Source: Foreign Correspondents’ Club of Japan
Date: September 24, 2013
Martin Kölling, reporter at Handelsblatt (German financial newpaper): Regarding this frozen wall […] some are concerned that this ice wall could work as a neutron reflector and increase the risk of recriticality in the reactor cores. Have you heard about this concern and what do you think about it?
Gregory Jaczko, Former Chairman of the U.S. Nuclear Regulatory Commission: I have not heard of the issue of neutron reflection. My gut reaction is that that would not necessarily be an issue. You have water at the site. So I would be skeptical that that would be an issue to be concerned about. But certainly I’m sure it’s something that should be looked at if there is a possibility of that, but I would not initially think that that’s something that would be of concern.
BBC, Sept. 4, 2013: Dr. Komei Hosokawa from Kyoto Seika University, Japan, warns that in some respects, the ice wall idea could make matters worse: “Underground ice walls surrounding the reactor basement may work as neutron reflectors, which might make an easier condition for the melted fuel debris to go back to criticality (i.e. chain reaction).” Watch the FCCJ event here