” IRID announced details of work that is now underway to determine if a method for repairing the unit 2 suppression chamber might work.
IRID determined based on previous investigations that there may be a hole or series of holes of around 50mm in the unit 2 suppression chamber. Current research work will determine if filling that structure with concrete would work. The process that would be used and the extent of the research work is significant.
The proposed plan would use a concrete pump truck with a 5 inch diameter flexible hose to inject concrete into the suppression chamber. Initial work took place at the Ando Hazama Technical Research Institute (Tsukuba City, Ibaraki Prefecture) on October 15th.
It does appear they were successful in layering the concrete mixture and having it sink properly in the bottom of the suppression chamber tube. A 28 day pressure test will be conducted to assure the concrete properly plugs the leak. Future work may be conducted at the new decommissioning research center at Naraha. ”
source with construction illustration and photos