nikkkom said:
News seem to dry up, but there should be some activity.
For example, what's the status of basement water level reductions? How many tons are still there?
Their mid-term goal is not to reduce water levels but to keep them stable : "based on the view of limiting inflow of underwater to buildings and reducing the amount of emerged accumulated water, we are planning to transfer accumulated water keeping its level in the building below OP. 3,000 considering water tank capacity." :
http://www.tepco.co.jp/en/press/corp-com/release/betu12_e/images/120125e5.pdf
nikkkom said:
The plan was to seal off reactor building basements, to at least stop leaking into turbine buildings and further into the ground. Is there progress?
On
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/111221e14.pdf page 42/94, "Target:Complete Switch to Water Withdrawal from Reactor Building (or lower part of PCV)" is set for mid-fiscal year 2015. There is also "(HP1-1): Completion of stopping inter-building water leakage between reactor and turbine buildings and repairing lower part of the PCV" which is planned for the middle of phase 2 around 2017. On page 48/94 you can see that "R&D for PCV Leakage Point Survey/ Repairs (including stopping inter-building water leakage)" is scheduled for fiscal years 2012-2013-2014 including "Design, Manufacture and Test, etc. of PCV Leakage Point Survey Equipment ②" and "Design, Manufacture and Test, etc. of PCV Repair Equipment ③⑥", with "Investigation of Leakage Points (including field test of R&D results)" starting in mid fiscal year 2014.
In the documents of the mid-long term meeting of 26 December you can find a slideshow about accumulated water :
http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/m111226_08-j.pdf page 16/37 - 24/37. It is divided into 3 parts:
1) Radical countermeasures against inflow of groundwater : they want to repair the subdrains that were damaged by the tsunami, then decontaminate them, and finally pump ground water from the subdrains to control ground water level and reduce ground water inflow into the turbine buildings.
2) Increase removal capacity and secure stable operation of decontamination facility
3) Further install on-land equipments. (The red areas are already used. The blue areas are still free for adding more tanks)
There was a second mid-long term meeting on 23 January. The documents are available on Japanese only (as far as I know) at
http://www.tepco.co.jp/nu/fukushima-np/roadmap/conference-j.html (for example including the following presentations on mock-up debris :
http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/r120123_04-j.pdf and water treatment secondary waste products (sludge, zeolite) :
http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/r120123_05-j.pdf and an announcement of a workshop on fuel removal techniques (open to the public and press) to be held on 24 February
http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/r120123_06-j.pdf ).
There is also a detailed review of what was done during the past 30 days up to January 23, and what they plan to do in the coming months at
http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/m120123_05-j.pdf, which includes a report on the water levels of unit 4 pool, drywell pit, and skimmer surge tank, and another report on the installation of new water-treatment facilities (tanks, or waste storage areas), and new areas to store wood from the cleared forests. The trial run of unit 3's PCV gas managing system is scheduled for February 23. The "basic design of shortening the water injection loop" is mentioned as a continuous line from January through April, or possibly later. The basic design of the multi-nuclide removal equipment [1] ends at the end of January, and the detailed design of the same starts in February. A forest clearance is more or less scheduled at the end of February in connection with this multi-nuclide thing. A subdrain purification test was started at unit 2 in the second week of January. There is a plan to change the seismic isolated building into a zone outside the controlled area, which means decontaminating (like cleaning the roof) and shielding the building (with steel and lead sheets). The design for the shielding ends at the end of January. At unit 4 reactor building, in January, they took care of the top part of the operating floor crane and removed rows R5 and R6 of the roof steel frame [this is on the south side]. In February they will remove rows R3 and R4, and remove "big machines" from the operating floor. They will start removing unit 4's north side wall and steel frame at the end of March.
[1] an equipment that would remove strontium, according to http://www.japantimes.co.jp/text/nn20120112a9.html
http://www3.nhk.or.jp/news/genpatsu-fukushima/20120129/index.html On 29 January Tepco announced 14 leaks [!]. It is believed that these leaks are due to the frost. One of them is a 40 litre leak found at unit 4 at 9:30 AM. Another one is a 600 litre leak found near one of the pumps that inject water into the reactors. Another one is a 7 ton leak of the circulating water of unit 6 (not contaminated). In the morning of 29 January, the temperature was 8°C of frost. Tepco's Junichi Matsumoto said "the freezing countermeasures are far from being sufficient. It is necessary to install heat insulating material at a higher pace than until now".
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120129_01-e.pdf "Water leakage in Fukushima Daiichi Nuclear Power Station (Discovered on 29 January)"
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120129_02-e.pdf (map of the leaks)