Praxair - Theodore, AL - Executive Summary |
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The Praxair facility at Theodore, Alabama is a hydrogen storage location. We deliver liquid hydrogen, primarily from our McIntosh, AL plant, into two cryogenic storage vessels. The liquid hydrogen is then vaporized and compressed, and the hydrogen gas is then transferred via underground pipeline to two nearby customers. This hydrogen storage facility is not manned, but it is monitored around-the-clock by operators at Praxair's air separation plant located several miles away. Operators make site checks of the hydrogen operation periodically, drivers routinely visit the site to deliver product, and routine and preventive maintenance is performed regularly by Praxair service technicians. Hydrogen is listed as a regulated flammable substance in EPA's Risk Management Program rule, with a threshold quantity of 10,000 pounds. The storage process at the Theodore facility contains about 21,000 pounds of hydrogen, and is therefore subject to the RMP rule. Under the RMP rule, Praxair is req uired to report a Worst Case Scenario for the Theodore hydrogen process, which is defined by the EPA as the release of the entire contents of the largest hydrogen vessel in our process, with essentially none of the safety systems and devices that are in place to prevent such an occurrence functioning as designed. The release is assumed to ignite, causing a vapor cloud explosion. Given these conditions, we are then required to estimate the distance to an EPA-specified flammable endpoint, which is defined to be an overpressurization effect of 1 pound per square inch. At the Theodore facility, the largest hydrogen vessel contains about 11,000 pounds. Using the criteria listed above, the Worst Case Scenario would result in a maximum impact distance of about 0.25 miles to the EPA-specified endpoint. To determine this distance, we used the Compressed Gas Association's "Risk Management Plan Guidance Document for Bulk Liquid Hydrogen Systems." We are also required to report an Alternativ e Release Scenario, or planning scenario, under the RMP rule. While an Alternative Release may never occur at a facility, it is generally accepted to be more likely, or more credible, than the Worst Case Scenario, and can be used by the facility and local response organizations to plan community emergency response activities. The RMP rule assumes more typical atmospheric and weather conditions for an Alternative Release Scenario, and allows a facility to take credit for safety devices and other mitigation systems that are in place to minimize the likelihood and effects of a release. When selecting an Alternative Release Scenario, EPA suggests a facility consider scenarios such as transfer hose releases, valve and flange leaks, pump seal leaks, and shipping container mishaps, among others. For the Theodore hydrogen storage process, a credible release would be the failure of a liquid hydrogen line on the tank, with the released hydrogen gas igniting and causing a small vapor cloud ex plosion. At the Theodore facility, a release of this type would result in a maximum impact distance of about 0.07 miles, or 360 feet. To determine this distance, we used the Compressed Gas Association's "Risk Management Plan Guidance Document for Bulk Liquid Hydrogen Systems." Although the Theodore hydrogen process is not subject to OSHA's Process Safety Management standard, the Theodore facility has a comprehensive accident prevention program in place to ensure the safety of our employees, our neighbors and the community around us. On a local level, this prevention program is built around process safety concepts such as: 7 Documented safety information to ensure the process design is understood and maintained throughout its life; 7 Hazard reviews to identify and control all of the hazards associated with handling hydrogen; 7 Trained operators, using written operating procedures, to safely operate the process as intended; and 7 Maintenance programs and procedures to ensure the on- going mechanical integrity of the process. The prevention program is audited periodically, by our corporate assessment group, to ensure that the process safety concepts and practices are in place and working effectively. As a result of our process safety and risk management practices, the Theodore facility has not had an accident involving hydrogen in the last five years. In the event of an emergency, the facility has an emergency action plan in place, which contains procedures for employees to follow, including notification of local response agencies. All facility employees are trained in their role in the emergency action plan, and Praxair policy requires that emergency drills be conducted at least annually. Praxair is committed to continuous improvement of its safety and environmental programs. Although the Theodore hydrogen facility is unattended, it is closely monitored by personnel at our air separation plant several miles away. These operators and maintenance personnel ap ply the same safe work practices and safety programs to any tasks performed at the hydrogen station. Additionally, all hydrogen drivers are rigorously trained in order to safely handle and deliver hydrogen. Praxair is a producer and distributor of industrial gases with almost 100 years of experience. We are committed to being the best performing industrial gas company in all aspects of our business, including safety, health and environmental affairs. Praxair is a member the Chemical Manufacturers Association's Responsible Care initiative, which is intended to ensure the safe operation of chemical facilities and enhance the relationships between the chemical industry and the communities in which we operate. Praxair uses a combination of extensive engineering standards and design safety work processes, coupled with operational and personnel safety programs, to ensure the safe operation of all of our facilities. Our company-wide goal of "Zero/Zero" (which means zero accidents and ze ro injuries or illnesses at every location) reflects the dedication and commitment to safety throughout the entire Praxair organization. |