[R. Cromack] This is not over. (From NHK World News)
http://www3.nhk.or.jp/daily/english/12_23.html
----------------------------------------------------------------------
Water likely leaking from No.1 reactor
Tokyo Electric Power Company says water may be leaking from breaches in the No.1 reactor at the Fukushima Daiichi nuclear plant, causing a sharp drop in the water level inside the reactor.
Tokyo Electric sent workers inside the building to adjust the water gauge of the reactor.
The utility had suspected the gauge wasn't working properly because the water level hasn't been rising despite pumping in 150 tons of water daily to cool the reactor.
On Thursday morning, it was found that the water level was more than one meter below the bottom of the fuel rods, suggesting a large volume of water is leaking into the containment vessel.
The utility company also believes that the water is leaking from the containment vessel into the reactor building. This is because the estimated volume of water inside the containment vessel appears to be less than what leaked into it from the reactor.
Tokyo Electric says temperatures at the bottom of the reactor are between 100 and 120 degrees Celsius, suggesting that the fuel has fallen and is being cooled in the water below.
The utility says it does not believe the fuel has completely melted and spilled through the bottom of the reactor. It adds that instead, the fuel appears to be being cooled inside the reactor.
Tokyo Electric says the company will now have to review its ongoing procedure of filling the containment vessel with water to cool the reactor.
It says it will reveal a new plan on Tuesday next week when it is set to announce a revised schedule for containing the emergency.
Work to cool the reactors had made the most progress in the No.1 reactor, with the volume of injected water being increased. The cooling of the reactors is the most important step in the containment process.
Chief Cabinet Secretary Yukio Edano told reporters that the reactor appears to be stable because it's been steadily cooled for a long period. But he said the condition of the reactor must be reassessed as some figures from the gauge are contradictory.
The Nuclear and Industrial Safety Agency said that if the latest data is accurate, it seems parts of the fuel have melted and accumulated at the bottom of the reactor. But it added that it believes the fuel rods are being cooled.
----------------------------------------------------------------------
Thursday, May 12, 2011 15:08 +0900 (JST)
----------------------------------------------------------------------
I'm not going to make statements about "what this could mean" -- I am no more an expert than any other observer here -- but it's pretty clear, I think, that TEPCO is playing for time... and losing. And Reactor 1 is considered the MOST "achievable" of the three active reactors, in terms of effecting a cold shutdown and finally bringing this crisis to a close.
This ain't over, folks, not nearly. Would love to hear UCBNE's thoughts on this. Here's five questions I have for the the Berkeley Nuclear Engineering staff:
[1] Won't continued, long-term pumping of massive amounts of water into the RV (reactor vessel), serve to eventually widen these (presumed) cracks, weakening the RV AND, it seems, the also-breached CV (containment vessel)?
[2] Couldn't said weakening, taken together with damage the various structures have suffered as a result of the March 11 earthquake, the tsunami, scores of aftershocks, as well as the higher temperatures resulting from an only minimally contained pile and the natural long-term corruption that nearby substances face as a result of long-term exposure to radiation, eventually COLLAPSE the RV, CV, and the reactor building altogether?
[3] If they're only able, despite their best efforts, to flood the RV to only about one meter below the height of the rods, doesn't that mean that tbe BEST we can hope for for Reactor 1, is a long, slow, prolonged, steady percolation and VERY long-term release of (currently nominal) radionuclides?
[4] Won't TEPCO have to "trade off" LOWER RV water levels, for HIGHER core temperatures, as continuing to push 150 tons-plus of fresh water in there every day will continue to degrade the unit's strustural integrity?
[5] Even in the BEST-case scenario from this point forward, isn't there a "law of diminishing returns" at work, here, in that it will become more and more difficult to cool a pile that has now, at least by some accounts, slagged together at the bottom of the RV? In short -- isn't TEPCO just playing for time, as I said at the outset?
Very, very disturbing. And our Government has decided, in its wisdom, that this ongoing emergency is no longer worthy of the effort of monitoring it. Even from a quarter-world away. Their silence is deafening.
Until the last 24 hours or so, I had been, recently, quite optimistic. Not too sure about that now. Am I wrong?
Rick Cromack.
Allen, Texas
Apologies -- these were covered in another thread below. [nt]
Rick.
Yes he said it nothing more to see move on
U are on a nuclear Engeeniring forum Roger they havle bias and interests in this industry funny how tepco is destroying there futures and nuclear energy.Example..
Extrapolating from our
Submitted by bandstra on Thu, 2011-05-12 18:00.
Extrapolating from our recent data and current detection limits, all of the isotopes should be undetectable by around 5/12-5/15. There is already no I-131 in the sample we are currently counting (5/6-5/10).
Although news is coming out that fuel rods have been exposed, since the reactors have cooled down I would not expect any further major releases from Japan.
Mark [BRAWM Team Member]
Okay...
...Guess I missed that post, Mark, thanks.
No way to put that horse back in the barn, now, I understand that, but if they're experiencing "sharp drop[s]" in water levels as they (now) try to, once again, fill the reactor, then aren't we potentially looking at additional breaches, or at least rapid and uncontrollable expansions of previous ones, that will PREVENT them from continuing to experience / achieve a "cooled down" reactor status?
Thanks again,
Rick Cromack.
Allen, Texas
I personally expect the
I personally expect the unexpected as this has been the case so far...
Even worse... (From Kyodo News Service)
http://english.kyodonews.jp/news/2011/05/90715.html
------------------------------------------------------------------------
Nuclear fuel at Fukushima No. 1 unit melted after full exposure
TOKYO, May 12, Kyodo
Tokyo Electric Power Co., the operator of the crippled Fukushima Daiichi nuclear power plant, revealed Thursday that holes had been created by melted nuclear fuel at the bottom of the No. 1 reactor's pressure vessel.
The company said it has found multiple holes adding up to several centimeters in welded piping. Earlier in the day, it said the amount of water inside the troubled reactor was unexpectedly low -- not enough to cover the nuclear fuel -- hinting that a large part of the fuel melted after being fully exposed.
The finding is raising concerns that the company will face difficulty achieving its plan to bring the damaged reactors to a stable condition known as a ''cold shutdown'' in about six to nine months, observers said.
----------------------------------------------------------------------
Not good not good not good.
I don't think anyone needs my commentary on this. It pretty much speaks for itself, folks.
Rick Cromack.
Allen, Texas
With picture good article
Reactor 1 in worse shape than thought
Cracks suspected in containment after fuel rods found fully exposed
http://search.japantimes.co.jp/cgi-bin/nn20110513a1.html
Gee
Matsumoto also said that, considering the situation with the No. 1 reactor, the water level data from reactors 2 and 3 may not be credible.
From above link
Here's what I want to know...
...IS THE WATER LEVEL STILL DROPPING in Reactor 1?
...Amid all this, IAEA hasn't deigned to update its supposed "latest" Fukushima Nuclear Accident log since MAY 5. What the...?
I find myself wondering if the next indication we'll have that something ELSE has gone seriously, irrecoverably wrong at Fuke, will be in BRAWM's air monitoring data, necessarily several days, if not weeks given the increased counting times, after-the-fact. Certainly, our Government will be in no hurry to make any sort of information available...
Rick Cromack.
Allen, Texas
Now IAEA Fukushima log will
Now IAEA Fukushima log will be on weekly basis.
This the info the gave us, May 12th.
only this... 12 May they say us that logs will be 1 time per week...
They said too that they work 24/7.
Great institution IAEA...
oh my god... oh my god... oh my god.
Where did you get the weekly update statement from?
I don't see that in their web site:
http://www.iaea.org/newscenter/news/tsunamiupdate01.html
Tepco gets
Rog I believe there doing a flush through cool down no matter the state of fuel rods and breaches in containment.so water in and radioactive water out and as tepco states it "maybe"leaking into ocean this is there plan it's all they can do.
To your point
Nothing we received or will receive( i hope )will be acute exposure it wasnt even near chernoble .so we are told we are safe ..when in fact we are increasing our risks of cancer down the road but at acute levels we are safe.so don't worry be happy until u have cancer or a loved one who does.
Ps you won't be able to link
Ps you won't be able to link cancer to Fukushima, weapons tests or chernoble releases .more likely it's all the airplane travel and bananas I ate.types of radiation are a carcinogen some our way worse than others and they have different effect and different equations to measure exposure long and short term If u question me on this heres my reference.this document is the holy grail to me.
http://140.194.76.129/publications/eng-manuals/em385-1-80/c-3.pdf
Diffrences
Pg3-12
water level data from reactors 2 and 3 may not be credible
Reactor 1 in worse shape than thought
Cracks suspected in containment after fuel rods found fully exposed
By KAZUAKI NAGATA
Staff writer
Tokyo Electric Power Co. said Thursday that the water level in the No. 1 reactor's pressure vessel at the Fukushima No. 1 power plant is much lower than thought and that some of the fuel rods have melted and sunk to its bottom.
Pressure job: A worker in protective gear checks a water-level indicator at the Fukushima No. 1 nuclear power plant¥x81fs reactor No. 1 on Tuesday. TEPCO / KYODO
But Tepco also said the temperature in the pressure vessel has been kept at around 100 to 120 degrees, which is cool enough to keep the reactor safe, for now.
The low water level, however, indicates that the pressure vessel could have holes or cracks through which radioactive water is leaking.
Tepco's latest discoveries were found after workers entered the main building, where they were finally able to check and fix water-level indicators damaged when the March 11 monster earthquake and tsunami crippled the nuclear power plant.
The workers also learned that the water in the containment vessel, which Tepco has kept spraying to cool down the pressure vessel from the outside, is also much lower than earlier believed. There might be some holes or cracks in the vessel or components connected to it, Tepco said.
Any holes or cracks in the pressure and containment vessels are sure to make repair work more difficult.
The utility plans to keep cooling the reactor's core by attaching air-cooling machines that will recirculate the water inside the containment vessel.
Tepco has poured about 10,000 cu. meters of water into the containment vessel so far. But only about 7,500 cu. meters should be necessary to cool the fuel rods if a way can be found to reuse the water instead of letting it flow away.
"We're not sure how much of the fuel rods fell down to the bottom and in what form, but the temperature shows that they are being cooled," Tepco spokesman Junichi Matsumoto said at a news conference.
On March 12, reactor No. 1 suffered a hydrogen explosion after the fuel rods were fully exposed for hours and generated hydrogen, which reacted violently with oxygen.
But Matsumoto said Tepco believes such an explosion at this time is unlikely because nitrogen has already been poured inside the containment vessel to purge explosive gases.
Matsumoto also said that, considering the situation with the No. 1 reactor, the water level data from reactors 2 and 3 may not be credible.
Tadashi Narabayashi, a professor of reactor engineering at Hokkaido University, also said it is likely that the melted fuel rods are being cooled with coolant water at the bottom of the pressure vessel.
According to Narabayashi, the zirconium encasing the fuel rods becomes weak and brittle when it is fully exposed to oxygen and then covered with cold water again.
Suiting up: Local residents of Kawauchi, Fukushima Prefecture, change into protective gear Thursday as they prepare to make quick trips home for the first time since the Fukushima nuclear crisis forced them to evacuate on March 11. KYODO PHOTO
According to Tepco, the water-level indicators of the pressure vessel had indicated the water surface was about 1.65 meters below the top of the fuel rods. But as of Thursday morning the reading was more than 5 meters below the top. The fuel rods, if undamaged, are only 4.5 meters in height.
Although the water is leaking from somewhere in the pressure vessel, Tepco officials don't believe the melted fuel has penetrated the bottom of the pressure vessel and dropped into the containment vessel below, given that the thermometer placed at the bottom of the pressure vessel is still working. If a big chunk was missing, it would malfunction, Tepco said.
There are actually no tools specially designed to check the water level in the containment vessel, but Tepco said it made estimates based on other factors, including the pressure in the containment vessel.
information from kyodo added