Sysco Food Services of San Francisco - Executive Summary
ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES |
Sysco Food Services of San Francisco has an emergency response plan in effect. The Emergency Response Plan (Plan) is detailed in the Emergency Planning and Response section of this PSM/RMP document. This Plan was designed 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.
Sysco Food Services of San Francisco maintains Steering Committee whose members are the designated emergency coordinators for the facility. The Plan provides the response organization and notification procedures, evacuation routes, chlorine 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, RMP, and CalARP regulations, and t
o ensure that the plan is kept current.
STATIONARY SOURCE AND REGULATED SUBSTANCE
The Sysco Food Services of San Francisco ammonia refrigeration system was built in 1991. The ammonia refrigeration process was designed and constructed in accordance with all applicable federal, state, and local regulations. The facility is located at 5900 Stewart Avenue, Fremont, California 94538.
The ammonia refrigeration system uses 10,500 pounds of ammonia for dock operations, cold storage, and freezer storage. Refrigeration process equipment at the facility operates continuously. Compressors and condensers cycle on and off to comply with system demand during operation.
The refrigeration system serves to maintain low temperatures for cold storage including warehouse and dock areas, and freezer storage. The refrigeration cycle begins with the transfer of high pressure liquid ammonia from the High Pressure Receiver to the Controlled Pressure Receiver (CPR), where the pressure is reduced from
181 psig to 75 psig. The CPR serves as the main storage vessel for the system. It also supplies liquid ammonia to the cooler (16) and dock (5) evaporators and the High Temperature Suction Accumulator, which maintains a liquid/vapor mixture of ammonia at 28 psig. As the liquid ammonia enters the various evaporator coils,it expands reducing the temperature. These evaporators are used to maintain low air temperatures for the cooler and dock areas. As the air is chilled by the cooler/dock evaporators, the ammonia is partially vaporized and returned to the High Temperature Suction Accumulator.
The High Temperature Suction Accumulator provides liquid ammonia for supply to the freezer evaporators (9), which return two-phased suction to the Low Temperature Suction Accumulator. The Low Temperature Suction Accumulator further reduces the pressure of the ammonia to 1.3 psig. The Booster Compressors (2) pull low pressure ammonia vapor from the Low Temperature Suction Accumulator and discha
rge higher pressure vapor back to the High Temperature Suction Accumulator. The High Stage Compressors (2)pull the ammonia vapor (booster discharge) from the High Temperature Suction Accumulator and compress it, discharging high pressure ammonia vapor (hot gas) to the condenser. Hot gas is also used for defrost in the cooler and freezer evaporators and for pressurizing liquid transfer tanks associated with the accumulator vessels. At the condenser, the ammonia is condensed to high pressure liquid and recycled to the High Pressure Receiver. The system also has an emergency dump tank (into which a common relief header vents), which is kept full of water.
HAZARD ASSESSMENT SUMMARY
Worst Case Release Result Summary
Scenario Description: Release of the maximum quantity of ammonia that is stored in the refrigeration system - 10,500 pounds in 10 minutes. The largest vessel, controlled pressure receiver is located in an open engine room, therefore, no passive mitigation measures were u
sed to calculate the release rate. The most pessimistic meteorological conditions were used: 1.5 meters/second wind speed, and F stability. The facility is located in an urban setting. The reference table 4-4 from the EPA's RMP Guidance for Ammonia Refrigeration, Nov 1998 was used to find the distance for the worst case release scenario to 200 ppm. This potential scenario reaches off-site and may affect public receptors. No environmental receptors were affected by this potential scenario.
Alternative Release Result Summary
Scenario Description: A release of ammonia gas from a 1/4 inch diameter leak from orifice leading to an airborne release, representative of a pump seal leak, a gasket rupture, pinhole leak due to corrosion, flange seal leak, or valve bonnet seal leak. The release rate of ammonia due to the pressure of the tank is 86 pounds per minute. No passive mitigation measures were used due to the likely potential for an outside release. The meteorological conditions
used were 3 meters per second wind speed, and D stability. The reference table 4-5 from the EPA's RMP Guidance for Ammonia Refrigeration, Nov 1998 was used to find the distance for the alternate release scenario to 200 ppm. This potential scenario reaches off-site and may affect public receptors. No environmental receptors were affected by this potential scenario.
ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS
The Sysco Food Services of San Francisco facility was designed and constructed in accordance with the Uniform Mechanical Code which specifically outlines requirements for the safe operation of ammonia refrigeration systems. These safety features include ammonia sensors in the engine room as well as sensors in selected cold storage areas, and automatic shut down systems. In addition, the majority of the ammonia is maintained inside the engine room or outside on the roof above the engine room (condensers).
In addition to the Uniform Mechanical
Code, the facility will operate in accordance with the International Institute of Ammonia Refrigeration (IIAR) guidelines. In particular, the IIAR Bulletin 110, "Startup, Inspection, and Maintenance of Ammonia Refrigeration Systems."
There are ammonia and temperature sensors placed in strategic locations in the freezer, cooler, and dock areas. In the event of ammonia detection, a facility alarm sounds and a visible alarm is triggered. Ammonia sensors are located throughout the facility in the engine room, dock area, cooler areas, and freezer area. These sensors are tied to a central computer that alarms and calls an outside alarm company. The alarm will activate at one set concentration level.
FIVE YEAR ACCIDENT HISTORY
The accident history researched back five years to June 1994 shows that the Sysco Food Services of San Francisco facility had an ammonia release on June 21, 1995. Approximately 110 pounds of ammonia were released due to an equipment failure. The fire departmen
t responded to control the ammonia leak and assisted in evacuation of the Sysco Food Services of San Francisco employees. Some of the employees were treated at the scene or transported to the nearest hospital. The causes of the release, the facility's subsequent actions, and the mitigation measures that resulted from the incident were discussed as part of the HAZOP study.
EMERGENCY RESPONSE PROGRAM
The Sysco Food Services of San Francisco has an emergency response plan in effect at the facility. The Emergency Response Plan (Plan) is detailed in the Emergency Planning and Response section of the PSM/RMP document. This Plan was designed 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.
The Sysco Food Services of San Francisco maintains Steering Committee whose members include the emergency coordinators for the facility. The Plan provides the response organization and notif
ication procedures, evacuation routes, and mitigation procedures which will be implemented to respond effectively to emergency situations that may arise at the facility.
The Plan also includes the Emergency training for all Sysco Food Services of San Francisco employees. Sysco Food Services of San Francisco performs periodic emergency evacuation drills to enhance the emergency response skills of its personnel.
The Emergency Response Plan is reviewed and updated by the Sysco Food Services of San Francisco responsible person, Safety Manager at least once a year. This Plan will be review and updated to ensure compliance with the PSM, RMP, and CalARP regulations, and to ensure that the plan is kept current.
PLANNED CHANGES TO IMPROVE SAFETY
The Hazard Analysis provided the mitigation measures outlined below to improve safety at Sysco Food Services of San Francisco The changes will be completed by June 1, 2000.
R01 Develop and implement an emergency response plan. This includes d
etermining who will be primary emergency responders, and if facility employees are expected to use SCBAs.
R02 Consider installing an emergency kill switch outside the northern exit door to the engine room.
R03 Include in the maintenance program to replace relief valves on a 5 year basis or any time one vents.
R04 Ensure that the relief header is correctly piped to the water diffusion tank.
R05 Establish a procedure for a refrigeration operator to complete a daily log sheet on the ammonia system including key pressure/temperature and compressor readings.
R06 Do not store waste oil or other petroleum products in the engine room.
R07 Regarding SCBAs: ensure that only qualified/trained people use them, that the equipment is properly maintained, and that the storage location is prudent.
R08 Ensure that eye wash/safety shower stations are in locations that are easily accessible for operators including at least one outside the engine room. This could include portable stations for roof
R09 Ensure that operators are properly trained and that all employees (and contractors) are aware of the hazards associated with the ammonia refrigeration system.
R10 Develop and implement a written oil draining procedure.
R11 Establish a procedure to clean up and dispose of spilled liquid ammonia with an absorbent material.
R12 Establish a procedure to manually test the high level switches on the two accumulator vessels at least annually.
R13 Include checking evaporator piping runs on the roof in periodic maintenance activities (at least weekly).
R14 Do not adjust the factory set safety cut out switches on the compressors.
R15 Establish a procedure to follow manufacturers' recommendations regarding all ammonia equipment including compressors, condensers, ammonia sensors.
R16 Establish a maintenance program for the condensers which includes water treatment and cleaning the inside.
R17 Perform a periodic pH test on diffusion tank water to ensure that a significant
ammonia leak has not taken place.
R18 Label all valves in the control box and indicate the destination/origination of each line.
R19 Ensure that equipment not essential to the operation of the ammonia refrigeration system is not stored or kept in the engine room.
R20 Ensure that two people are present during an oil drain on the High Stage Accumulator.
R21 Post placards on the engine room entrance doors warning of the presence of ammonia.
R22 Consider posting labels on piping indicating the state of ammonia and the direction of flow.
R23 Consider labeling key valves including: those to be used during an emergency, and those that are used regularly (oil draining).
R24 Consider installing a reproduction of the refrigeration control panel (at least with the alarm lights) in a more traveled, accessible location.
R25 Consider installing visual and audible alarms at the northern door to the engine room that function identically to the alarms at the southern entrance.
R26 Ensure that
the area is cordoned off (with cones, signs, tape, etc.) during ammonia delivery operations.
R27 Install wind socks or other wind direction indicators that can be seen from all sides of the facility.
R28 Install an eye wash/safety shower station outside the engine room.
R29 Ensure that operators have a portable eye wash station when working on the equipment on the roof.
R30 Determine if the inside of a condenser is considered a confined space by Sysco and take the appropriate actions.
R31 Ensure that the specific piping run is isolated when an ammonia sensor is triggered in a particular cold area.
R32 Install concrete posts along the outside of the northern engine room wall to protect against trucker error at dock door #55.
R33 Ensure that evacuation locations are not near sewer vents.