- #12,146
djm51x
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what do you think about letting the cavity water boil for 48 hours, while the reginative heat exchangers are being repaired...the fuel pool was also boiling?Am I over reacting?
djm51x said:what do you think about letting the cavity water boil for 48 hours, while the reginative heat exchangers are being repaired...the fuel pool was also boiling?Am I over reacting?
elektrownik said:And what is with unit 2 temperature: http://www.tepco.co.jp/nu/fukushima-np/f1/images/12011612_temp_data_2u-j.pdf ?
And some other sensors related to the RPV bottom are also fluctuating.zapperzero said:... SOMETHING must have changed.
Rive said:Maybe the cooling water found some way through the crust and now escaping as steam?
duccio said:Looks like they want to send an endoscopic probe into reactor 2...
duccio said:Looks like they want to send an endoscopic probe into reactor 2...
http://www.asahi.com/national/update/1226/TKY201112260664.html
I'm not sure about the reliability of the source, and it's only in Japanese, but easy to understand with Google Translator
LabratSR said:They announced their intention to do this a month or so ago. Should be interesting when they do.
tsutsuji said:http://www.shimbun.denki.or.jp/news/main/20120116_04.html On 16 January Tepco said it had started the work to inspect inside unit 2's PCV using an endoscope. First they must install the drilling machine, then drill the "end plate of the penetrations", then install the endoscope. If everything goes well, they can take pictures and measure temperatures on 19 January. The goal is to measure temperatures, water levels and water temperatures.
The details of what they plan to do are on http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/m111226_08-j.pdf pages 5/37 to 12/37. Even if you don't read Japanese you may enjoy looking at the diagrams. Do you have any idea what this "penetration X-53" is for, in normal times ? On the diagram on page 8/37 they show the welding of a "short pipe", the drilling, then the pushing of a concrete block with a stick until it falls down [?], then the installation of the guide pipe flange, and at last the insertion of the endoscope with its guide tube. On page 10/37 they say they will use ultrasonic testing to be sure there is no water in the penetration before they start drilling. They also say that in order to reduce steam (which might prevent from taking good photographs) they will increase the water injection to lower the temperature. The yellow area on page 9/37 is the area they expect to photograph. The violet triangles are "examples of photographs" taken with the "mock-up" performed at unit 5. CRDレール means "CRD rail".
zapperzero said:That particular sensor holds the record for highest indicated temp, iirc. But other than a huge spike in the beginning, it has been tracking the others quite well until very recently, so SOMETHING must have changed.
Other temps seem to be creeping up as well. May be more than instrument error.
jim hardy said:be aware that thermocouples, when wet and insulation damage let's moisture contact their metal, will give wildly erroneous readings
so be on lookout for water spillage in area of an erratic sensor like that. if misbehavior correlates with washdowns, well, give it some time to dry out.
part of the pressure behavior of the reactor pressure vessels and primary containment vessel drywells of Units 2 and 3 as well as part of the venting operation at Units 1, 2 and 3 at Fukushima Dai-ichi NPS, TEPCO have not been made clear. This is to inform the public that NISA directed TEPCO to report the points mentioned above to NISA by December 22, 2011 as described in the Appendix.
http://www.nisa.meti.go.jp/english/press/2012/01/en20120113-2-1.pdf
Yamanote said:You can follow this link to a video of this trial run:
http://www.tepco.co.jp/en/news/library/movie-01e.html
Just select the tab "Video For Press" and choose the first video in the list.
tsutsuji said:Thanks for the link. What is this "snow" on the video ? Dust ? Steam ?
The operator of the crippled Fukushima Daiichi nuclear power plant has failed in an attempt to get clear images from inside damaged reactors using fiber-optic lines.
clancy688 said:http://www3.nhk.or.jp/daily/english/20120119_28.html
Let me get this straight - they are boring into the primary containment of a melted down reactor, with the reactor vessel in question being perforated and leaking water and corium into the said containment - and they are surprised that steam and radiation are causing poor visibility?
Tokyo Electric Power Co. (9501) disconnected an emergency power source at its Fukushima nuclear plant four months before the earthquake and tsunami in March last year wrecked the station, the Sankei newspaper said.
The supply was cut during maintenance work in November 2010 and wasn’t reconnected, the paper reported, without citing the source of its information.
The backup would have provided power for transmitting temperature and radiation data from monitors near the Fukushima Dai-Ichi plant’s reactors and helped assess the severity of the situation once the main electricity supply was knocked out, the Sankei said.
Tokyo Electric is checking the Sankei report and can’t immediately comment, spokeswoman Ai Tanaka said.
The Emergency Response Support System (ERSS), which monitors status of reactors and forecasts progress of the accident in a nuclear emergency, got errors in the data transmission function of the system right after the occurrence of the accident. Therefore, necessary information from the plant could not be obtained and the intended functions of the system V-2 could not be utilized.
duccio said:Yup, I'm also curious. And in reactor 2, the dots are caused by radiation on the sensor... or not?
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120119_03-e.pdf
SteveElbows said:I doubt they are really surprised by this at all, they knew conditions inside would not be ideal for imagery. I assume they hoped for more, but the mission isn't exactly a failure, NHK story is badly worded.
Of more concern is that they appear surprised that the water level inside containment was not visible and so does not seem to match their estimates. I don't know exactly what their estimates told them but I am not really surprised that they estimated this stuff wrong again, as they seem to like to assume things that give some reassurance, rather than err-ing on the side of caution.
clancy688 said:Does anyone have a clue what exactly this ERSS is monitoring? Reactor data (pressure, temperatures) for example?