Endoscope fails to reach water at Fukushima reactor

asahi.com ^ | January 19, 2012 | The Asahi Shimbun

[Razzz42]

A remote-controlled endoscope with a thermometer showed the temperature inside the No. 2 reactor of the crippled Fukushima No. 1 nuclear power plant on Jan. 19 was about 45 degrees, Tokyo Electric Power Co. said.

But the endoscope lens became covered in water droplets and the reception was sometimes fuzzy, so the operator of the plant could not determine the condition of the melted fuel or if the pipes were damaged.

In addition, the endoscope, 8.5 millimeters in diameter, did not reach the surface of the water.

TEPCO had predicted the water level would be 4.5 meters based on the pressure level in the containment vessel.

But after about an hour of operation using the endoscope, TEPCO said the actual water level was probably about 4 meters or lower.

“The pressure level we used for our prediction must have been wrong,” a TEPCO official said, adding that he doubted the lower level was caused by a heavy leakage of water.

It was the first time TEPCO has directly investigated inside the containment vessel of a reactor at the plant since the nuclear accident started on March 11.

TEPCO plans to use the latest observations with the endoscope to confirm the reactor has entered a stable “cold shutdown” stage ahead of work to decommission the damaged reactors.

[Razzz42]

They were hoping to see a water level just below where the borehole enter the containment vessel (dry-well). Yes, normally the containment vessel is dry but since a meltdown occurred in the pressure vessel (inner), they need to flood the containment vessel (outer) to assist in cooling any melted fuel. They didn't find/see the water level, so it lower than they anticipated. Where for sure is the water level? They don't know but they hope it is covering any melted fuel which can't be seen either (melted core is nearby or on its way to China???).

Of course this is a big success according to TEPCO because the temperature is about 112 degrees (not near boiling), the containment vessel is not destroyed even though it can't hold water but radiation ruined the camera after an hour of looking around.

[MIchaelTArchangel]

Dang! I thought my proctologist was really inserting that endoscope pretty deep. All the way to Fukushima!

[CrazyIvan]

You’re tempting an atomic piles joke!

[kidd]

radiation ruined the camera after an hour of looking around.

I didn't see this in the article. The article said the lens became covered with droplets.

I don't think there is an actual camera on the end of the endoscope. It is just a fiber-optic cable that transmits the image to a camera at the other end of the cable. I don't think there is anything that is radiation-sensitive at the end of the endoscope.

[Right Wing Assault]

Who was driving it, an engineer or a poop-ologist? That could be the problem.

[Right Wing Assault]

They need to rent the longer model.

[justa-hairyape]

They now have no idea if the corium is covered with water in #2. They state that it should be. Before the endoscoping, they stated that it was covered with water. That estimate was based on computer models and measured pressure differences.

If you want to see something out of this world, check the long form videos that Tepco released. They will be available for download for about 6 more days. Check the videos uploaded at the site below on January 20th (Inside the Primary Containment Vessel Unit 2, Videos 1-4).

TEPCO News

Latest news is that a Tepco worker claims the steel Containment Vessel may not last the 10 years it will take Tepco to remove the cores due to erosion.

[justa-hairyape]

Here is a picture of the end. Could not find engineering drawings.

[Razzz42]

TEPCO took a temperature reading but didn't bother with taking radiation readings using the bore hole or at least didn't report readings if they did. Radiation eventually damages pixels on the sensor. Use this link to view videos of the Fukushima Unit 2 probe/endoscopy with a few notes of the event and other links. (White dots or speckles are gamma ray interference). http://ex-skf.blogspot.com/2012/01/full-video-of-reactor-2-containment.html

[Razzz42]

I’ll try that hot link again...

http://ex-skf.blogspot.com/2012/01/full-video-of-reactor-2-containment.html

[Razzz42]

Yeah, I have been following it the best that I can understand it.

Hard to say anything about how futile the situation is when you have to rely on ‘official’ statements from TEPCO or the Japanese government for current status.

Unit 2 is emitting the lowest amount of radiation in the work areas. Units 1 & 3 are much worse.

[Razzz42]

http://www.youtube.com/watch?feature=player_embedded&v=oqiPZ39ljjw

[MARTIAL MONK]

They need some little bitty windshield wipers.

[justa-hairyape]

Supposedly they just found abnormally high beta ray ? radiation in squid off of Peru. The original story appears to be in Japanese or some language my browser does not support. At any rate, possibly something may have been lost or messed up in the translation.

Beta ray from squid of Peru

Tepco expected to be able to look with the endoscope downwards and see the water surface slightly above the floor grate. No water there. In fact that environment seems very hostile for being just the dry well area of the CV. They wont go back in their even with the endoscope until 2017 according to what is reported. Do not know where to even insert the probe in Unit #1 and Unit #3.

Was ludicrous when the best thing they could report on the MSM was that there appeared to be no earthquake damage. Duh. Who ever stated the RPV or CV were damaged by the earthquake ? What was stated was that piping leading to and from the CV housing was possibly damaged in the quake. That is what workers evacuating the building said they saw. And some have speculated that the concrete foundation might have been cracked under the CV.

[Razzz42]

What I read firsthand accounts from onsite workers at the time of the earthquake and before the tsunami, walls moving, foundations cracked, pipes cracked, pipes dislodged, Unit 1 venting, at least one ground fissure near Unit 1 was created, superiors warning of a possible meltdown...but it is all unofficial, supposedly.

[justa-hairyape]

That is about right, but obviously no one said they saw the RPV crack or the CV crack or even that pipes inside the CV leaked, since no one was inside the operating reactor CV during the earthquake. Tepco/Japan just threw out the no earthquake damage inside the CV straw man, cause straw men is all they got.