Dyno Nobel Carthage Plant - Executive Summary |
|
Dyno Nobel Carthage Plant Risk Management Program Executive Summary 1. Accidental Release Prevention and Emergency Response Policies Dyno Nobel is committed to the protection of the safety, health and environment in our routine operations and emergency responses. Our prevention and emergency response practices are developed to protect the public as well as our own employees. It is our policy to comply with applicable laws, and to support and work with local emergency response agencies. 2. Description of Facility and Regulated Substances Handled Dyno Nobel's Carthage Plant has operated at its current location under various owners since the 1890's. The plant manufactures a number of explosive products for commercial uses such as mining and construction. Products include dynamite, emulsion explosives, and cast boosters. Some ingredients for these products are made at the plant and require the handling of regulated substances at levels above the threshold of applicability of Risk Management Planning Requirements. Those substances include: Anhydrous Ammonia, NH3 Nitric Acid, (HNO3), in strengths over 80%, and Oleum, which is a mixture of sulfuric acid (H2SO4)and sulfur trioxide, (SO3) Anhydrous ammonia is stored at one location. It is used as a feedstock in a process which converts reclaimed nitric acid from explosives manufacture into ammonium nitrate. The ammonium nitrate is then used as an ingredient in explosives. Nitric acid over 80% strength is stored in two locations. It is blended with oleum to produce nitrating acids for the synthesis of nitrate ester explosives such as nitroglycerine. Nitric acid is also used directly in the synthesis of one ingredient of cast explosives boosters. Oleum is stored at one location. It is blended with nitric acid to produce nitrating acids for the synthesis of nitrate ester explosives such as nitroglycerine. 3. Worst Case Release Scenario and Alternative Case Release Scenario Dyno Nobel is requir ed to estimate the impact of a worst case release and a more likely alternative case release for each of its three regulated substances. The specified worst case release model includes conservative assumptions for wind and other meteorological conditions which least favor dispersion of the released materials. Only passive mitigation techniques are considered for the worst case. Active measures such as responses by plant or external responders cannot be considered. Releases were modeled using EPA's dispersion modeling software, RMP*Comp, unless otherwise noted. For anhydrous ammonia stored as a pressurized gas, the worst case release is defined as the loss of the entire contents of the largest tank within ten minutes. Our largest tank could hold up to 80,000 lbs, although operating procedures normally maintain the tanks to half that level or less. Modeling of this release was performed using EPA's dispersion modeling software, DEGADIS. If the entire contents of this tank were to be released in ten minutes, vapors could produce off site impacts up to 2.7 miles from the tank. Most of this impact zone would lie upon Dyno Nobel property. The alternative release case for anhydrous ammonia was based upon the rupture of a one inch ammonia transfer line from the tanks to the point of use. This release was modeled using EPA's dispersion modeling software, SLAB. The modeled release would produce an impact zone located almost completely upon Dyno Nobel property. For nitric acid and oleum stored as liquids, the worst case release is defined as the instantaneous loss of all tank contents. In Dyno Nobel's case, the worst case release rate would be reduced by the passive mitigation of a concrete containment around both the oleum and nitric acid tanks. The alternative case release chosen for both oleum and nitric acid involves a rupture of the respective 2 inch truck unloading lines. This is considered to be more likely to occur than the worst case scenario. In t he event of the sudden failure of the largest vessel containing nitric acid to the diked spill containment area, the subsequent volatilization of the spilled material could produce an impact radius of 1.35 miles, which could affect off site public receptors. This release was modeled using EPA's dispersion modeling software, DEGADIS. The alternative release chosen for nitric acid involving the rupture of a truck unloading hose would produce an impact area which would fall almost entirely upon Dyno Nobel property. In the event of the sudden failure of the largest full tank of oleum, the material would be released to the containment, and subsequent volatilization of the spilled material would produce an impact radius of 1.0 mile which could affect off site public receptors. The alternative release scenario chosen for oleum involving the rupture of a truck unloading hose would produce an impact area which would fall almost entirely upon Dyno Nobel property. 4. General Accidental Rel ease Prevention Program Dyno Nobel is subject to OSHA standards, including Process Safety Management, which requires systematic documentation and periodic review of processes. Additionally, processes with the potential for off site impacts per EPA's Risk Management Planning rule are subjected to additional hazard assessment related to potential off site effects. These hazard assessments have resulted in such protective steps as containment walls around tanks, improved controls and alarms, and more intensive periodic process safety reviews. 5. Five Year Accident History No accidental releases reportable under Risk Management Planning rules have occurred from the covered processes in the past five years. 6. Emergency Response Program Dyno Nobel maintains a written Emergency Plan to help assure timely, safe, compliant responses in the event of an emergency. Drills are conducted, including some with outside agencies. The Carthage Fire Department visits the plant regularly t o maintain familiarity with the facility. 7. Planned Changes to Improve Safety In addition to programs required by law, Dyno Nobel undertakes other initiatives to improve safety. Dyno Nobel has a company-wide policy of documenting and reporting near misses where a potential for a more serious incident exists. This allows us to identify potential problem areas for correction before an accident actually occurs. We plan to improve our techniques for analyzing and responding to near misses. Dyno Nobel is upgrading process instrumentation and controls to modern systems, including some computer controls to provide more positive control of processes. |