U.S. Nuclear Regulatory Commission Chairman Gregory Jaczko said in Washington on Wednesday that all the water was gone from the spent fuel pools at Unit 4 of the Fukushima Dai-ichi complex, but Japanese officials denied it. Hajime Motojuku, spokesman for plant operator Tokyo Electric Power Co., said the “condition is stable” at Unit 4.
U.S. Nuclear Regulatory Commission Chairman Gregory Jaczko told members of Congress today that there is no water remaining in the fuel pool at reactor 4 at Fukushima Daiichi nuclear power plant. Jaczko told members of the House Energy and Commerce Committee that “we believe that secondary containment has been destroyed and there is no water in the spent fuel pool…radiation levels are extremely high, which could impact the ability to take corrective measures.”
If Jaczko is correct, it would mean there’s nothing to stop the fuel rods from getting hotter and ultimately melting down. The outer shells of the rods could also ignite with enough force to propel the radioactive fuel inside over a wide area.
However, if Jaczko of the NRC is wrong, then what would happen to a someone in his position giving out wrong (and not first hand) information ?
Either that or some of the Japanese are lieing. the water level is lower but not dry.
There is also the possibility that the quakes and aftershocks have sloshed out a lot of the water and the answer is in between. Water levels are lower but not dry.
UPDATE: It appears that water levels have been low, as they are now using fire engines and military helicopters to drop water onto the cooling ponds.
The IAEA can confirm the following information regarding the temperatures of the spent nuclear fuel pools at Units 4, 5 and 6 at Fukushima Daiichi nuclear power plant:
14 March, 10:08 UTC: 84 ˚C
15 March, 10:00 UTC: 84 ˚C
16 March, 05:00 UTC: no data
14 March, 10:08 UTC: 59.7 ˚C
15 March, 10:00 UTC: 60.4 ˚C
16 March, 05:00 UTC: 62.7 ˚C
14 March, 10:08 UTC: 58.0 ˚C
15 March, 10:00 UTC: 58.5 ˚C
16 March, 05:00 UTC: 60.0 ˚C
Late Wednesday, government officials said they’d asked special police units to bring in water cannons — normally used to quell rioters — to spray water onto the spent fuel storage pool at Unit 4.
The cannons are thought to be strong enough to allow emergency workers to remain a safe distance from the complex while still able to get water into the pool, said Minoru Ogoda of Japan’s nuclear safety agency.
World Nuclear News coverage – The Japan Atomic Industry Forum reports that the level of water in unit 4’s fuel pond is low and damage to fuel stored there is suspected. Efforts are underway to refill the pool, including an abandoned attempt to douse the building with water from an army helicopter, hoping to get some to go through the damaged building. The temperature of the pond was last known to be 84ºC on 14 and 15 March, said the International Atomic Energy Agency. There was no data for today.
Unit 3’s pond is also low and engineers are preparing to add water to both. This is the urgent focus of work for Tepco engineers. Without proper containment, the risk of serious radioactive release in the event of fuel damage or fire is very real. Tepco has not announced the original issue that allowed the water levels in the fuel ponds to drop so low.
Dose limits to workers under emergency regulations have been raised to 250 millisieverts from 100 millisieverts after which they may not return. This compares to usual nuclear worker limits of 20 millisieverts per year.