At 0040hrs today, a fire alarm sounded inside the Prototype Fast Reactor complex. One person who was in the building at the time immediately evacuated the area.
The site fire brigade attended and discovered a fire inside a tented enclosure in part of the former steam generating building. The enclosure contained small bags of sodium residues and a redundant pipe.
The fire was extinguished quickly. The fire crew wore breathing apparatus to protect them from caustic fumes.
The sodium was transferred to metal drums and layered with graphex, a fire suppressant.
The fire brigade maintained surveillance of the area until 0430hrs when the crew returned to station.
No-one was injured. Fire damage was confined to the tented enclosure, the bags and a wooden barrier.
Work in the localised area has been halted pending an investigation into the cause. The rest of PFR decommissioning is unaffected.
PFR was a sodium-cooled fast reactor. The bulk of the sodium has been destroyed and decommissioning work is now focussed on removal and destruction of the residues as part of ongoing work to dismantle the ancillary systems of the plant.
The small bags contained an estimated 2-3kgs of sodium in the form of crusts. These crusts are associated with the removal yesterday of a section of pipework during preparations to lift the next “dump tank” for cutting up.