Stating the Obvious: #Fukushima Reactor 2's Suppression Chamber May Be Leaking

TEPCO may have hoped that it was one of those vent pipes from the dry well to the suppression chamber in Reactor 2 that was leaking the water injected into the RPV, but the awkward 4-legged Robot by Toshiba couldn't find any leak. So the conclusion is that the suppression chamber is probably leaking.

I would think it will be much harder (near impossible) to plug, because the suppression chamber is submerged in highly contaminated water.

From Jiji Tsushin (3/15/2013; part):

圧力抑制室から漏水か＝福島第１原発２号機－東電

TEPCO says leak may be from the Reactor 2 suppression chamber

東京電力は１５日、福島第１原発２号機格納容器下部の圧力抑制室につながる「ベント管」を調べた結果、水漏れはなかったと発表した。原子炉建屋地下に漏れ出している水は、圧力抑制室から出ている可能性が高くなったという。

TEPCO announced on March 15 that there was no leak after examining the "vent pipes" that connect to the suppression chamber of Reactor 2 containment vessel at Fukushima I Nuclear Power Plant. The water leaked into the basement of the reactor building was likely to be coming from the suppression chamber.

In that press conference on March 15, TEPCO's spokesman (no longer Mr. Matsumoto, I don't know the name of this young person who croaks when he speaks) didn't explicitly admit that the leak was from the suppression chamber; instead, he said, in response to a question by the reporter from Tokyo Shinbun on how TEPCO felt about the discovery (after 27 minutes):

Since the leak is not from the PCV (primary containment vessel), it will be easier to plug the leak.

How could a repair job in an inaccessible part of the suppression chamber (lower half) be easier?

His reasoning was that the PCV was closer to higher contamination, so any repair work away from the PCV would be easier. He tried to spin it as a positive discovery. "The PCV is sound, and it's a good thing", he said. The only problem was how to find the leak in the lower half (submerged part) of the suppression chamber, or other locations, he said.

It didn't seem like an answer to me, but as usual, the reporter said "OK, I got it", and that was the end of his questions.

(I miss the previous spokesman Matsumoto, who looked like Doraemon. He didn't try to spin, like the current one does.)

One of the photos taken by Toshiba's robot, released on March 15, 2013. Lots of white noise (click to enlarge):

The radiation levels inside the Reactor 2 torus room is not known. TEPCO couldn't lower the camera and dosimeter through the hole drilled on the 1st floor when they found out there were unexpected pipes blocking the way.

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#Fukushima I Nuke Plant: Sediment Sample Collected from Flooded Torus Room of Reactor 1

Uh... They put the sediment sample in a plastic bottle?

According to TEPCO, the plastic bottle is emitting 4 millisieverts/hour radiation with the sediment in it.

From TEPCO's Photos and Videos Library, 2/22/2013:

Workers in full gear collecting samples through the hole on the first floor of the Reactor 1 building, where the air radiation dose ranges from 2 to 10 millisieverts/hour. It took 20 workers 2 hours and 35 minutes to complete the task, for which they received 1.46 millisievert (maximum) of radiation exposure.

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#Fukushima I Nuke Plant Reactor 1 Torus Room Video Shows a Pile of Sediments on the Floor

Workers lowered the video camera, thermometer, and dosimeter through the hole on the first floor of Reactor 1 building in the 2 to 10 millisieverts/hour environment.

Water is murky, 4.9-meter deep from the torus room floor. TEPCO said in the 2/20/2013 handout (in Japanese; there is no English handout) that visibility was about 60 centimeters.

From TEPCO's Photos and Videos 2/21/2013, with brief explanations of the photos from the Japanese version:

Suppression Chamber wall (OP 3200, in the water):

Torus room floor (OP -800):

Water surface (OP 3700):

Torus room ceiling (OP 7700):

(OP is "Onahama Peil", average sea level used for the plant. The numbers are in millimeters. So, OP 3700 means the level is 3700 millimeters (or 3.7 meters) above the sea level.)

It is stating the obvious, but it nonetheless did not occurred to me until I read the comment from the blog reader Atomfritz - that the Reactor 1's Suppression Chamber is also broken.

TEPCO's video shows (from 35 to 45 seconds in the video) a large pile of sediments on the torus room floor under water:

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#Fukushima I Nuke Plant: Reactor 1 Torus Room Max Radiation 920 Millisieverts/Hour

（UPDATE) Video and photos in the latest post.

=========================

After successfully drilling a hole through the 1st floor of Reactor 1 building and finding no obstruction, TEPCO sent workers to lower the camera, thermometer, and dosimeter through the hole into the torus room in the basement.

The highest radiation dose was right above the water, at 920 millisieverts/hour.

It took 20 workers 2 hours and 25 minutes to do the first day of work, with maximum radiation exposure of 1.78 millisievert. From TEPCO's February 14, 2013 handout (see my post), the air radiation level at the hole on the first floor of the reactor building is 10 millisieverts/hour, and at 1.2 meter above the hole it is 2 millisieverts/hour.

From TEPCO's Handout for the Press, 2/20/2013:

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#Fukushima I Nuke Plant: TEPCO Successfully Drilled a Hole Into Reactor 1 Torus Room

Workers drilled a hole through the 1st floor concrete on February 13 and 14. And unlike in the Reactor 2 torus room the other day (1/28/2013), there was no unexpected pipe blocking the way.

The atmospheric dose level on the 1st floor before the drilling was 1 millisievert/hour. After the drilling, the radiation went up to 2 millisieverts/hour right above the hole, at 1.2 meters off the floor. At the hole, the radiation was 10 millisieverts/hour, and at the end of the hole through to the torus room, it was 210 millisieverts/hour. TEPCO says the investigation will proceed, now that they've found out that the radiation level didn't change much before and after.

The radiation levels inside the Reactor 1 Containment Vessel, measured in October last year, were 4.7 to 11.1 sieverts/hour (or 4,700 to 11,100 millisieverts/hour).

From TEPCO's Photos and Videos, 2/14/2013:

The white dot in the dark in the photo must be the reflection of the camera light on the water.

The atmospheric dose level in the Reactor 2 (about the same location) was much higher, at 4 to 8 millisieverts/hour.

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#Fukushima I Nuke Plant: Pipes That Should Not Be There Are Blocking the Way in Reactor 2 Torus Room

TEPCO send the workers to Reactor 2 building on January 27 to drill a hole through the 1st floor to the torus room. The location was carefully chosen so that they would have a clear shot at the water accumulated in the torus room. Through the hole, the workers were to feed the camera, dosimeter, and thermometer.

Surprise! When the workers managed to carefully drill a hole and looked in, huge pipes and gratings were in the way, and there was no way for the workers to do the planned work at that hole.

From TEPCO's Photos and Videos, 1/28/2013, "Drilling Holes for the Investigation of Unit 2 Torus Room at Fukushima Daiichi Nuclear Power Station":

From the handout, this was what TEPCO had planned:

How did this happen? TEPCO chose the location because there wasn't supposed to be anything, according to the original drawings. However, as repairs and renovations were done over the years, the original drawings from the time the reactor was built became obsolete.

Don't they have the drawings of those repairs and renovations? Yes they do. But those drawings were stored in one of the buildings that was devastated by the March 11, 2011 earthquake and declared too dangerous to enter. There is no information as to whether anyone has gone back in to retrieve any document or data from the main building. Probably not, because, as we know well by now, TEPCO carefully abides by the rules and regulations from the authorities:

(Photo of the 2nd floor of the main building, Fukushima I Nuke Plant)

Independent journalist Ryuichi Kino tweeted:

福島第一の現況の把握が難しいことは、以前からわかっていた。原子炉の基本的な構造は設計当初のままだが、配管や細かい設備などは後から追加、修正をうけて、元の状況とは大きく変わっている。だからこれまでも、構造物に手を着ける作業は慎重に進められた。

It has been known that it is difficult to completely grasp the condition of Fukushima I Nuke Plant. The basic structures of reactors have been the same since the plans were drawn up, but pipes and other small facilities were added and modified later, making the current condition vastly different from the original condition. Therefore, any work that has to do with the structures have been carried out very carefully.

もうひとついうと、改修で配管が変更されていたため、窒素封入や冷却水の注入に使う配管の確認に手間取ってもいた。旧保安院もそうした経緯は知っていて、簡単ではないことも認識していた。では現況が把握できる図面はどこにあるのかと、保安院で聞いたことがある。

One such example: TEPCO had a difficult time in confirming which pipe to use for nitrogen gas injection and for cooling water injection, because the pipes had been switched around after repairs and renovations. Nuclear and Industrial Safety Agency knew this, and was aware that it was not easy. I once asked NISA, where, then, are the drawings that will allow us to grasp the current condition?

すると、図面や工事の書類などはすべて、福島第一の事務本館にあるという。だから、取りにいけないのだとのことだった。事務本館は地震でボロボロになって、立ち入り禁止になった。

They answered, all the drawings and documents from construction work are stored in the main building at Fukushima I Nuke Plant, and therefore they couldn't go in and retrieve them. The main building was devastated by the earthquake, and declared off-limits.

ということを聞いたのは、１年くらい前だったか。そういえばその後、事務本館に書類の回収に行ったのかどうか聞いてなかったので要再確認。とはいえ、今回の作業で予想外の配管が、何もないはずの場所の真ん中に通っていたことで、疑問が倍増してしまった。

That was about one year ago. I have to ask again if someone did go to the main building to retrieve the documents. However, the most recent work [drilling a hole through the floor of Reactor 2] revealed unexpected pipes right there in the middle of where they were not supposed to be. So I wonder.

現況の把握ができないと、実際に見えている範囲の作業を進めるのが精一杯になる。そうなると２号機トーラス室だけでなく、人が入れない場所の作業に大きく影響する。ロボットで作業するといっても、指示ができない。手探りの事故収束作業が、まだまだ続いている。

If they cannot grasp the current condition, the best they can do is to do the work in the areas that they are able to see. That wold affect the work not just in Reactor 2 torus room but everywhere where human workers cannot enter. Robots may be able to enter, but [since no one knows the actual condition of the place] no one can give directions to the robots. It is as if they feel their way in the dark, as they continue the work to end the accident.

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Update from TEPCO's Press Conference on Toshiba's 4-Legged Robot That Crashed in #Fukushima I Nuke Plant Reactor 2 Torus Room

It's so pathetic it is almost funny. Or at least the dialog between the reporters and TEPCO during the December 12, 2012 press conference was, probably unintentionally.

It was funnier reading about it via the tweets by @ystricera, who has tweeted almost all press conferences by TEPCO and the government regulatory agencies since March 2011.

Reporter: What time did the robot stop?
TEPCO: In the morning.
Reporter: It's evening now, and you don't know the exact time?
TEPCO: We will investigate all day tomorrow.

Two human colleagues from Toshiba had to get exposed to 1.36 millisievert radiation to retrieve the robot, but just to the outside the torus room.

For more of the mission of this clumsy Toshiba robot, see my previous post.

From his tweets on December 12, 2012, the remarks in parenthesis are either his explanation or the reporters' questions:

（2号機4本足ロボット調査、もともと1階北東側三角コーナーから親機入れて階段を降りてから）東電「階段をまず降りて地下のところまでいってトーラス室に行くのに登り階段がある、そこから登る操作していた所足をかけて上に上がろうとしていた所前足が浮いて後ろに倒れる形に　」

(Investigation of Reactor 2 by the 4-legged robot, it was to enter from the northeast corner on the first floor and climb down the stairs, then..?) TEPCO "The robot first climbed down the stairs to go to the basement, then there are stairs to climb up to the torus room. The robot started to climb. Then the forelegs went up in the air and the robot fell backward."

東電「遠隔段階、動作不能になったので2人いって回収。結果的には倒れているので想定していない不具合があったのかと思うが、状況としては前足を前にかけていて後ろ足をあげる段階で後ろ倒しになったと、バランス崩す制御になったと」

TEPCO "The robot was on a remote control. Two people went to retrieve the unresponsive robot. Since it fell down, we assume there were some unexpected problems. But the situation was that the forelegs were on the step already, and the robot was lifting the hind leg, then lost control and fell backwards."

東電「動作開始の直後。登り始めるところからスタートで登りはじめたらすぐ。」

TEPCO "It was right after the robot started to climb."

東電「2号機ベント管調査の件、キャットウォークに登る階段を登りはじめた所で厳密に言うとトーラス室に入ったところ」（人がいって回収したのは間違いないか）「2人いって回収、入り口なのでそんなに大きいわけではなく実際の被曝量は多い方の方で1.36mSv」

TEPCO "The robot was just starting to climb the stairs leading to the catwalk. So to be precise, it was right inside the torus room." (So human workers went to retrieve it, is that correct?) "Two people went to retrieve the robot. Because the location was right at the entrance, the radiation level was not that high. The max exposure was 1.36 millisievert."

（共同池上　調査前にひっくり返った）東電「開始直後ですので調査はできていない」（明日は調査しない、終わり時期がよくわからないがいつくらいまでやる予定）「1日1本、2本、状況に応じてだが全部で8本あるのでそういうオーダーでできると作業継続」

(Ikegami of Kyodo News: So the robot flipped over before the investigation.) TEPCO "It happened right at the beginning of the work, so no, there was no investigation done." (So you're not going to do the investigation tomorrow? When will the investigation be over?) "One or two vent pipes a day, so depending on the situation, there are 8 vent pipes, we hope to carry out the investigation at that pace."

（回収は東電社員）「協力企業」（東芝の人）「そうだと思います」

(Did TEPCO employees retrieve the robot?) "Affiliate company." (Were they from Toshiba?) "I think so." [TEPCO doesn't even know that??]

（壊れた部分は）東電「倒れかかったということで、そんなに大きく壊れてないと。後ろの壁にもたれかかった。回収は手で運び出した」（建屋の外まで）「トーラス室の外の三角コーナーまで」（ロボット自体は今どこに）「三角コーナーに」

(What broke?) TEPCO "The robot didn't completely fall down, so we don't think it's damaged much. It was leaning against the wall behind it. Workers hand-carried it." (To outside the reactor building?) "To the landing just outside the torus room." (Where is the robot now?) "On the landing."

（仮置きしたのはおもいっちゅうのもあると思うが）東電「そこでバッテリーチャージもできますし」

(I suppose it is because the robot was so heavy that the workers had to leave it there for now.) TEPCO "Well, we can charge batteries there."

（ロボット三角コーナーに仮置きというお話されたが故障原因わからずにその場に仮置きだと修理しようがないが外に持ちだして確認したりは）東電「どういう調査するか含めて確認中」

(So the robot is temporarily placed on the landing, you say. But if you have it there temporarily without knowing the cause of the problem, there is no way to repair it. Are you going to take it outside [the reactor building] and inspect?) TEPCO "We're trying to figure out what to do."

（止まったのは何時）東電「朝」（夕方になってもわからないと）東電「明日1日調査する」

(What time did it stop?) TEPCO "In the morning." (It's evening now, and you don't know the exact time?) TEPCO: "We will investigate tomorrow all day."

AAAAGGGGHHHH....

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Photos of #Fukushima Reactor 3 Torus Room by Survey Runner

At the bottom of each photo, you can see the radiation levels encountered by the robot at that location. (See my previous post for the video.)

From TEPCO's Photo and Video Library page:

Torus Room entrance (18 to 117 millisieverts/hour):

Manhole, southeast (177 to 234 millisieverts/hour):

Primary Containment Vessel side (234 to 254 millisieverts/hour):

Stairway, southwest (192 to 324 millisieverts/hour):

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#Fukushima I Nuke Plant Reactor 3 Torus Room Video Taken by Robot "Survey Runner" Before It Became Inoperable

The tethered robot also carried a recording equipment to record any sound of water in the Reactor 3 Torus Room, but the equipment was stand-alone.

Since the cable was apparently damaged and the robot became inoperable, there is no way for now to retrieve any audio recording it did. The radiation levels inside the Torus Room is too high for human co-workers (100 to 360 millisieverts/hour), as you see below in TEPCO's handout for the press (7/12/2012):

According to the handout, the survey was about three-quarters done. The workers and the robot spent about 3 hours on the work, when the cable communication to the robot was interrupted. 6 TEPCO employees who had been scheduled for 8 millisieverts radiation exposure for their work of carrying the robot through the narrow passage in the basement and holding the Torus Room door open actually got 5.32 millisieverts.

The photographs and video released show no major damage inside the Torus Room. The stairway in the southwest corner shows damage. (The photographs and the video can be downloaded at TEPCO's site, here.)

Video by Survey Runner:

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Robot "Survey Runner" Lost in High-Radiation Reactor 3 Torus Room at #Fukushima I Nuke Plant

(UPDATE 7/12/2012: TEPCO released the photographs and the video taken by Survey Runner. See my latest post.)

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On the second job since its debut in June surveying the Reactor 2 Torus Room, the robot Survey Runner became inoperable inside the Reactor 3 Torus Room. TEPCO says the radiation levels inside the Torus Room are just too high to retrieve the robot. The maximum radiation recorded by the robot before it became inoperable was 360 millisieverts/hour.

The robot was tethered. TEPCO does not have the footage of the mission available.

(For the details of what the robot and its human co-workers had hoped to achieve, see my previous post.)

From Jiji Tsushin (7/11/2012):

東京電力は１１日、放射線量の測定や映像撮影のため、福島第１原発３号機原子炉建屋地下に無人走行ロボットを投入したところ、操作不能になったと発表した。同社は「放射線量が高く、当面ロボットの回収は難しい」としている。

TEPCO announced on July 11 that the robot became inoperable after it was sent to the Reactor 3 building basement at FUkushima I Nuclear Power Plant to measure radiation levels and take the video. The company said it would be difficult to retrieve the robot for the moment because of the high radiation levels.

東電によると、ロボットを使った作業は１１日午前１１時から午後３時まで行われた。格納容器の一部で、水をためる圧力抑制室を収納する「トーラス室」でロボットを走行させ、調査を実施。線量は最大で１時間当たり３６０ミリシーベルトを記録した。

According to TEPCO, the work using the robot was done from 11AM to 3PM on July 11. The workers operated the robot that went inside the Torus Room that houses the Suppression Chamber (which is part of the Containment Vessel) to survey. The highest radiation level recorded [inside the Torus Room] was 360 millisieverts/hour.

ロボットは有線で操作していたが、途中で動かすことができなくなった。東電は「原因はまだ分からないが、有線のケーブルが損傷したことなどが考えられる」としている。ロボットには水の流れる音などを把握するため、録音機器も取り付けており、その回収も当面できなくなった。

The robot was tethered, but it became inoperable in the middle of the work. TEPCO said, "We don't know the cause yet, but it is possible that the cable got damaged." The robot was fitted with the recording equipment to record the sound of running water, but the equipment cannot be retrieved for the moment, either.

Quince 1 is still stranded in the Reactor 2 building, "for the moment", in much lower radiation, relatively speaking (10 millisieverts/hour where it sits).

I do hope TEPCO will release whatever footage they have, as well as the detailed information of what they did find. If anything, the new TEPCO under the control of the national government is releasing less information, not more. When they do release, they do so without detailed enough explanation on what they were doing.

Case in point is the set of photos of the upper floors (operational floors) of Reactor 3 that the company released also on July 11. It is just photographs of the mangled upper floors, with no explanation when it was taken and how it was taken. I suppose everyone is expected to tune in to their press conference to find more (if there's more). From the looks of the photos, they seem to have been taken from the boom of the crane they use to take air samples above the reactors at Fukushima. The air sampling at Reactor 3 was done on July 5, 2012, and the result of the nuclide analysis was released on July 10.

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#Fukushima I Nuke Plant Reactor 3 Torus Room Survey Planned on July 11, 2012

TEPCO is sending 11 TEPCO employees and one robot (Survey Runner, which looks like a smaller version of Quince and has already gone inside Reactor 2's Torus Room in April this year - photo, video) down to the basement of Reactor 3 to survey the inside of the Torus Room. Planned radiation exposure for the human workers is 8 millisieverts.

No information of how long each worker will have to stay there to assist their robot co-worker. They won't go inside the Torus Room, as the very high radiation levels are expected inside. Instead, Survey Runner will go. The human workers will carry the robot through the narrow passage in the basement to the Torus Room door, which they will open for the robot.

8 millisieverts of radiation exposure. Before the Fukushima accident, it was rare even for the nuclear plant workers to get 1 millisievert exposure in one year. Now, the workers may get 8 years' worth of radiation in a day's work at Fukushima I Nuke Plant.

When the workers tried to enter the Reactor 3 Torus Room in March this year, the access door was warped and didn't open. The workers didn't stick around to open the door, because the radiation levels were probably too high for the work (it was 75 millisieverts/hour in front of the door). TEPCO sent workers again in June to measure the water level in the basement.

From TEPCO's handout for the press, 7/10/2012:

Investigation Outline

Purpose: As water leak investigation and water stop measure implementation are planned for the area from PCV / Reactor Building to the Turbine Building, it is critical to understand the current condition of the Torus Room. A robot will investigate the inside of Torus Room with high radiation dose to obtain inputs to be leveraged for planning the water leak investigation and water stop measures.

Investigation Items

The following will be done in the Torus Room in Unit 3 Reactor Building basement.
-Visual confirmation (Acquire photos and moving images)
-Dose rate measurement
-Collect sound samples in the Torus Room

Equipments: Remote control robot (Survey runner)
Members involved: 11 TEPCO employees
Investigation date: Wednesday, July 11, 2012

Planned expose dose
8 millisievert: 6 Carrying the robot through the triangle corner, opening doors
2 millisievert: 5 Robot operation, preparation

*Robot operation control is done in Unit 3 S/B (0.1mSv/h)

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#Fukushima I Nuke Plant Reactor 1 Torus Room: Over 10 Sieverts/Hr on Water Surface

TEPCO, soon to be "effectively" nationalized, sent own workers to the Reactor 1 building at Fukushima I Nuclear Power Plant on June 26 to measure the water level, radiation levels and temperatures inside the Torus Room. The workers used the CCD camera fitted with thermometer and dosimeter, and fed the cable through the gap in the floor from the 1st floor of the reactor building.

Right near the surface of the water, it was 10,300 millisieverts/hour, or 10.3 sieverts/hour.

TEPCO reports that the dosimeter failed in the water, at it exhibited the values of "10^8 - 10^9" (100,000,000 to 1,000,000,000) millisieverts/hour.

If you recall, this was the reactor building where the steam measuring 4 sieverts/hour was gushing through the gap between the pipe and the floor on the first floor.

From TEPCO's Photos and Videos Library, June 27, 2012 (there is also a 40-minute video, I'll post here later):

TEPCO also reports on page 4 of the handout,

• The accumulated water level was OP. 4,000. (The Torus Room floor is at OP. -1,230, so the water is 5,230 millimeters (5.23 meters) deep.)

• Transparency of the water confirmed at least to 60 centimeters.

• Floating sediment on the bottom.

And no, they didn't do the water sampling.

There is no information on the document about the radiation exposure of the workers. They were in the vicinity of extremely high radiation for at least 40 minutes (length of the video). I hope several groups of workers took rapid turns.

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TEPCO Measures Water Levels in Torus Rooms in Reactors 2 and 3 at #Fukushima I Nuke Plant

TEPCO sent carbon-based workers down to the Torus Rooms of Reactors 2 and 3 on June 6 to measure the water levels. No information about how long the work took, but the maximum radiation exposure for the workers was 6.49 millisieverts for going into both Reactors 2 and 3. No information about how many workers (or whose workers) TEPCO sent in. Probably the company sent in its own employees because of the high levels of radiation.

The last time the workers went near the Torus Rooms of Reactors 2 and 3 was on March 14, 2012. Six TEPCO workers spent total of 28 minutes in the reactor buildings with the radiation levels in the basements (where the Torus Rooms are located) that ranged from 15 to 160 millisieverts/hour (inside the Reactor 2 Torus Room). At that time, they couldn't enter the Reactor 3 Torus Room because the door was bent. Judging by the radiation levels in front of the Reactor 3 Torus Room door that were more than twice as high as those of the Reactor 2 Torus Room, we can guess the levels inside the Reactor 3 Torus Room were much, much higher:

The water levels in "O.P" (Onahama Peil) are indicated in the first slide below, but if the mid point of the torus is OP1900 and the water levels measured are about OP3000 (as per the last slide), and the mid basement level is OP4000, the picture is not exactly to the scale.

From TEPCO's Photos and Video Library, 6/7/2012:

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Videos of Reactor 2 Torus Room at #Fukushima I Nuke Plant

Below is the first installment of the 6 videos, showing the contaminated water underneath the grating.

There is no discernible damage along the catwalk or the upper part of the Torus Room.

This is the third video that shows the manhole in the northeast side with some paint peeling and discoloration (the video will be live in about 30 minutes):

For the other 4 videos, go to TEPCO's Photo for Press page for the April 18, 2012 videos, here.

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More Photos and Videos of #Fukushima I Nuke Plant Reactor 2 Torus Room

TEPCO released more photos of the Reactor 2 Torus Room taken by the robot "Survey Runner" on April 18.

As I posted yesterday, about 90% of the circumference of the torus was covered by the robot, instead of about 1/3 to 1/2 that TEPCO had anticipated.

It looks dry for the most part, but the robot did see the water (the 7th photo).

From TEPCO's Photo for Press page, 4/19/2012:

Toward PCV (Primary Containment Vessel):



Above the southeast S/C (suppression chamber) manhole:



The southeast S/C manhole:



The north S/C manhole:



Northeast passage:



Above the northeast passage:



Lower part of the Torus Room:



Above the south passage:

I'm downloading the videos (there are 6 of them), but you can view them at TEPCO's page here.

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Photos of Reactor 2 Torus Room at #Fukushima I Nuke Plant, Highest Radiation 120 Millisieverts/Hr

The robot "Survey Runner" went down to the Reactor 2 Torus Room on April 18, and TEPCO released two photos of two manholes.

From the TEPCO's survey plan, the robot was to cover slightly over 1/3 of the Torus Room, but in the press conference TEPCO's Matsumoto said about 90% of the Room was covered.

Things look almost clean after seeing the mess in other reactors' upper floors. The robot must have taken more photos and probably videos, but for now TEPCO is willing to release only these photos.

From TEPCO's Photos for Press, 4/18/2012:

North S/C [suppression chamber] manhole:

Southeast S/C manhole:

Note the air radiation levels display at the bottom of the photos. At the north manhole, it is 47.4 millisieverts/hour, and at the southeast manhole 61.4 millisieverts/hour. The numbers next to the per-hour radiation level may be the cumulative radiation level sustained by the robot.

In about 30 minutes between when the robot was at the southeast manhole and when it was at the north manhole, the cumulative radiation (if that's what it is) went up from 57 millisieverts to 82.2 millisieverts.

From TEPCO's press conference on April 18,

• The robot was in the Torus Room for 3 hours, from 10:52AM to 1:51PM.

• 6 TEPCO workers accompanied the robot, receiving 0.28 millisievert radiation.

• The robot got 186 millisieverts cumulative radiation in the 3-hour work.

• 120 millisieverts/hour in the northwest corner.

• 90% of the Torus Room covered.

• No discernible leak, damage observed. Clean.
  

• Video, audio recorded by the robot, will be released on April 19.
  

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#Fukushima I Nuke Plant: TEPCO to Send a New Robot to Reactor 2 Torus Room

The robot, "Survey Runner", is made by Topy Industries Co. in Tokyo, and looks like a smaller version of Quince. The robot is going into the Torus Room of Reactor 2 on April 18.

From TEPCO's handout for the press, English, on April 17, 2012:

Topy Industries Co. is a company located in Shinagawa-ku, Tokyo. It has been developing the robots for disaster response in collaboration with Professor Shigeo Hirose of Tokyo Institute of Technology Department of Mechanical and Aerospace Engineering since 2003. For more on the free loan of the robot to TEPCO, see their English press release.

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