Prairie Packaging - Bedford Park Plant - Executive Summary
EXECUTIVE SUMMARY |
'68.155(a) Accidental Release Prevention and Emergency Response Policies
This facility stores and uses isopentane, which is considered a regulated flammable substance pursuant to Title 40 of the Code of Federal Regulations, Part 68 (40 CFR 68). It is our policy to adhere to all federal, state, and local rules and regulations. To provide additional safety, this substance is contained in an underground storage tank (UST), which provides passive mitigation. This UST complies with all applicable Federal requirements pursuant to 40 CFR 280, which includes U.S. Environmental Protection Agency's (EPA) UST upgrade requirements. Additionally, the process equipment is designed to comply with National Fire Protection Association (NFPA) Code 30, Flammable and Combustible Liquids Code.
If an emergency were to occur, it is our policy to immediately contact the Bedford Park Fire Department by dialing 911. The Fire Department is also coordinated with the Cook County Local Eme
rgency Planning Committee (LEPC). This company takes a proactive position to reduce the risk of accidents occurring at this facility and is proud of its safety record. A summary of the accident prevention program follows.
'68.155(b) The Stationary Source and Regulated Substance Handled
This facility uses isopentane as a blowing agent in the polymer extrusion process for the manufacture of foam packaging products. A low-pressure pneumatic pump at the UST transports the isopentane to a set of mechanical high-pressure pumps at the pump house, which then delivers the isopentane to the process lines in the manufacturing building.
Access to the site is restricted to authorized facility employees and authorized contractors. A contractor delivers the regulated substance (isopentane) by transport truck. The transfer of isopentane is gravity fed to the UST. The UST is vented to maintain atmospheric pressure. The 12,000-gallon capacity of the UST has an equivalent weight of 62,520 p
ounds (using a density of 5.21 pounds/gallon), which exceeds the regulated threshold quantity of 10,000 pounds. Overfill level alarms and a ball-float valve are also employed to prevent overfilling.
'68.155(c) Worst-Case Release Scenario and Alternative Release Scenario
Although there is no evident reason for a potential catastrophic explosion of the UST, a worst-case release scenario analysis was performed to determine the 1 pound per square inch (psi) overpressure (shockwave) endpoint distance. An overpressure of 1 psi may cause partial demolition of houses and shatter glass windows. It should be recognized that the fact that the tank is underground does provide passive mitigation. The EPA offsite consequence analysis (OCA) guidance, Chapter 4, page 4-11, Q's and A's, Worst-Case and Mitigation, does address UST's: "The worst case scenario for salt domes would be examined in a manner similar to that for underground storage tanks. Reservoirs or vessels sufficiently buried under
ground are passively mitigated or prevented from failing catastrophically. You should evaluate the failure of piping to underground storage for the worst-case and alternative scenarios." The piping to the UST is also below grade and is double-walled.
A pull-away hose failure from the tranport tank truck was used for the worst-case and alternative release scarios. The scenario assumes a failure of a 20 foot length of 3 inch diameter hose. The contents of the hose is released (38.26 pounds), and a vapor cloud explosion is assumed. A 10 percent yield factor was used in the TNT-equivalency formula pursuant to the EPA OCA guidance document . The 1 psi overpressure endpoint distance is 142 feet. No offsite public or environmental receptors would be impacted from this shockwave.
'68.155(d) General Accidental Release Prevention Program and Specific Prevention Steps
This facility complies with all applicable state and local codes and regulations. This UST complies with all applicable f
ederal requirements pursuant to 40 CFR 280. Additionally, the process equipment design complies with NFPA Code 30, Flammable and Combustible Liquids Code.
The process area is restricted to authorized personnel and has hazard signs posted. Isopentane is stored as a liquid at ambient pressure and temperature in a corrosion-resistant. double-walled underground storage tank.
Accident prevention measures include process area lower explosive limit (LEL) monitors, perimeter LEL monitors, and underground leak detection probes. The facility has a quarterly maintenance program, which addresses this system. Loading of the UST is administratively controlled at 90% capacity to prevent tank overfilling. Additionally, overfill ball-valve and level alarms are also employed to prevent overfilling of the tank. The storage tank and piping is double-walled and corrosion resistant. The pneumatically controlled valves will fail-safe in the closed position. The process area is designated with hazard
signs. Maintenance operators are trained and only use brass tools to prevent sparks, which would be an ignition source. If an isopentane system pressure drop occurs, corrective action is immediately taken including shutting the pumping system down. A safety interlock is employed such that if a LEL sensor alarms, the pumping system automatically shuts down.
'68.155(e) Five-Year Accident History
There has never been an accident related to this isopentane.
'68.155(f) Emergency Response Program
The facility has contacted the Bedford Park Fire Department's Fire Marshall and has submitted this RMP. The Fire Marshall conducts an annual inspection at the facility. In the event of an emergency, Prairie Packaging would dial 911 to contact the fire department. The Bedford Park Fire Department would contact the Cook County LEPC.
'68.155(g) Safety Improvement Plans
The safety improvement program includes internal safety audits, which are performed on a regular basis. Based upon the
most recent internal safety audit, the facility will require the isopentane transport carrier contractor to chock the wheels and ground the tank truck prior to unloading.