Saturday, April 02, 2011

Crack Of Doom

Radioactive water is leaking into the sea around Fukushima. Very radioactive water.

Water with high levels of radiation has been confirmed to have seeped into the sea from the No. 2 reactor at the troubled Fukushima Daiichi nuclear power plant, government officials said Saturday, raising wider fears of environmental contamination by the release of radioactivity.

The water has been leaking into the sea from a 20-centimeter
[8 inches - ed] crack detected at a pit in the reactor where power cables are stored, the government's nuclear safety agency said, adding that Tokyo Electric Power Co., known as TEPCO, is ready to encase the fracture in concrete.

The first detection of tainted water flowing out into the Pacific Ocean could force the government and the operator to limit further expansion of radioactive contamination, likely hampering efforts to restore the crippled cooling functions at the complex.

The government ''wants (the utility) to start the operation of covering the crack in concrete as soon as possible,'' said Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency.

''We will also check whether there are cracks at other reactors as soon as possible,'' he added.

The radiation level in the pit at the No. 2 reactor was more than 1,000 millisieverts per hour, according to the agency. TEPCO noted that it will analyze how much radioactive materials are in the water found in the pit.
Just to add to the rumor factory. I have seen mentioned that the radiation monitors can read a maximum of 1,000 millisieverts per hour. Which is a very high level for human habitation. If that is the case we do not in fact have a maximum number for dose rate except that it is above 1,000 millisieverts per hour.

It appears that the exclusion zone is insufficiently exclusive.
A source of highly radioactive water escaping into the ocean from the Fukushima Daiichi nuclear power plant was identified Saturday, but authorities weren't able to say if the discovery will stop the ongoing contamination that has already spread 40 kilometers (25 miles) into the open seas.

Tokyo Electric Power Co. (9501), the operator of the plant, said it has found a 20-centimeter crack in a two-meter-deep chamber holding cables for the No. 2 reactor, which is believed to be leaking highly toxic water from its nuclear core.
The current exclusion zone is 20 km. And all marine life in the area has been advised to go elsewhere to avoid the radiation. Like that is going to work.

The trouble with expanding the exclusion zone on land to 40 km is that you would have another 130,000 people homeless.

And homelessness is already a significant problem.
Toyoko Takada, in her blue smock and white face mask, paused from hanging up her freshly washed laundry in what was once a school bicycle park.

"Home? I don't know when we will go home again. We fled on the day of the earthquake and tsunami but never thought we would stay away for long. But I'm not sure how we can go back now."

Mrs Takeda, 62, is one of 1,300 evacuated residents from the small town of Futaba in Fukushima prefecture in northeast Japan, who has no idea when – if at all – she will be able to return home.

Located in the shadow of the stricken Fukushima Daiichi nuclear plant inside the 20km exclusion zone, the town remains strictly out of bounds having been contaminated with dangerously high radiation levels.
Officials in Japan say the accident will not be another Chernobyl. They could be correct. It could be much worse.
"The kids have been putting on a brave face but some have had to move four or five times since the earthquake. This is an opportunity to create more long-term stability."

What was at first seen as a temporary emergency evacuation while the nuclear power plants were brought under control is now becoming more permanent. Nobody has yet suggested it will be as bad as Chernobyl, where homes have stood untouched for 25 years this month since the world's worst nuclear accident. But on Friday, Japanese government officials said that residents would not be able to return home for "a long time".
And Tokyo Electric has a public relations problem.
...the plant operators, Tokyo Electric Plant Co [TEPCO], faced a growing litany of criticism for its handling over the affair, from its disaster procedures to miscalculation of radiation levels.
It is just about unanimous. TEPCO is incompetent.

Update: 2 April 2011 1737z

Pumping concrete is not working.
"With radiation levels rising in the seawater near the plant, we have been trying to confirm the reason why, and in that context, this could be one source," said Hidehiko Nishiyama, deputy head of the Nuclear and Industrial Safety Agency (NISA), said on Saturday.

He cautioned, however: "We can't really say for certain until we've studied the results."

Leakage did not stop even after concrete was poured into the pit, and Tokyo Electric is now planning to use water-absorbent polymer to prevent contaminated water from leaking out into the sea.

Officials from the utility said checks of the other five reactors found no cracks.

Nishiyama said that to cool the damaged reactor, NISA was looking at alternatives to pumping in water, including an improvised air conditioning system, spraying the reactor fuel rods with vaporized water or using the plant's cleaning system.
Yeah the answer to everything is plastic (polymer). I wonder if it has been tested in a high radiation environment?

The use of cement under water is known technology.
...all concrete cures under water without the need for you to do anything special. However, you can purchase a special type of cement at your local home improvement center or hardware store known as hydraulic cement. This type of cement has extra calcium added to it which speeds up the drying process--believe it or not, this formula was actually discovered by the ancient Romans, who used volcanic ash in their underwater concrete.
And using cement in contact with salt water?
Cements for use under salt water may contain as much as 5 percent iron oxide, and those with as much as 40 percent aluminum oxide are used to resist the action of sulfate-bearing waters.
So the technology is there (at least to a first order approximation). The story of why the process is not working is incomplete. Maybe the hole is so wide that they need some kind of form under it. Maybe the first step should have been to see if they couldn't stuff something in the crack to hold the cement in place until it could harden. The short version? Murphy strikes again.

It is looking like they are making up stuff as they go along. And they always seem to be a few days behind the curve.


Anonymous said...

Zero Hedge (Tyler Durden) is reporting first attempt to seal crack with concrete failed because of moisture.

Would moisture also obviate the feasibility of a "Chernobyl Solution" sarcophagus, if necessary?

Who's on first?

M. Simon said...


As you can see I started my update a couple of minutes before you posted. But keep them coming. I miss things from time to time.

Yeah. Charlie Foxtrot.

Richard said...

Hydraulic cement actually expands as it cures. (a brand name="Water Plug"). It is designed to repair cracks that have hydraulic pressure that is pushing the concrete back out of the crack.

The Romans invented marine concrete to build harbor works like breakwaters under sea water. The problem is delivering the concrete to the bottom of standing water without it falling through the water, which washes the cement out of the aggregate. This is done by pumping, but the hose must be extended to the bottom of the water column to place the concrete directly on the bottom, withdrawing the hose as the concrete displaces the water.
Man handling a concrete hose that is charges with concrete is HEAVY WORK under the best of conditions. I assume that most nuclear workers are not construction roughnecks. Even empty concrete hoses are very heavy and hard to handle. Pray for them.