Tom Thumb Alliance Distribution Center - Executive Summary |
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ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES The Tom Thumb Alliance Distribution Center has an emergency action plan in effect. The Emergency Action Plan (Plan) is detailed in the Emergency Planning and Response section of the PSM/RMP document which is maintained at the facility. 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. Tom Thumb maintains a safety committee whose members are the designated emergency coordinators for the facility. The 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 was reviewed and updated to ensure compliance with the PSM and RMP regulation s. Tom Thumb has coordinated emergency response efforts with the local fire department. In the case of an ammonia-related emergency, the Tom Thumb Emergency Response Team will assemble and work with the fire department/HazMat Team to respond to the emergency. STATIONARY SOURCE AND REGULATED SUBSTANCE Construction of the ammonia refrigeration system at Tom Thumb was completed in February 2001. The facility serves as a distribution point for chilled goods. The facility is located at 743 Henrietta Creek Road in Roanoke, Texas about 0.5 miles west of Route 377 and 0.5 miles north of Route 170. The immediate area is primarily undeveloped with other warehouse storage facilities. The ammonia system was constructed in accordance with all applicable federal, state, and local regulations including the Uniform Fire and Mechanical Codes. The ammonia refrigeration system uses approximately 20,000 pounds of ammonia for various freezer and storage areas. The majority of the system is located i n the machine room including vessels, compressors, and associated piping. The condenser is mounted outside on a platform, and all of the evaporators are located in their respective cold storage rooms/areas or roof-top penthouses. The refrigeration cycle begins with the transfer of high pressure liquid ammonia from the High Pressure Liquid Receiver (HPLR-1) to the High Pressure Recirculator (HPR-1) and the Low Pressure Recirculator (LPR-1). The High Pressure Liquid Receiver also supplies liquid ammonia for oil cooling to the five compressors (C-1, C-2, C-3, C-4 and C-5), and vapor to the Hot Gas Coils and evaporators for hot gas defrost. The High Pressure Recirculator pumps liquid ammonia to the Glycol Chiller (HE-1) and the following evaporators: Shipping Dock Evaporators (D-EV-1 - D-EV-9), 55?F Produce Evaporators (EV-1 & EV-2), 34?F Wet Produce Evaporators (EV-3 & EV-4), 34?F Dry Produce Evaporators (EV-5 & EV-6), 30?F Packaged Meat Evaporator (EV-7 & EV-8), 34?F Dairy/Deli Eva porators (EV-9 - EV-16). The Low Pressure Recirculator (LPR-1) pumps liquid ammonia to the freezer evaporators (EV-17 - EV-22) located in the large and small freezer, and the ice cream freezer. As heat is absorbed, the ammonia is partially vaporized before it is drawn back to its respective recirculator. Vapor from the LPR-1 is pulled through Compressor 2 (C-2), while vapor from the Suction Trap (ST-1) is pulled by Compressor 1 (C-1). Both C-1 & C-2 discharge to the HPR-1. Compressor 3 (C-3) is a swing compressor which draws suction from HPR-1, but is also plumbed to pull from the LPR-1 and/or ST-1. C-3 discharges to the condenser, but is also plumbed to discharge back to the HPR-1. Compressors 4 & 5 draw suction from HPR-1 and discharge to the condenser. The condenser converts compressor discharge (hot gas) into high pressure liquid and recycles it to the High Pressure Liquid Receiver. HAZARD ASSESSMENT SUMMARY * Worst Case Release Result Summary Scenario Descriptio n: Release of the maximum quantity of ammonia that can be stored in a vessel - 15,000 pounds in 10 minutes. (The capacity of the High Pressure Liquid Receiver is approximately 15,000 pounds of ammonia.) The most pessimistic meteorological conditions were used: 1.5 meters per second wind speed, and F stability. Reference tables in the EPA-approved Risk Management Program Guidance for Ammonia Refrigeration were used to determine the maximum distance to the toxic endpoint of 200 ppm in rural conditions. This release reaches off site and may impact population receptors. No environmental receptors were affected by this potential release. * Alternative Release Result Summary Scenario Description: A release of ammonia from resulting from a 1/4 inch diameter hole in a pipe. The release rate of ammonia due to the pressure of the tank is 110 pounds per minute. The meteorological conditions used were 3 meters per second wind speed, and D stability. Reference tables in the Risk Manage ment Program Guidance for Ammonia Refrigeration were used to determine the maximum distance to the toxic endpoint of 200 ppm in rural conditions. This release reaches off site and may impact population receptors. No environmental receptors were affected by this potential release. ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS The Tom Thumb ammonia refrigeration system has many safety features. Much of the safety of the system is inherent in the policies and procedures that govern the operation of the system. For example, the Tom Thumb facility operates in accordance with OSHA's Process Safety Management regulation. The Tom Thumb facility including each ammonia system was designed and constructed in accordance with the Uniform Mechanical Code which specifically outlines requirements for the safe operation of the ammonia refrigeration system. These safety features include ammonia sensors in the machine room as well as sensors in the penthouses and automatic shut down systems that prevent equipment damage and ammonia releases. In addition, the majority of the ammonia inventory is maintained inside the machine room and just outside of the machine room (condensers). All pressure vessels are equipped with pressure relief valves that automatically engage in case of a high pressure situation and vent through a common header to the atmosphere. 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." FIVE YEAR ACCIDENT HISTORY The ammonia refrigeration system is new as of February 2001; therefore, there is no ammonia-related accidents at the facility to report. EMERGENCY RESPONSE PROGRAM Tom Thumb has established an Emergency Response Team trained to handle an ammonia release. The Emergency Response Team includes Refrigeration Technicians and selected Managers trained to the First Responder - Technician Level (24 hour) and the Maintenance Manager and Director of Engineering & Maintenance trained to the Incident Commander level. The Emergency Response Team conducts semi-annual response drills that include donning Self Contained Breathing Apparatus and acting out an emergency situation. All members of the team receive an eight hour refresher training annually. The Tom Thumb Emergency Response Plan contains a list of the Emergency Response Team personnel, emergency telephone numbers, outside agencies to contact, evacuation plan, and response procedures. PLANNED CHANGES TO IMPROVE SAFETY The Process Hazard Analysis provided mitigation measures to improve safety at the Tom Thumb Roanoke Distribution Center located at 743 Henrietta Creek Road in Roanoke, Texas. Many of the recommendations are complete and implemented as of the system startup date. All recommendations are scheduled to be compl ete by September 1, 2001. High Pressure Liquid Receiver (HPLR) R01 Ensure that there is another remote location for a computer that has dial-in capabilities to shut down the refrigeration system from a safe distance. R02 Meet with local fire department and the Denton County LEPC to determine the roles of the Emergency Response Team (including Tom Thumb personnel, fire department, and LEPC). Also consider an emergency response drill with appropriate team members (including Tom Thumb personnel, fire department, and LEPC). R03 Provide Hazard Communication training (right-to-know information - ammonia on site, who to report a release to, and how/when to evacuate) for all employees. R04 Verify the discharge pressure at which the compressors will shut down. Ensure that this pressure is less than 220 psig. R05 Do not store flammable materials under or near the high pressure liquid receiver. R06 Develop a standard operating procedure for manual purging non-condensibles from the sys tem. R07 Conduct inspections per the IIAR Bulletin 110 for insulated vessel and include these procedures in the Mechanical Integrity section of the PSM/RMP books. (Visually inspect external appearance weekly; detailed examination of the external surface / insulation at least every 12 months, this should include any effects of dampness or deterioration of the insulation which could lead to corrosion, surface treatment should be applied if required and the insulation repaired; Five Year Independent inspection per IIAR Bulletin 110 guidance.) R08 Include in the delivery procedures to bleed remaining ammonia from between check valve and fill valve. R09 Ensure two refrigeration technicians are present during delivery and follow the delivery procedures included in Operating Procedures section of the PSM / RMP books. R10 Obtain written delivery procedures from contractor for initial fill of new system. R11 Ensure that the Mechanical Integrity section of the PSM/RMP books and the Line Ope ning Permit system mandate that two trained Refrigeration Technicians are present when opening the ammonia system for maintenance, etc. R12 Consider installing and eyewash / safety shower station outside the engine room and insulate properly to compensate for weather extremes. R13 Conduct Emergency Response Team drills quarterly and hold facility evacuation drills annually. High Pressure Recirculator (HPR) / Low Pressure Recirculator (LPR) R14 Review the various options regarding additional monitoring for the ammonia system alarms. For example, consider having certain alarms monitored by an outside agency (or security) or consider interlocking the computer alarm system (or key alarms) to an auto-dialer system to notify Refrigeration Technicians. R15 Consider having a visual alarm outside the engine room to alert personnel in the event of a leak inside the engine room. R16 Determine whether the liquid pumps will be switched automatically via the computer control system or manu ally. If they are switched manually, consider keeping the suction side hand valve closed so that in the event that the check valve fails, there will be no damage to the pump. R17 Annually test high-high level switch(es) to ensure that the compressors will shut down. R18 Periodically check the level in the HPR (LPR) vessels and compare the results to the computer indication to ensure that the level transducer is properly calibrated. R19 Prepare an operating procedure for draining oil and use this procedure for on-the-job training. Document the on-the-job training by having both the employee and the trainer certify that the training was understood and that the employee demonstrated this understanding to the trainer. R20 Include testing of the ammonia detectors in the Mechanical Integrity program which is part of the PSM/RMP books. This test should include calibration per the manufacturer's recommendations and a test to ensure that the desired response is achieved when activated (a larms, shut down, ventilation fan startup, etc.). R21 Prepare a procedure for restarting the system in the event of high level in one of the recirculators (HPR or LPR). Prior to using this procedure, be sure to follow the Management of Change program included PSM/RMP books because this is not a normal operation. R22 It is recommended that each pump be operated for approximately one month at a time (HPR and LPR). Dock Evaporators R23 Following the IIAR Bulletin 110 recommendations for cleaning / inspecting evaporators. Upon inspection, determine whether the dock and produce area evaporators need additional cleaning and adjust schedule accordingly. R24 Implement the Management of Change procedures included in the PSM/RMP books in the event that manual defrost is necessary. R25 Obtain a supply of sulfur sticks for leak detection and develop a standard operating procedure for leak detection. R26 Include a roof policy / eyewash policy in the Mechanical Integrity section of the PSM /RMP books (for evaporator and condenser maintenance). In addition, ensure in line opening permit that two Refrigeration Technicians are required when opening the system. R27 Determine the need for lighting on the roof whether it be portable lighting or permanent lighting on the penthouses, etc. Hot Gas Coils R28 Consider contacting other users of the hot gas coils (air curtain) to determine the maintenance schedule/procedures necessary for this equipment and include this information in the Mechanical Integrity section of the PSM/RMP books. R29 Investigate the spare parts necessary for this equipment so that in the event that the fan fails, the air ?curtain" which keeps the cold air in the freezer can be repaired as soon as possible. Penthouse Evaporators (20) R30 Inspect the freezer pans frequently during startup to ensure that there is no ice build up in the pan. R31 Consider including in the Mechanical Integrity section of the PSM/RMP books the procedure for a Refrigeration Technician to inspect the hot gas valves during defrost (Randalls does this test quarterly) for leaks of ammonia. Penthouse 11 Evaporators and Surge Drums (2) R32 Install a relief vent line on the Penthouse 11 Surge Drum oil pot pressure relief valve to ensure that it vents up and away from eye-level. R33 Ensure that Refrigeration Technicians (2) bring the appropriate personal protection equipment and eyewash protection when they drain oil from the Penthouse 11 surge drums located on the roof. R34 Include in the Operating Procedures section of the PSM/RMP books an operating procedure for manual restart in the event of high liquid level in the suction trap. Compressors R35 Review manufacturer's recommendations regarding replacing the coalescer and oil in the compressors and include in the Mechanical Integrity section of the PSM/RMP books. R36 Verify the compressor safety shut down features and include in the Operating Procedures section of the PSM/RMP books. R37 Investigate an oil company that will remove the used ammonia-oil prior to the first maintenance cycle and commence with the necessary paper work (EPA Identification Number, if do not already have one). R38 Plan in advance when deciding to change the compressor oil and coalescers so that the procedure is completed during a low-load time (i.e. winter). Also outline the necessary personal protective equipment and procedures for this activity. R39 Review and prepare a procedure for operating the swing compressor. Penthouse 11 Evaporators (2) and Surge Drums (2) R40 Ensure that there is an oil draining procedure specific to this oil pot that incorporate the proper use of the heater. Condensers R41 Incorporate the maintenance practices outlined in the IIAR Bulletin 110 in the Mechanical Integrity section of the PSM/RMP books. This includes periodic cleaning of the pan and pH testing of the condenser water supply. R42 Incorporate a water treatment program for corrosion control of the condenser coil s. R43 Incorporate the company Lock Out/ Tag Out program when entering the condensers for cleaning. CHECKLISTS / SITE INSPECTION R44 Once the ammonia refrigeration system is operational, determine whether a formal hearing protection program is required under 29 CFR 1910.95. R45 Investigate the type of "lift" that will be used to perform maintenance on the valves that are located out of reach in the engine room (i.e. HPR / LPR liquid solenoid valves or pressure relief valves). Ensure that all safety considerations have been reviewed prior to allowing a Refrigeration Technician to open the ammonia system while situated on a "lift". R46 Once the system is operational and the emergency shut down procedures have been fully developed, determine which valves are critical and then develop an exercise program for these typically unused valves (annually). R47 Review emergency exits to determine if signs directing personnel to the exits have been adequately provided. R48 Review items 4. 1 through 4.14 once the HENCH system is operational to determine if it satisfies the criteria listed. R49 Determine if there are any "left-hand" valves in the system and tag as such. R50 Review items 5.4 through 5.8 once the HENCH system is operational to determine if it satisfies the criteria listed. R51 Install windsocks in various location on the roof of the facility so that employees can determine the wind direction from all sides of the facility. R52 Determine the alarm for notifying employees to evacuate in the event of an ammonia release (i.e. same as fire alarm). Also review whether the alarm condition should be directed to the Fire Department and/or Denton County LEPC, etc. R53 Consider installing a cover over the floor drain in the engine room. R54 Include notification to the sanitary sewer in the event that an ammonia spill goes down the engine room floor drain in the Emergency Response & Planning section of the PSM/RMP books. R55 Ensure evacuation assembly areas ar e not located near sewer man-holes. R56 Review the Incident Command System with the other Distribution Center Managers. R57 Establish a clear chain of command for emergencies and appoint a responsible person and backup coordinators to orchestrate emergency activities. Include this information in the Emergency Response & Planning section of the PSM/RMP books. |