IBP, inc. - Executive Summary
EXECUTIVE SUMMARY |
Accident Release Prevention Program and Emergency Response Policy
It is the policy of the IBP, inc. (IBP) Perry, Iowa, facility management to implement the requirements of this Risk Management Program (RMP) in accordance with the USEPA regulations under 40 CFR Part 68 and with the corresponding regulations under OSHAs Process Safety Management (PSM) program. The objective is to minimize the risk of a release of a hazardous material and if a release occurs, to minimize the potential impact to IBP employees, the public and the environment. This objective will be accomplished by utilizing general good operating procedures, providing appropriate training to all employees, and coordinating response activities, as necessary, with the local emergency response providers. This plan covers all IBP owned activities at this facility.
IBPs management is committed to providing the resources necessary to implement this policy.
IBP operates a hog slaughter a
nd processing facility at this location. Hogs are trucked to the facility, slaughtered and fabricated. IBP operates rendering systems to produce meat scraps, dried blood, lard and grease. Support operations include a wastewater treatment system, truck repair facilities, cold storage, an analytical laboratory, and administrative offices.
Two chemicals are utilized at the facility in sufficient quantities to be subject to the requirements of 40 CFR Part 68. These chemicals are chlorine and ammonia. Chlorine is used to treat wastewater and ammonia is used as a refrigerant throughout the facility.
Worst-Case and Alternative-Release Scenarios
RMP regulations require that each facility identify worst-case and alternative case release scenarios. EPA has defined a worst-case release as the release of the entire contents of the largest vessel that contains a regulated substance in a 10-minute period. This release rate is then evaluated using modeling techniques and/or reference tables to
define the distance to a specified endpoint (concentration or overpressure). The distance to the endpoint is affected by several factors including molecular weight, volatility, heat of combustion, and physical setting (urban or rural).
The alternative release scenario must be one that is more likely to occur than the worst-case scenario and that reaches an endpoint off-site, unless no such scenario exists. The alternative release scenario is also evaluated to define the distance to the specified endpoint.
Under 40 CFR 68 Subpart B '68.22(e), the RMP rule identifies surface roughness as a parameter to be used in the hazard assessment to determine the physical setting of the site, urban or rural. Urban means there are many obstacles in the immediate area; obstacles include buildings or trees. Rural means there are no buildings in the immediate area and the terrain is generally flat and unobstructed.
Due to the presence of trees, hills, and/or other structures in the immediate vicin
ity of the Perry, Iowa, facility, an urban dispersion environment was assumed.
The Perry, Iowa facility has one chlorine and two ammonia refrigeration systems: the Processing and Slaughter refrigeration systems. The worst-case release area for the chlorine system would contain the area impacted by the worst-case release for the Main Plant and TCCS ammonia systems. Therefore, one worst-case toxic release was specified for the entire facility.
The dispersion model applied to the worst-case and alternative chlorine release scenarios was the EPA-approved model, HGSYSTEM. HGSYSTEM is a consequence model that has seven distinct modules that are used to predict the potential ambient concentrations resulting from single (gas) and two-phase jet (gas and aerosol) releases from pressurized vessels, vapor releases, liquid spills and the subsequent evaporation of the spill pool. HGSYSTEM was selected for this application because of its flexibility in simulating the necessary release ch
aracteristics, plume dispersion (e.g., dense gas dispersion), and its capability of simulating the dispersion environment through which the plume travels (e.g., time varying meteorological conditions).
The worst-case release scenario for chlorine included a release of all the contents of the storage vessel (2,000 pounds) in a 10-minute period. This release translates to a release rate of 200 lbs/min. Other assumptions for the worst-case chlorine analysis include the chlorine is a liquefied gas; the 1-ton cylinder is not diked; no passive mitigation system (including buildings) are in place; the nearfield dispersion environment is characterized as urban; 10-minute averaging period; the windspeed is 1.5 meters/sec and the atmospheric stability is classified as F (stable). The results of the worst-case assessment for chlorine show that the regulatory defined endpoint of 3.0 ppm is found to occur at a distance of 3.23 miles (5.2 kilometers) from the release point.
The selected alternati
ve-release scenario for the chlorine system is a release resulting from a fusible plug failure that leads to the release of the entire contents of the 1-ton chlorine cylinder. Based on information in the Chlorine Institute Chlorine Handbook, the release rate of vaporized chlorine from the fusible plug opening is an average of 14.6 lbs/min. Based on the calculated release rate of 14.6 lbs/min, the duration of a 2,000-pound release is 136 minutes. The model assumes no active or passive mitigation measures are currently in place. The meteorological data used for this alternative release scenario was a wind speed of 3 meter/sec, an atmospheric stability classification of D (neutral stability), and an urban dispersion environment in the nearfield. The results of the alternative-release scenario for a chlorine release indicates that the endpoint of 3.0 ppm is reached at a downwind distance of 0.31 miles (500 meters) from the release point.
The data provided in the document Model
Risk Management Program and Plan for Ammonia Refrigeration (May 1996) was used to estimate the toxic endpoint distance for the worst-case and alternative ammonia release scenarios. The EPAs RMP Off-site Consequence Analysis Guidance (May 1996) was not used to determine the toxic endpoint since it classifies ammonia as a neutrally buoyant gas. Since the worst-case ammonia release would involve liquid and would come from a pressurized system containing liquid, the released gas should be classified as a dense gas (a result of evaporative cooling). The ammonia refrigeration document provides calculated endpoint distances for typical meteorological conditions.
The worst-case release scenario for an anhydrous ammonia release included a release of all the contents of the control pressure receiver in a 10-minute period (per EPA guidelines). This release translates to a release of 16,303 pounds of ammonia in 10 minutes or 1,630.3 lbs/min. Other assumptions included in the worst-case as
sessment are: the ammonia is a liquefied gas; the control pressure receiver is not diked; the release does not take place indoors; the nearfield dispersion environment is characterized as urban; 10-minute averaging period; the wind speed is 1.5 meters/sec and the atmospheric stability is classified as F (stable). The results of the worst-case assessment for ammonia show that the plume must travel 1.47 miles (2.37 kilometers) before dispersing to the endpoint concentration of 201 ppm.
The selected alternative-release scenario for the ammonia systems is a release from a relief valve due to overpressure of a compressor unit. The largest relief valve in the system was used in this scenario. The largest relief valve has a relief rate of 128 pounds of air per minute. As a matter of convention, the specified release rate of any relief valve is always in pounds of air per minute. The release rate of 128 pounds of air per minute correlates to a release rate of 91.8 pounds of ammonia vapor
per minute. This release rate was applied to a release from the ammonia header on top of the building.
The ammonia refrigeration document provides calculated endpoint distances for typical meteorological conditions (3 m/s wind speed, D atmospheric stability, 50% relative humidity). It has been determined, through a review of IBPs operational history, that the total release would likely be 500 pounds of ammonia. Based on the release rate of 91.8 lbs/min, the duration for a 500-pound release is 5.4 minutes. Other assumptions include that no active or passive mitigation measures are currently in place and an urban dispersion environment in the nearfield. The results of the alternative-release scenario for an ammonia release indicates that the endpoint concentration of 201 ppm is reached at 0.083 miles (133 meters) from the release point.
General Accidental Release Prevention Program and Chemical Specific Prevention Steps
The Perry, Iowa, facility is governed by a set of OSHA and USE
PA regulations that require planning and facility activities intended to prevent a release of hazardous material, or if a release inadvertently occurs, to minimize the consequences of a release to the employees of the facility, the public and to the environment. These regulations include:
? 40 CFR Part 68, Accidental Release Prevention
? 40 CFR Part 112, Spill Prevention, Control and Countermeasure
? 40 CFR Part 264, Hazardous Waste Contingency Plan
? 29 CFR Part 119, Process Safety Management
? 40 CFR Part 302, Emergency Planning and Community Right-to-Know Act (EPCRA)
The key concepts in IBPs release prevention program are employee participation, appropriate design and maintenance of equipment, and appropriate training of all employees. IBP has developed and documented these elements in their process safety management plan (PSM). The PSM plan is incorporated with this document by reference.
Employee participation in the release prevention program is encouraged and supported by IB
P management. Key personnel are responsible for conducting and implementing the findings from the Process Hazard Analysis (PHA) for the ammonia and chlorine systems. IBP employees are also members of the facility emergency response team.
IBP policy is to construct all new equipment, systems, and facilities to ensure the appropriate safety and release prevention systems are included from the beginning of each project. IBP maintains a computerized program of maintenance activities to ensure that key systems are maintained appropriately to minimize the risk of a release.
IBP is committed to providing appropriate training to all employees regarding safety procedures. Each new employee is provided comprehensive safety training during their initial orientation for the facility. In addition, IBP conducts regularly scheduled safety training for all employees each year. Additional training is provided to maintenance personnel for the systems they are responsible for. Members of IBPs eme
rgency response team receive annual training to ensure that response actions are promptly and safely completed.
Five Year Accident History
Between June 1997 and July 1997, IBP has had three releases of ammonia from the Perry, Iowa facility that resulted in seven OSHA recordable injuries. None of these releases affected the public or the environment. IBP does not have records of the time and duration of the releases or the release quantities of two of these releases. IBP has process alarms in the rooms where the releases occurred. If the concentration of ammonia reaches 20 parts per million the alarm will sound. During these incidents the alarms did not activate. Therefore, because the alarms did not sound, IBP believes the release quantity was small. The releases were small and did not require an incident investigation. IBP has assumed, after reasonable inquiry, the time of the incident is 12:00 PM, lasted one minute, and released one pound of ammonia.
On July 14, 1997 an ammon
ia line on an ice-making machine was broken with a forklift. Maintenance personnel immediately responded and the system was isolated within approximately 3 minutes of the release. The room was evacuated within approximately 13 minutes of the release. The system was modified to prevent this type of accident in the future. IBP has not had an OSHA recordable incident related to the ammonia system since the system was modified.
Emergency Response Program
IBP has personnel trained in emergency response at the facility 24 hours per day, seven days per week. These personnel receive annual training on emergency procedures and response techniques.
Planned Changes to Improve Safety
IBP completes a thorough review of the ammonia systems and chlorine system each time a design change is implemented. IBP is committed to using these methods to identify and implement ways to improve the safety of these systems