Giant Distribution Center - Executive Summary |
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EXECUTIVE SUMMARY This Risk Management Program is designed to comply with the Environmental Protection Agency regulations detailed in 40 CFR Part 68. The stationary source is Giant Distribution Center. which is located at 1621 Industrial Drive, Carlisle, PA 17013. The site is owned by Giant Food Stores, Inc. The only RMP regulated substance at this facility is anhydrous ammonia - classification is as a toxic substance, liquefied under pressure. This facility has a current expansion and building project that is scheduled for completion by the endo of November 1999. The existing small ammonia refrigeration sytem will be expanded for additional cold storage space and also to replace an existing freon refrigeration system. The new complete system is included in this RMP with the Process Overview describing the system as it will be, when completed. It will have a total inventory of approximately 26,903 pounds of anhydrous ammonia in its refrigeration system. This process does not meet th e requirements of Program 1and is subject to OSHA's PSM standard. Therefor, this RMP is written to meet the Program 3 level of compliance. ACCIDENTAL RELEASE PREVENTION POLICY The facility has a complete Process Management Program in compliance with Occupational Safety and Health Administration (OSHA), Process Safety Management (PSM). This program includes a process hazard analysis using the what-if techniques. In addition, there is a five volume PSM program that covers process safety information, operational procedures, contractors, training, pre-startup safety review, mechanical integrity, hot work permits, P& ID's, and refrigeration drawings. The facility continues to follow the plans and procedures set forth in this program. EMERGENCY RESPONSE POLICY The facility has a comprehensive emergency response plan that meets established criteria. This facility has a good working relationship with their LEPC. The plan has been provided to and reviewed with the local LEPC. PROCESS OVERV IEW This food distribution facility operates a two temperature, single stage, anhydrous ammonia (R-717) refrigeration system with an engine room capacity of 509.4 TR @ +300F high temperature and 768.2 TR @ +140F medium temperature. This refrigeration system is a liquid re-circulation system and is designed to operate at an overfeed ratio of approximately 4:1 for all evaporators. Anhydrous ammonia (R-717) refrigerant is a Group II refrigerant. Rotary screw and reciprocating compressors are used in the refrigeration system. This facility contains six separate ammonia refrigeration sub-systems: Medium temperature system (+140F @ 27.5 PSIG). High temperature system (+300F @ 45.0 PSIG). Thermosyphon pilot receiver system (950F @ 181.1 PSIG). Condenser system (950F C.T. 770F W.B.). Compressor medium temperature system (+140F @ 27.4 PSIG). Compressor high temperature system (+300F @ 55.5 PSIG). Major equipment contained inside the engine room includes: Four medium temperature compressors ( two Frick RWBII-76 's @ 137.7 TR/182.3 BHP and two Frick RWBII-134 's @ 246.4 TR/310.5 BHP ). Two high temperature compressors ( one Frick RWBII-100 @ 263 TR/ 240 BHP and one Frick RWBII-134 @ 350 TR/ 320 BHP). One 84" dia.x 12'-0" OAL high pressure receiver. One 66" dia.x 11'-0" OAL high temperature pump re-circulator package . One 66" dia.x 12'-0" OAL medium temperature pump re-circulator package. Major equipment located outside on the roof includes: One- evaporative condenser: EVAPCO, ATC-485P, 7,130 MBH. One- evaporative condenser: EVAPCO, ATC-1090, 16,023 MBH. MITIGATION MEASURES There are some mitigating measures in place. The location of the ammonia vessels is inside the engine room. There is a fire sprikler system in the refrigeration machinery room and throughout this facility. Although there are doors and windows, the overall enclosure acts as a dike creating liquid pooling and limiting the liquid run-off. Ammonia leak detection is installed in this area that sounds alar ms and starts emergency ventilation. The emergency ventilation is automatically controlled and discharges the engine room air through the roof which creates a lower level of concentration in the engine room for responders. It also starts air dispersion at lower concentration levels and disperses the ammonia with greater air turbulence. SUMMARY OF HAZARD ASSESSMENT The definitions and parameters for the release scenarios are based on the "Risk Management Program Guidance for Ammonia Refrigeration" as described in Chapter 4: Off-site Consequence Analysis. Meteorological conditions also were taken from this source. The worst-case release scenario (OCA-1) used in this assessment identifies the high pressure receiver as the vessel with the potential to hold the largest quantity of ammonia. This is based on the common use of the high pressure receiver as a pump-down holding receiver. The worst-case release scenario is based on over-filling the vessel causing the released quantity to be eq ual to the total vessel volume with no piping volume included. The distance to Toxic Endpoint for this scenario is 1.5 miles. The population at risk within the area of concern, for this scenario, is 3,693 people. The alternative release scenarios evaluated in this hazard assessment include two possible scenarios. First alternate scenario (OCA-2) is the direct release of ammonia vapor from the largest pressure relief valve with a duration of sixty minutes. The size of the release is based on the rated capacity of the pressure relief valve (79.6 lbs/min) with a release duration of sixty (60) minutes. The distance to Toxic Endpoint for this scenario is 0.1 miles. The population at risk within the area of concern, for this scenario, is 96 people. This scenario was not used as the Aternate Scenario in PMP-Submit. The second alternative scenario (OCA-3) is the direct release of liquid from a > " diameter hole/valve in a vessel having an internal pressure of 181.1 psig. The size of this r elease is based on a ten (10) minute release duration at a release rate calculated from the simplified Bernoulli equation found on page 4-14 in Chapter 4 of the "Risk Management Program Guidance for Ammonia Refrigeration". The distance to Toxic Endpoint for this scenario is 0.2 miles. The population at risk within the area of concern, for this scenario, is 192 people. ACCIDENT PREVENTION PROGRAM This facility follows the OSHA Process Safety Management Program, in addition to special requirements stipulated by the EPA. There are 13 elements to the Accident Prevention Program. Participation - Community participation is through coordination and cooperation with the local Fire department and LEPC. Employee awareness is for employees, not directly involved with the process. Involved employees participate directly in reviewing and revising all elements of the PSM/Accident Prevention Program Process Safety Information - Process Safety Information includes a wide variety of books and manua ls. These are available to employees that operate, maintain, or repair the process equipment or piping. There are three categories of information: ammonia data such as MSDS, safety information, first aid, IIAR safety bulletins; process information such as piping & instrumentation diagrams (P&ID's), block flow diagrams, safety systems and devices, safe operating limits; and process equipment information such as equipment specifications, operating and maintenance manuals, and manufacturer's manuals. Process Hazard Analysis - A Process Hazard Analysis (PHA) was completed using the "What-if" technique. This addressed hazards, engineering and administrative controls, consequences of failure of engineering and administrative controls, facility siting, human factors, and a qualitative evaluation of the possible safety and health impact. The results of the PHA were prioritized and incorporated into a PHA Findings Report for follow-up as a corrective action log. Standard Operating Procedures - SOP's are provided for all process equipment. Topics include general information such items as objectives, hazards, location, equipment needed, P&ID's, task flow diagrams, and step-by-step procedures with specific warnings and comments. The SOP's cover different phases of operations such as: initial startup; normal, temporary and emergency operations; emergency shutdowns; and startup following a shutdown. Training - All employees are who are involved with anhydrous ammonia have been properly trained, at a minimum, in understanding the MSDS, routine refrigeration system operation, emergency refrigeration system operation, emergency and normal refrigeration safety practices, and, if appropriate, the individual's role in the emergency response plan. Contractors - This site follows strict guidelines for qualifying contractors who directly influence the safety of the process. The contractor qualification procedure ensures that contractors and their employees are fully aware of the po tential dangers involved with the process, that contractors understand their responsibility and train their people, and that a contractor's safety record is considered in reviewing the bids. Pre-Startup Review - Pre-startup safety reviews are required on all new or modified equipment/systems. This involves process safety information, process hazard analysis, training, safety procedures, operating procedures, and verification that construction and equipment are in accord with the design specifications. Mechanical Integrity Audits - The purpose of the Mechanical Integrity Audit program is to ensure that all process equipment is maintained in good working condition Hot Work Permits - This permit process is to protect against fire, explosion and other dangers resulting from hot work (welding and cutting outside the designated areas). Hot work permits must be obtained before any work is done outside the shop area. Management of Change - The Management of Change (MOC) procedure requir es that all changes (even "replacement in kind") be reviewed to see if there is a possible negative effect on process safety. Incident Investigation - The company requires an incident investigation be performed any time there is an incident which resulted in, or which could reasonably have resulted in, a catastrophic release of ammonia. The findings and recommendations will be studied and appropriate corrective action taken. Emergency Response Plan - This facility has a comprehensive emergency response plan that meets established criteria. This plan has been provided to the local fire department and the Cumberland County Emergency Planning Committee. Compliance Audits - To insure that all the other 12 areas of PSM program are followed, the company requires compliance audits. At a minimum, these must be completed every three years. Resubmission of the RMP shall be within five years of postmark or as may be required by regulations. ACCIDENT HISTORY - LAST FIVE YEARS There was onl y one ammonia release at this site that may fit the accident reporting criteria. This occurred during a severe snow storm/blizzard in 1996. The roof collapsed, under the excessive snow load, resulting in an ammonia release from piping. Corrective structural repairs and process piping repairs were done at that time. There were no off-site deaths, injuries, property damage, or environmental consequences. There was a facility evacuation and an off-site evacuation of about 100 people. There were no on-site deaths, injuries, or environmental consequences. PLANNED CHANGES TO IMPROVE SAFETY This facility has a project underway to computerize and update its process control system, to meet the most current industry standards. It has recently revised its PSM program, implemented revised SOPs, and provided refrigeration training to the process operating personnel. |