Metalor USA Refining Corporation - Executive Summary
METALOR USA Refining Corporation (METALOR) operates a precious metals refinery in North Attleboro, Massachusetts which is subject to U.S. EPA regulations governing Accidental Release Prevention (ARP) Requirements: Risk Management Programs under Section 112(r) of the Clean Air Act (40 CFR Part 68). This Risk Management Plan (RMP) has been developed in accordance with the requirements specified under 40 CFR Part 68, Subpart G. The RMP certifies that METALOR has instituted a Risk Management Program at their facility that is in compliance with U.S. EPA ARP requirements.
The RMP includes an Executive Summary and Data Elements following the format published by U.S. EPA. In addition to identifying the applicable corporate policies and risk management systems, the RMP identifies a set of worst case and alternative release scenarios, the potential off-site consequences of those releases, and the facility's five-year accidental release history. This RMP certifies that prevention
and emergency response programs are in place so as to minimize risks to both workers and the potentially affected public.
Accident Release Prevention Program and Emergency Response Policy
It is the policy of METALOR management to implement the requirements of this Risk Management Program (RMP) in accordance with the USEPA regulations under 40 CFR Part 68. The objective is to minimize the risk of a release of a hazardous material and if a release occurs, to minimize the potential impact to METALOR employees, the public and the environment.
This objective will be accomplished by utilizing good operating procedures, providing appropriate training to all employees, and coordinating response activities, as necessary, with the local emergency response providers. METALOR's management is committed to providing the resources necessary to implement this policy. Further, METALOR recognizes that it has a duty to protect its employees and neighbors from the effects of all dangerous chemicals.
METALOR has developed a management system to implement and maintain compliance with the ARP Program and related OSHA Process Safety Management and emergency response programs. At METALOR, the Miller Department Supervisor has primary responsibility for ensuring overall implementation and compliance with these programs. Other individual employees such as the Environmental and Safety Coordinator, Maintenance Supervisor, and Vice President of Production are responsible for the technical implementation of individual sections of these programs.
The METALOR USA Refining Corporation facility in North Attleboro, Massachusetts is classified by the North American Industrial Classification System (NAICS) as industry number 331419 which includes primary smelting and refining of nonferrous metal (except copper and aluminum). METALOR operates a high temperature chlorine process, known as the Miller process, to separate silver and base metals from materials containing high co
ncentrations (>25%) of gold and platinum group metals.
Through the Miller process, gold and other platinum group metals are separated from silver and other less noble metals by pyrometallurgically reacting chlorine with the base metals. The resulting base metal chlorides are collected in gas cleaning equipment or as a slag. Gold and other platinum group metals remain in the molten metallic state and are cast into anodes for subsequent electrolytic refining. The Miller process is well established and has been used in the refining industry for over 100 years.
METALOR uses a number of hazardous compounds at the site. Of these, chlorine gas, which is used in the Miller process exceeds the threshold amount of 1500 lbs. Other hazardous compounds that are used at the site are either not of sufficient quantity to be regulated or are found at such a concentration that they are exempt from the RMP regulations.
Program Level Identification
The EPA Risk Management Regulation identifies three
levels of requirements defined as "programs". Program 3 applies to all processes, such as those present at METALOR, that are subject to the Occupational Safety and Health Administration (OSHA) Process Safety Management Standard (PSM). METALOR's Accident Prevention Program elements are adopted directly from the compliance program for the PSM standard, consistent with the Program Level 3 RMP Program requirements under 40 CFR Part 68. Program 3 related information is included in the Data Elements section of the Risk Management Plan
Worst-Case and Alternative-Release Scenarios
The RMP regulations require that each facility identify worst-case and alternative case release scenarios. For the purposes of developing and maintaining adequate Risk Management Plans, the EPA has defined in its governing rules and guidance a series of modeling methods and assumptions, which are to be used as administrative guides for planning purposes. In order to standardize and simplify the many factors tha
t can potentially occur in an accidental release situation, some of these assumptions may not take into account the available preventive measures or mitigation methods that could diminish or even eliminate the implied risks that are suggested by "worst-case" analyses. For that reason, both the results for the standardized "worse-cases" defined by the EPA methods and a set of alternative cases which are believed by METALOR to more realistically represent situations that may possibly, but rarely, occur within the lifetime of the facility are also presented.
EPA has defined a worst-case release as the instantaneous release of the entire contents of the largest vessel or connected piping that contains a regulated substance. For toxic gases such as chlorine stored at ambient temperatures it is assumed that the release occurs over a 10-minute period.
In the immediate vicinity of the METALOR facility, the aerodynamic surface roughness is 'urban' in nature, due to the many large buildings, ta
nks and other structures at the site. At greater distances the surface roughness is a mixture of both urban and rural. For both the worst-case scenario analysis, and alternative release analysis, which used EPA RMP*COMP model, urban surface roughness was used.
The EPA RMP*COMP software was used to simulate the worst-case release scenario for METALOR.
The worst-case scenario consists of a 10-minute gaseous ground-level release of 2000 lbs. of stored chlorine gas, dispersed under atmospheric conditions of F stability and 1.5 m/sec wind speed. The chlorine cylinders are kept in a separate room adjacent to the main building. Access to the site is controlled and monitored full time by a security detail. Within the storage room there is a chlorine alarm which would notify security of a leak from the tanks or piping. The selection of the worst-case release for chlorine should, therefore, be viewed as a regulatory necessity, rather than a realistic representation of
a worst-case release event.
The modeling results for the regulatory defined worst-case release indicate that the distance to the toxic endpoint is approximately 0.9 miles. Within this radius are both public and environmental receptors, including additional industrial facilities, residences, a school, and a park. Public and environmental receptors were identified using 1:24,000 scale U.S.G.S maps, supplemented with comprehensive maps of the local area (DeLorme Street Atlas USA, Version 5.)
Alternative releases are intended to represent release scenarios that have a greater likelihood of occurrence than a worst-case release. Alternative releases do not necessarily represent the types of releases that the PSM hazards analysis and/or accident history indicate would be most frequent, but rather a release that is somewhat more likely than the worst-case release and that generally still has the potential to affect off-site receptors. In accordance with the EPA's OCAG, a si
ngle alternative release scenario is reported.
METALOR performed a thorough review of the facility utilizing engineering plans, operational experience, and maintenance records, and the results of the OSHA PSM review in order to determine potential alternative release scenarios that would result in the greatest toxic endpoint distance.
In accordance with the RMP rule, alternative releases are modeled under typical (rather than worst-case) dispersion conditions. The EPA OCAG default dispersion conditions are neutral atmosphere, with dispersion neither enhanced nor limited (D stability and 3 m/sec wind speed). Unlike the worst-case release (for which an instantaneous spill or 10-minute ground-level gas release is assumed), alternative scenarios can account for the actual release configuration, and account for both active and passive mitigation.
The alternative release scenario that resulted in the greatest toxic endpoint distance was a meltdown of one of the 3/4 inch diameter safety rel
ief plugs located on the 1 ton chlorine cylinder. At 158 0 F or higher, the fusible plugs in the storage cylinders will melt and chlorine will escape into the storage shed. While METALOR estimates that facility personnel would be able to respond and stop the flow prior to emptying the tank (the facility maintains a chlorine alarm that would alert facility personnel to the tank leak) it was conservatively assumed that the tank would completely empty and that the tank was full at the time of the incident.
The EPA RMP*COMP software was used to estimate the distance to the toxic endpoint for the alternate release scenario. The model estimated release rate for this scenario was 165 lbs./min. The resulting toxic endpoint distance for this alternative release scenario is 0.2 miles. Within this distance around Metalor are other industrial facilities and limited public receptors.
Accidental Release Prevention Program
METALOR is governed by a set of OSHA and USEPA regulations that require p
lanning and facility activities intended to prevent a release of hazardous material, or if a release inadvertently occurs, to minimize the consequences of a release to the employees of the facility, the public and to the environment. These regulations include:
7 40 CFR Part 68, Accidental Release Prevention
7 29 CFR Part 119, Process Safety Management
The chlorine process subject to the Risk Management Regulation is also subject to Occupational Safety and Health Administration (OSHA) Process Safety Management (PSM) Standard. METALOR's Accident Prevention Program elements are adopted directly from the compliance program for the PSM standard, consistent with the Program Level 3 RMP Program requirements under 40 CFR Part 68. The RMP Program 3 Prevention Program elements are:
7 Employee Participation
7 Process Safety Information
7 Process Hazard Analysis (PHA)
7 Standard Operating Procedures
7 Management of Change (MOC)
7 Pre-Startup Safety Reviews (PSSR)
7 Safe Work Practices
7 Incident Investigation
7 Compliance Audits
Five Year Accident History
METALOR has an Incident Investigation program in place to investigate and document incidents that occur in the plant due to the chlorine process that could lead to a major accident involving a METALOR employee. The relevant information is documented on the Incident Investigation report and kept on file for five years.
During the past five years, there has been no accident involving chlorine gas that qualifies for reporting under 40 CFR Part 68. This means that no accident has resulted in reportable:
7 On-site deaths, injuries, significant property damage, or
7 Offsite deaths, injuries, property damage, environmental damage, evacuations or sheltering in place.
Emergency Response Program
Consistent with Program 3 requirements, METALOR has implemented an emergency response program that includes an emergency response plan, emergency response equipment procedures, employee train
ing, and procedures to ensure the program is up to date. Their detailed emergency response plan is part of the process safety management plan. METALOR has developed a detailed contingency plan to provide protection by providing prompt action to control an emergency and minimize the amount of toxic material released and lessen or eliminate the hazards to employees and the community. Response activities are coordinated with the local fire department to ensure the appropriate level of response.
Planned Changes to Improve Safety
METALOR, under the recent RMP program, as well as its existing PSM and earlier SARA Title III Community Right-to-Know Act compliance programs has organized its management system to effectively address all hazards and potential risks. Both the advanced planning aspects of process design, operating procedures, and emergency preparedness, and the operational elements of system maintenance, safe operating practices and ongoing personnel training are necessary to supp
ort a continual improvement in facility safety. These programs are thoroughly documented so that information about the safe handling of chemicals present at the facility is available to all employees, and can be readily interpreted by emergency response team staff and the Incident Commander. This is especially important when questions arise from public safety officials regarding potential risks to the community. All of these features of the RMP and the PSM program at METALOR lead to operations that are safe today, but will be even safer tomorrow.
METALOR's safety program incorporates continuous improvement through use of audits, inspections, and on-going evaluations of in-plant safety and program effectiveness. The information gathered is evaluated and improvements that are identified are incorporated into the program.