This is the reposting of the post that Google/Blogger wiped out in their maintenance mishap that is still on-going after 24 hours.
(UPDATE: MBS News has been updated (12:04PM JST) and it includes this bit of new information from TEPCO's press conference that just ended:
To prevent radioactive materials from further escaping into the atmosphere, TEPCO will start work on May 13 to cover up the Reactor 1 reactor building with cloth made of synthetic cloth.
As to the water level, it is "more than 5 meters below the top of the fuel rods" and "unmeasurable". (So, "more than 5 meters below the top of the fuel rods" is just an estimate.)
Murphys have never left Fukushima I Nuke Plant, and they are coming out from their hiding places.
After the workers braved the very high radiation inside the Reactor 1 reactor building and repaired the pressure gauge and the water gauge inside the Containment Vessel and the Reactor Pressure Vessel (RPV), TEPCO is finding out that the number they've been reporting on the level of water inside the RPV that houses the nuclear fuel rods was very, very wrong, and there's hardly any water inside the RPV.
It also turns out that there is little water in the Containment Vessel that houses the RPV.
There goes the "water entombment" scheme. All the water that has been poured into the reactor has gone somewhere. Both the RPV and the Containment Vessel of the Reactor 1 have been breached.
From MBS Mainichi News (latest revision at 8:31AM JST 5/12/2011):
JNN's investigation has revealed that there is hardly any water inside the Reactor Pressure Vessel (RPV) and the Containment Vessel of the Reactor 1 at Fukushima I Nuclear Power Plant. The planned "water entombment" to cool the reactor would have to be vastly revised.
１号機には作業員が原子炉建屋 の内部に入り、今週、水位計や圧力計の修理を行いました。圧力容器の水位は、これまで高さ４メートルの燃料棒が半分以上、 水に浸かっている位置を示していましたが、水位計を修理したところ、実際の水位は大幅に低く、水がほとんどたまっていないことが政府関係者への取材でわか りました。
Workers entered inside the Reactor 1's reactor building this week, and repaired the water gauge and the pressure gauge. The water level inside the RPV had shown that more than half the height of the fuel rods (4 meters) was under water. However, when the water gauge was repaired, the actual water level turned out to be so much lower that there was hardly any water in the RPV, according to the JNN's interview with a government source.
燃料棒がむき出しになり、空だき状態になると水素爆発の危険が高まりますが、原 子炉の状態が安定していることから、燃料が 溶けて圧力容器の底にたまり、かろうじて水で冷やされている可能性もあるということです。また、外側の格納容器にもほとんど水がたまっていなかったという ことです。
If the fuel rods are exposed, there is an increased danger of hydrogen explosion. However, the condition of the reactor seems stable, so it is possible that the fuel rods have melted to the bottom of the RPV, and the molten mass is being cooled by the water at the bottom, according to the source. There was hardly any water in the Containment Vessel, the source also revealed.
The "water entombment" that was planned for the Reactor 1, in which the Containment Vessel would be filled with water to cool the reactor, will have to be revised now that the Containment Vessel is likely to be broken and leaking water. (May 12, 2:29AM)
MBS News is an Osaka-based broadcasting company (AM radio, TV).
So, here's a puzzle:
TEPCO has been pouring water into the Reactor 1 RPV to the tune of 6 tons/hour, 24/7: 144 tons per day, 1,008 tons per week, 7,056 tons for 7 weeks.
Now they find out that there is hardly any water inside the reactor.
Yet, neither the iRobot's Packbots nor the human workers have found leaks from the Containment Vessel in the Reactor 1.
Where has the water gone?
(h/t anon reader)