ALASKA NITROGEN PRODUCS LLC - Executive Summary
FACILITY DESCRIPTION and RMP REGULATED SUBSTANCES |
Alaska Nitrogen Products LLC owns and operates an ammonia and urea manufacturing facility near Nikiski, Alaska (Nikiski Plant). Using natural gas extracted from the Cook Inlet region, approximately 3,800 tons of ammonia and 3,500 tons of urea are manufactured at this plant daily. Four substances are present in quantities greater than the RMP thresholds, including two toxic chemicals (ammonia and chlorine), and two flammable gases (methane and hydrogen).
The plant is located 10 miles north of Kenai on the Spur Highway in an industrial area of Nikiski. The surrounding area is heavily forested and mostly rural, with small commercial operations along the highway and several side-roads leading to small subdivisions. The full-time population living within one-half mile of the plant is less than 10, and less than 100 residents live within one mile of the plant. The plant is situated on a bluff overlooking Cook Inlet to the west, approxim
ately 80 feet above sea level. It is bounded by industrial sites to the north and east, and a cleared field graded for industrial development to the south.
ACCIDENTAL RELEASE PREVENTION and EMERGENCY RESPONSE POLICY
Programs and procedures have been implemented to prevent fires, explosions, and releases of hazardous substances. If such events do occur, then emergency response programs and procedures are in place to protect the safety and health of plant personnel and the surrounding community, and to minimize any environmental impact. These programs and procedures are contained in the plant's Hazardous Materials Release Prevention, Control and Countermeasures Plan (RPCC). The RPCC fulfills all applicable federal, state, and local emergency preparedness and contingency planning requirements.
The plant is subject to the Program 3 Prevention Program requirement. RMP Program 3 Prevention Program elements include process safety information, process hazard anal
ysis, operating procedures, training, mechanical integrity, management of change, pre-startup safety review, compliance audits, incident investigation, employee participation, hot work permit, and contractor safety. These requirements mirror OSHA 1910.119 Process Safety Management (PSM) prevention program elements, but with an off-site focus. Since the plant is a PSM-regulated facility, these prevention program elements have been previously developed and implemented. Modifications to these programs have been made to incorporate off-site considerations, to meet RMP requirements.
In addition to these PSM/RMP mandated programs, the safety program at the plant is designed to make safety and accident prevention an integral part of day-to-day operation. The plant adopted a comprehensive safety management system in 1988 designed by the International Loss Control Institute, which provided a systematic approach to identify potentially unsafe acts or conditions and to increase safety awaren
ess. Since that time, this management system has been changed and fine-tuned to enhance its usefulness and address Plant-specific issues.
EMERGENCY RESPONSE PROGRAM
The plant has a 150-member emergency response team, trained and equipped to respond to chemical and fire emergencies. The Incident Command System structure is used, and an emergency response plan is in place. In the event that additional assistance or greater expertise is required, an emergency response strike team is contracted to provide immediate response. Through a Mutual Aid Agreement between emergency responders and local industry, the plant conducts joint fire response and hazardous material awareness training with various fire departments in the Borough. The Nikiski Fire Department is familiar with the plant and prepared to respond to an emergency if necessary.
The plant maintains an active membership on the Kenai Peninsula Borough Emergency Planning Committee, and is continually working with other committee
members to develop community-wide emergency plans. One of the most important considerations in dealing with emergencies is alerting the community in a timely manner. For releases that could potentially impact the community, the plant emergency siren would be initiated, and the Borough would be asked to activate the Community Alert Network (computerized call-down system) to notify people in the area of potential impact. The plant has provided the community with instructions on how to shelter in place to help people protect themselves during a chemical release.
FIVE-YEAR ACCIDENT HISTORY
The plant had six releases that meet the RMP criteria for reporting in the past five years. These releases resulted in minor injuries to employees in the immediate area and/or property damage to the plant. There were no offsite losses or injuries resulting from the releases.
OFFSITE CONSEQUENCE ANALYSIS
The worst case release scenario is defined as that release from a single vessel that results
in the modeled furthest distance to endpoint. The endpoint concentrations for Nikiski Plant RMP toxic substances are 200 parts per million (ppm) ammonia and 3 ppm chlorine, and the endpoint for flammables is one pound per square inch (psi) overpressure (enough pressure to break a window) from explosion of a vapor cloud of flammable gas. Passive mitigation systems may be considered in worst case scenarios, but administrative controls may not.
Alternate case scenarios must also be defined and modeled for all RMP toxics and flammables. By definition, no accident can be defined as "likely" to occur. Nevertheless, the unlikelihood of occurrence of an alternate case scenario is somewhat less than a worst case scenario (i.e. worst case scenarios are extremely unlikely to occur, while the alternate case scenarios are highly unlikely to occur). Both passive mitigation systems and administrative controls may be considered for alternate case scenarios.
The worst-case toxic release scen
ario determined for the Nikiski Plant was release of the full capacity of a refrigerated ammonia storage tank into a containment dike. The dike reduces the surface area of the ammonia pool, reducing the release rate due to vaporization. The alternate release scenario selected for anhydrous ammonia was a total failure of a pump gland. No passive mitigation measures or administrative controls were considered for this release scenario. The alternate release scenario identified for chlorine was failure of tubing connected to a one-ton chlorine cylinder, with no passive mitigation measures or administrative controls. Computer modeling shows the distance to endpoint for the worst case chemical release scenario extends beyond the boundaries of the plant. The alternate case scenario for ammonia extends beyond the plant boundary, but the alternate case for chlorine does not.
A vapor cloud explosion of hydrogen gas was identified as the worst-case flammable scenario. There were no passi
ve mitigation measures applicable to this scenario. Computer modeling shows the distance to endpoint does extend slightly beyond the plant boundary. An alternate case flammable scenario involving complete failure of a reformer transfer line resulted in a modeled distance to endpoint that did not extend beyond the plant boundary.
There are extensive programs, procedures, and controls in place at the plant that make these scenarios very unlikely to occur. Process units are designed to codes and standards, automated controllers keep the process operating within safe limits, critical systems are equipped with redundant protection, pressure relief valves and overflow lines are located throughout the plant, and the process is equipped with monitoring systems and alarms and automatic shutdown systems. Other examples of safety systems and controls at the plant include well-trained employees, routine inspections, preventive maintenance, emergency ammonia flares, safe work practices, stand
ard operating procedures, and administrative procedures.
PLANNED CHANGES TO IMPROVE SAFETY
Safety improvement projects receive a high priority when allocating capital budget. For example, in the past five years, $7.5 million were voluntarily spent installing emergency flares to prevent ammonia releases. With the completion of the emergency flares and other safety improvement projects in previous years, no further safety improvement considerations have been identified requiring large capital expenditures. However, safety recommendations are continually generated from process hazard analyses and incident investigation. These recommendations are evaluated, and implemented if they are practical and beneficial. For example, in 1999 over $700,000 has been allocated for safety and environmental improvement projects.