American Yeast Corporation - Executive Summary
EXECUTIVE SUMMARY |
Accidental Release Prevention and Emergency Response Policies
American Yeast Corporation (American Yeast) utilizes anhydrous ammonia and ammonium hydroxide (aqua ammonia) at their yeast manufacturing facility in Bakersfield, California. It is American Yeast's policy to comply with all applicable governmental regulations.
Description of the Stationary Source and Regulated Substances
American Yeast, a subsidiary of Lallemand Inc., owns and operates a yeast manufacturing facility located at 5455 District Boulevard in Bakersfield, California. The plant began operation in 1974. The anhydrous ammonia system was added in 1992.
At American Yeast, anhydrous ammonia is stored on-site and is mixed with water in an ammonia conversion system to produce ammonium hydroxide (aqua ammonia). The anhydrous ammonia system consists of a pressure vessel and piping to the ammonia reactor.
Aqua ammonia is used as a nutrient for the baker's yeast produced at the facility. T
he aqua ammonia system begins at the ammonia reactor. This system consists of the reaction chamber, a shell and tube heat exchanger and the aqua ammonia storage tank, and the piping system to the fermentors.
For purposes of the offsite consequence analyses, 40 CFR Part 68 (the RMP regulations) define the toxic endpoints for both anhydrous ammonia and ammonia solutions as 0.14 mg/l (200 ppm). This concentration has been established by the American Industrial Hygiene Association as the Emergency Response Planning Guideline Level 2 (ERPG-2).
ERPG-2 is the maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to one hour without experiencing or developing irreversible or other serious health effects or symptoms which could impair an individual's ability to take protective action.
Worst-Case Release Scenario and Alternative Release Scenario
Offsite consequence analyses are used as tools to assist in emergency response plannin
g. The RMP regulations require the owner or operator of a stationary source to analyze the offsite impacts due to an accidental release of a regulated substance. The offsite consequence analysis for both Program 2 and Program 3 processes must analyze the worst-case release scenario and an alternative release scenario. Since American Yeast's anhydrous ammonia system is considered a Program 3 process and the aqua ammonia system is considered a Program 2 process, both release scenarios were evaluated in the offsite consequence analysis.
Since the facility has more than one covered process, additional worst-case release scenarios were developed to determine if the worst-case release scenario from one covered process would potentially affect public receptors different than the worst-case release scenario from the other covered process. If the worst-case release scenario from one covered process affects all of the receptors identified under the other covered process worst-case release s
cenario, only the worst-case release scenario from the process that affects all of the receptors needs to be presented.
The offsite consequence analysis must include an estimate of the residential population within an area potentially affected by the accidental release scenario. This area is defined as a circle with a radius equivalent to the distance the release would travel with concentrations at or above the endpoint. The circle also defines the area in which potential environmental receptors must be identified.
The worst case release is defined by the U.S. EPA as the total release of the contents of the single largest vessel or pipe within 10 minutes. For liquefied gases stored under pressure, the entire contents of the vessel or pipe are assumed to be released as a vapor. A total vapor release is highly unlikely. However, this standardized worst case scenario was developed for emergency response agencies to use for planning purposes.
An alternative release scenario is a re
lease that is more likely to occur than the worst-case release scenario. For American Yeast, the alternative release scenarios were selected based on the results of the Process Hazard Analyses (PHAs) for the ammonia conversion process. A credible release event with a high discharge rate would potentially have the greatest offsite impact.
The PHAs for the anhydrous ammonia portion of the conversion process identified the partial failure of the delivery hose as a release event having a potentially high release rate. For the aqua ammonia segment of the ammonia conversion process, the PHAs also identified a hose failure (or sudden uncoupling) as a release event that would potentially have a high release rate. Therefore, the delivery hose failures (or sudden hose uncoupling) were chosen for the respective systems.
American Yeast has analyzed the offsite consequences of the worst-case and alternative release scenarios. For the worst-case release scenario, the release of approximate
ly 71,500 lbs. of anhydrous ammonia over a 10 minute period, the plume would travel 3.1 miles at concentrations at or above the endpoint. This worst-case release scenario from the anhydrous ammonia process was estimated to create the greatest distance in any direction to an endpoint resulting from an accidental release and affected all public receptors identified in the worst case release scenario from the other covered process.
Sensitive receptor information is provided in the RMP*Submit forms. Using 1990 Census data, the population potentially affected within the worst-case release scenario circle is 91,000 people. There are no environmental receptors within the worst case release scenario circle.
In the alternative release scenarios, the partial failure of the ammonia delivery hose was modeled as a release of liquefied ammonia stored under pressure. For a release of 996 lb/min of anhydrous ammonia, the model calculated that the plume would travel 0.2 mile at concentrations at
or above the endpoint.
Using 1990 Census data, the population potentially affected within the anhydrous ammonia alternative release scenario circle is 34 people. The sensitive receptors within the anhydrous ammonia alternative release scenario circle are identified in the RMP*Submit forms. There are no environmental receptors within the alternative release scenario circle for anhydrous ammonia.
Since the RMP*Comp model does not handle 26% ammonia (which is produced by the ammonia conversion process), model runs were conducted for the alternative release scenario for aqua ammonia at 24% and 30%. Assuming a discharge from a total failure of the delivery hose (or coupling) at the delivery rate of 120 gallons per minute, the RMP*Comp model estimated the distance to the endpoint for both 24% and 30% concentrations to be 0.1 mile.
Based on observation, there would not be any population potentially affected by the alternative release for aqua ammonia. The sensitive receptors within
the aqua ammonia alternative release scenario circle are identified in the RMP*Submit forms. There are no environmental receptors within the aqua ammonia alternative release scenario circle.
General Accidental Release Prevention Program and Chemical-Specific Prevention Steps
A PSM program, which meets the requirements of the general accidental release prevention program, has been developed at American Yeast to address the anhydrous ammonia system. The PSM program includes the following chemical-specific prevention steps:
Written process safety information, including information pertaining to the hazards of ammonia, the technology of the process, and the equipment in the process has been compiled.
An initial Process Hazard Analysis (PHA) was performed and will be updated and revalidated at least every five years.
Written operating procedures have been developed, will be implemented, and will be reviewed at least annually.
Safe work practices, such as lockout/tagout, co
nfined space entry, opening process equipment or piping, and control over entrance into the facility have been developed and will be implemented.
Each employee involved in operating the ammonia system has received initial training and refresher training at least every three years.
Written mechanical integrity procedures have been established and will be implemented.
A Management of Change (MOC) program has been developed and will be implemented to address all proposed changes to the ammonia system.
Pre-startup safety reviews will be performed when a modification is made to the ammonia system that is significant enough to require a change in the process safety information.
Audits will be conducted at least every three years to evaluate compliance with the CalARP regulations.
Incident investigation procedures have been established.
A written plan of action regarding the implementation of employee participation has been developed and will be implemented.
Hot work p
ermits are issued for all hot work operations conducted on or near the ammonia system.
A Contractor Safety Policy has been developed and will be implemented.
To ensure that the general accidental release prevention program and the chemical-specific prevention steps are implemented, American Yeast has assigned overall responsibility for the RMP elements to the Plant Manager. The Plant Manager has the overall responsibility for the development, implementation, and integration of the RMP elements.
Five-Year Accident History
American Yeast has not had any accidental releases from the anhydrous ammonia system or the aqua ammonia system that have resulted in deaths, injuries, or significant property damage on site, or known offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage in the last five years.
Emergency Response Program
American Yeast has established an emergency action plan and a chain of command to respond to emergencies and to
notify emergency responders when there is a need for a response. However, an emergency response program does not need to be developed for the facility since American Yeast employees will not respond to accidental releases of ammonia, the facility is included in the community emergency response plan, and appropriate mechanisms are in place to notify emergency responders.
Planned Changes To Improve Safety
Anhydrous Ammonia System
Based on the revalidation of the PHAs for the anhydrous ammonia system performed on May 25, 1999, the following changes were recommended and will be implemented by October 1, 1999.
1) Installation of remote shutoff valves on the ammonia delivery pipelines.
2) Removal of the level transmitter and all associated tubing. The level transmitter does not provide reliable level readings due to condensate forming in the tubing above the level transmitter. The tubing below the liquid level indicator is equipped with 1/2 inch isolation valves that can trap liquid
3) Installation of a hydrostatic (thermal) relief valve on the one inch liquid ammonia pipeline where liquid ammonia could be trapped by closing two one inch ball valves.
4) Tightening of the nuts to secure anhydrous ammonia tank to foundation.
5) Installation of a barrier to protect liquid line (south of CIP tanks) from possible damage due to forklift forks.
Aqua Ammonia System
Based on the hazard review of the aqua ammonia system on May 25, 1999, the following changes were recommended and will be implemented by June 21, 1999.
1) Installation of a pipe plug in the ball valve on the soft water line near the ammonia conversion system reactor to eliminate inadvertent discharge from the reactor due to operator error. An option to plugging the valve would be the removal of the valve and plugging the threaded tee fitting with a pipe plug.
Through the accidental release prevention program, American Yeast regularly evaluates the need for any changes to improve safety.