Fukushima Update: Nuclear Situation in Japan

Note — this page contains a special edition podcast.

Greetings, Fellow Critters:

I’ve been trying to gather what I can about the current situation at the Fukushima nuclear plants. I’ve been working with Nuclear Information Resource Service (NIRS) to locate accurate information that you may not be seeing in the mainstream media. In a nutshell, what happened is that the quake on Friday morning knocked out the power grid, cutting power to the nuclear plants; external power is crucial because it runs the cooling systems when the plants are not generating electricity. For about an hour the diesel backup generators functioned; then those went out, leaving the plant to run on battery power. In the process of all these events, the reactor cores of several plants became damaged, presumably by both the quakes and cooling system failures.

The upshot at the moment is that there appear to be leaks beneath the containment structure of Fukushima Unit-3, preventing water from staying within the housing. One source is reporting that six feet of the reactor’s core is above the surface of the water. The potential implications of this are potentially pretty serious. They have got to keep this part of the reactor cool, or they risk both zirconium explosions and a meltdown.

As has been widely reported, engineers were pumping seawater into two of the reactor cores (Unit-1 and Unit-3), in last ditch efforts to prevent full meltdowns. One Japanese official is on record as stating that a partial meltdown has occurred at one of the plants. Some distressing news from today is that Unit-3, which is experiencing the leak and may have six feet of core exposed to the air, is made of a mix of plutonium and uranium — much more radioactive and toxic than uranium alone.

One thing you get used to covering nuclear issues is that we will always be told that the situation is better than it is. All of the units involved, by the way, were manufactured by General Electric. There are 23 similar plants currently operating in the United States. I am sure GE engineers have been assisting with this situation, and I plan to call the company Monday to get some details.

First, here is an audio interview with Karl Grossman, the journalism professor who has written many books on the nuclear industry. http://planetwaves.fm/podcast/grossman-sunday-013-edit.mp3

Next, here is some information from the most recent statements of NIRS, written by Michael Marriottte:

UPDATE 2:30 pm, Sunday, March 13, 2011. Tokyo Electric Power is reporting that some six feet of the core of Unit-3 remains uncovered and has been for some time despite efforts to pump water into the core. Tepco speculates there may be leaking pipes and water is not remaining in the core. A translation of part of the statement from our Japanese colleagues: “The fuel’s integrity has been considerably compromised. We are assessing a considerably serious situation.”

UPDATE, 1 pm, Sunday, March 13, 2011. The International Atomic Energy Agency reports that a first-level (lowest-level) emergency has been declared at the three-unit Onagawa nuclear station north of Fukushima. Immediately after Friday’s earthquake a fire broke out at this facility, but it was said to have been extinguished fairly quickly. However, on Saturday, elevated radiation levels were measured at the Onagawa site (about 10 microSievert/hour or about 1 millirem/hour) for a few hours. The emergency was declared due to these elevated levels, but utility officials say the reactors there are under control.

Venting of the Fukushima Daiichi Unit-3 containment took place on Sunday morning, according to the IAEA, to relieve pressure building up inside the containment. Venting of a containment releases radiation into the air. According to an IAEA statement, “Subsequently, following the failure of the high pressure injection system and other attempts of cooling the plant, injection of water first and sea water afterwards started. The authorities have informed the IAEA that accumulation of hydrogen is possible.” IAEA statement is here.

An accumulation of hydrogen is believed to be the cause of Saturday’s explosion at Fukushima Daiichi Unit 1. As noted below, Fukushima Daiichi Unit-3, unlike every other reactor at the site, uses plutonium-based MOX fuel.