I don't know what to think of this but it may be one of the reasons why the meme of "Fukushima Reactor 4 is leaning (or listing, or collapsing, or falling apart)" and "Reactor 4 Spent Fuel Pool is in danger" has started to circulate widely again since March this year.
Mr. Mitsuhei Murata is a former Japanese Ambassador to Switzerland and Senegal and the current Executive Director of the Japan Society for Global System and Ethics (according to his website) who seems to have been very active in anti-nuclear movements. There are tweets and blogs citing his website as the source of his comments which appeared on the English site by a Japanese diplomat (I think) Akio Matsumura.
Assuming that it is indeed Mr. Murata's website, here's the letter that Mr. Murata sent to UN Secretary General Ban Ki-Moon on March 25, 2012, as it appears on his site:
The Honorable Ban Ki-Moon
Secretary–General of the United Nations Organization
New York City, NY.
Tokyo, March 25, 2012
Honorable Ban Ki-moon,
I wish to express my heartfelt gratitude for your considerate letter dated 2 March, 2012. Your moral support for a United Nations Ethics Summit will remain a constant source of encouragement for my activities.
Please allow me to pay a tribute to your great contribution to strengthen nuclear safety and security. The current Nuclear Summit in Seoul is no doubt greatly benefiting from the high-level meeting you convened last September.
I was asked to make a statement at the public hearing of the Budgetary Committee of the House of Councilors on March 23. I raised the crucial problem. of N0.4 reactor of Fukushima containing1535 fuel rods. It could be fatally damaged by continuing aftershocks. Moreover, 50 meters away from it exists a common cooling pool for 6 reactors containing 6375 fuel rods !
It is no exaggeration to say that the fate of Japan and the whole world depends on NO.4 reactor. This is confirmed by most reliable experts like Dr.Arnie Gundersen or Dr.Fumiaki Koide.
Please allow me to inform you of an initiative being taken by a former UN official who is endeavoring to have the Nuclear Security Summit take up the crucial problem. of N0.4 reactor of Fukushima. He is pursuing the establishment of”an independent
assessment team. I think his efforts are very significant ,because it is indispensable to draw the attention of world leaders to this vital issue.
I am cooperating with him, writing to some of my Korean acquaintances that this issue deserves the personal attention of President Lee Myung-bak. I have written today to Prime Minister Yoshihiko Noda. I asked him to consider taking the initiative of mobilizing human wisdom on the widest scope to cope with the Fukushima reactor No.4 problem, fully taking into account the above-mentioned “independent assessment team".
The world has been made so fragile and vulnerable. The role of the United Nations is increasingly vital.
I wish you the best of luck in your noble mission.
Please accept, Secretary-General Ban Ki-moon, the assurances of my highest consideration.
Former Japanese Ambassador to Switzerland and Senegal
Executive Director, the Japan Society for Global System
I don't recall any prominent nuclear researcher named "Fumiaki Koide". I googled the name just in case but I think Mr. Murata is talking about Hiroaki Koide of Kyoto University.
I'm interested in knowing what prompted Mr. Murata to get very concerned about Reactor 4 Spent Fuel Pool. It is possible he has been concerned about it all along.
As far as I know, the situation of the Reactor 4 Spent Fuel Pool is not much different from what it was last summer after the wall underneath it was reinforced with metal support beams and concrete. Since my understanding is based on what TEPCO has been willing to disclose, it is quite possible that I've been missing something big.
There are a few Japanese experts, including Mr. Matsumura, who seem to have been advising many US nuclear experts on the situations in Fukushima I Nuclear Power Plant since the March 11, 2011 accident. They all communicate in English only, and their information is usually not shared or known in Japan.
If you understand Japanese, here's the video of Mr. Murata testifying in the Upper House Budget Committee (foreign affairs and national security issues) in the Diet on March 22, 2012 (0:30:30, 2:13:54, 2:16:07, 2:53:00), warning about Fukushima Reactor 4.