Any power station or hydrocarbons facility can easily be a death pit. The use of extreme heat, the complexity of the electrical infrastructure and the constant maintenance work carried out at plants and refineries presents no end of risks and challenges to fire protection staff.
Each area within the energy sector – be it an offshore facility, coal-fired plant or refinery – presents individual challenges to fire protection staff but the common theme of prevention, fire resistance and emergency response remain constant throughout.
US National Fire Protection Association (NFPA) fire protection engineer and staff liaison officer Paul May says that while regulations can differ from region to region the challenges are interchangeable.
“The challenges of fire protection are…universal and have to do with cost and implementing the necessary designs into existing plants,” he says.
Fire protection design and engineering, as well as the implementation of the most appropriate fire detection technologies, can ensure the safety of workers and the public. For the plant operator, they can also minimise downturn and increase operational efficiency.
Accidental fires at power plants and oil refineries are surprisingly common but because of the speed and professionalism with which they are usually dealt events rarely hit the headlines. In the instances where they do, however, the effects of the fire can be truly catastrophic.
In two upcoming Arena International events later in the year leaders in their particular fields will meet to discuss how they are overcoming the tests they face in their day-to-day operations.
The first, Fire Protection and Safety of Power Plants, will be held in Boston in the US on 3–4 November and the second, Fire Protection and Safety in Oil and Gas Facilities, will be on 8–9 December in Houston, US.
Anyone within the power sector will be aware that it is the nuclear power stations that present the most unique challenges and arguably the biggest fire hazards for the industry.
Consequently, nuclear is also subject to some of the most stringent regulation, which is being reviewed and reworked.
New to nuclear regulations
Those in the nuclear industry will be familiar with the NFPA 804 and 805 guidelines. The first follows the industry’s accepted requirements for safety in advanced light water reactor electric generating plants. It provides minimum fire protection requirements to ensure safe shutdown of the reactor and minimise the release of radioactive materials into the environment. The NFPA 805, meanwhile, is intended for protecting the safety of the public, environment and plant personnel.
Revisions of both are expected towards the end of the year or in early 2010 when the new NFPA 806 regulation will also be published. “Its purpose is to address the fact that there are not any other documents that handle fire protection concerns during any change processes,” May says.
“This involves fire protection considerations for anything that could be considered a change process during construction and all phases of plant operation, new designs or systems, or any other matter of renovation.”
The overarching trend of the new regulations is a step towards performance-based measures, replacing the restrictive prescriptive codes of the past. In practical terms, implementing the legislation and preventing fire is now down to realistic modelling of the potential causes and risks.
US nuclear power operator Progress Energy fire protection supervisor Jeffery Ertman says that any power, pump or transformer is a potential ignition source. In any one of Progress Energy’s four nuclear generating plants the number of potential sources could be as many as 3,000. “We have ways to analyse fire growth and assess what could be realistically impacted and affected,” Ertman explains.
Ertman says the move away from prescriptive regulations to using a performance-based analysis is a positive step for the industry. Instead of the traditional method of looking at a large section of the plant at a time and assuming all of it would be impacted in the event of a fire, the performance approach allows the fire supervisor to model which fires have potentially the most impact on the plant and therefore need the most attention.
In addition, the industry is moving towards developing a streamlined approach to fire-probabilistic-risk analysis to accurately predict and address risks within the facility. This is an integrated assessment of the risk and the safety margins. In many cases, teams will have to make accurate fire-damage predictions based on insufficient fire history.
Fire mitigation methods
Specialised software can now analyse a number of different fire scenarios based on a variety of ignition sources. In addition to a selection of modelling techniques, however, plant operators are also keen to ensure there are a number of ways to cope if a fire does break out. “There is always a certain amount of fire risk in plants so you want to make sure you have different approaches to prevent the fire or mitigate it if it was to occur,” Ertman says.
The measures used are not unique to nuclear plants and include suppression systems, sprinklers and on-site fire brigades.
Operator action is also important to shut down areas of the plant that could exacerbate any potential dangers. Ertman says that although small fires are reasonably common in nuclear plants only a few will ever be big enough to be reported to the country’s nuclear watchdog.
Constantly monitoring cables, transformers and other ignition sources and then having a range of mitigation measures in place is the only way to make sure a small spark does not become a more lethal flame.