TST Inc. - Executive Summary
E. EXECUTIVE SUMMARY |
In response to 40 CFR Part 68, this Risk Management Plan (RMP) has been developed for the TST Incorporated facilities located in San Bernardino County. The results from this RMP will:
*** Help protect the public health and the environment by ensuring proper emergency response and mitigation procedures when handling Acutely Hazardous Materials (AHM).
*** Assist TST Inc. and the local government agencies in their communication and coordination efforts to improve facility safety while handling AHMs.
The TST Inc. facility is an aluminum recycling plant that produces specification aluminum alloys from aluminum scrap and virgin metal. The Acutely Hazardous Material present at the facility and the focus of this program is chlorine, present as a gas and liquid.
The TST Inc. facility uses two processes to treat feedstock metal ultimately producing aluminum ingot and billet. Although the two processes are similar in that they both use chlorine they differ
in that the raw aluminum feedstock is of different quality. Both processes use chlorine which is stored in a liquid form in a rail car (60 ton), and a storage tank (12 ton). In addition chlorine is used to treat process water.
Chlorine from the rail car or storage tank is piped to the vaporizer where it is heated under pressure and converted to a gaseous state. The chlorine gas is then piped to the furnaces and the process water system via a chlorine injector. In the furnaces, it is sparged into melted aluminum feedstock where it removes magnesium and other alloy constituents. At the water tower, chlorine is used for treatment of microbiological growth. Chlorine gas is used in trace concentrations to remove oxide inclusions from the molten aluminum while casting aluminum billet.
1.0 FACILITY DESCRIPTION
1.1 FACILITY DESCRIPTION
The TST Inc. facility is an aluminum recycling facility that began operating in 1984. The facility covers approximately 20 acres and is located in Font
ana, California, on Etiwanda Avenue just southeast of the intersection between Interstates 10 and 15. The surrounding area is industrial and agricultural.
The AHM process equipment is located in and around the vaporizer room, inside the furnace building, and inside the billet foundry building. Liquid chlorine is piped from one of the chlorine storage vessels to the vaporizer room where it is converted into gas. Feed lines guide the gaseous chlorine to the TIMCO furnaces and chlorine injector at the Tandem water cooling tower. In the billet foundry building, chlorine gas is piped into flux units from the gas side of the bulk storage tank.
1.2 OPERATION THEORY
Liquid chlorine is stored at the TST Inc. facility in one 60 ton rail car, and one 12 ton fixed bulk storage tank. The rail car and storage tank are stored outside the vaporizer room. The chlorine from the rail car and storage tank is used for the production of aluminum ingots while the chlorine from the bulk storage tank is u
sed for the production of aluminum billets and as a back-up to the 60 ton rail cars. The two processes are described below.
***Production of aluminum ingots: Liquid chlorine flows from either the rail car or the storage tank to the vaporizer which is capable of vaporizing 1,000 pounds of chlorine per hour. While both the rail car and storage tank can be used interchangeably, the normal mode of operation utilizes chlorine from the rail car at a rate of approximately 250 pounds/hour. The chlorine enters the vaporizer as a liquid, becomes heated via a hot water tube exchanger, and exits the vaporizer as a gas. The chlorine gas exits the vaporizer through the gas discharge line and continues on to the furnaces. In the furnaces, it is sparged into melted aluminum via gas injection molten metal pumps.
***Production of aluminum billets: Chlorine gas is drawn off the bulk storage tank and piped into flux units where it is used as a scavenger to remove hydrogen and inclusions from the melt i
n the production of aluminum billets. Chlorine gas is also piped to the water cooling tower for the control of microbiological growth.
1.3 MAXIMUM PROCESS CAPACITY OF THE AHM SYSTEM
The AHM examined in this document is the liquid and gaseous chlorine used for the production of aluminum ingots and billets at the TST Inc. plant. Table 1-1 lists the state of chlorine, and the maximum process capacity of the chlorine equipment at TST Inc. plant.
TABLE 1-1 Maximum Process Capacity of the AHM Equipment
AHM STATE CONC. AMOUNT/CONTAINER
Chlorine Liquid/Vapor 100% 60 Ton Rail Car
Chlorine Liquid/Vapor 100% 12 Ton Fixed Tank
2.0 ACCIDENT HISTORY
The chlorine incidents occurred between June 1994 and June 1999 and were investigated and responded to by TST Inc. personnel. There has been a total of five accidents during this period, with the largest release estimated to be 1 pound of chlorine. All of the releases had been confined to t
he facility premises with no off site consequences.
An accident investigation program exists at the TST Inc. facility and is triggered in case an accident/incident occurs. Causes of incidents are identified and corrective measures are suggested, evaluated, implemented, and verified. The accidents/incidents are supplemented by Emergency Services personnel when called to respond.
The accident investigation is conducted by the Department Supervisor, Engineering/Maintenance Manager, and Plant Manager and consists of examining the contributing factors in terms of: man, machine, material, methods practiced and environment. This program has been further developed to include at the minimum the following:
*** A Fact Finding Meeting: When an accident/incident occurs, the personnel must report it to their Shift Supervisor who will notify the plant manager who will in turn determine if the event requires an accident investigation. If so, the Plant Manager will trigger the accident investigation
program by organizing a fact finding meeting. This meeting should commence within hours (if possible) of the accident/incident occurrence and take place near the scene. The participants should be the personnel involved directly with the event, their Supervisor, the Human Resources Manager, the Safety Manager, the Maintenance/Engineering Manager, the Environmental Coordinator and a report writer who will document the findings of the meeting. During this meeting the underlying cause(s) of the accident/incident will be determined, and the appropriate recommendations to avoid reoccurrence of the event will be discussed. If there are differences of opinion among the participants, appropriate codes, policies, memoranda, manuals, etc. will be used. The accident/incident report will be maintained by the Human Resources Manager.
*** Teamwork and Training: The outcome of the "fact finding" meeting will be documented in a report which will consist of an event summary, the operating/engineering
design principles or safety that apply to the event, the event participants by title only, the underlying cause(s) of the event, the resulting or potential hazard, the recommendations including a list of the necessary modifications (i.e. hardware, training etc.), and the person responsible for implementing the recommendations.
*** Training: A follow up on report recommendations is an essential part of the investigation program. Each recommendation will specify follow up responsibility in the report.
3.0 CHLORINE EQUIPMENT HISTORY
This section provides a brief description, including the nature and operational information of the chlorine process equipment used to produce aluminum ingots and billets at the TST Inc. facility. System start-up, shut-down, and preventive maintenance practices are described in Section 4.0 of this RMP program.
3.1 PROCESS DESCRIPTION
3.1.1 Chlorine Storage Vessels
*** Rail car: The TST Inc. plant usually receives liquid chlorine in one 60 ton rail car. T
he car is equipped with an outlet dome that is approved by the Chlorine Institute. The dome contains two liquid and two gas outlet valves as well as a relief valve that will vent to the atmosphere in the event of internal pressure conditions over 375 psi. Each liquid outlet line has an excess flow valve, which will shut tight in case of a break in the angle valves or in the chlorine unloading pipeline. This shut-off rate is approximately 15,000 lb/hr. The cars are insulated with 4-6 inch cork or combination fiber glass and foam insulation, and covered with an outer steel jacket for minimizing vaporization and pressure build up during transportation. Currently, the rail car vendor is Pioneer.
*** Storage Tank: If the 60 ton rail car empties prior to receiving a full one, the TST Inc. plant utilizes liquid chlorine from a 12 ton storage tank. The tank is constructed in accordance with the Department Of Transportation (DOT) regulations and Chlorine Institute. guidelines. It has a minimum
of 4 inch insulation and is covered with a protective metal jacket to minimize vaporization and pressure build up. Further, there are two liquid valves, two gas outlet valves, an excess flow valve, and a safety pressure relief valve. The latter releases chlorine gas to the atmosphere should the internal pressure exceed 225 psi. The excess flow valve is designed to shut-off the chlorine flow should the unloading chlorine rate exceed 7,000 lb/hr. The storage tank is owned by DX Systems.
*** Expansion Chamber: Feed lines that transfer the liquid chlorine from the storage area to the vaporizer contain one expansion chamber. The chamber prevents chlorine liquid line rupture by averting pressure build up in the pipeline. This is accomplished by a rupture disk, which will burst at 250 psi, allowing expansion of chlorine.
There is one chlorine vaporizer to handle the amount of chlorine required for the production of aluminum ingots. The vaporizer is capable of vaporizing 1,
000 lb/hr of liquid chlorine and meets American Society of Mechanical Engineers (ASME) requirements. The major components associated with the vaporizer are described below.
*** Chlorine Expansion Shell: Liquid chlorine is transferred from the chlorine storage vessels to the vaporizer's expansion shell, which is rated at 250 psig. The expansion shell has a chlorine level sensor, which is constructed of a steel chamber and has a Monel float and trim. Tubes, constructed of nickel, are immersed in the chlorine bath and carry hot water. The water is heated to approximately 120 degrees F by either a gas or electric water heater to provide the necessary heat to vaporize the liquid chlorine. Also, the chlorine expansion shell is equipped with a pressure relief valve rated at 250 psi.
The chlorine gas leaves the chlorine expansion shell at approximately 80 degrees F, passes through a cast carbon steel strainer where any impurities are retained, through the pressure reducing valve where the pr
essure is reduced to 40 psi, and continues on to the TIMCO furnaces, to the tandem flux units and the water cooling tower chlorine injector.
4.0 DESIGN AND OPERATION
4.1 DESIGN AND SAFETY FEATURES
The TST Inc. facility was designed to operate to produce aluminum alloys by using chlorine efficiently.
A fence encloses the entire facility with restricted access at manned gates. All visitors must check in at the office and must sign in. The following subsections describe the safety and design features of the TST Inc. plant.
4.1.1 AHM Process Flow Lines
Process gas lines, which handle significant quantities of chlorine, are constructed primarily from steel. The exceptions to this are the flexible pipes off the rail car and the storage tank, and the hoses just before each furnace. All flexible hoses are made of chlorine compatible materials.
4.1.2 Emergency Power Features
In case of a power failure, the pump that circulates the hot water inside the tubes in the vaporizer will stop.
In addition, the water flow switch will shut down the automatic shut off valve, which stops the chlorine supply to the vaporizer. With these safe guards the system will shut down safely.
4.1.3 Safety Features
There is an expansion chamber with a pressure switch on line between the rail car/storage tank and the vaporizer. Should the pressure in the line exceed 250 psi, the rupture disc will burst, and the pressure switch will activate visual and audible alarms at the control panel in case of overpressure conditions. Pneumatic control valves will close at the railcar and bulk storage tank.
Another safety feature is the pressure relief valve on the vaporizer that will relieve should the pressure in that vessel exceed 250 psi. Meanwhile the pressure switch on the vaporizer will close the automatic shut off valve, which will also stop the chlorine supply to the vaporizer. Additionally, the high level switch on the vaporizer will close the automatic shut off valve should the chlorine leve
l exceed a certain level. The automatic shut off valve will have to be manually reset after the cause of the "shut down" is corrected.
Another safety characteristic of the chlorine process system is the flow switch that is present on the water system side. The switch will activate the automatic shut off valve should the pump or the power supply fail.
4.2 BUILDING CODES
All buildings were constructed according to local, state, and federal codes at the time of construction. The buildings were constructed in 1979.
4.3 CHLORINE HANDLING PRACTICES
The operations manual (written procedures) regarding rail car set up procedures, connecting/disconnecting procedures, rail car padding procedures, and fixed tank and vaporizer start up/shut down procedures are kept in the maintenance and engineering office. The procedures are reviewed and kept by the Engineering/ Maintenance department, and the Engineering Manager will be responsible for updating the manuals as needed.
4.4 STANDARD OPERATING
At the beginning of each shift a visual inspection of the chlorine equipment is performed by an operator who records the results on a check list. The operator is trained to realize any deviations from the normal operation readings and should this happen, he will notify his shift Supervisor who will notify the maintenance department. During the visual inspection, the following will be checked:
Flex Lines Condition
Rail Car Pressure
Storage Tank Pressure
Vaporizer Pressure Temperature
Furnaces Pressure Flow Indicators
4.5 AHM EQUIPMENT MAINTENANCE
Pioneer and DX Systems perform the maintenance of the rail car and fixed tank. Table 4-2 shows the maintenance frequency of the chlorine equipment.
TABLE 4-2 Maintenance Frequency of the ARM Equipment
AHM Equipment Description Frequency
Rail Car Thickness T
Fixed Tank Thickness Test Vendor
Empty the tank and visually
inspect the inside cavity
Rail Car Chlorine psi gauge reading Every Shift
Access Tower Nitrogen psi gauge reading
Water line psi gauge reading
Liquid chlorine line expansion
chamber (#4) psi gauge reading
Safety water shower & eye wash
C-Kit available with seal intact
SCBA air couplers cleaned and capped
Compressed air psi gauge reading
Chlorine Rail Car Wheels choked Every Shift
De-railer in position
Warning sign in position (lighted
Bulk Storage Tank Expansion chamber #1 psi gauge reading Every Shift
Expansion chamber #2 psi gauge reading
Expansion chamber #3 psi gauge reading
Chlorine Gas psi (to Tandem)
C-Kit available and seal intact
SCBA air couplers cleaned and capped
Compressed air psi gauge reading
Vaporizer Room Liquid chlorine psi gauge reading Every Shift
Gas chlorine psi gauge reading
Gas chlorine psi gauge reading
Chlorine gas temperature
Hot water temperature
Water reservoir level (low-medium-high)
Vaporizer Control High limit controller temperature Every Shift
Check all alarms
Regular preventive maintenance is performed on the chlorine vaporizer system as outlined in the operations manual.
4.6 TST INC. SECURITY
4.6.1 Facility Security
The TST Inc. plant is staffed 24 hours a day, seven days a week. A fence around the entire facility limits access. Any unmanned gate is locked at all times. All visitors sign in at the office. There is a guard on duty 24 hours a day, seven days a week.
4.6.2 Shift and Hours of Operation
There are thr
ee shifts at the TST Inc. facility and are described below:
Day shift 7:00 am - 3:00 pm
Swing shift 3:00 pm - 11:00 pm
Graveyard 11:00 pm - 7:00 am
During all shifts (weekdays and weekends), three operators (one Leadsman, one Foreman and one Supervisor) are available on site. Maintenance personnel are available 7 days a week.
5.0 DETECTION AND MONITORING
Indicators monitor the status of the devices associated with the chlorine process equipment. Chlorine sensors are located in the process areas and are connected to an automatic shut-off system a well as a PA/alarm.
The rail car manway is continuously monitored through a video system located in TIMCO production office.
6.0 RECOMMENDED ACTIONS AND IMPLEMENTATION SCHEDULE
An angle valve emergency shut-off actuator to fit the rail car and storage tank will be in place in October 1999 as well as 5 additional chlorine process sensors.
7.0 CONSEQUENCE ANALYSIS SUMMARY
Chlorine gas is a strong irritant to the mucous membranes
of the eyes and the respiratory tract since it forms hydrochloric acid and liberates oxygen when combined with moisture. Both these substances could cause inflammation of the tissues with which they come in contact when present in quantity. A chlorine concentration of 3.5 ppm by volume in air produces a detectable odor. The maximum amount of chlorine that could be inhaled for an hour without serious effects is 5 ppm. Concentrations of 15 ppm and 30 ppm are the least amounts required to cause irritation of the throat and coughing, respectively. Exposures to 40-60 ppm for 30-60 minutes are dangerous while exposures to 1000 ppm are fatal even at a few breaths. Skin contact with the vapor or liquid may result in ulceration and necrosis of the tissue. Chlorine gas is heavier than air.
From the technical studies conducted, chlorine releases from the most likely hazards at the TST Inc. facility would result from a flange leak. These flanges are used to connect the flex lines to the 1 inch s
teel lines. They are flanges designed for chlorine service, approved for use by the Chlorine Institute and use a lead gasket as a seal. These releases are quite small and impact neither TST Inc. employees nor the public. They are easily detected and repaired. When they do occur, it is during the connecting/disconnecting operation. According to the Operating Procedures, the operator making the connection/disconnection will be donned in a Self Contained Breathing Apparatus (SCBA) while another one will be on stand by wearing a SCBA. During the connecting operation, all lines will be leak checked, and if a leak is found the operator will rapidly isolate the upstream valve. This greatly limits the volume of chlorine released, and these small releases are not even detectable 15-20 m from the flange.
Hazards that either had low or medium probability of occurrence are mitigated by the following measures:
*** Mitigation 1: The remotely activated shut off valve upstream of the rail car/storage
tank flex hose and immediately downstream of the expansion chamber. These valves are interlocked with chlorine sensors. This mitigation provides a fast response in shutting down the system should a line rupture occur.
*** Mitigation 2: The remotely activated shut off valve immediately downstream of the pressure reducing valve. This valve is interlocked with chlorine sensors located along the piping outside the furnace buildings. This prevents chlorine flow should the pipe downstream the vaporizer fail.
The worst case scenario: Both the 60 ton rail car and the 12 ton stationary tank were included in this scenario since they are interconnected through piping. This scenario represents a catastrophic event with a next to nothing chance of occurring. The specifics for this event are having both tanks completely full (72 tons total) and releasing the contents in 10 minutes. In order for this scenario to happen, multiple angle valves, normally closed, would have to be open as well as automa
tic shut-off valves and excess flow valves would have to fail, along with multiple punctures to both vessels.
The alternate scenario: This release scenario represents the maximum chlorine release that could occur if the piping downstream of the rail car ruptured and the internal excess flow valve closed immediately after the break (flow rate exceeded 15,000 lb/hr). Thus, this release scenario is a liquid chlorine release of the volume enclosed in the pipeline between the rail car and the vaporizer plus all the chlorine mass in the vaporizer and up to the pressure reducing valve (backflow from the vaporizer). Further, an additional 10% chlorine mass was included to account for unknowns in the volume of the system and to allow time for the excess flow valve to close. Thus, the total chlorine mass released was calculated to be 77 lbs. Using a two-phase release model for a 1" diameter hole in the pipe, the release rate was calculated to be 8.8 lbs/sec which would yield a total release t
ime of 8 seconds. However, the release will not be constant but would begin at a maximum and decrease with time. Therefore, the release was assumed to be 1 minute in duration with total release mass of 77 lbs. This results in a calculated release rate of 1.28 lbs/sec.
This alternate release would have little to no impact offsite, as the toxic endpoint would be located just past the facility's boundaries with no people normally located within this area.
8.0 AUDITING AND INSPECTION
8.1 RMP Implementation Audit
The RMP Coordinator will be checking annually that the items included in the RMP are practiced as described in the corresponding documents. For example, the RMP Coordinator will note if any training, maintenance, accident investigation procedures, and emergency response planning have been implemented or changed. In case procedural modifications are made to any of these items, the RMP Coordinator will be informed and ensure that the changes comply with 40 CFR Part 68 requireme
nts. The RMP Coordinator will keep all procedural modifications on file.
If major modifications that would affect the handling of chlorine are made, the RMP Coordinator should record the changes and update the RMP document within 60 days of the modifications.
The recordkeeping practices at the TST Inc. facility will include maintaining and updating the following:
TABLE 9-1 Record Maintenance
RECORD RESPONSIBILITY UPDATE FREQUENCY
Personnel Training Personnel Manager Annually
Standard Operating Procedures Plant Engineer Annually
Maintenance Procedures Plant Engineer Annually
Emergency Procedures Plant engineer Annually
10.0 EMERGENCY RESPONSE
The emergency response procedures, outlined TST Inc.'s Emergency Response Plan (ERP), were designed to minimize or avoid hazards to human health and the environment. In the event of an emer
gency, the Emergency Coordinator or designated alternate will ensure that the emergency response procedures are enforced. The Emergency Coordinator is familiar with the Contingency Plan, the Fontana TST Inc. facility, and the properties of the materials handled. He is also available at all times, either at the facility, or on call.
All TST Inc. personnel will adhere to specific emergency operations as detailed in the ERP. The ERP provides the response notification, evacuation, and mitigation procedures, which will be implemented in order to respond effectively to emergency situations that may arise at the facility. These emergency procedures are summarized in the following three sections.
10.1 RESPONSE ORGANIZATION AND NOTIFICATION PROCEDURES
In case of an incident, the emergency response summary is as follows:
*** Individual that witnesses the chlorine incident notifies the supervisor.
*** The Supervisor investigates the incident and determines its severity.
*** If chlorine inci
dent constitutes an emergency, the supervisor will call 911 and posted phone numbers for emergency services as needed.
*** The Supervisor will use the Public Announcement public announcement (PA) /alarm system to direct employees to assemble in the appropriate area(s), depending upon wind direction.
*** The Supervisor will notify the Emergency Response Coordinator, Safety Manager, Plant Manager, Environmental Coordinator and the Human Resources Manager.
*** The Emergency Response Coordinator will coordinate with the emergency Services.
*** The Supervisors will account for all employees.
In case a major chlorine leak occurs, the fire department is notified. The outside emergency response team is CHEMTREC. Further, all employees have the authority to shut down the system in case of a major chlorine leak.
10.2 EVACUATION PLAN
In case of a major chlorine leak, the Supervisor on duty will decide to evacuate the facility. The wind direction will be determined from the wind socks that
are located throughout the facility. A head count performed by the Supervisor/ Foreman will verify that all employees evacuated.
In case of a major chlorine leak, windsocks located throughout the facility will help determine which evacuation routes the employees should use. In addition there are two Self Contained Breathing Apparatus (SCBA) units, and two chlorine emergency repair kits located and maintained at the storage tank and on the railcar access tower. Supervisory personnel on each shift are trained in their use.
TST Inc.'s training regarding chlorine handling practices, includes new employee orientation to normal and emergency operating procedures, on going training for informing employees on all procedures and safety practices related to handling chlorine, and operator emergency decision making. Drills regarding handling a chlorine release scenario are performed annually.
Employees attend required training courses for each job position wi
thin weeks of their date of hiring. At the time of assignment to jobs that engage in hazardous operations and emergency response, no employee will participate in field activities until they have been trained to a level required by their job function and responsibility. Refresher training will be required annually for employees that participate in hazardous operations and emergency response. Employees that do not participate in these operations will receive awareness level training annually.
Safety meetings will be performed weekly by supervisors. The topics discussed will be specific to safe work practices and relate to hazards of assigned work and workplace. The attendance training rosters will be maintained by HR and the Supervisors responsible for conducting safety meetings. The employees required to attend the training programs are notified by a memo that informs them about the date and the time that the training classes/meetings take place.
The training program will ensure:
2. knowledge about regulations, policies, and procedures relative to their job(s),
3. effective response to environmental hazards, potential exposure to hazardous substances and fire hazards,
4. proper use of necessary personal protective equipment,
5. safe use of engineering controls and equipment,
6. full compliance with applicable laws and regulations.