The inside of the PFN cabinet of NLCTA Modulator 1, where the fire took place. The coils are what remain of the high voltage capacitors. (Photo by Keith Jobe)

On July 9, a small fire occurred just after midnight in the PFN cabinet of NLCTA Modulator 1. This fire highlighted both the effectiveness of our emergency response systems and the ongoing need to analyze and respond to events such as this.

Even a small fire can be destructive. In this case, the fire destroyed the cabinet and its contents, melting nearby water-cooling hoses. Water from the hoses then entered and overfilled the insulating oil tank which, in turn, caused the release of about 100 gallons of oil into the building.

Quick, safe response by the Palo Alto Fire Department (PAFD) and SLAC personnel allowed the fire to be extinguished and the spill to be contained within the building. Hence, there were no injuries or environmental releases.

The staff that responded were very effective in making correct and timely decisions to keep this emergency from being worse than it could have been, and the fire was quickly contained. However, the modulator will be unavailable for at least several weeks and possibly longer.

Two reviews of this incident were conducted and lessons learned were identified. These lessons include exploring the usefulness of enhancing the fire suppression systems in this

equipment and possibly streamlining, coordinating and enhancing SLAC emergency response plans.

DOE’s Integrated Safety Management System (ISMS) ‘circle of improvement’ provides a road map for the SLAC response to any incident such as this. Using ISMS, we analyzed the hazards highlighted by this event, developed further controls and are in the process of implementing them. In the future, we will perform the work with these additional safety elements in place. Subsequent feedback on these fixes will ensure that this improvement process is continuous.