On the Fire in the Power Supply Building of J-PARC Hadron Experimental Facility
High Energy Accelerator Research Organization (KEK) 
Nuclear Science Research Institute, Japan Atomic Energy Agency (JAEA) 
1. Time and Date :
Around 0:51 on Thursday, June 22, 2023
2. Location :
The Power Supply Building of J-PARC Hadron Experimental Facility (Radiation Controlled Area), Tokai Campus, High Energy Accelerator Research Organization (KEK)
(This building is located in Nuclear Science Research Institute, Japan Atomic Energy Agency (JAEA) ) 
3. Description :
On June 22, 2023 (Thu.), during beam tuning operation, a fire alarm system was issued in the Power Supply Building of Hadron Experimental Facility, and at 0:54 the fire department was called. At 0:59, a KEK staff and a JAEA staff inspected the site and observed smoke inside the building. At 1:00, the KEK staff observed a fire from a polarizer (the device that switches the polarity of a magnet power supply and changes the direction of the electric current) and conducted initial fire extinguishing with powder fire extinguishers. At 1:46, the fire department judged this as a fire incident. At 1:55, the fire department confirmed the fire had already been extinguished. 
 (Time series) 
Around 0:51    Fire alarm was issued. 
0:54    The fire department was called. 
0:59    A KEK staff and a JAEA staff confirmed smoke in the building. 
1:00    The KEK staff observed a fire from a polarizer, and started initial fire extinguishing with two powder extinguishers. 
1:15    The fire department arrived. 
1:46    The fire department judged this as a fire incident. 
1:55    The fire department confirmed that the fire had already been extinguished. 
4. Cause of the fire incident :
Under investigation
5. Effects :
There was no leakage of radioactive material to the environment, no radiation exposures, no injuries. There was no impact on other facilities.
※ J-PARC (Japan Proton Accelerator Research Complex) is a research facility jointly operated by High Energy Accelerator Research Organization (KEK) and Japan Atomic Energy Agency (JAEA). The Power Supply Building of J-PARC Hadron Experimental Facility, the facility in this case, is under the jurisdiction of KEK.
