Norco Chemical Plant - East Site - Executive Summary

| Accident History | Chemicals | Emergency Response | Registration | Source | Executive Summary |

26336 LDEQ Facility ID Number 
Shell Chemical Company 
Norco Chemical Plant - East Site 
Risk Management Plan - Executive Summary 
The Norco Chemical Plant - East Site is one of three Shell Chemical Company facilities operated by Shell's  Norco Chemical Plant (NCP).  Shell Chemical Company is a signatory to Responsible Care., a Chemical Manufacturers Association (CMA) program committed to the continuous improvement of chemical safety management.  In accordance with Responsible Care., the Norco Chemical Plant maintains Health, Safety, and Environmental (HSE) management systems to ensure the safe operation of its facilities.  As part of this commitment, NCP invests resources in various areas of accident prevention such as: 
- Safety in process design 
- Safe operating policies and procedures 
- A comprehensive mechanical integrity program 
- Management of process changes 
- Training 
- Incident investigation and auditing 
- Emergency response. 
This document provides an overview of the risk ma 
nagement activities at the Norco Chemical Plant - East Site, including: 
- A description of the facility and substances regulated by the EPA RMP rule. 
- A summary of potential release scenarios and potential off-site consequences. 
- An overview of the Accident Prevention Program to prevent accidental chemical releases. 
- A five-year history of accidental releases of chemicals regulated by EPA's RMP rule. 
- An overview of the emergency response program 
- Existing and planned improvements to prevent accidental chemical releases. 
The Norco Chemical Plant - East Site operates five (5) processes with regulated substances in sufficient quantities to be covered under the RMP rule.  All are Program 3 processes as follows: 
1. BD-5 
Refines C4 hydrocarbon streams into 1,3-butadiene used as a building block for a variety of plastic products.  RMP regulated substances include 1,3-butadiene, hydrogen and two (2) NFPA 4 flammable mixtures with acetyle 
ne, butane, 1-butene, Cis-2-butene, isobutane, isopentane, methane, and trans-2-butene.  
2. Gasoline Hydrotreater 
Produces various C5, C6, and C7 products used in the production of other building block olefins products, aromatic hydrocarbons, and gasoline.  RMP regulated substances include hydrogen and an NFPA 4 flammable mixture containing isoprene, isopentane and pentane. 
3. OL-5 
Produces ethylene, propylene, and crude butadiene used as building blocks for other materials used to make a variety of plastic products.  Other byproducts include gasoline, ethane, methane and hydrogen.  RMP regulated substances include ethane, ethylene, hydrogen, methane, propylene, and two (2) NFPA 4 flammable mixtures containing butane, 1,3-butadiene, isopentane, and pentane. 
4. GO-1 
Produces ethylene, propylene, and butadiene used as building blocks for other materials used to make a variety of plastic products.  Gasoline is also produced as a byproduct.  RMP regulated substances include ethane, e 
thylene, methane, propane, propylene and four (4) NFPA 4 flammable mixtures.  The flammable mixtures include a combination of butane, 1,3-butadiene, cis-2-butene, trans-2-butene, ethane, ethylene, hydrogen, isobutane, isopentane, methane, propane, and propylene. 
5. Utilities East 
Provides water treatment utility services to NCP-East Site and Motiva Norco Refining Company.  Chlorine is the only RMP regulated substance in the Utilities East process. 
An offsite consequence analysis (OCA) was performed on the potential worst-case scenarios (WCS) and alternative release scenario (ARS) involving toxic and flammable substances at the Norco Chemical Plant -East Site.  The WCS is considered to be unrealistic because it does not reflect actual operating conditions, nor allow credit for all mitigations in-place.  On the other hand, the ARS is a more realistic scenario which takes into account actual operating conditions and applicable mitigations. 
The following are brief summaries of the Worst-case and Alternate Release scenarios at the Norco Chemical Plant - East Site, including information on mitigation control measures which can reduce offsite impact.  All OCA release modeling was performed using the ABS Group, Inc. RMPlanner 2.0 software tool.  This tool is based on the 1996 EPA OCA Guidance Tables.  Population estimates, public receptors and environmental receptors were analyzed using the U.S. Department of Commerce, Economics and Statistics Administration, BUREAU OF THE CENSUS Landview . III Environmental Mapping Software (1997). 
1. Worst-Case Toxic Release Scenario - Chlorine 
The worst-case scenario is an instantaneous failure of a cylinder that results in a release of  2,000 lbs. of chlorine over a 10 minute period.  The release calculation assumes urban topography due to the close proximity of congested process areas.  No passive mitigation (i.e. containment) credit was applied to the release model calculation.  The  
RMP toxic endpoint (0.0087 mg/L based on the AIHA ERPG-2 level) was calculated at 4.5 miles (23,700 ft.).  A population estimate of 12,000 people offsite, including residential, religious, recreational, school, commercial, and environmental receptors could be potentially affected by the release. 
Although the RMP rule does not allow credit for mechanical safety systems on worst-case scenarios, there are various prevention measures that significantly reduce the potential of a worst-case scenario.  These measures include: 
- Review of supplier hydrostatic testing program for chlorine cylinders 
- Visual inspection of cylinders when brought on-site 
- Barriers to protect the cylinders from external damage 
- Flow regulators which control the flow of chlorine under vacuum  
- Operating procedures on chlorine cylinder changeouts 
- Routine operator surveillance and leak detection  
2. Alternative Toxic Release Scenario - Chlorine 
The alternative release scenario involves a 2000 lb. chlorine rel 
ease due to the failure of a 9/16" fusible plug on the cylinder.  The fusible plug failure is assumed to fail on the liquid side of a full cylinder and was estimated to empty the cylinder contents in approximately 10 minutes.  No passive (i.e. containment) mitigations were applied to the release model calculation. The release calculation also assumes urban topography due to the close proximity of congested process areas.  Operator surveillance allows for detection and intervention within 3-5 minutes.  Area firewater monitors would be activated to apply water on the release.  This scenario was selected because of a 1998 incident in the industry which involved a  fusible plug failure on the vapor side of a chlorine cylinder.   The RMP toxic endpoint (0.0087 mg/L based on the AIHA ERPG-2 level) was calculated at 1.5 miles (7820 ft.).  A population estimate of 970 people offsite, including residential, recreational, religious, school, and commercial receptors could be potentially affected  
by the release.  No environmental receptors were identified.  The prevention steps used to manage chlorine cylinders (identified in the WCS above) significantly reduce the potential of this scenario occurence. 
3. Worst-Case Flammable Release Scenario - Flammable Mixture 
The worst-case scenario for a flammable release assumes the instantaneous failure, release, and vapor cloud explosion of 8,000,000 lbs. of a flammable mixture (butane, 1,3-butadiene, isopentane, and pentane) from a process vessel in the OL-5 process.  Although the vessel operates liquid filled to 50% capacity, there are no procedures to regulate inventory.  Therefore, the vessel had to be assumed liquid full per the RMP requirements for WCS analysis.  No passive (i.e. containment) mitigation credit was applied to the release model calculations.  The release calculation also assumes urban topography due to the close proximity of congested process areas.  The maximum impact distance to a 1 PSI endpoint was calculated at 
1.6 miles (8,570 ft.).  A population estimate of 1,100 people offsite, including residential, recreational, religious, school and commercial receptors could be potentially affected by the release.  No environmental receptors were identified. 
4. Alternative flammable Release Scenario - Propylene 
The alternate flammable scenario involves a 40,000 lb. propylene release and vapor cloud explosion resulting from a valve stem blowout on a 48" power assisted check valve downstream of a propylene compressor.  The release calculation assumes urban topography due to the close proximity of congested process areas and a 5 minute release duration before explosion.  This scenario was selected because of a 1997 incident in the industry involving a similar event in an identical process.   It is assumed that release detection would be immediate due to the noise generated by a high pressure release.  Operator intervention is assumed to deactivate the compressor to stop propylene flow, as well as activ 
ate area firewater monitors to contain any fire and cool equipment.  The maximum impact distance to a 1 PSI endpoint was calculated at 0.11 miles (588 ft.).  A population estimate of 30 people offsite, including commercial receptors could be potentially impacted by the release.  No environmental receptors were identified. 
The following is a summary of the Norco Chemical Plant (NCP) management system on accident prevention used at the East Site.  Each of the NCP sites contain processes that are also regulated under the OSHA Process Safety Management (PSM) standard.  This Accident Prevention description applies to all the NCP sites and summarizes the general management system according to each of the RMP/PSM prevention elements. 
Employee Participation 
NCP encourages employee participation in all phases of its accident prevention management system.  There is an NCP Employee Participation policy that addresses participation requirements o 
f various teams and committees, including Health & Safety Committees, Process Hazards Analysis (PHA) teams, and various safety awareness teams.  Participants include employees from Operations, Maintenance, Engineering & Technical Support and Management.  
Process Safety Information (PSI) 
The Norco Chemical Plant maintains a variety of technical documents to ensure the safe operation of its processes.  The Process Safety Management policy requires operating departments maintain and update PSI applicable to their processes.  Chemical-specific information is contained in material safety data sheets (MSDS'), including properties, exposure hazards, emergency response, and exposure treatment considerations.  Other PSI documents include, but are not limited to process drawings, descriptions of safe operating parameters and limits, chemical inventories, basis for process design, safeguarding, protective instrument and equipment construction information.  Many of the documents, including MSDS' 
are electronically available to all NCP employees and Contractors.   The Process Safety Management policy also includes a summary table to assist employees in locating process safety information documents and drawings. 
Process Hazards Analysis (PHAs) 
The Norco Chemical Plant maintains a comprehensive Process Hazards Analysis (PHA) program to identify and control hazards associated with its processes.  These include processes covered under one or a combination of: (1) RMP Program 3, (2) OSHA PSM, and (3) Shell internal criteria.  NCP uses the hazard and operability (HAZOP) PHA methodology to conduct process unit PHAs.  PHA team members must include experienced employees with operating, maintenance, and engineering backgrounds who are familiar with the affected process.  The PHA team is chartered to identify the safety hazards in the process, evaluate the adequacy of  existing safeguards in-place, determine the risk of the event occurring, and recommend additional accident prevention  
mitigations when the team believes such measures are necessary to reduce event risk.  All safety related PHA findings are risk ranked to ensure mitigation measures receive timely attention based on their risk priority.  All PHA findings are forwarded to local Management for review and resolution.  Safety related mitigations approved by Management begin immediately after Management review, starting with the highest risk scenarios.   When a final mitigation can not be implemented within a reasonable time (e.g. hardware change scheduled to a unit maintenance turnaround), interim solutions such as administrative controls (i.e. operating and work practice changes) must be implemented to mitigate the risk.  PHA mitigations are tracked on a quarterly basis until resolved.  Process unit PHA's are revalidated every 5 years for the life of the process.  Written PHA reports are also retained for the life of the process. 
Operating Procedures 
Norco Chemical Plant operating departments maintain wr 
itten procedures to address a variety of operating modes such as (1) unit startup, (2) normal operations, (3) temporary operations, (4) emergency shutdown, (5) normal shutdown, and (6) initial startup of a new process.  These procedures provide a reference to experience operators, as well as serve as a training tool for new operators.  Each PSM covered operating department must annually certify their procedures as current and accurate.  The management of change process is also used to ensure operating procedures are updated as necessary to reflect changes in the process unit.  Operating procedures are accessible to all NCP employees either electronically or in hard copy. 
The Norco Chemical Plant implements a comprehensive training program for all operating, maintenance, and technical personnel.  New operating employees receive classroom training on basic operating principles and the operating procedures of their process.  In addition to classroom training, on-the-job trainin 
g is accomplished by working with experienced operating personnel.  Along with routine operating practices, the training places a significant emphasis on unit specific safety and health hazards, and emergency operating conditions (including shutdown).  Employees involved in operating a process must be qualified to perform the job on that process.  Operators must re-qualify on their jobs every three (3) years and work a predesignated number of hours by job to maintain qualification.  Competency is assessed through a combination of methods such as written and oral tests, and demonstrating skills in the field.  The training program complements the written operating procedures to ensure operating employees are properly qualified for their job.  All training is documented and managed by the NCP Training Department. 
The Norco Chemical Plant routinely uses contractors to supplement its maintenance and technical workforce, particularly during periods of increased maintenance or  
construction activities.  Since contractors may work on or near process equipment, NCP has procedures in place to ensure that contractors have the proper knowledge, skills, and training to perform their work in a safe manner prior to working on-site.  Contractor safety programs and performance are primary factors influencing the Contractor selection process.  Contractors are routinely monitored by a Contract Coordinator to ensure compliance with regulatory and Shell requirements.  Contractor safety performance is also part of NCP weekly safety statistics communications to employees and contractors.  
Pre-Startup Safety Review (PSSR) 
The Norco Chemical Plant conducts a PSSR for any new facility or facility modification that requires a change in process safety information.  In addition, major projects and maintenance turnarounds require a PSSR to be completed.  The purpose of the PSSR is to ensure that safety features such as P&ID and other process drawings, operating and/or maintenance 
procedures, training and equipment are up to date and appropriately prepared for startup prior to placing the equipment in-service.  This review provides an additional check to ensure construction is in accordance with design specifications, that all supporting systems are operationally ready, and personnel are appropriately trained on the modification. 
Mechanical Integrity 
The Norco Chemical Plant has well-established practices and procedures to maintain the integrity of pressure vessels, storage tanks, piping systems, relief and vent systems, process controls, pumps, and critical instrument systems.  The basic aspects of the mechanical integrity program include (1) training for process maintenance activities, (2) ongoing inspection and testing of process equipment, (3) correction of identified equipment deficiencies as appropriate, and (4) quality assurance in construction, installation and spare parts.  Maintenance personnel are trained on the safety and health hazards in their w 
ork areas, applicable maintenance procedures, emergency response plans, and applicable safe work practices to help ensure they can perform their job in a safe manner.  Inspections and tests are performed to ensure that the process equipment functions as intended and that the equipment is within acceptable limits (e.g. acceptable wall thickness for pressure vessels).   If a deficiency is identified, the operating department must correct the deficiency before placing the equipment back in service. The appropriate mechanical integrity support group (i.e. Inspection and Pressure Equipment, Mechanical, Electrical, or Instrumentation) review equipment use and determine any necessary actions to ensure the safe operation of the equipment. 
Safe Work Practices and Permitting 
The Norco Chemical plant has long-standing safe work practices in place to help ensure worker and process safety.  Examples include: (1) the control of entry and exit of support personnel in a process area, (2) equipment l 
ockout and tagout procedures to ensure isolation of energy sources for equipment undergoing maintenance, (3) procedures for the safe removal of hazardous materials before opening process piping or equipment, (4) a permit process to control hot work, and (5) a policy and permit process to ensure adequate precautions are in place before entry into a confined space.  These safe work practices, along with training of affected personnel, form a system to ensure operations and maintenance activities are performed safely. 
Management of Change 
The Norco Chemical Plant has a comprehensive system to manage changes to its processes.  This system requires that changes to equipment hardware, chemicals, operating variables (including critical process operating conditions), procedures, operating staff and any other facility changes be properly reviewed and authorized before being implemented.  Changes are reviewed to ensure that adequate controls are in place to manage any new hazards and verify th 
at existing controls have not been compromised by the change.  Affected chemical hazard information, process operating limits, equipment information, and procedures are updated to incorporate these changes.  In addition, all personnel affected by a change must be provided the necessary notification and training.  
Incident Investigation 
The Norco Chemical Plant promptly investigates incidents resulting in, or could have reasonably resulted in fire, explosion, significant toxic gas release, major property damage, environmental loss, or personal injury affecting site personnel or the community.  The goal of each investigation is to determine the facts and develop corrective actions to prevent a recurrence of the incident.  The investigation team documents its findings, develops recommendations to prevent a recurrence, and forwards these results to NCP Management for resolution.  Corrective actions taken in response to the investigation team's findings and recommendations are tracked unt 
il they are complete.  The final resolution of each finding or recommendation is documented and the investigation results are reviewed with all potentially affected employees and contractors.  Incident investigation reports are retained for at least 5 years so that the reports can be reviewed during PHA revalidations. 
Compliance Audits 
The Norco Chemical Plant maintains a comprehensive audit program to ensure accident prevention policies and procedures are in place and functioning properly.  Compliance audits consist of: (1)  OSHA PSM compliance audits conducted every three years at each NCP site, (2) external compliance audits by Shell's Corporate Office on a three year cycle, and (3) internal management system audits conducted annually to evaluate the accident prevention system for each unit.  Employees ranging from hourly, engineering and technical, and management personnel participate as audit team members in the internal audit process.  The audit team(s) develop findings that ar 
e forwarded to NCP Management for resolution.  Corrective actions taken in response to the audit team's findings are tracked until they are complete.  The final resolution of each finding is documented and audit findings are retained for six (6) years. 
Site-Specific Prevention Steps 
The Norco Chemical Plant's accident prevention program is applied to the East Site due to potential hazards that must be managed to ensure continued safe operation.  These prevention steps help to prevent potential accident scenarios that could be caused by (1) equipment failures and (2) human error.  The East Site has various safety features to: (1) detect,  (2) contain and control, and (3) mitigate the consequences of a release that include: 
1. Release detection 
- Process alarms 
- Operator surveillance 
- Portable hydrocarbon monitoring equipment  
2. Release containment and control 
- Relief systems designed to prevent equipment overpressurization (i.e. relief valves and flare) 
- Dikes to contain liquid 
- Redundant equipment (i.e. back-up firewater pump) 
- Control valves to allow isolation of the process 
3.   Release Mitigation   
- Area firewater monitors 
- Mobile emergency response equipment 
- Trained emergency response personnel 
Over the last five (5) years, there has been only one incident which has met the RMP reporting requirements of 40 CFR Part 68, Section 68.12.  The incident involved a furnace explosion in the OL-5 process in 1994.  This is considered an RMP reportable event since 5 employees were injured and extensive damage occurred to the furnace.  There were no offsite consequences from the incident.  
The overall emergency response program for the Norco Chemical Plant is coordinated with the St. Charles Parish Department of Emergency Preparedness (DEP), MOTIVA ENTERPRISES LLC - Norco Refining Company and the St. Charles Parish Local Emergency Planning Committee (LEPC).  This coordination includes periodi 
c committee meetings with or communications to local emergency response officials, local government officials, community members and industry representatives.  NCP and Norco Refining Company maintain trained and fully equipped firefighting, HAZMAT, and medical/rescue teams capable of managing a broad range of emergency incidents.  NCP also maintains a 24 hr. communications capability with St. Charles Parish DEP officials, as well as area emergency response organizations (i.e. local fire departments, Sheriff's department, State Police, etc.).  In addition to established lines of communication with area emergency response organizations, NCP is also a member of the St. Charles Parish Industrial Mutual Aid Association.  Periodic emergency drills are held with the LEPC, DEP, Mutual Aid Organization members and local emergency response organizations.  Refresher training is also provided to local emergency response organizations on the hazards of regulated substances at NCP facilities. 
The S 
t. Charles Parish Department of Emergency Preparedness (DEP) is responsible for maintaining written plans for the preparedness, mitigation, response and recovery of any natural or technological disaster that may occur in St. Charles Parish.  This responsibility includes coordination with neighboring Parishes who may be affected by an emergency incident within St. Charles Parish.  The DEP is also responsible for coordinating the plans and operations of various emergency response agencies in St. Charles Parish such as fire, police, emergency medical services, public works, volunteers and other groups that respond to emergencies.   
NCP maintains a written emergency response program designed to protect workers, public safety, and the environment.  This program consists of policies and procedures for responding to releases, including actions to be taken in the event of a fire, explosion, or chemical release.  These procedures address all aspects of emergency response, including first-aid a 
nd medical treatment,  evacuation, personnel accountability plans, notification requirements to St. Charles Parish DEP and the public in the event of a release, post-incident cleanup and area decontamination requirements.  In addition, there are procedures that address maintenance, inspection, testing, and use of emergency response equipment.  Employees receive training in these procedures as necessary to perform their specific response duties.  The emergency response program is updated as needed to address changes to NCP processes.  The Management of Change process is used to trigger updates to the emergency response plan, including notification and training of personnel affected by the change.  
The Norco Chemical Plant strives for continuous improvement in the areas of process safety, operations and equipment reliability, maintenance effectiveness and control systems.  Changes to enhance the safety of the proce 
ss are identified through the Management of Change process, the PHA program, mechanical integrity program, incident investigation findings, audit findings and communications dialogue with NCP employees and community stakeholders.
Click to return to beginning