NFPA- DUST EXPLOSION HAZARD RECOGNITION AND CONTROL: NEW STRATEGIES SYMPOSIUM Best Practice Guidance for Identifying and Mitigating Hazards- Panel Discussion Electric Generating Perspective W. D. Snell Loss Prevention Manager Luminant This session is on “Best Practices” and I feel that the best “Best Practice” is exactly what we have been doing here the last couple of days. That is to share information, learn from others, develop a network of contacts that help each of us to expand and refine his knowledge of the hazards with combustible dusts and the means to mitigate or eliminate the potential for dust explosions. From the electric utility perspective, our main dust hazard is coal dust. If you look at the numbers, coal dust has a Kst of 129 – 1511, has a dust layer ignition temperature of 338-3560F, and a dust cloud ignition temperature of around 8240F2. Coal has a heat release rate ranging from 15,000 BTU/lb for anthracite to a low of around 4,000 BTU/lb for lignite. From this it appears that coal is an excellent fuel and that is why according to the US DOE3 in 2007 1,127,997 short tons of coal were consumed in the US with 92.7% being consumed by the electric utility industry. The benefit of this is that coal has been used in the generation of electric power for a long time and it is still the number one type of fuel used in the United States in the generation of electric power (48.5 % in 2007)4. This has a benefit when it comes to the way the electric industry views dust from two perspectives. First, since it is the main fuel utilized in the combustion process in utility boilers, the industry understands that the fuel will burn and can lead to explosions. The process that is utilized in the power plants is to take the solid coal, run it through pulverizers to grind the solid coal into a fine powder/dust, dry the product with heated air, and then inject it into the boiler for combustion. The second point is that the coal is an integral part of the process and the loss of fuel through fugitive dust impacts the cost of generation. Keeping fuel in the process not only reduces the potential for a dust explosion but also adds to the bottom line in the cost to generate electricity. As I stated in the beginning, the number one best practice is to get involved. In regard to the issue of coal dust in the electric industry, there are three groups that I would recommend. These groups get together to address the hazards found in the generating facilities, discuss common issues, hear about losses and the lessons learned, and develop documents that can provide guidance to addressing the hazards. The first group is the NFPA. Obviously you agree, which is demonstrated by your attendance and participation in this symposium. NFPA provides the documents that pave the way for addressing numerous hazards in not only our workplaces but in our lives. In the Electric Utility area of NFPA, I would like to propose your involvement and utilization of NFPA 850 “Recommended Practice for Fire protection for Electric Generating Plants and High Voltage Direct Current NFPA 68 “Explosion Protection by Deflagration Venting” 2007 Edition Appendix F Coal Dust Explosion Hazards by Clete R. Stephan, P.E. 3 Energy Information Administration, http://www.eia.doe.gov/cneaf/coal/page/acr/table26.html 4 Energy Information Administration, http://www.eia.doe.gov/cneaf/electricity/epa/figes1.html 1 2

Converter Stations”. The current published version is the 2005 edition but the document is in revision for the 2009 fall approval. The document was first officially released in 1986. The document covers all aspects of the generating facility including: Fire Risk Control program General Plant Design General Fire Protection Systems and Equipment Identification of and Protection against Hazards Fire Protection for the Construction site In regards to coal dust, the chapter on Identification of and Protection against Hazards addresses: coal storage and cautions about spontaneous heating and how that can be limited in the coal pile storage through separation of different types of coal that are not chemically compatible, working the pile to prevent dead pockets of coal, and locating the pile away from heat sources storage in bins, silos and bunkers including the provision of dust tight barriers between boiler houses and the area above the silos, bunkers, or bins dust suppression and control including methods to control dust, proper cleaning methods, warning against the use of vigorous sweeping or compressed air and the use of listed vacuum cleaners for the dust environment or the use of low velocity water coal conveying and handling structures with attention to designing the structures to limit the ledges for the accumulation of dust by utilizing beam shields or placing the structural members exterior to the building; the section also addresses the use of approved equipment in the areas, the electrical classification of the areas and means to reduce the hazard of static electricity through permanent bonding and grounding fire protection being recommended in coal handling structures, conveyors, bag-type dust collectors The document is in revision and with the most recent revisions to NFPA 654 “Standard for the prevention of Fire and Dust Explosions from the Manufacturing, processing, and handling of Combustible Particulate Solids”, there are also references to utilize NFPA 654 in addressing the hazard of dust. There are many other aspects of protecting an electric generating facility contained in the document. I would strongly encourage those associated with electric utilities to utilize the document and become part of the consensus process. This can be accomplished through the use of the document, and by reviewing the document and providing proposals and comments through the NFPA process. The second group I would encourage you to participate in is the Edison Electric Institute (EEI) Fire Protection and Loss Control Sub-Committee. The EEI is the association of U.S. Shareholder-Owned Electric Companies. EEI members serve 95 percent of the ultimate customers in the shareholder-owned segment of the industry, and represent approximately 70 percent of the U.S. electric power industry. The members of the committee are those individuals involved in the area of fire protection at their respective utilities. While you have to be a member of EEI to be a member of the committee, there are others representing insurance companies, AE firms, manufactures, and consultants, who are involved in one way or another with electric generating facilities. The committee generally meets twice a year and during the meeting there are presentations on losses, topics of interest, topics that are receiving attention such as dust, updates on codes and standards of interest to the group, tours as applicable and available such as new generating technologies, and very importantly the opportunity to discuss with your peers similar problems and suggestions for solutions. The committee has also published many papers addressing the industry best practices and it is presently getting ready to publish a white paper

titled “COAL DUST A PROBLEM HERE AND NOW A PRIMER ON HOW TO DEAL WITH AN EXPLOSIVE ISSUE” If you are interested in becoming a part of this group , you should contact the present committee Chairman, Bob Green, Senior Consultant, Risk Management, PSEG Services Corp, Newark, New Jersey, (973) 430 6501, email [email protected]. The third group that is relatively new is the PRB Coal Users Group. Its website is www.prbcoals.com. PRB stands for Powder River Basin Coal which represents the low sulfur western coals that utilities began to utilize to address the EPA national standard to restrict the emission of sulfur dioxide. The western fuel is a sub-bituminous coal that is usually blended both with the lower ranked lignite grade coal and the higher BTU bituminous coal. When utilities started to integrate the PRB coal, there was a notable increase in the frequency and severity of fires associated with the coal. Since the PRB is a lower grade of coal, it is more likely to experience spontaneous combustion, which was new to the utilities that had previously only burned bituminous coal. The PRB coal also produces more dust than the bituminous coal and since it had a lower BTU content, more fuel was being processed than the original systems may have been designed for. This could increase the chance of spillage. With this increase in problems, the PRB coal users group was formed to address this issue in a unified approach and to provide a means to share information. The goals of the PRB Coal Users group are: promote the safe, efficient and economic use of Powder River Basin coals by generating companies who currently use, or are considering the use of PRB coals encourage the safe, economical use of PRB coals by those who elect to utilize the resource establish best practices for the safe operation and maintenance of PRB coal handling and storage systems based on “best available technologies” develop and maintain a data base of PRB coal users, both in North America and overseas work with EEI, the American Coal Council and other involved industry groups The users group membership is comprised of not only electric generating utilities but also vendors, manufacturers, and other experts who are involved with the industry in addressing this issue. The PRB Coal users Group has been very active in addressing combustible dust through the provision of free Webinars, especially PRB 101 which is available on its website, the publishing of Best Practices paper including one being drafted on Electrical Best Practices, and providing for an annual meeting to share information and present papers. This annual meeting is held in conjunction with the annual Electric Power Conference. Another function that the PRB Coal Users group performs is to recognize each year the PRB Coal Plant of the Year for its innovation and the implementation of “best practices and best available technologies”. An article is also published in Power magazine about the selected facility. Luminant is proud to state that its Monticello Steam Electric Station was given this recognition in 2006 and the Big Brown Steam Electric Station was recognized in 2008. Luminant, a subsidiary of Energy Future Holdings Corp.(EFH), is a competitive power generation business, including mining, wholesale marketing and trading, construction and development operations. Luminant has over 18,300 MW of generation in Texas, including 2,300 MW of nuclear and 5,800 MW of coal-fueled generating capacity. Luminant is also the largest purchaser of wind-generated electricity in Texas and fifth largest in the United States. EFH is a Dallas-based energy holding company that has a portfolio of competitive and regulated energy subsidiaries, primarily in Texas.

At Luminant, we have always been keenly aware of the issues involving coal and dust since the fuel that we use is lignite. With lignite, there is more susceptibility to spontaneous combustion. Due to the low BTU content, Luminant facilities handle a large volume of fuel. In the mid 90’s Luminant began to introduce the use of western fuel to address the EPA standard for reduction in sulfur dioxide emissions. With this introduction of a new fuel and based on the experience that other utilities were having, a review of the fuel handling operations began. Upgrades were made in the following areas: containment improvements on all loading zones of transfer points throughout the fuel handling system through new impact and support roller beds and rubber skirting and sealing of chutes and head boxes the height and length of the load zone containment was increased to allow the dust time to settle inside the containment area capital improvements for dust suppression at unloading stations, crushers, and transfer points equipment is taken out of service on a daily basis to allow for wash down repainted the tunnels and coal handling structures improved the lighting repaired beam shields that had corroded utilization of high efficiency loading systems at transfer points dust collector upgrades to N type rotoclones While the above improvements are significant and resulted in an investment of budget dollars, the most important action in the plants was a renewed level of management support, retraining, and an increased emphasis on housekeeping. All of these have added greatly to improving the risk at the Luminant coal fired units. At the fall 2006 meeting of the EEI Fire Protection and Loss Control Sub-Committee, a presentation was made on the Chemical Safety Board (CSB) investigation in the hazards associated with combustible dust. Beginning with that presentation, the EEI has been actively tracking and reporting on the activity associated with combustible dust. At Luminant, this was reported to upper management and Luminant began to track the actions of the CSB. The CSB report was released in November 2006. This report followed by the release in October 2007, of OSHA’s Combustible Dust National Emphasis Program inspired Luminant to again look at the dust control program within the Luminant coal handling facilities. Management decided that while we had made significant progress in addressing the concerns of combustible dust, the issues involved and the catastrophic results of the Imperial Sugar explosion mandated that we take another focused look at our facilities. Upper management directed a Coal Dust Task force be developed headed by a coal plant Director of Generation and the Luminant Generation Director of Safety. The team consists of the fuel handling superintendents from each of the coal plants, members of the Luminant Loss prevention group, a facilitator with both plant and environmental experience, and a member of the Luminant Operating System. The team decided that the best approach would be to develop a corporate program that would require each site to develop a site specific program that mirrors the corporate program. The decision was made to standardize, as far as practical, the training, forms, procedures, and audits that would be utilized throughout the fleet. The corporate program was developed based on the elements discussed in the National Emphasis Program, the 2005 OSHA Safety and Health Information Bulletin issued in July 2005 titled “ Combustible Dust in Industry: Preventing and Mitigating the

effects of Fire and Explosion”, NFPA 654, OSHA 1910.272 Grain Handling Facilities, and the principles of Process Safety Management. After much discussion, the team decided on the program consisting of the following parts: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

Scope Requirements Responsibility Emergency Action Plan Training Housekeeping Dust Control equipment Preventative Maintenance Fire protection Control of Ignition Sources Audits Management of Change Record keeping

In the scope, it has been determined that the program will apply to the fuel handling area of the facility from unloading of the coal cars to the bottom of the silos on the boiler. These areas are defined in the NESC Article 127A as coal handling areas and therefore are classified as Class II Division II Group F in all areas except for the inside of chutes, headboxes, or silos where we consider that to be Class II Division I group F locations. The area from the silo through the feeders, the pulverizers, and to the boiler are not considered as fuel handling per item 5 of the NESC, where it states that “locations having completely dusttight pulverized systems designed and installed in compliance with NFPA 8503-1997 shall not be considered classified”. It is also necessary to realize that the Luminant plants are open design with the boiler structure not enclosed. It is recognized that sometimes there might be a leak in fuel piping or other equipment that could release dust in an area that is not intended to have dust. The program recognizes this and states that if dust is found in an area not covered by the program that: the Fuel Housekeeping procedures developed for handling dust be utilized; the reason for the dust be investigated and corrected to prevent future infiltration of dust; and if the reason for the dust cannot be corrected, then the area where the dust was found might need to be reclassified and be added to the program. The requirements of the corporate program call for each site to develop a site specific program, a site drawing showing the areas of the facility covered by the program including the electrical classifications contained within the scope of the program, and a sheet containing factual information of the facility. Overall responsibility for the corporate program is given to the Senior Vice President over fossil generation and each site’s director of generation has responsibility for their site. The program also calls for the appointment of a coal dust management program coordinator who will be responsible for the implementation of the program of the site. They will not be

responsible for performing all activities with the program but are responsible for ensuring that it is being completed. The site’s Emergency Action Plan is referenced which already exists and details actions to take in the event of an emergency. The provision of escape routes for the areas covered by the program and annual drills are also specified. Training is a key part of the program, as the team felt that it was the lynchpin of the entire program. The program calls for initial training for all new employees to address dust control, recognition, and prevention of combustible dust hazards. This is in addition to the basic safety training that covers hot work, lock out tag out, confined space, HAZCOM, proper use of personal protective equipment, etc. The program calls for initial site training for site specific actions and annual refresher to cover all of the above. A training program was also developed to be provided to contractors who work on site to ensure they are aware of the hazards of coal dust associated with the area they will be working in at the specific site. Keeping the area free of combustible dust and ensuring that proper methods are employed is covered through the use of a Fuel Handling Housekeeping procedure which calls for daily wash down, reporting of fuel spills, and cautions involving hot fuel. Large fuel spills and dust accumulations should only be removed utilizing non-sparking tools or water hoses. The use of compressed air is strictly prohibited. Vacuums must meet the proper classification to be used. Vacuuming by a contractor who specializes in the removal of coal dust is acceptable if they have written procedures for the activity that have been reviewed and approved by the site’s coal dust coordinator. This includes ensuring that the vacuum truck is grounded and the area is watered down initially and during operations. The vacuuming is not of dry dust but wet coal/dust. A Luminant form has been developed for each site listing the dust control equipment that has been provided on site. The form will list each piece of equipment including the name plate data, the design basis, and the procedures for the inspection, testing, and maintenance of the equipment. While the procedure is not included, the number of the PM is listed along with the frequency. The handling of impairments to dust control equipment identical to the handling of fire protection system impairments was also included. The inspection and maintenance practices for the equipment in the fuel handling area are also listed in a summary table. The equipment includes: fuel flow elements such as chutes, hoods, belt scrapers, electrical ignition sources including lights, grounding, control cabinets; mechanical heat sources such as bearings, belt alignment, pulleys and couplings, and safety equipment such as emergency lighting, magnetic separator, emergency stops, pull cords, misalignment switches and guarding. In our review we found that some of the PMs for these activities needed to be revisited and that some needed additional development to be developed to ensure the equipment was being properly maintained. Each site has a Site Fire Protection Program which covers all aspects of the site’s fire protection including: systems, procedures, fire brigade organization and response, development of fire preplans, fire impairment handling, and the inspection, testing, and maintenance of fire protection equipment including the areas covered by the dust management program.

Control of ignition sources was one of the easiest sections but also the one we are having the most difficult finishing. The section was easy as Luminant already has existing programs for prohibiting smoking, and a cutting and welding permit program. Added to the program was the requirement for the placement of dust warning signs. The difficult task was the development of a program to address the use or limiting the use of spark producing equipment in the classified areas covered by the program. Through our property insurance carrier, FM Global, we were made aware of the criteria contained in ISA RP-12.12.03-2002 Recommended practice for Portable Electronic Products Suitable for Use in Class I and II, Division 2, Class I Zone 2 and Class II, Division 1 and 2 hazardous ( Classified) Locations. This document provides guidance for handheld equipment such as cell phones that might be needed in a classified area. It also contains a permit system referred to as a “Gas Free Work permit” that details a program for allowing work involving potential ignition sources to be performed in a classified area by ensuring that the atmosphere where the work is to be conducted does not contain an ignitable concentration of flammable gas or vapors. The document mentions that it could be utilized in class II locations. The team is working through the development of a permit system for utilization in the classified areas of the plant following the guidance in the ISA document. The team realizes that in some instances that equipment not listed or approved for the classified area has to be used. In those instances, similar to cutting and welding, the area has to be made and remain safe during the work operations. The program also calls for audits to be conducted and documented. Audits consist of both internal audits and external audits and even a five year overall independent review of the entire program by a company not involved in the other audits to ensure that the program is functioning as intended and to add a third party review. The internal audits consist of daily inspections by operators, monthly inspections by the fuel area superintendant/supervisor, monthly fire prevention inspections as called for by the site’s Fire protection Program, and a semi-annual Corporate Loss Prevention inspection of the entire facility including the area covered by the dust control program. The program also requires that a biennial audit of each site’s program by an internal audit team be performed to ensure compliance with the Dust Control Program. External inspections of the areas covered by this program are conducted by Luminant’s property insurance carrier and annually by an organization/vendor knowledgeable in dust control. An integral part of the audit program is the provision of a tracking system to capture the results of the audits, prioritize the recommendations/actions and then track the recommendations to closure. Documentation of implementation of the recommendation or justification for not implementing is also necessary. In following the guidance of process safety management, the program requires that an audit of the entire Luminant Dust Control Program be conducted by a third party every five years. The intent of this audit is to provide a complete review of the corporate program to ensure that the program is dynamic and is keeping current. A Management of Change procedure is necessary to ensure that changes that could impact personnel safety, safe equipment operation, and process reliability in the coal handling process, other than “replacement in kind,” are identified, assessed, and the results of the assessment are communicated to employees. The documentation to provide evidence of the completion of the components of the program is required to be kept in a readily available location and format. Without any other requirements, the team decided that the following criteria shall be used.

annual drill- five years training- duration of employment housekeeping /audits as applicable o

daily- three months

o

weekly- six months

o

monthly – one year

o

quarterly/semiannual- two years

o

annual - five years

o

greater than annual – life of plant

A great deal of effort and time has been committed to the development of the Luminant Coal Dust Management Program and it is recognized that the program will be a dynamic living document that must be modified to address site needs and integrate potential legislation. Luminant management discussed that we had what is considered a “good approach” in addressing combustible dust and that in the absence of a specific standard, it might be better to wait for its development. However, due to the nature of the problem and potential impact, management decided that it would not be prudent or in the best interest of the company to wait. It has been and continues to be a great lesson in teamwork to address a common problem that the Luminant’s coal plants need to address. As I said earlier, the best “Best Practice” is get involved. Talk to your peers and jointly and together solve your problems. In closing I would like to quote Edmund Burke Irish orator, philosopher, & politician (1729 1797) who said “"Nobody makes a greater mistake than he who does nothing...".