Sinclair Duffie, Chief Fire Officer, Nawah Energy Company, examines the role of firefighting in a nuclear setting

As one of many thousands of firefighting professionals throughout the world I have developed my skills through regular practice at the many incidents I have attended in various roles. Over time we tend to develop a broad categorisation of the type of incident that faces us, and we are able to dig into our subconscious and pull out some experience gained previously to help us formulate a plan and achieve the results we desire.

We can add multiple variables into this basic formula which make each one different but essentially, they follow a similar pattern or template with which we base all our firefighting learning and development on. It is a truly valuable asset a firefighter has in their armoury and gives them a level of perspective when facing a situation knowing their outcomes and expectations are developed from some previous experience and can help form the basis of a successful approach to what they are about to do.

This opinion leads me to look at the approach to firefighting in traditional terms which includes mobilising, or getting to the incident, using visual cues gained at the point of arrival, accessing the scene, choosing the appropriate extinguishing method, assessing the life risk, determining the fire spread characteristics and a myriad of other critical considerations to allow the response to be coordinated, effective but most of all to mitigate the risk to those involved and to the firefighters themselves.

This long-standing philosophy was challenged when I undertook the fire response lead role at a developing Nuclear Power Plant in the UAE. This is where my lifelong formed outlook on how I approached my fire response duties was challenged due to this new environment I was now exposed to.

New challenges

Nuclear, as is common in many industries, regards fire as a combination of threat to the workforce and disruption to the business process and the appropriate assessment of that threat is included in the overall risk management process. In many instances this threat is generally restricted to within the physical boundaries of the business but as has been witnessed on numerous occasions, those barriers can be breeched with the rapid escalation of fires due to reasons where control is not able to be effectively applied.

In that respect the nuclear power industry is no different to other industries in terms of physical barriers, with the exception of radiological containment, the buildings and infrastructure are designed along similar lines to gas or other types of fossil fuel generating facilities with some subtle differences particular to the process.

However, the nuclear power industry differs from the others, clearly by virtue of the fuel used in the process of that power generation. The health physics associated with the industry provides the greatest hazard to the workforce but also the effect on the population and environment should there be an uncontrolled release which is widely documented and been the subject of great debate for years by the lobbies both opposed and in support of nuclear power generation.

The process of safety engineering in a nuclear power station is carried out relative to the risk and the measures which are supplied and maintained to assure fire protection is calculated and provided on a beyond design basis. Part of this includes the provision of a capability for manual fire suppression which is in the form of a fire response facility either locally based and within reach of the establishment or as is the case at my location, an in-house, full-time fire brigade.

The challenges faced at a nuclear power generating facility throw up many dilemmas to the responding firefighter and incident commander. Traditional values of primarily saving life then assessing property and environmental concerns in a moral, hierarchal methodology become less routine.

This immediately puts the fire response team in a position where they must prioritise protecting the process first whilst simultaneously deal with any immediate threat to life. Conventional processes of a non-nuclear nature are unlikely to produce such a radical rethink of strategy and planning as there are also significant hazards created by fire in those types of locations.

Access issues

Access to affected areas within the plant can prove problematic as the design of the structure strongly leans towards an enclosure which does not encourage free movement air in order to control and contain the accidental release of contaminants.

The responding team must rely on accurate information from the pre-fire plan, the fire alarm system or someone on scene to direct them to the location which may be obscured by multiple doors and a range of access corridors.

Restrictions in air movement invariably can cause respiratory issues as HVAC (Heating, Ventilation and Air Condition) systems are under the control of the supervisor in charge of the Main Control Room. They are unable to forcibly ventilate areas requested by the Fire Officer until strict radiological monitoring is carried out which adds time to the duration locations are classified as IDLH (Immediately Dangerous to Life or Health) which is another consideration for determining a safe position for occupants, firefighters, and evacuees.

Traditional methods of deploying hose and equipment from staging areas to the fire scene must be adjusted due the practicalities of having the equipment in a safe and quickly retrievable location. Multiple floor levels encapsulated in concrete boxes with a mixture of radiologically sensitive areas alongside equipment with high pressure steam and high voltage apparatus makes the assignment of staging areas difficult due to access and exit, distance from the scene of operations, limited visibility, and many other variables which have to be taken into consideration.

Plan of action

A fire responder arriving at a fire in a nuclear power generating facility has to consider dealing with a set of objectives which may have to focus more on plant protection in the longer term sense of people protection than of immediate life risk, they have to contend with being unable to see a fire location within the building due to the nature of construction and no natural light apertures, be faced with a potential delay in access to the scene due to a combination of extensive corridors, multiple doors many of which are security barriers and require special permissions for opening and confrontation with an extended IDLH due to restrictions and control of ventilation in areas considered radiologically sensitive.

Plant design, extensive safety systems, high quality management and an exceptional safety culture have driven nuclear power generation into a position today where the lessons learned of past experiences are used to provide a platform for promoting excellence in everything that is done to safely generate electricity.

Firefighters within the nuclear industry must be familiar with the process to understand the fundamentals of operation and appreciate the consequences of their actions during firefighting. Control of the process under normal operating conditions is absolute within the Main Control Room which has highly qualified, dedicated staff who are ultimately responsible for the safe operation of the plant but more importantly able to safely shut down the reactor where conditions exist that compromise its effective and safe operation.

Firefighting affects that level of control applied to the process and must be carried out with full consultation and approval of the Main Control Room stepping away from convention where the fire Incident Commander knows best in terms of where to deploy resources, which area of the fire to concentrate on and more controversially, where priorities lie when it comes to life risk.

To date, fires in nuclear plants across the world have had minimal impact on the communities that surround them with very few experiencing the potential for radiological release. Most fires were generally recorded as being extinguished within fifteen minutes, some burned for over an hour. Those which burned longer were identified as being in less critical locations and did not pose a threat to the fuel used in the reactor.

This observation supports that whilst nuclear plants do report fires, similar to many other industries, there is a healthy respect for fire prevention which keeps numbers low and a similarly healthy respect for intervention which quickly extinguishes those fires and takes effective measures to prevent spread and increased risk by having trained, qualified and experienced fire response members available and ready for deployment.

This article was originally published in the January edition of IFSJ. To read your FREE digital copy, click here.