Devro-Teepak, Sandy Run, SC - Executive Summary

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Devro-Teepak's accidental release prevention and emergency response policies show that the facility is strongly committed to employee, public and environmental safety, and adheres to all applicable regulations. The comprehensive accidental release prevention program covers response procedures such as pre-emergency employee training, lines of communication and authority, emergency recognition, evacuation routes and procedures, and emergency medical treatment. It is Devro-Teepak's policy to implement appropriate measures to prevent possible release of regulated sustances. 
Devro-Teepak has one (1) regulated substance at the facility above threshold quantity. The regulated substance is anhydrous ammonia. Ammonia is used in the facility's manufacturing process. Ammonia is stored in one 10,000 gallon nominal tank, and in a 12,000 
gallon nominal tank. The maximum amount of ammonia that could be released is 44,000 pounds. The facility is mandated to meet Program 3 requirements because a release would result in off-site impact, and is subject to OSHA's Process Safety Management regulation. 
The offsite consequence analysis includes consideration of two anhydrous ammonia scenarios, identified as "worst case release", and as "alternative scenario". The worst case scenario is defined by the US EPA as a release of the largest storage vessel over a 10 minute period due to an unspecified failure. The alternative release is defined by the US EPA as a release that is more likely to occur than the worst case release. The facility and consultants chose DEGRADIS+ to perform the air dispersion consequence modeling due to the nature of the chemical and the release scenarios. 
The worst case release scenario submitted for the facilty involves a catastrophic release of 44,000 pounds in a 10 minute period. The  
worst case release rate would be 2420 lbs/min. The worst case release was analyzed at class F atmospheric stability, 1.5 m/s wind speed, 103 F, 71% humidity, and 0.25 m surface roughness for the maximum distance to the toxic endpoint of 140 mg/m^3. Passive mitigation was considered. The worst case release did result in offsite impact. 
The alternative release scenario for ammonia is a conservative release which involves a pipe breakage during transfer from truck to storage tank. The alternative scenario assumes that all ammonia in the piping would be releasedin a one (1) minute period. The amount of ammonia was calculated to be 154.7 pounds. Thus the rate would be 154.7 lb/min for one (1) minute through a 3" nominal pipe. The alternative release scenario was analyzed at Class D atmospheric stability, 3.0 m/s wind speed, 62.9 F, 71% humidity, and 0.25 m surface roughness for the maximum distance to the toxic endpoint of 140 mg/m^3. The alternative resulted in offsite impact. 
The altern 
ative release is much more likely to occur at the facility than the worst case scenario. The worst case result is unrealistic because at that high of a release rate, the ammonia will likely freeze over the hole in the container which will prevent or limit futher realease of gas. 
Devro-Teepak has taken the necessary steps to comply with the accidental release prevention requirements set out under 40 CFR part 68 of the EPA. The process is subject to the OSHA PSM standard under 29 CFR 1910.119 and is already in compliance. The following steps are key to the prevention program: 
1. Detailed records of safety information describing chemical hazards of ammonia, process technology, and process equipment; 
2. Comprehensive process hazard analysis are conducted with manangement, technical personel, and operators to ensure that hazards are recognized and evaluated; 
3. Operating procedures were developed and implemented which describe  
tasks to be performed, dates to be recorded, operation conditions to be maintained, emergency operating procedures, and safety and health precautions to be taken; 
4. Employee training program is in effect to ensure that employees at the site are properly trained, aware of ammonia safety practices, hazards, emergency procedures, and maintenance procedures; operators, technicians, and managers are trained; 
5. An on-going mechanical integrity program is in place to ensure continued safe process operation and physical condition; 
6. Incident investigation procedures are in place to ensure that unplanned events effecting process safety are properly investigated in a timely maner to identify the causes of the incident, and to implement corrective action. 
Devro-Teepak has had an excellent record for preventing accidental releases over the last five years. Due to the effective release prevention policies, there have been no accidental release of ammonia of reportable 
quantities during the last five years. 
The site has a writtten emergency response plan to deal with the accidental release of ammonia, and other hazardous substances, which has been coordinated with local emergency response personnel. The plan contains the aspects of emergency response including adequate first aid and medical treatment, evacuations, and notification of the local emergency response groups, and the public. 
The last Proces Safety Hazard Analysis was performed in May 1997. Since the analysis, piping and the tanks have been tested and items changed to ensure compliance with ANSI, UL standards, an ammonia sensor installed, and a remote shutoff for ammonia transfer installed. The building that contains the ammonia tanks will be changed to include a pipe and spray system controlled by the ammonia sensor such that high concentrations of ammonia will activate a water spray to help contain or mitigate offsite impact.
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