Versacold / Cascade - Executive Summary
EXECUTIVE SUMMARY |
This Risk Management Program and Plan has been prepared for the Versacold/Cascade Refrigerated Cold Storage facility located in Lynden, Washington.
This document contains the necessary information to satisfy the EPA Risk Management Program 3 regulations for facilities handling in excess of 10,000 pounds of ammonia. This document contains the necessary information that will be submitted to the EPA, Section 6.0. This single submission will be deemed equivalent to a submission to the administrating agency, state, and local planning and response agencies with jurisdiction for the area where the stationary source is located. The Program is the system that supports the plan and ensures that the plant is being operated safely. A large portion of the Program information can be found in the Versacold Process Safety Management (PSM) program document. The existing PSM program is referenced throughout this document.
The Covered Process
The facility uses approximately 54,0
00 lbs. Pounds of ammonia as a refrigerant, within a closed system. The system, consisting of piping, valves, and equipment, cycles ammonia through various physical states (high pressure liquid, low pressure liquid, low pressure vapor, high pressure vapor, then back to high pressure liquid) in order to provide refrigeration for cold storage.
The refrigeration process uses high pressure ammonia at approximately 150 psig and 850F (corresponding saturation temperature). Once the ammonia expands, the pressure decreases to approximately 30 psig. Typically, the pressure conditions consist of high pressure liquid, (150 psig), low pressure liquid (10 - 60 psig), low pressure vapor (10 - 60 psig), and high pressure vapor (150 psig).
There are seven additional sections as follows:
Lists all of the Program 3 prevention programs in place at the facility as well as a brief summary of each program. These programs are included in the Versacold PSM program document. A revi
ew of the programs is also included in this section.
Worst Case Release and Alternative Release Scenario:
This section describes a release of the total quantity of ammonia stored in the largest vessel at the facility, taking into account administrative controls that limit the maximum quantity in that vessel.
Describes the methodology used for conduction the hazard assessment to determine the off site consequences due to the worst case release as well as an alternative release.
Includes the RMP qualifies person, record keeping and updating requirements under the RMP regulation, and the certification by the qualified person.
Risk Management Plan:
Contains the EPA submittal documentation, including the executive summary and the data elements forms.
Emergency Response Plan:
Outlines the Emergency Response Plan in place at the facility. In addition, this section includes the Emergency Response Plan Components which are required to be included in the R
isk Management Plan submittal.
RMP Recommendation Summary:
Contains a list of all the recommendations that resulted from the RMP Development Team Review and Preparation process.
The RMP development process was conducted in three steps:
1. Facility Prevention Program and Emergency Response Plan Review
2. Hazard Assessment
3. Documentation Preparation
The RMP development team conducted a review of the existing prevention programs in place at the facility on 12/30/93. The development team consisted of the following personnel:
Ron Langwell - General Manager, Versacold/Cascade
Chuck Boies - Chief Engineer, Versacold/Cascade
Chuck Marshall, P.E., MAC Engineering
The prevention program review included an examination of the implementations of all of the PSM programs, a review of the Process Hazard Analysis recommendations and their implementation status, and a determination of the worst case and alternative release scenarios for the Hazard Assessment. Following the on
-site review, the hazard assessment was conducted to determine maximum downwind distances to the listed concentration (200 ppm for ammonia). Using these distances, the receptor data (including sensitive, environmental, and public receptors) were collected in addition to the population data within these zones. Finally, the Risk Management Program and Plan document was developed.
Versacold established a Process Safety Management (PSM) Program at this facility in May 1994. The PSM program includes all of the RMP Program 3 Prevention Program elements. The prevention program elements are detailed in the Versacold/Cascade, Washington facility Process Safety Management notebook. This document is maintained by the Chief Engineer. In addition to the Process Safety Management notebook, the Chief Engineer maintains a Piping Diagram and IIAR Form notebook. This book includes the piping diagrams for each piece of ammonia refrigeration equipment as well as the Internatio
nal Institute of Ammonia Refrigeration Bulletin 109 forms. These forms include physical as well as operational data for each piece of ammonia refrigeration equipment. On 12/30/94, a review of the prevention programs was conducted. It was immediately determined that the Prevention program elements were incomplete and in need of review and update n view of the major remodel project underway. At the completion of the remodel, the program will be reviewed for completeness.
WORST CASE SCENARIO:
The worst case release scenario is a release of the total quantity of ammonia stored in the largest vessel at the facility, taking into account administrative controls that limit the maximum quantity in that vessel. In accordance with the RMP regulation, the release duration is over a 10 minute period. No passive mitigation measures were used for this release scenario.
The amount of ammonia modeled in the worst case scenario is 20,000 lbs. This was determined by taking the Lesser quantity of
ammonia (in pounds) of the following:
1) The total charge of ammonia in the system.
2) The greatest capacity of a vessel taking into consideration administrative controls on the vessel.
For analyzing the worst case release scenario, EPA requires the use of the most pessimistic meteorological conditions that will allow for the maximum downwind exposure. Low wind speeds (1.5 m/s) and stable conditions (F stability) will allow the gas cloud to travel as far as possible by limiting cloud dispersion. The results will be conservative.
The EPA computer program "RMP Comp." was used to calculate the Worst Case toxic end point distance, using the following input conditions: Total Gaseous Release is 20,000 lbs. The resulting Worst Case toxic end-point distance is .8 miles.
ALTERNATIVE RELEASE SCENARIO
The criteria for selecting an alternative release scenario are as follows:
1) The alternative release should be no more likely to occur than the worst case scenario.
2) The alter
native release scenario should reach and endpoint offsite.
The alternative release scenario chosen for this facility is that of a 0.25 inch diameter orifice leading to an airborne release, representative of a pump seal leak, a gasket rupture, pinhole leak due to corrosion, flange seal leak, valve bonnet seal leak, etc. It is assumed that this release is from the high side of the system; therefore at a pressure of 150 psig.
This release will be for 60 minutes, thereby incorporating mitigation measures such as the emergency response plan and actually shutting down the system. EPA allows a facility to use typical meteorological conditions at the facility. For this scenario, a wind speed of 3 meters/second and neutral conditions, D stability, were used.
The EPA computer program "RMP Comp." Was used to calculate the Alternative Release Case toxic end-point distance, using the following input conditions: Total Gaseous Release Rate of 100 lbs/min. The resulting Alternative Release Case
toxic end-point distance is: 0.10 miles.
This off-site Consequence Analysis was conducted to fulfill the Hazard Assessment requirement of the Risk Management Program (RMP) for the Versacold/Cascade facility located in Lynden, Washington. The EPA "RMP Comp." Computer program was used to calculate the hazard and determine the end-point consequences for both the Worst Case Release and the Alternative Release.
The RMP regulation requires that the off-site consequence analysis be reviewed at least once every five years. This Hazard Assessment serves as the initial analysis. The five year review will include determining if the worst case release quantity has increased and reviewing the sensitive and environmental receptors to ensure that no new receptors have moved into the vulnerable zone. Any new receptors will be added to the list. In the event that there are changes to the process, quantities stored or handled, or any other aspect of the stationary source might
reasonably be expected to increase or decrease the distance to the endpoint be a factor of two or more, this analysis must be revised within six months of the change and a revised RMP submitted.
Release Rate: The Model Risk Management Program and Plan for Ammonia Refrigeration", Science Applications International Corporation, May 1996, uses the Bernoulli equation for predicting the rate of release of liquid from a vessel. This is a very conservative equation in that is assumes that the release is on the liquid side of a vessel or a rupture of a very short pipe. This equation does not take into consideration any flashing at the orifice or pressure drop of a long pipe run which would reduce the rate of release.
The regulated substance is ammonia. Anhydrous ammonia is a colorless gas or liquid with a very strong, intensely irritation odor. It has a D.O.T. classification as a non'flammable gas but it does have explosion potential when mixed with air and the appropriate initiator is
present. This flammability range is very narrow, 15-25%. Explosions, when they occur, are usually in confined spaces and require a high energy initiator such as an electric arc.
Ammonia is not a poison. It has no cumulative toxic effects. However, it has a powerful corrosive action when in contact with tissue that causes eye, mucous membrane, and systemic irritation by inhalation. Inhalation of concentrated ammonia vapor could cause edema of the respiratory tract, spasm of the glottis, and asphyxia. Treatment must be prompt to prevent death if exposed to high concentrations. During emergency conditions, a positive pressure-demand, full face piece, self contained breathing apparatus (SCBA) or pressure-demand, supply air respirator with escape (SCBA) and a fully-encapsulated, chemical resistant suit is required for response. For additional information, the Process Safety Information section of the PSM notebook provides detailed information regarding the health effects associated
with exposure to ammonia.
FIVE YEAR ACCIDENT HISTORY
There has been one reported release of ammonia at this facility during the last five years, 12/30/93 through 12/30/98. A minor release of approximately 90 lbs of ammonia was released on Dec. 3, 1996.
EMERGENCY RESPONSE PLAN
The RMP Development Team conducted a review of the Emergency Response Plan, which included the written program as well as how effectively the program is being implemented on 12/30/93. A copy of the Emergency Response Plan is maintained by the Chief Engineer.
RMP RECOMMENDATION SUMMARY
During the RMP Development, the Development Team noted several recommendations to improve safety as well as more efficient ways to implement the PSM programs already in place. These recommendations resulted from the review of the PSM prevention programs as well as the Emergency Response Program. The recommendations are summarized as follows:
1. Complete remodel of ammonia system high pressure equipment currently underway
2. Remodel ammonia system low pressure equipment.
3. Review and update Facility Emergency Response Plan.
4. Provide training to engineering staff on updated Emergency Response Plan.
5. Review and update Process Safety Management program.
6. Install ammonia detection and alarm system in facility.