Power failure at Fukushima Nuclear plant UPDATE
Cooling water supplies to fuel storage pools halted
Tokyo Electric Power Company (TEPCO), operator of the Fukushima Daiichi Nuclear Power plant, has reported that power supply to parts of the facility “momentarily stopped” on March 18th. The company later confirmed that power to the spent fuel pool alternative cooling systems at Units 1, 3 and 4 at the plant had been suspended, but said that temperatures in the pools would “not immediately reach the maximum allowed temperature (65C)”.
The company is continuing to investigate the blackout, which some reports attribute to a faulty switchboard at the plant. The power at the facility’s control centre was also reportedly briefly offline, but has now been restored.
TEPCO’s own reports on the length of time it would take for the temperature in the spent fuel pools to reach the critical 65 C, ranged from 4.52 days at Unit 4, to 26.86 days at Unit 1.
Reports from Japan have said that no immediate abnormality in radiation levels in surrounding areas has been recorded, and TEPCO has been quick to state that there is “no room to worry”.
March 20th UPDATE
A series of updates over the last 24 hours have reported that the following systems at the plant are now operational:
- Primary and secondary systems of Unit 1 spent fuel pool’s alternative cooling system.
- Primary system of Unit 4 spent fuel alternative cooling system, with the secondary system restarted using a diesel generator.
- Unit 3 spent fuel pool alternative cooling system’s primary and secondary systems were restarted, with a recorded pool temperature of 17 degrees Celsius (below the operational limit of 65 degrees Celsius).
- The common pool cooling purification system has been restarted, with a temperature of 31.8 degrees Celsius upon restart.
TEPCO has said that an investigation into the incident found that the regular M/C (metal-clad switchgear) in the Process Building, common M/C4A and Units 3-4 temporary M/C (A) were stopped due to the incident.
March 21st Update
The latest news coming from TEPCO’s continued investigations into the power outage that left cooling systems offline at the Fukushima plant has suggested that a rat may have been the cause of the electricity cut. The operator has provided photos showing the carcass of a rat close to a power panel that is thought to have been the likely location of the outage. Soot – investigated by fire authorities and found not to have been caused by fire – was also found around the panel.
A TEPCO spokesperson has, so far, confirmed the presence of the rat, but said that more investigation would be needed to establish if it was the cause of the problem.