Combined-cycle power plants are currently gaining popularity as industries and utilities seek to meet growing electricity demands, reduce emissions and lower energy costs. According to the U.S. Energy Information (EIA), from 2022 to 2023, 13 combined cycle-gas turbine (CCGT) plants came online in the United States with a combined capacity of 12.4 GW.
The EIA expects another 4.9 GW of additional CCGT additions in 2024 and 2025. Given increases in energy consumption, environmental regulations promoting sustainability and emissions reduction, and technological advancements, the number of combined-cycle power plants will only continue to grow over the next ten years.
Combined-cycle power plants are at risk for fire events and create special concerns for life safety. Gas-fired turbine engines, coupled with the presence of extremely hot surfaces and the use of lubricating oils, pose a fire risk. If fire is not recognized and extinguished quickly, it can result in millions of dollars in damage, prolonged downtimes and loss of productivity.
Following the recommendations provided by NFPA 850 can help ensure effective fire protection systems and reduce the risk of fire/explosion in combined-cycle power plants, maximizing the safety of personnel, facilities and the community.
NFPA 850: A Basis for Good Industry Practice
NFPA 850 facilitates a systematic approach to identifying and managing fire and explosion risks in non-nuclear electric generating plants and high-voltage direct current converter power stations. While this standard has been in effect since 2020, it has not been widely implemented, perhaps due to it being considered recommended guidance rather than requirements.
Ultimately, the recommendations presented in NFPA 850 represent good industry practice and may be applied to new and existing oil, gas, coal, and alternative fuel electrical generating plants, including combustion turbine units used for electric generation. It also provides guidance for protecting plant personnel and the surrounding environment while promoting the protection of critical plant equipment from both an asset replacement and business interruption perspective.
Determining and implementing NFPA 850 recommendations typically involves conducting a Fire Risk Evaluation (FRE) and creating a fire protection design basis document (DBD). NFPA 850 provides the framework for a Fire Protection DBD, which describes the design rationale for a power facility’s fire protection system based on the potential fire/explosion risks and goals, objectives, and criteria established for the acceptable level of fire protection. A Fire Risk Evaluation is essential for identifying fire/explosion risks and developing the DBD.
Determining Fire Risk and Recommendations for Protecting Facilities
Fire Risk Evaluations help determine the specific hazards and the level of acceptable risk for facilities while providing a basis for recommending fire protection strategies. FREs typically include a qualitative risk assessment to achieve the following goals.
1) Identify the fire and explosion hazards. The plant is subdivided into physical areas from the plot plan, and fire and explosion hazards are identified for each area.
2) Characterize the frequency and consequences of each hazard. The hazards (i.e., ignition sources) and mitigation strategies identified for each area are then used to determine hazard frequency and support a consequence analysis. The consequences of a fire/explosion in each area include the potential for personnel injury, critical asset/function loss, suspended plant operations, and environmental damage. The availability of effective mitigation measures may influence the consequence ranking.
3) Determine the risk results. Using a risk matrix, the resulting risk level for each area (or scenario) is then obtained from the different combinations of frequency and consequence. Areas determined as compliant with the applicable code(s) are typically treated as “adequate for the hazard,” given that the proposed fire protection design is consistent with code requirements/recommendations. This may include areas equipped with (or designated for) automatic suppression consistent with NFPA 850 recommendations as well as areas with no automatic suppression requirements/recommendations, as long as the treatment is consistent with performance-based industry practice.
4) Communicate recommendations. Areas identified as “below standard” from a mitigation strategy perspective are identified in the FRE, along with recommended measures to maintain tolerable risk levels. These measures may include training to heighten awareness or administrative controls to reduce or control the hazard risk.
Mitigate Fire Risks and Ensure Compliance
Developing FREs and DBDs is an iterative process, especially for new installations where the fire mitigation strategies for each area may not have been fully established. Together, the FRE and DBD provide input to the various stakeholders to support decision-making.
Jensen Hughes has considerable experience performing fire risk evaluations for the power industry. In addition to developing FREs and DBD, Jensen Hughes experts can review applicable designs to determine compliance with owner, AHJ, and insurer fire and life safety requirements.
