R. Cromack] (from Asahi.com) "TEPCO drastically revises cooling plan..."
From Asahi News:
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TEPCO drastically revises cooling plan, but sticks to cold shutdown schedule
BY EISUKE SASAKI STAFF WRITER
2011/05/19
Tokyo Electric Power Co. is sticking to its goal of stabilizing the crippled Fukushima No. 1 nuclear power plant by July despite radical revisions to its initial strategy after larger-than-expected damage was confirmed.
New data has painted a clearer picture of what happened at the plant immediately after the March 11 Great East Japan Earthquake and tsunami, including the start of a meltdown at the No. 1 reactor hours after the disaster.
Under TEPCO's new plan, the goal remains to achieve a cold shutdown of the reactors within five to eight months.
"There have been no changes that would have made us change" the goal," Sakae Muto, a TEPCO executive vice president, said.
But there have been major alterations in what TEPCO now plans to do. And because workers have still been unable to enter many locations within the plant, further revisions could be required if new problems arise.
The most progress has been made so far at the No. 1 reactor building, which workers entered in May. Based on their findings, they started a study of preparations on constructing a cooling system.
Under the company's strategy announced April 17, one of the first tasks was filling the containment vessels with water to cool the fuel rods within the inner pressure container.
The volume of water pumped into the No. 1 reactor building was increased in preparation for submerging the containment vessel at the No. 1 reactor.
However, workers realized that work within the reactor building would be difficult because of the high radiation levels found. And when the water gauge was adjusted, it showed that water was not accumulating in the reactor core as expected.
After a huge amount of water was found in the basement of the reactor building, TEPCO officials acknowledged that a meltdown had occurred in the No. 1 reactor and damaged the pressure vessel.
With the water leaking as soon as it was pumped into the core, workers faced the problem of finding and plugging the leaks in preparation for filling the containment vessel with water.
Realizing the extreme difficulty of that task, TEPCO officials abandoned the plan to submerge the vessel and downgraded that measure to a step requiring further study if water could not be pumped into the reactor.
High radiation levels prevented workers to take specific measures over the past month at the No. 2 and No. 3 reactors, including injecting nitrogen gas to prevent hydrogen explosions
Robots have been used to study the situation within the reactor buildings, but TEPCO could not determine specific levels of radiation in the No. 2 and No. 3 reactor buildings and whether workers could safely enter.
The suppression pool in the No. 2 reactor building that is connected to the containment vessel is believed to have cracks. The TEPCO plan calls for closing those cracks with concrete, but work has not started on that task.
One addition to the revised work schedule is consideration of ways to stop the flow of contaminated water underground or into the ocean.
Until now, TEPCO officials were considering moving radioactive water and storing it before decontaminating it.
Under the new plan, contaminated water will be recycled back into the reactor building to cool the core, meaning that radioactive water will accumulate in the building for long periods. TEPCO needs to come up with measures to prevent that water from leaking outside plant facilities.
Contaminated water that has already accumulated within the plant has posed persistent problems for the workers.
As delays emerge in moving the contaminated water to a storage pool, water must still be pumped into the reactor buildings to cool the fuel rods.
The water pumping is now a one-way process. That water is believed to be leaking through damaged parts to the basements of the reactor and turbine buildings as well as trenches outside the buildings.
The danger exists that this contaminated water could spill into groundwater or the ocean.
If TEPCO is unable to come up with a way to purify the contaminated water before recycling it for cooling purposes, radioactive water will continue to increase in volume.
About 87,500 tons of contaminated water is believed to have accumulated within the plant. That figure could increase to 200,000 tons by December.
Contaminated water in the turbine building of the No. 2 reactor and outside trench had particularly high levels of radiation and caused further problems because some of it flowed into the ocean. Work began from April 19 to move that water to the central waste processing facility within the plant.
However, checking the No. 2 reactor building for leaks has been a time-consuming task. Under the new plan, TEPCO officials decided to reduce the amount of water moved to minimize the risk of leakage.
Even when water was moved, the levels in the trench and building basement did not decrease very much. Instead of trying to move all the water as originally planned, TEPCO officials have decided to move only enough water so that it does not overflow from the trench.
Other measures are needed to prevent contaminated water from flowing into the ocean from the trench.
On May 11, highly contaminated water was found leaking into the ocean from near the water intake of the No. 3 reactor. The possibility exists that radioactive water can leak from anywhere at anytime into the groundwater or ocean.
TEPCO officials said work to install a temporary tank for the contaminated water by mid-July is continuing.
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Some comments:
> TEPCO's I'm-okay, you're-okay doublespeak is pretty impressive. Okay, so -- for now -- they're not "changing the goal". Is that supposed to reassure us? So, they're going to continue to aim for a mark they cannot possibly hit. Same old, same old.
> What NO ONE seems capable of saying out loud is, that TEPCO's "new strategy" of merely continuing this feed-and-bleed-out dance (fresh water in; nearly immeasurably contaminated, off-the-scale radioactive water out -- WAYYY out) means that they have effectively abandoned any hope of finessing the reactors into anything approaching "cold shutdown". A low boil, perhaps a sustained simmer, is about the best that can be accomplished, now.
> If I'm doing the math right and remember previous reporting accurately, they're managing to pump out -- from ALL sources -- no more than about 25 tons of water per hour at present, and very likely quite a bit less than that. So, call it 600 tons per day, from all over the site. In the last couple of days, I've seen estimates of highly contaminated, radioactive water on-site ranging from 87,500 tons (this article) to nearly 100,000. Let's split the difference and call it 93,750. At that rate -- ASSUMING no setbacks, malfunctions, delays or unanticipated disasters, which have been legion at Fukushima since the crisis began -- we're talking 150 days, minimum, before that water can be removed, assuming there was EVER a hope of that much storage capacity at the plant, let alone the ability to actually process, treat and purify that much waste water. I'm not certain all the nuclear waste processing facilities in Japan put together could handle that much if they were given five years to do so, frankly.
...But, lest we forget: That number, whether it be 87,500, 93,750, or 100,000 is by NO means, "STATIC". It's increasing all the time -- at last count, according to the IAEA, by a rate of 6 cubic meters per hour in Reactor 1, 7 m^3/hr. in Reactor 2, and something like 15 m^3/hr. in Reactor 3 -- not to mention, any additional feeding, injecting, and spraying occurring at the Spent Fuel Pools, which happens at least every third day. (1 cubic meter = 1 metric ton.) So, that is, AT A MINIMUM, 672 ADDITIONAL TONS BEING DEPOSITED SOMEWHERE IN THE PLANT EVERY SINGLE DAY -- not counting what turns to steam, and assuming these flow rates remain constant, naturally. That means that, at the current rate of removal, ADDITIONAL DEPOSITION TO THE TUNE OF SOME 70 TONS PER DAY IS OCCURRING -- which means this entire enterprise is a Sisyphian Moebius loop, unless something changes radically, and soon.
Not trying to throw cold water on things, here... And I am, for the most part, very very encouraged by most of what I'm hearing and reading, these days. But I think it's helpful to take an occasional good, hard, uncompromising look at these nagging, often glossed-over realities, if for no other reason than to realize that TEPCO's latest so-called "plan" -- to recirculate already-contaminated water, ad infinitum, through once-impregnable reactor vessels that may at this point more closely resemble colanders, and hope it doesn't continue to leak into the open sea as it has since virtually the beginning of this ongoing event -- is really the only option left available to them, and is NOT the preferred strategy by ANY means. Let's also not forget that there is likely to be a real deficit of fresh, distilled water in Japan at the moment... Yeah, I think it's safe to say that TEPCO's pretty well up against it at this point. Note that it came out today that the Russian Federation is contributing a staggering amount of potable water to Japan -- these are not unrelated stories.
I still don't understand why every single country in the world hasn't donated military and industrial assets out the bahookie to Japan -- or why half the world's oil tankers aren't being sent over to help evacuate the water on-site. If there was EVER a time, a justification, an excuse for any number of so-called "international organizations", cooperative ventures, or treaty invocations, good Lord above, you would think it would come into play NOW. But the world shrugs, and sighs, and gazes off into the distance, and the band plays on, and on, and on.
Rick Cromack.
Allen, Texas


An interesting editorial from Asahi News...
...Following up on what I was saying above... Also from Asahi News:
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http://www.asahi.com/english/TKY201105180362.html
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TEPCO needs to stop ignoring the 'inconvenient'
BY TORU OMUTA SCIENCE AND MEDICAL NEWS EDITOR
2011/05/19
Tokyo Electric Power Co.'s timetable for stabilizing the Fukushima No. 1 nuclear power plant promises: "We will devote ourselves wholeheartedly so that evacuees can return home and the people in Japan can live with peace of mind."
We believe in the efforts by the many employees of TEPCO, the operator of the Fukushima No. 1 nuclear plant.
However, even now, the company does not change its corporate posture that "what is inconvenient should be ignored as much as possible."
What is typical of this is seen in the melting down of fuel rods. A series of reports, including one by The Asahi Shimbun reported a view that core meltdowns had taken place in the No. 1, No. 2 and No. 3 reactors immediately after the period when they entered a "boil-dry situation."
Two months after the onset of the accident, TEPCO finally admitted the plant's No. 1 reactor had reached a complete core meltdown, apparently finding it could no longer deny the fact because of data based on new calculations. Still, it has yet to admit core meltdowns at the No. 2 and No. 3 reactors on the grounds that there is not sufficient data.
A column on "the current status," which existed in the initial timetable released in April, is not present in the revised timetable released May 17.
Could the company have been reluctant to change the former phrase "partial damage to fuel" to "core meltdown"?
The expression "core meltdown" is not found in the new timetable, either. TEPCO officials only kept reiterating at a news conference "the same countermeasures shall be taken."
This is nothing but a halfway measure.
It often happens in disasters and accidents that operators have to take measures even if the entire situation cannot be grasped.
Convenient interpretations should not be given, for the gap between the interpretation and the reality could hamper repair work or trigger a new crisis.
The government should listen to experts who are critical of nuclear power plants. It should not shift the blame to TEPCO, just by saying, "TEPCO's approach to containment has been too insufficient," while letting it ignore what is inconvenient in the crisis.
TEPCO needs to prepare a timetable that is based on the correct perception of the current situation.
Otherwise, the residents in the evacuation areas and the people of Japan will really be kept in the dark.
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So... Apparently I'm not the only one who thinks TEPCO's, as I have termed it before, whistling past their own graveyard. Let's hope others take up the call.
Rick Cromack.
Allen, Texas
"We will devote ourselves
"We will devote ourselves wholeheartedly so that evacuees can return home"
300 years from now.
(Asahi) "No. 2, No. 3 reactors...volatile; meltdowns suspected"
Asahi News is knocking it out of the park today, and is really surging ahead of NHK and Kyodo (which, annoyingly, is restricting much of its nuclear crisis-related content lately, hoping to increase online subscriptions by denying the world its reporting on the biggest story of the decade)...
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http://www.asahi.com/english/TKY201105170429.html
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No. 2, No. 3 reactors remain volatile; meltdowns suspected
By HIDENORI TSUBOYA Staff Writer
2011/05/18
Three reactors at the hobbled Fukushima No. 1 nuclear power plant could be leaking highly radioactive water outside the reactor buildings following damage to pressure vessels by suspected meltdowns.
Plant operator Tokyo Electric Power Co. has injected water into the No. 1, No. 2 and No. 3 reactors to cool fuel rods after normal cooling systems failed following the March 11 Great East Japan Earthquake and tsunami.
But with the meltdown of fuel rods at the No. 2 and No. 3 reactors considered highly likely, it is probable radioactive water is escaping the reactor buildings through holes in the pressure vessels and in the outer containment vessels as well.
After analyzing data, TEPCO acknowledged May 15 that fuel rods in the core of the No. 1 reactor had fully melted by the morning of March 12, 15 hours and 20 minutes after the tsunami swamped the plant.
The utility planned to bring the No. 1 reactor to a cold shutdown by starting a system as early as this month to recirculate water leaked from the containment vessel after cooling it.
Of the three crippled reactors, the No. 1 reactor was believed to be somewhat under control with technicians able to safely enter the building to begin work to restore the cooling system.
But TEPCO found more than 3,000 tons of water in the basement of the reactor building on May 13, an accumulation far larger than anticipated.
The discovery could significantly delay work to bring the new cooling system online.
With data pointing to a meltdown at the No. 1 reactor, the likelihood is high that the water in the basement is highly radioactive.
And, with workers unable to enter reactors No. 2 and No. 3 because of high levels of radiation, repair work is going slowly.
At the No. 2 reactor, some highly radioactive water in the turbine building flowed into the sea through a trench.
TEPCO is trying to prevent a recurrence by transferring the contaminated water to a disposal and treatment facility.
Inside the pressure vessel at the No. 2 reactor, pressure began dropping precipitously on the night of March 15, falling to almost the same level as the outside atmosphere.
The following day, March 16, pressure in the surrounding containment vessel rose in the afternoon.
The heat generated by a core meltdown likely burned holes through the bottom of the pressure vessel, accounting for the rise in pressure.
Data acquired by a robot sent into the No. 2 reactor building indicated that it will be impossible for engineers to work inside the building any time soon because of high levels of humidity and radioactivity.
At the No. 3 reactor, pressure in the pressure vessel started to fall on the night of March 15.
Similarly, as it fell to almost the same level as the outside atmosphere around midnight March 16, pressure in the containment vessel surged.
Again, the bottom of the pressure vessel may have been damaged in a manner similar to the No. 2 reactor.
Pressure in the containment vessel jumped March 20. It is believed this was caused by melted fuel rods dropping to the concrete bottom of the containment vessel through damaged piping, some of it used to gauge neutron levels.
As a result, gray smoke rose from the No. 3 reactor building shortly before 4 p.m. on March 21.
Like the No. 2 reactor, robot data indicated that it is unsafe for humans to work in the No. 3 reactor building, with radiation levels in some areas above 100 millisieverts per hour.
Debris after a hydrogen explosion on March 14 remains scattered inside the building and is another obstacle to repair work.
To add to growing concerns, the No. 3 reactor remains volatile, with temperatures inside the pressure vessel increasing since late April after dropping earlier.
TEPCO began pumping water from a new site into the reactor May 12, but engineers are concerned that sufficient water is not remaining in the pressure vessel because of the broken piping.
Also, the utility has been unable to start pumping nitrogen gas into the containment vessel to deter another hydrogen explosion.
It began injecting water mixed with boric acid to contain the nuclear reaction May 15.
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Some highlights:
> "Data acquired by a robot sent into the No. 2 reactor building indicated that it will be impossible for engineers to work inside the building any time soon because of high levels of humidity and radioactivity." Since four workers entered Building 2 today, but were forced out (due to high levels of "steam", supposedly) after less than 15 minutes, I guess that statement was true in effect if not in fact...
> "Pressure in the containment vessel jumped March 20. It is believed this was caused by melted fuel rods dropping to the concrete bottom of the containment vessel through damaged piping, some of it used to gauge neutron levels. // As a result, gray smoke rose from the No. 3 reactor building shortly before 4 p.m. on March 21." This is by far the BEST public explanation I have yet heard of the incidence of so-called "gray smoke".
I just wish that Asahi updated its English-language content more.
Rick Cromack.
Allen, Texas