TEPCO ready to try again with water decontamination system

TOKYO —

Tokyo Electric Power Co (TEPCO) said Sunday that it plans to start full-scale operations of its system to decontaminate highly radioactive water at its stricken Fukushima Daiichi nuclear power complex on Monday.

The system has been experiencing a number of glitches since last week. TEPCO said it had replaced the chemicals in the absorption equipment and made the necessary repairs.

Goshi Hosono, director of the government’s nuclear crisis task force, said the system has met operational requirements and had decontaminated nearly 5,000 tons of tainted water in test runs on Saturday.

Workers have cooled the reactors and spent fuel by pumping in fresh water, which becomes contaminated with radiation. About 110,000 tons of tainted water have accumulated, and it could start overflowing in early July unless workers get a trouble-plagued water treatment system working properly.

The system became fully operational a week ago but shut down after a few hours when one of the radiation absorbing cartridges reached its limit much more quickly than expected.

Hosono told NHK that one problem is that heavy rain due to the rainy season might increase the amount of contaminated water.

Compiled from news reports

  • 0

    some14some

    Is it trial and error or a science? why? because human lives are at risk.

  • -1

    ihavegreatlegs

    I keep asking and researching. Why does contaminated water have to be decontaminated in order to be used as a coolant? It will get contaminated again. Weird. Anyone have an answer?

  • 0

    miamum

    I`m not an expert but i am guessing that the isotopes contained in the contaminated water are giving off radioactivity, a bi-product of which is heat. Decontaminate the water by removing the isotopes and you cool the water dpown so it can be re-used?

    Again - no expert so please someone correct me if I`m wrong, just guessing here!

  • 2

    jaredinosaka

    greatlegs- anyone who has any experiance with mechanical reactor systems will tell water has to be 100% to be effected as coolant. 100% pure water is really what blocks radiation from getting outside the reactor compartment. this water is also satuated with salt water now and this is a serious problem because reactor sheilds are really not designed like stainless steel it actually screws up compartment encasement. this is the problem with the 1st generation of reactor plants and they should all be decommision. After working on USN reactors for 6 years i am 100% anti-nuke.

  • 0

    nandakandamanda

    Whether they reuse the water, whether they store it as low-level waste in the containers they shipped in, or whether they pour it into the sea they will want to have a way of pumping it safely up and out of the basements. As jared says, it's full of impurities, including salt, and can be used for nothing right now. Besides, it's deadly to approach.

    If they can get such a system up and running, with constant purification, then it will be much easier for the workers to design ways of funneling/channeling/piping the water in the right directions.

    Incidentally, besides problems supporting the wobbly No.4 fuel pool, they are having corrosion problems with aluminium racks holding fuel rods in Pool No.3. By pouring in boric acid, according to NHK, they are hoping to stop such corrosion, which threatens to allow the rods to come into direct contact with each other and possibily restart criticality.

  • 0

    Hockeybuff

    The issue is that they keep adding water to cool the reactors, but since they leak, they keep adding more water. The water run-off becomes contaminated with radioactive isotopes which is getting into the environment. That is the issue. If the fuel rods can cool down without heating up again, they wouldn't need to keep adding water. They are trying to shut down the reactor all together. Currently, the water used to cool the fuel rods is drained and held in pools. The pools are getting full. In the meantime, they will try to clean the water to reduce possible harm to the environment in case they they need to release more water. Ideally, having pure water is ideal for cooling but, more important than cooling now is preventing further harm to the area. The contamination will have huge impact on fisheries, agriculture, food supply, health, among other issues. Indirectly, the economy would get worse and worse.

  • -1

    yildiray

    They are trying to shut down the reactor all together

    The reactor shut down on March 11th...

  • 0

    gogogo

    So this press release was a phony?

    http://www.japantoday.com/category/national/view/water-treatment-system-at-fukushima-plant-achieves-decontamination#comment_988464

    Tepco are blowing smoke... again... They seems to be panicking and running around in circles.

  • 0

    YongYang

    'More quickly than expected'. Who is sick and tired of the undestatement regime established by the players in this 'game'? It reached its capacity in 5 hours.

  • 0

    ihavegreatlegs

    Thanks for the info

  • 0

    nandakandamanda

    gogogo, your link of two days ago says that they hope to get it going by the end of June.

    Well, it is still not the end of June, so I see no real contradiction there. Or are you talking about some other aspect?

  • -1

    WilliB

    ihavegreatlegs:

    " I keep asking and researching. Why does contaminated water have to be decontaminated in order to be used as a coolant? "

    Because you don´t want to make the entire machinery in the cooling circuit not ever more radioactive. Of course you want clean water in the ciruit. If the problem is immediate overheating, of course you can throw everything and the kitchen sink on the heat source. Heck, they even used seawater iniitally, did you forget that? But luckily, that stage is passed now.

  • -1

    WilliB

    Hockeybuff:

    " They are trying to shut down the reactor all together. "

    Come again? The reactors shut down on March 11. What they are dealing with now is decay heat, and that they will have to battle that for many months to come. (You can google the decay heat curves yourself easily.)

  • 1

    Osakadaz

    they are having a big problem in pool 3 now...the cement that fell into the pool during the explosion, has made the pool extremely alkaline.This could corrode the rack holding the spent fuel rods and cause a re-criticality, so they are pumping acid into No.3 reactor now to even out the Ph.

  • 0

    Utrack

    @ YongYang

    when one of the radiation absorbing cartridges reached its limit much more quickly than expected.

    TEPCO just has to have alot of these radiation absorbing cartridges on hand to keep the machine running.

  • 0

    the_odeman

    Quote from todays news from Reuters:

    But an hour and a half later, it was stopped after workers found water leaking from hoses.

    Another fail.....

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