Century Aluminum of West Virginia, Inc. - Executive Summary
Executive Summary |
1. Accidental Release Prevention and ER Policies
Century Aluminum of West Virginia, Inc. (CAWV), Ravenswood, West Virginia Plant, utilizes chlorine in its secondary production of aluminum. Chlorine is considered hazardous by the United States Environmental Protection Agency (USEPA). CAWV is committed to analyzing the hazards associated with the use, handling, storage, and processing of chlorine and to eliminate, where possible, or minimize the potential for accidental releases that could affect the public, the environment, or CAWV employees. CAWV has given utmost consideration to safety in the design and use of the chlorine process per the Occupational Health and Safety Association (OSHA) standards. CAWV has a dedicated safety training program for employees associated with the use, handling, and storage of chlorine.
CAWV's emergency response program has been specially designed to handle emergencies involving chlorine. It complies with OSHA's Hazwoper (29 CFR 1910
.120) and Employee Emergency Plan (29 CFR 1910.120) regulations, as well as USEPA's RCRA and SARA regulations. The plan includes provisions for notifying appropriate Federal, State, and Local emergency authorities and notification of potentially affected neighbors.
2. Facility Description and the Regulated Substance Handled
CAWV's Ravenswood plant produces aluminum through both primary and secondary processes. It includes sorting, crushing, cleaning, drying, melting, refining, and pouring. Vaporized chlorine is injected into molten aluminum to remove unwanted contaminants. This process is known as "fluxing.' Chlorine (liquefied under pressure) is received via 55-ton rail cars. Rail cars are spotted on the rail spur beside the chlorine house. There are two rail car hook-ups available, however, only one rail car is unloaded at a time. The maximum number of rail cars on site is two.
After hooking up to a rail car, chlorine is sent to a steam-heated vaporizer. The vaporized chlor
ine is then sent to a gas injection tube at the melting furnace. There are a number of remote air operated shut off valves in series with manual shut off valves, that can be utilized to shut down the flow of chlorine, if necessary.
The RMP regulated substance at CAWV is chlorine.
3. The Worst-Case Release Scenario and the Alternative Release Scenario
-The Worst-Case Release Scenario is dictated by 40 CFR 68.25) and is postulated to be the amount of liquefied chlorine in a single rail car, 55 tons (110,000 pounds) release as a gas over a 10 minute period. Per 40 CFR 68.22(a)(1), CAWV calculated the distance that a cloud of gaseous chlorine would travel out to a concentration equal to the Emergency Response Planning Guideline 2 (ERPG-2), which was developed by the American Industrial Hygiene Association (AIHA). EPRG-2 is defined as the maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to 1 hour without experiencing or deve
loping irreversible or other serious health effects or symptoms that could impair their ability to take protective action. To arrive at a worst case distance, the USEPA's Offsite Consequence Analysis Guide (OCAG) was utilized. There are public receptors within this radius. (Schools, Residences, Hospitals, and Major commercial, office, or industrial areas). There are also Environmental Receptors within this radius. (National or State Parks).
-The Alternate Release Scenario is defined as one that is more likely to occur than the Worst Case Scenario and that will reach an offsite endpoint. For this scenario, CAWV chose the failure of a 3-inch pipe connecting the Chlorine House to the Casting House. After automatic shut off valves close, there will be 500 ft of 3-inch pipe that contains chlorine that could be released to the atmosphere. It is assumed that this release will take one hour. CAWV used a leading air dispersion model, PHAST by DNV Technica, to calculate alternate release
4. The General Accidental Release Prevention Program and Chemical-specific Prevention Steps
This facility complies with OSHA's Process Safety Management rule (29 CFR 1910.119) and with the USEPA's Accidental Release Prevention rule (40 CFR 68). Chlorine piping and equipment have been installed according to the Chlorine Institute Guidelines.
5. The 5-Year Accident History
CAWV has not experienced a reportable release of chlorine.
6. The ER Program
In the event of an accidental release significant enough for off-site impacts, trained facility personnel at CAWV would directly respond to the release with backup from local and contract emergency response teams. CAWV has an Integrated Contingency Plan (Policy name: CAWV-ICP 1.1) which outlines the actions necessary to respond to a release and the procedures for informing the public and local agencies responsible for responding to an accidental release. The contingency plan also includes the location and nature of emergency
health care available to employees of CAWV and the public in the case of an accidental release of chlorine. This plan is coordinated with the Local Emergency Planning Commission for Jackson County.
7. Planned Changes to Improve Safety
CAWV has recently implemented several changes that improved safety. Shut-off valves were installed in the cast house chlorine line to stop chlorine flow in the event of a loss of pressure. In addition, a caustic scrubber was installed to purge/evacuate the cast house chlorine line.
CAWV also plans to install a bi-gas panel at the furnace. This panel will be equipped with PC controls to accurately monitor and control chlorine usage.