http://www.tepco.co.jp/nu/fukushima-np/roadmap/2018/images1/d180329_07-j.pdf (in Japanese) Pages 4-12: They will make a big opening in the West wall of the Reactor Building of Unit 2 and install an "antechamber" in front of that opening. The idea is that, at some point in the future (2020~) they plan to remove the whole roof and upper side of the reactor building, in preparation for the works for removing the fuel bundles stored in the SFP. Before that, they need to investigate the operating floor (5th floor) foor radiation and dust and take measures to decrease these, and in order to carry out these operations they will cut a 5m x 7m opening in the West wall. The antechamber will be air-tight and equipped with purification installatons and HEPA filters.The opening should be ready around June or July. Pages 13-18: Progress on the installation of the new cover on the operating floor of Unit 3. In fact, as you know, the cover is completed. The drawings on page 15 show that at step 1 there are some insulation/shielding layers placed on the operating floor (not sure if this is a satisfactory answer to nikkkom's question at post 1623 above). 2 pages give info on the number of people who worked durign this phase and the amount of radiation they were exposed to. The schedule on page 18 shows that they are planning to begin removing the spent fuel from the SFP sometime in the 3rd trimester of Fiscal year 2018, so maybe mid October.