Friday, March 25, 2011

Ill Wind

That report is now about two days old. Since then there have been "developments". That is an euphemism around here for MSHTF. M = more. I'm sure you can take it from there.

Here is a good one: Reactor 3 containment feared breached.
A suspected breach in the core of a reactor at the stricken Fukushima nuclear plant could mean more serious radioactive contamination, Japanese officials revealed Friday, as the prime minister called the country’s ongoing fight to stabalize the plant “very grave and serious.”

A somber Prime Minister Naoto Kan sounded a pessimistic note at a briefing hours after nuclear safety officials announced what could be a major setback in the urgent mission to stop the plant from leaking radiation, two weeks after a devastating earthquake and tsunami disabled it.

“The situation today at the Fukushima Dai-ichi power plant is still very grave and serious. We must remain vigilant,” Kan said. “We are not in a position where we can be optimistic."
FWIW I haven't been optimistic since day 3 or 4. Hydrogen explosions are a very bad sign. At least the Japanese government is starting to tell the truth: things will be getting worse for a while.

There is also some technical data available.
Workers were also trying to fix a pump using an outside power source that had been pumping seawater into the No. 5 reactor, but which stopped Wednesday night.

Figures obtained from instruments indicate that between half to one-third of the approximately 4-meter long fuel rods are exposed, but TEPCO officials do not know what the actual situation is like.

The temperature of the core of the No. 1 reactor at one time reached about 400 degrees, above the design limit of 302 degrees. To cool the core, the amount of seawater being pumped in was increased early Wednesday from 2 cubic meters an hour to 18 cubic meters an hour.

The temperature decreased to 243 degrees as of 1 a.m. Thursday, leading one TEPCO official to say the situation was improving.

However, pressure within the containment vessel that holds the pressure container in the core of the No. 1 reactor increased from about 1.7 atmospheres (atm) at 11 a.m. Tuesday to 3.6 atm at 6 p.m. Wednesday.

The amount of seawater being pumped in was reduced to about 10 cubic meters per hour from 2:30 a.m. Thursday.

At a Wednesday night news conference, Haruki Madarame, chairman of the Nuclear Safety Commission, said: "Personally, I am concerned about the increase in pressure in the No. 1 reactor. We may have to open the vent (to release steam)."
So why are they so slow to vent reactor #1? My guess is that they can't pump make-up water into the reactor and venting will cause the fuel rods to be uncovered. Another alternative is that they fear a hydrogen explosion. What ever it is they are holding off venting until the last possible moment. Of course if their judgment is wrong and they go beyond the last possible minute....

In any case, a sure sign that the core has been breached is radioactive iodine. About 99.9% of it is gone 90 days after a shutdown. There is a lot of it in a core that has just shut down. So spent fuel is not going to provide much radioactive iodine. I have been saying total containment breach - rods, reactor vessel, containment bldg. - since the radioactive iodine was reported. Nice to get confirmation.

More evidence of a meltdown. Radioactive zirconium found. Follow the link for the whole dismal story.

Cross Posted at Classical Values

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