Aristech Chemical Corporation - Executive Summary

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ARISTECH CHEMICAL CORPORATION 
HAVERHILL, OHIO PLANT 
RMP EXECUTIVE SUMMARY 
 
ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES 
 
At Aristech Chemical Corporation - Haverhill, Ohio Plant, we are committed to operating and maintaining all of our processes (especially those using hazardous substances) in a safe and responsible manner.  We use a combination of accidental release prevention programs and emergency response planning programs to help ensure the safety of our employees and the public as well as the protection of the environment.  This document provides a brief overview of the comprehensive risk management activities that we have designed and implemented, including: 
 
* A description of our facility and use of substances regulated by EPA's Risk Management Program (RMP) regulation 
* A summary of results from our assessment of the potential offsite consequences from accidental chemical releases 
* An overview of our accidental release prevention programs 
* A five-year accid 
ent history for accidental releases of chemicals regulated by EPA's RMP rule 
* An overview of our emergency response program 
* An overview of planned improvements at the facility to help prevent accidental chemical releases from occurring and adversely affecting our employees, the public, and the environment 
* The certifications that EPA's RMP rule requires us to provide 
* The detailed information (called data elements) about our risk management program 
 
 
STATIONARY SOURCE AND REGULATED SUBSTANCES 
 
Our facility produces Phenol, and Phenol-derivatives, using a variety of chemicals and processing operations. The plant consists of five operating units: three Phenol Units, the Aniline/Diphenylamine (DPA) Unit and the Bisphenol A (BPA) Unit.  In addition, the Utilities plant supplies the necessary steam, treated water, nitrogen, air, and wastewater treatment for the operating units.  In our processes, we use the following chemicals that EPA has identified as having the potential to cause si 
gnificant offsite consequences in the event of a substantial accidental release: 
 
Toxics 
 
We store a maximum of 840,000 pounds of anhydrous ammonia onsite in three storage vessels. The ammonia is used exclusively by the Aniline unit as a reactant that combines with Phenol to form the Aniline product. 
 
We also store 4,000 pounds of chlorine in two 1-ton containers at each of six cooling towers for a facility total of 24,000 pounds. The chlorine is used as a disinfectant in the cooling water systems to prevent biological fouling of these systems.  
 
Flammables 
 
Hydrogen is stored onsite in a 20,000 gallon (12,000 pounds) storage tank. Hydrogen is used in a byproduct recovery operation in the Phenol 2 unit.  
 
 
Our accidental release prevention programs and our contingency planning efforts help us effectively manage the hazards that are posed to our employees, the public, and the environment by our use of these chemicals. 
 
 
KEY OFFSITE CONSEQUENCE ANALYSIS SCENARIOS 
 
EPA's RMP rule requires 
that we provide information about the worst-case release scenarios and alternative release scenarios for our facility.  The following are brief summaries of these scenarios, including information about the key administrative controls and mitigation measures implemented to limit the exposure distances for each scenario: 
 
Worst-case Release Scenario - Regulated Toxic Chemicals 
 
The Haverhill facility's worst case release scenario is the catastrophic release of the entire contents of a pressurized storage tank containing anhydrous ammonia.  Administrative procedures limit the inventory of this tank to 280,000 pounds.  A release of this nature would reach offsite public receptors.  The facility has many physical controls in place to prevent such a release from occurring.  However, the regulations stipulate that these measures, other than the administrative controls that limit the quantity stored, are not to be considered when evaluating a worst case release scenario.  
 
Alternative Release 
Scenarios - Regulated Toxic Chemicals 
 
Alternate Release Scenario - Anhydrous Ammonia 
 
The alternate release scenario for anhydrous ammonia is the partial failure of the ammonia vapor hose at rail car unloading, during the unloading operation.  Approximately 5,460 lbs of ammonia has been estimated could be released prior to isolation and control.  No offsite public receptors would be affected, although the endpoint reaches beyond the plant boundary.  Active mitigation includes 1) manual and automatic emergency shutdowns in the unloading area, 2) the unloading area is manned at all times during the unloading process, and 3) excess flow valves that close in case of complete failure of the vapor line.  
 
Alternate Release Scenario - Chlorine 
 
The alternate release scenario for chlorine is the failure of a vapor line and vacuum valve on a  1-ton chlorine cylinder.  The entire contents of the cylinder (2000 lbs) are released over 55 minutes. The release would reach nearby offsite public rec 
eptors. 
 
Worst-case Release Scenario - Regulated Flammable Chemicals 
 
The worst case scenario for flammables at the Haverhill Facility is the failure of a 20,000 gallon liquid hydrogen storage tank.  The release occurs instantaneously and the hydrogen forms a vapor cloud.  The cloud ignites, resulting in a vapor cloud explosion.  For worst case, 10% of the material is assumed take part in the explosion.  Offsite receptors would be affected.  
 
Alternative Release Scenario - Regulated Flammable Chemicals 
 
This alternate release scenario is failure of the liquid hydrogen storage tank containing 12,000 pounds of hydrogen.  The release occurs instantaneously and the hydrogen forms a vapor cloud.  The cloud ignites, resulting in a vapor cloud explosion.  For the alternate case, 3% of the material is assumed to take part in the explosion.  Nearby offsite receptors would be affected.  
 
 
We are using this information to help us ensure that our emergency response plan and the community emergency 
response plan address all reasonable contingency cases. 
 
 
GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS 
 
We take a systematic, proactive approach to preventing accidental releases of hazardous chemicals.  Our management systems address each of the key features of successful prevention programs including: 
 
* Process safety information 
* Process hazard analysis 
* Operating procedures 
* Training 
* Mechanical integrity 
* Management of change 
* Pre-startup review 
* Compliance audits 
* Incident investigation 
* Employee participation 
* Hot work permits 
* Contractors 
 
As part of our prevention efforts, we have implemented the following chemical-specific prevention steps: 
 
Ammonia 
 
There are actually four ammonia storage vessels; however, in order to minimize onsite inventory, one vessel has been removed from service.   Also, by written procedure, each vessel is maintained at a level of 60% of maximum storage capacity to limit the amount in storage at any 
one time.  
 
The vessels are 130 feet long, 11 feet in diameter and are made of all welded carbon steel having a thickness of 0.9375 inches.  The vessels were constructed in 1981 in accordance with American Society of Mechanical Engineers (ASME) Code.  (The ASME Code is a set of standard rules of safety governing the design, fabrication, and inspection during construction of pressure vessels with the objective of affording a reasonably certain protection of life and property and a long, safe period of usefulness.) The design pressure for these vessels is 250 psig and they were pressure tested to 434 psig after fabrication.   
 
Each storage vessel is equipped with excess flow valves on the liquid connections on the bottom of the vessels to mitigate a release should a piping failure occur.  Each vessel has a total of eight relief valves sized in accordance with ASME Code to provide overpressure protection for the vessel.  Four relief valves are required per vessel to provide the necessary 
protection; however, there are eight relief valves on each vessel.  The valves are mounted on the vessel on a series of 4 manifolds with two relief valves per manifold.  This provides a way to isolate one valve while having the other valve in service on each manifold.  The valves are on a rigorous preventive maintenance schedule to insure proper operation. 
 
Instrumentation on the vessels includes local level, pressure and temperature gauges as well as temperature indication.  These parameters are continuously fed to the computer system in the unit's control room and are continuously monitored by the system and the control room operators.          
 
The vessels are physically located away from the process area and a safe distance from other storage vessels containing flammables.   Fire monitors are located at each corner of the storage vessels to provide a water curtain/fog to absorb the ammonia should a release in the storage area occur.  The gravel area under and around the storage a 
rea is kept free of weeds and other debris that could pose a fire hazard. 
 
Every two to three years a comprehensive inspection is conducted on each vessel to determine fitness for operation.  Metal thickness of each vessel is measured using state of the art equipment.  Vessel nozzles, steel supports and concrete piers supporting the vessel are also inspected.  These inspections are performed by a certified third party inspection company. 
 
The unloading of ammonia is conducted by material handlers who have been certified in the unloading operation and are required to fill out a checklist during the process.   The unloading process requires that two hoses for liquid flow and one hose for vapor flow be connected to the railcar.  These hoses are fabricated of braided stainless steel and are pressure tested twice a year.  The material handler is present at all times during the unloading process.  Unloading connections are inspected for leaks during the entire process.  Wheels are chocked an 
d brakes set so the car will not move during unloading.  Emergency stop buttons are located on the ammonia unloading rack and at the unloading compressor to stop the unloading process should an emergency occur.  Automatic shutdowns are incorporated into the compressor control system that sense operation outside of normal boundaries and shutdown the unloading process. Railcars are equipped with excess flow valves on the liquid and vapor connections to prevent a release should a hose burst or disconnect.  Fire water monitors are located 50 feet from the unloading rack to provide a water curtain should a release occur at the unloading rack.    
 
In liquid ammonia piping, relief valves are installed in any section of piping between valves where liquid may be trapped to prevent the possibility of line rupture due to thermal expansion of the liquid.  Relief valves are on a preventive maintenance schedule.  
 
Chlorine 
 
At each cooling tower there are two, 1-ton chlorine cylinders.  Only one of  
the cylinders is in operation at a time.  The one ton chlorine cylinders are constructed of steel and designed according to guidelines set by the Chlorine Insititute.  The cylinders are equipped with a dome over the valves to protect the valves while the cylinder is not in use.  Three fusible plugs are installed in each end of the cylinder to provide overpressure protection in case of fire.  Should a release occur on a cylinder, repair kits designed specifically for one ton cylinders are onsite to help mitigate a release. 
 
Chlorine is stored under pressure; however, flow from the cylinder is controlled under vacuum.  A vacuum regulator fabricated of chlorine resistant material is mounted on the cylinder valve.  A water ejector pulls vacuum on a spring-loaded diaphragm on the regulator.  When vacuum is present, the diaphragm opens and chlorine flow starts.  Should the chlorine supply line break, the diaphragm would close and chlorine flow would be stopped, preventing a release.   
 
Hydro 
gen  
 
Hydrogen is used as a reactant in the byproduct recovery section of phenol production. The hydrogen is supplied by a packaged hydrogen storage and supply unit that is owned and maintained by Air Products, Inc.  This type of installation is regulated by OSHA 1910.103, which specifies design and safety considerations for hydrogen storage and supply units leased or sold to consumers.  In addition, all pumps and compressors in hydrogen service in the phenol unit are equipped with dry pipe deluge type sprinkler systems which are actuated by means of a pneumatically operated heat actuated device (HADs) strategically located over each pump or compressor. Flammable atmospheres are prevented from forming in vessels by nitrogen purging, and in the vent stack by steam injection. The hydrogenation system is also equipped with remote shutdowns and isolation valves, which are tripped by a variety of abnormal operational parameters.  
 
Over the last year and half, the Haverhill facility has  
been actively addressing the issue of Year 2000 (Y2K) readiness.  The plant has been systematically identifying, evaluating, testing, and upgrading (where necessary) computer hardware, software, process control equipment, safety systems and emergency protection equipment at the facility for Y2K readiness. In addition, impact assessments to evaluate potential business risks and exposures posed by Y2K have been conducted.  Haverhill is also working to obtain assurances from vendors regarding readiness of their systems.  The plant's Y2K activities have been communicated to Haverhill employees to enhance their awareness of the issues.  The work on Y2K readiness is expected to be completed by October 1999.  
 
These individual elements of our prevention program work together to prevent accidental chemical releases.   Our company and our employees are committed to the standard that these management systems set for the way we do business, and we have specific accountabilities and controls to en 
sure that we are meeting our own high standards for accident prevention. 
 
 
FIVE-YEAR ACCIDENT HISTORY 
 
We keep records of all significant accidental chemical releases that occur at our facility. We have had one accident meeting the reporting requirements of the Risk Management Program in the last five years.  A fire occurred on a process heater in the Aniline Production Unit on November 13, 1997 that resulted in $260,000 of onsite damages.  The Green Township Fire Department was contacted and responded.  Aristech notified the Local Emergency Planning Committee's (LEPC's) for Scioto and Lawrence counties in Ohio and Greenup county in Kentucky.  The Greenup county LEPC issued a voluntary evacuation for the residents of downtown Greenup.  The Coast Guard shut down a section of the Ohio River due to smoke from the fire.  Two Aristech employees were taken to the hospital as a precaution due to smoke inhalation.  No fatalities occurred onsite.   No known offsite injuries or fatalities occurr 
ed and no known offsite damage occurred.  A formal incident investigation was conducted to identify and correct the root causes of this event. 
 
 
EMERGENCY RESPONSE PROGRAM 
 
We maintain contingency plans that meet all of the various federal, state, and local regulatory requirements for emergency response planning. These contingency plans are periodically reviewed and employees are trained in their implementation.  Our program provides the essential planning and training for effectively protecting workers, the public, and the environment during emergency situations.  Furthermore, we coordinate our plan with the community emergency response agencies.   
 
 
PLANNED CHANGES TO IMPROVE SAFETY 
 
The following is a list of improvements that we are investigating for implementation at the facility to help prevent and/or better respond to accidental chemical releases: 
* The installation of an automatic water deluge system in the ammonia storage/unloading areas. 
 
* The installation of ambient air amm 
onia monitors in the unloading and storage areas. 
 
* The installation of additional automatic shutdowns to isolate the ammonia system. 
 
* The use of Sodium Hypochlorite (bleach) as a replacement biocide for chlorine at every cooling tower.
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