Around at 4:36pm today, sounded a fire alarm on the basement 1st 
floor (the uncontrolled area) of the service building at the unit 1, 
we reported to the fire department around at 4:39pm.

Upon immediate investigation, the origin of the smoke had been 
identified to be a temporary compact transformer (width, depth, and 
height of about 25cm, 24cm, and 18cm, respectively) of lighting 
equipment and electrical machine tools used for concrete restoration 
work in the underground connection tunnel for power cables (outside 
of the physical protection area). The smoke subsequently flowed into 
the basement 1st floor of the unit 1 service building and set off the 
fire alarm.  
A field worker promptly conducted initial fire extinction by an 
extinguisher.

Later, the fire department came to the spot and confirmed extinction 
of the fire at 5:23pm.

No field workers were injured and no effects of radiation to the 
environment were found because of this event.