Developing procedures for the purging, handling of natural gas
AEP Natural Gas Plant Fleet
Twenty-three gas-fired plants with a total generating capacity exceeding 8000 MW
Key project participants: Patrick C Myers, team leader, and AEP’s Natural Gas Fuel Facilities and Operations Review Team
The fatal explosion during a gas blow at the Kleen Energy powerplant construction site in Connecticut on February 7, 2010, was the latest and most catastrophic in a series of similar events in recent years—including the ConAgra Slim Jim plant in North Carolina and Hilton Hotel construction site in San Diego.
Several months before the Kleen Energy explosion, the US Chemical Safety and Hazard Investigation Board (CSB) issued a safety bulletin entitled, “Dangers of Purging Gas Piping into Buildings,” and three days before the Kleen Energy explosion,the CSB approved urgent safety recommendations to the National Fire Protection Assn (NFPA), American Gas Assn (AGA), and International Code Council (ICC) to strengthen the national fuel gas code provisions on purging.
Our group of affiliated companies, with a fleet of 23 gas-fueled powerplants and four coal-fired plants that use gas-fired boilers, plus others under construction or likely to be constructed in the near future, needed to ensure that its gas facilities were not susceptible to similar events. These companies could wait for the regulators and standard-making bodies to issue new rules or it could take interim measures to ensure it was providing the highest level of personnel safety during the handling and use of natural gas fuel.
In February 2010, the companies began the process that led to the creation of the Natural Gas Fuel Facilities and Operations Review Team. This multi-disciplinary team of generation and safety and health professionals was charged to proactively evaluate the safety of the companies’ internal requirements, practices, and physical plant designs associated with the use of natural gas fuel for venting, purging, blowing down, and line-charging activities at its powerplants and make recommendations for improvement. The scope of the review was fourfold:
1. Review and evaluate existing internal requirements and practices that address the following aspects of the handling and use of natural gas fuel at its facilities:
- Design, construction, and modifications of facilities, equipment, and processes.
- Startup, operation, inspection, and maintenance of facilities and equipment.
- Training, qualification, and oversightof personnel involved in anyof the above.
- Management-of-change procedures involving any of the above.
2. Review and evaluate requirements and practices for protecting company personnel during gas handling and use activities performed by others at or in proximity to its power generation facilities.
3. Review and evaluate the designs, arrangements, and physical conditions of its power generation facilities that handle and use natural gas.
4. Research alternative practices, methods, or designs that would constitute “best practices.”
The team began work in early March 2010 and worked throughout the spring and summer. This included discussions with personnel responsible for gas purging and handling in other utilities and industries and gas transmission companies, plus an independent combustion engineering consultant with particular expertise is natural gas. The team also inspected a sampling of the gas plants within its fleet.
On Aug 31, 2010, the team delivered its draft findings and recommendations to its executive sponsors. The sponsors fully endorsed thereport, which was organized alongsix focus areas:
- Management of change.
The sponsors also authorized moving forward with certain recommendations immediately and directed the team to continue its ongoing efforts in other areas. The team subsequently inspected additional plants in order to develop draft checklists for conducting thorough gas-focused inspections of all of its facilities.
The team presented an update to the sponsors on Dec 20, 2010, and followed-up with a short list of high-priority issues in need of attention, whether plant-specific or fleet wide. The process of wrapping up the team’s work and handing-off responsibility for inspecting the entire fleet and implementing recommended improvements began at year’s end. A formal project management approach will be used for this purpose.