Asahi: Tepco checking if “chain of nuclear fission has occurred again in melted fuel” at Reactor No. 2 after temperature rises sharply

Published: February 6th, 2012 at 2:42 am ET


Title: Temperature rises sharply at Fukushima reactor
Source: AJW by The Asahi Shimbun
Date: February 06, 2012

Tokyo Electric Power Co. reported a spike in temperature in the No. 2 reactor at the crippled Fukushima No. 1 nuclear power plant on Feb. 5, forcing it to increase the volume of cooling water there as a precautionary step.

TEPCO said cooling water may not have reached part of the fuel in the reactor’s pressure vessel while it switched to different piping for injecting water and changed the volume of water.

According to TEPCO, a thermometer at the bottom of the pressure vessel measured 71.7 degrees as of 4 p.m. Feb. 5, up from 52 degrees on Feb. 1. […]

[T]hermometer readings can sometimes be out by as much as 20 degrees. Therefore, a reading exceeding 80 degrees could mean that conditions for cold shutdown have been compromised. […]

TEPCO will analyze gas in the reactor within a few days to check whether a chain of nuclear fission has occurred again in the melted fuel.

Read the report here

Published: February 6th, 2012 at 2:42 am ET


Related Posts

  1. Bloomberg: “Nuclear reaction threat” as temperature rises — Head of Japan nuke institute: “Nobody is sure about the location of melted fuel — A similar incident will probably occur again” February 7, 2012
  2. Defective Meter? Temperature in Reactor 2 doubles, rises above 100ºC — Tepco assuming low possibility of re-criticality January 14, 2012
  3. Exposed? Asahi: Water may not be reaching part of melted nuclear fuel from Reactor No. 2, says unnamed Tepco official February 7, 2012
  4. Asahi: Reactor No. 2 temperature stays high despite Tepco’s stabilization effort — Was back up to 72°C February 8, 2012
  5. Reactor No. 2 temperature shoots to 75°C — Tepco increasing water injections again — 5°C from warning level February 11, 2012

26 comments to Asahi: Tepco checking if “chain of nuclear fission has occurred again in melted fuel” at Reactor No. 2 after temperature rises sharply

  • BreadAndButter BreadAndButter

    I don’t fully understand this sentence from the article: “The amount of cooling water was increased by 1 ton per hour to 9.6 tons, and the temperature fell to 69.4 degrees as of 5 p.m.”

    Are they saying the temp. dropped again?

    • arclight arclight

      morning B
      wonder where they have the temperature gauge in the reactor? because if it is in the flowing water and they increased the flow rated mean that “whatever” is causing the increase is necessarily cooling down..

      smoke and mirrors?

      • rooks rooks

        Reactor 2 is the only one they have looked at. It was a dud explosion so they are investigating the dud instead of the ones that exploded in which we were told could never happen.

    • Anthony Anthony

      Found this:
      ***…206/index.html One of unit 2’s thermometers is rising. It displayed 45°C on 27 January, and it has been gradually rising since then, reaching 71.7°C a 04:00 PM on 5 February. At 1:30 AM on 6 February, the water injection rate was raised by 1 ton/hour to 10.6 tons/hour, but at 07:00 AM, the thermometer displayed 73.3°C. The other two PCV bottom thermometers are remaining stable at 44°C. Tepco says there is a possibility that the water flow changed when the injection was restarted after a temporary suspension on 26 January that was necessary for some works. ***

    • Total Radiation Released Into Ocean, Air, Groundwater, Storage Tanks, etc
      A Green Road Blog

      While all of this minutia such as temperature change is happening, the focus is off of how much total radiation has been released?

      Does anyone care?

  • Dr. McCoy

    Of courses Tepco has known about the state of the fuel the whole time they were trying sell the sham of cold shutdown. It’s finally getting to the point that even they cannot deny that something wicked this way comes…

  • rooks rooks

    Tepco will check and not report what they find just to to delay. It is over. Only another quake will bring this to an immediate close.

  • BreadAndButter BreadAndButter

    News from Tepco press release from Feb 6th:
    “The temperature was around 70.0 °C (approx. 70.3 °C at 11:00 pm on February 5) and in order to prevent further temperature increase, we decided to increase the amount of water injected to the reactor. At 1:29 pm on February 6, the water injection volume to the Unit 2 reactor through the feed water system was changed from approx. 5.8 m3/h to approx. 6.8 m3/h(the water injection through the reactor core spray system remains approx. 3.8 m3/h).

    At this moment, temperature indicates approx. 70.6 °C (as of 5:00 am on February 6). We will monitor it continuously.”

  • Heart of the Rose Heart of the Rose

    The people must not allow TEPCO to say.. just anything!
    They know the people are confused.
    How can there be recriticalities and cold shutdown at the same time?
    Do not allow the authorities to speak nonsense.

  • many moons

    Rooks, do you have plans to leave Japan because of this disaster?
    If so I woulf recommend leaving before the situation becomes worse…which it seems it’s headed in that direction given the fact that the reactors aren’t stable and continue to pollute.
    I would recommend going to Sao Paulo. There is a huge population from Japan and the economy is moving in a good direction.

  • radegan

    Hey TEPCO – I can easily tell you whether or not fission has occurred. Wait three days and check for stories about more hospital patients and their iodine laden urine.

    • StillJill StillJill

      I wish they were checking their urine for iodine. Sadly,..I don’t believe that they are,…until proven so.

  • CaptD CaptD

    NOTE: it will take TEPCO a few days to “check whether a chain of nuclear fission has occurred again in the melted fuel”.

    Given their track record, I suggest that nobody hold their breath!

  • CaptD CaptD

    What is wrong with this “Picture”:
    1. Tepco is one the “GANGS” that runs Japan.
    2. What is good for TEPCO is good for Japan.
    3. The Japanese people MUST OBEY TEPCO for the “GOOD” of the Country.
    4. The financial health of TEPCO is more important than the Physical health of the People!
    5. Only TEPCO knows what is best, all others must BOW to TEPCO’s rule.

    People in the Western World, need to reexamine the “way” they view Japan and that includes not only how that Country is governed but what actual “say” the Japanese people have in their Governments process!

    It has taken almost a year to realize that Japan is actually being “run” by its Powerful Utility Companies and this “business” relationship extends in a “Control Continuum” that extends at one end, from actual Utility direct financial support of the highest Government Leaders in the Country, to the widely known use of organized gangs to keep citizens in line at the other!

    The idea that individual Japanese people actually have a say in how they are governed, much less the way their Energy is generated, is just a well publicized fantasy that the Utilities uses to put a nuclear “smily face” on the grim reality that ever facet of Japanese life is less important than what is good for these Utilities! These Powerful Utilities ARE Japan, and the Japanese people are only “forced” customers of these Utilities since they have no other choice of providers when it come to basic needs like electricity, at lest until now! Solar panels have allowed many to get the electricity they need and this is a huge threat to these Utilities, that must be “crushed” ASAP if they are to maintain their complete control over the Japanese people!

  • CaptD CaptD


    Ever since 3/11, the rest of the World’s attention has been focused on the Trillion Dollar Eco-Disaster at Fukushima and Japan’s response to their triple melt down. What we have learned is that the Government has allowed TEPCO to not only remain in Control of this debacle but they have actually enabled the Utility to place huge numbers of Japanese citizens at risk rather than demand that the Utility think first of human health instead of Corp. shareholder profits. The fact that radioactive pollution has now spread Globally and is affecting the rest of the Planet is hardly mentioned in MSM which points to an even greater problem for the rest of mankind; we are helpless and as yet unable to demand any “better” treatment from Japan because our own Leaders are for the most part are in full support of the those Utility backed Leaders in Japan.

    Kudos to Germany and many other Countries for pointing the finger at Nuclear Power and the Trillion Dollar Eco-Disaster RISK every nuclear complex now represents! People globally now are becoming informed and starting to demand answers to basic questions and once people start asking questions perhaps change will occur, even if not for the Japanese themselves… one thing is for certain, the Japanese people will be affected by their Trillion Dollar Eco-Disaster for much longer than the estimated 40 to 100 years that it will take to “tidy up” after Fukushima…

    • I think it is actually much more than a triple meltdown, if we count the spent fuel pools.. Based on reports, at least one and possibly three spent fuel pools either melted down and/or exploded.

      That makes this a sextuplet potentially.. along with MOX fuel releases…