMP modeling requirements. Atmospheric dispersion modeling has to be performed to determine the distance traveled by the sulfur dioxide released before its concentration decreases to the "toxic endpoint" selected by EPA of 0.0078 mg/l, which is the Emergency Response Planning Guideline Level 2 (ERPG-2). This is defined by the American Industrial Hygiene Association (AIHA) as the "maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to one hour without experiencing or developing irreversible or other serious health effects or symptoms which could impair an individual's ability to take protective action". The residential population within a circle with a radius corresponding to the toxic endpoint distance has to be defined, "to estimate the population potentially affected". The worst-case release scenario at the AFG Indust ries, Inc. - Greenland Plant involves a failure of four one-ton tanks, which could be connected concurrently (a total of 8,000 pounds of sulfur dioxide). According to Risk Management Program (RMP) regulations, it should be assumed that, for toxic substances that are normally gases at ambient temperature and handled as a gas or as a liquid under pressure, the quantity present in a vessel will be released as a gas over ten minutes. The release rate is assumed to be the total quantity divided by ten, unless passive mitigation systems (such as berms or sumps) are in place. Sulfur dioxide is a gas that is handled as a liquid under pressure. In addition, there are no passive mitigation systems in place, with the exception of the location of the tanks in an enclosed area with direct contact with the outside air. The worst-case sulfur dioxide release rate was calculated by RMP*Comp as 440 pounds per minute. Since the facility is located in a hilly, partially wooded area, the topography wa s set to urban. Other assumptions specified by the regulations are automatically entered by RMP*Comp (i.e, EPA-mandated meteorological conditions, namely Stability Class F, wind speed of 1.5 m/sec, highest daily maximum temperature (116 F), and average humidity (65 percent)). When the worst-case scenario was performed using the RMP*Comp and the EPA assumptions, a maximum distance to the toxic endpoint (0.0078 mg/l) of 1.9 miles and an estimate of residential population potentially affected of 646 persons was obtained. The alternative release scenario involves the rupture of an sulfur dioxide supply line, possibly due to human error (i.e. running into the pipe with a forklift inside the furnace building) or to an external shock (i.e explosion). The supply line from the sulfur dioxide tank has a = inch diameter. From a structural aspect, the supply pipe is one of the weakest elements in the process. Based on incident release records (from the Accidental Release Information Pro gram), a pipe break or rupture is a common cause of gas releases. A pipe rupture, as an alternative scenario, is a more likely to occur than a catastrophic tank failure, as in the worst-case scenario. The pipe (= inch diameter) is assumed to rupture completely. Since the release occurs inside, the building would provide some passive mitigation in slowing the spread of the gas. RMP*Comp has an option which accounts for this factor. Other factors and assumptions (recommended by the RMP Offsite Consequence Analysis Guidance) included in the alternative release scenario were meteorological conditions, namely Stability Class D, wind speed of 3 m/sec, and an air temperature of 77 F. When the alternative release scenario was performed using the RMP*Comp and the assumptions, a distance to toxic endpoint of 0.1 mile and an estimate of residential population potentially affected of 2 persons was obtained. The alternative release scenario actually does not reach an off-site receptor. d. The general AFG accidental release prevention program is based on the following key elements: Operator training Preventative maintenance program Use of state-of-the-art process and safety equipment Use of accurate and effective operating procedures Performance of the hazard review of equipment and procedures Implementation of an auditing and inspection program The sulfur dioxide storage, transfer, and injection process has manual shut-off valves which can be closed if there is a leak in the system. All personnel are instructed to evacuate in the case of an accidental release. e. No accidental releases of sulfur dioxide have occurred at this facility in the past five years. f. The facility has an emergency response program, which has been coordinated with E.B. Noe, Civil Defense Director and Director of Emergency Management at the Local Emergency Response Planning Committee (LEPC). This program includes the procedures to be followed during an accidental release scenario, including a notification plan. Emergency operation and response procedures are reviewed periodically. g. The plan currently has no identified changes necessary to improve safety. |