By Washington’s Blog [5]
Temperatures are soaring within the reactor 2 containment vessel [6]. And see this [7].
Tepco says that no new nuclear chain reactions are occurring … but admits that the water may no longer be able to cool the reactor. As NHK reports [8]:
Attempts to cool the temperature in the No. 2 reactor of the disabled Fukushima Daiichi nuclear power plant have only partially succeeded despite the injection of more cooling water.
The temperature in the reactor has gradually risen from about 45 degrees Celsius registered on January 27th.
In the past 4 days, the temperature has climbed more than 20 degrees to above 70 degrees.
The plant operator, Tokyo Electric Power Company began pumping more water into the reactor at around 1:30 AM on Monday. But at 7 AM, the temperature stood at 73.3 degrees and at 5 PM, 69.2 degrees.
***
TEPCO says the rise in temperatures indicate that the flow of water in the reactor may have changed direction after plumbing work, and is no longer able to properly cool down the melted down nuclear fuel.
However, the utility says radioactive xenon has not been detected in gases around the reactor, and that nuclear criticality is not taking place.
***
TEPCO says it will increase the amount of water being injecting into the reactor to see if the temperature in the reactor drops.
The government’s Nuclear and Industrial Safety Agency says there is a need for a comprehensive study to determine whether the reactor is actually in a state of cold shutdown.
***
But he criticized TEPCO and the nuclear safety agency for their handling of the matter. He says they are failing to properly explain the state of the reactors to the people.
Gizmodo notes [9]:
Just when you thought it was over, the temperature at reactor number 2 at Fukushima's nuclear plant has soared 26.7 degrees Celsius in the last few hours. Worse: they don't know why the temperature is increasing after being stabilized for so long.
***
Tepco has admitted that they don't have a clue about what is going on. They have increased the amount of water pumped into the reactor ten percent, but their technicians don't know what is going on.
The temperatures in reactors 3 and 5 [10] are rising as well.
A journalist says that a member of the Japanese parliament put him in touch with a manager in Tepco’s engineering department who told him that reactor 4 is “very unstable and dangerous” [11].
Steam has been filmed rising [12] from the Fukushima complex.
Helicopters are flying over the complex [13] to check for increased releases.
The temperature in the spent fuel pool at reactor number 3 is also up 70% [14].
AP points out [15]:
The structural integrity of the damaged Unit 4 reactor building has long been a major concern among experts because a collapse of its spent fuel cooling pool could cause a disaster worse than the three reactor meltdowns.
Indeed, nuclear expert Arnie Gundersen, who used to build spent fuel pools, says that – if the fuel pool at reactor 4 collapses due to an earthquake – people should get out of Japan, and residents of the West Coast of America and Canada should shut all of their windows and stay inside.
The fuel pool number 4 is apparently not in great shape [16], and there have been countless earthquakes near the Fukushima region [17] since the 9.0 earthquake last March.
Why is the spent fuel of such concern?
As I noted [18] in March 2011, the amount of nuclear material in the spent fuel pools at Fukushima is greater than all of the nuclear fuel at Chernoybl:
Science Insider noted [19] yesterday:
The Daiichi complex in Fukushima, Japan … had a total of 1760 metric tons of fresh and used nuclear fuel on site last year, according to a presentation by its owners, the Tokyo Electric Power Company (Tepco). The most damaged Daiichi reactor, number 3, contains about 90 tons of fuel, and the storage pool above reactor 4, which the Nuclear Regulatory Commission’s (NRC’s) Gregory Jaczko reported yesterday had lost its cooling water, contains 135 tons of spent fuel. The amount of fuel lost in the core melt at Three Mile Island in 1979 was about 30 tons; the Chernobyl reactors had about 180 tons when the accident occurred in 1986.
And see this [20].
That means that Fukushima has nearly 10 times [21] more nuclear fuel than Chernobyl.
It also means that a single spent fuel pool – at reactor 4, which has lost all of its water and thus faces a release of its radioactive material [22]- has 75% [23] as much nuclear fuel as at all of Chernobyl.
However, the real numbers are even worse.
Specifically, Tepco very recentlytransferred many more radioactive spent fuel rods into the storage pools. According to Associated Press [24], there were – at the time of the earthquake and tsunami – 3,400 tons of fuel in seven spent fuel pools plus 877 tons of active fuel in the cores of the reactors.
That totals 4,277 tons of nuclear fuel at Fukushima.
Which means that there is almost 24 times [25] more nuclear fuel at Fukushima than Chernobyl.