Matheson Gas Products - New Johnsonville - Executive Summary |
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MATHESON GAS PRODUCTS - NEW JOHNSONVILLE, TN BRANCH BACKGROUND This Matheson Gas Products facility transfills industrial grade hydrogen sulfide, a liquified gas, into compressed gas cylinders of varying sizes. The source material gas is delivered by tanker and stored in two on-site tanks each with a capacity of approximately 35,000 lbs. The finished product cylinder capacities vary from 1,055 lbs. to less than 1 pound of gas. The amount of hydrogen sulfide used in the filling process qualifies this process for inclusion in the RMP program at the Program 3 level. We believe a large gas release from this facility is extremely unlikely. This facility has the equipment, the procedures and the training to ensure that a gas release impacting off-site areas will not occur. They are described in the Prevention Program section of this Executive Summary. DESCRIPTION OF WORST-CASE AND ALTERNATIVE CASE SCENARIOS Worst-Case Scenario In compliance with the USEPA definition of a wor st-case scenario, the loss of the entire contents of the largest container over a period of ten minutes was modeled using RMPComp. Such a release is extremely unlikely since 1) it assumes catastrophic failure of a tank that is built to withstand pressures and temperatures well above normal operating conditions; 2) it assumes the simultaneous failure of all safeguards; and 3) no allowance is made for the presence and use of active mitigation systems and procedures. Consequently this should not be considered a credible release situation. The worst-case release scenario at this location for hydrogen sulfide assumes the loss of 35,000 lbs. of gas in ten minutes, resulting in a theoretical off-site impact of 11.0 miles. Alternative case scenarios The alternative release scenario for hydrogen sulfide is a break or rupture in the filling line. Releases are most likely to occur during the filling process, and the most likely weak point in the filling process is the line or pipe used t o convey the gas from the tank to the product cylinder. Alternative release scenarios were modeled without considering any mitigating equipment such as the scrubber. The alternative case scenario for hydrogen sulfide filling assumes the loss of 1200 lbs. of gas over 60 minutes, resulting in a theoretical off-site impact of 0.3 mile. ACCIDENT HISTORY There have been no accidents in the last five years at this site involving RMP regulated processes. PREVENTION PROGRAM and EMERGENCY RESPONSE There are numerous safeguards at this facility. First and foremost is the construction of the tanks themselves. The National Fire Protection Association (NFPA) Codes and the Compressed Gas Association (CGA) guidelines mandate the way in which these tanks are constructed and used. The tanks are designed to withstand extremes of operation and overpressure conditions that make either catastrophic failure or routine leaks extremely unlikely. This facility is also equipped with mitigation equ ipment if a leak should occur. There is a scrubber to capture emissions from the ruptured pipe. Monitors and shutoffs are also present. Last but not least there are procedures in place at this facility to ensure leaks do not occur, or to mitigate a leak if it does occur. The tank, tank area, lines, valves and pumps are routinely inspected. There are trained, experienced operators who have the required knowledge, skills and abilities to safely carry out their responsibilities who are able to assess and resolve possible problems before they result in a release. These operators average over 10 years of experience at this facility on this process. The Emergency Response Plan at this facility includes notification of local agencies and medical providers. Employees have been trained and drilled in emergency response. There is an Emergency Response Team on site that has been trained in accordance with OSHA 29 CFR 1910.120 (Q)(6)(iii). They have access to the necessary equipment and training to quickly respond to an emergency release. |