SSI Dry Grocery & Frozen Foods Division - Executive Summary
ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES |
Pete Blasquez, Operations Manager at the Super Store Industries Dry Grocery and Frozen Foods Division, has implemented emergency response policies in order to meet the following objectives:
1.) To save lives.
2.) To minimize and avoid injuries.
3.) To protect the environment.
4.) To minimize property damage.
Super Store Industries maintains an emergency response committee whose members are the designated emergency coordinators for the facility. The Emergency Response Plan provides the response organization and notification procedures, evacuation routes, ammonia health hazards, and mitigation procedures which will be implemented to respond effectively to emergency situations that may arise at the facility. This Plan is reviewed and updated at least once per year. This Plan will be reviewed and updated to ensure compliance with the PSM and RMP regulations, as well as to incorporate any facility changes.
RCE AND REGULATED SUBSTANCE
The Super Store Industries facility chills and stores a variety of food products in their cold storage warehouse. The refrigeration process, 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 rooms. Changes in pressure are directly related to changes in temperature. For example, lowering the ammonia pressure lowers its temperature. Low pressure (cold) liquid ammonia provides refrigeration by removing ambient heat. Removal of ambient heat causes the liquid ammonia (contained within the system) to vaporize. Heat is later removed from the ammonia as it is condensed back into a liquid. Typical operating conditions range from 2 psig on the low pressure side of the system to 110-150 psig on the high side.
Ammonia is used as the refrigerant in
the refrigeration process.
The total ammonia inventory is 16,000 pounds.
HAZARD ASSESSMENT SUMMARY
Worst Case Release Result Summary:
The worst case release at this facility is a release of the entire charge of ammonia, 16,000 pounds, in 10 minutes. The high pressure receiver can hold the entire charge. This vessel is enclosed by the building and therefore passive mitigation measures were incorporated into the release rate. The most pessimistic meteorological conditions were used: 1.5 m/s and F stability. This facility is located in a rural setting. The maximum potential downwind distance to 200 ppm was determined using Exhibit 4-4 from EPA's "Risk Management Program Guidance for Ammonia Refrigeration Facilities", November 1998. This potential release scenario reaches off-site and may affect population receptors. No environmental receptors are affected by this potential scenario.
Alternative Release Result Summary
The alternative release scenario was that of a 0.25 inch
diameter leak of high pressure liquid ammonia for one hour. The quantity of ammonia released in one hour at this rate is 6300 pounds. This release could occur due to a gasket rupture, pinhole leak, flange seal leak, valve bonnet seal leak, etc. In addition, this release could occur outside; therefore passive mitigation measures were not utilized. The meteorological conditions used were 3 m/s and D stability. This facility is located in a rural setting. The maximum potential downwind distance to 200 ppm was determined using Exhibit 4-5 from EPA's "Risk Management Program Guidance for Ammonia Refrigeration Facilities", November 1998. This potential release scenario reaches off-site and may affect population receptors. No environmental receptors are affected by this potential scenario.
ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS
The facility operates in accordance with the International Institute of Ammonia Refrigeration (II
AR) guidelines and standards including the following:
IIAR Bulletin 107, "Suggested Safety and Operating Procedures When Making Ammonia Refrigeration Tie-ins"
IIAR Bulletin 109, "Minimum Safety Criteria for a Safe Ammonia Refrigeration System"
IIAR Bulletin 110, "Startup, Inspection, and Maintenance of Ammonia Refrigeration Systems"
IIAR, "A Guide to Good Practices for the Operation of an Ammonia Refrigeration System"
In addition, Super Store Industries has implemented a Process Safety Management program for compliance with the OSHA 1910.119 regulation since April 1992.
The facility was constructed to comply with the current edition of all applicable codes, ordinances, regulations, and requirements of the local, county, state, and national bodies having jurisdiction. Special attention is directed to but not limited to:
AHSI/ASHREA 15-1989 - Safety Code for Mechanical Refrigeration
ANSI/IIAR 2-1984 - Equipment, Design, and Installation of Ammonia Mecha
nical Refrigeration Systems
ANSI BB31.5-1983 - Refrigeration Piping
ASME - Pressure Vessel Code, Section IX
UMC - Uniform Mechanical Code
UFC - Uniform Fire Code
NFPA - Fire Protection
UBC - Uniform Building Code, 1991, Seismic Zone 3
The ammonia system uses a computer system to bring equipment on-line, off-line, control the hot gas (compressor discharge) defrosting process, manipulate solenoid valves, and monitor the system for alarms. Ammonia sensors are used throughout the facility and are connected to the computer system. The high pressure receiver has a solenoid actuated king valve that is closed when any of the emergency shutdown buttons are activated.
There are two remote emergency shut off buttons at the SSI facility; one at the back door of the machine room and one in the hallway near the control room. In the event that one of these switches is activated, all refrigeration system equipment will be shutdown. This includes the compre
ssors, ammonia pumps, defrost hot gas regulators, and King Solenoid Valve. The programmable controller will however, continue to read all the system sensors.
EMERGENCY RESPONSE PROGRAM
Super Store Industries has implemented an Emergency Response Team that is trained to handle an ammonia release. All refrigeration operators are OSHA Technician Level trained (24 hours) and all supervisors are OSHA First Responder Operations Level trained (8 hours). The Super Store Industries' "Emergency Response Plan", is designed to meet the requirements for "Process Safety Management", and give our employees and community the maximum protection in the event of an ammonia release.
The contents of this plan is used in the Hazardous Materials Management Plan which is filed with the San Joaquin County Office of Emergency Services, as well as to update the existing plan in the Training Program Manual. The process for developing the best possible mitigation to any release large or small is through empl
oyee participation using the "Process Safety Management Committee", and any site specific documented plan previously used.
The "Response Plan", includes continuously changing scenarios that are discussed during those meetings to always improve Response Safety. An "Emergency Response Team", located at this facility as well as "First Responders Operational Program" gives Super Store Industries both defensive and offensive protection.
Super Store Industries conducts on-site emergency drills to provide training and to evaluate employee response in the event of a potential release. Fire drills can be incorporated using the scenarios that the wind may have disrupted the designated area on occasion.
PLANNED CHANGES TO IMPROVE SAFETY
The Process Hazard Analysis (PHA) provided mitigation measures to improve safety at the Super Store Industries Lathrop facility located at 16888 McKinley Avenue in Lathrop, California 95330. A majority of the recommendations from the PHA were determined t
o be complete during the PHA Revalidation on December 15, 1998. The following recommendations were implemented by May 10, 1999:
1: Ensure that all of the implemented "maintenance" recommendations from the initial HAZOP Study are included in the Mainsaver Mechanical Integrity summary tables.
2: Ensure that the procedure to replace the Cornell pump seals once per year is included in the Mainsaver maintenance program.
3: Review the Management of Change procedure and use the procedure/form for all changes as defined in the program, including recommendations made during these studies.
4: Update piping diagrams (DGD-04, 05, 14, 15, 16, 18) to reflect dual pressure relief valves.
5: Include semi-annual roof piping support inspection in Mainsaver also include inspection during seasonal weather changes.
6: Consider adding safety equipment requirements to the operating procedures and the Mainsaver print-outs (i.e. an SCBA is required when working in the rafters).
7: Examine the Ca
l-OSHA requirements regarding hand-rails and determine applicability to the mezzanine area.
8: Review the ammonia refrigeration system for inaccessible areas and determine the need for catwalks, ladders, handrails, and other operator protection during maintenance.
9: Update piping diagrams to include valve numbers.
10: Consider modifying Mainsaver procedure for pressure relief valve change-out to include safety quipment. This should include having a respirator cartridge on person - at ready during change procedure.
The only outstanding recommendation from the previous techncal studies will be implemented by June 1, 2000 and is as follows:
Verify that the relief valves are properly sized using a table to show each relief valve, rating, size, and main equipment.
In addition to these aforementioned recommendations, the facility plans to have all refrigeration operators review training videos provided by the Refrigeration Engineers and Technicians Association (RETA) in an overall
effort to maintain awareness with respect to the hazards associated with operating an ammonia refrigeration system. All refrigeration operators are members of the local RETA organization and participate regularly in the monthly meetings, which furthers their education.