– Asahi: ‘Underground holes’ may be needed to search for Fukushima’s 3 molten cores — Did fuel ‘escape’ via basement? — Experts unsure if Tepco will allow them to search for corium (ENENews, Jan 25,2014):
Asahi Shimbun, Jan. 24, 2014: [Tepco] has yet to learn where the nuclear fuel currently lies. The locations and amounts of the melted nuclear fuel should be identified by the time the government and TEPCO plan to start extracting it in the first half of fiscal 2020. Even if the melted fuel has escaped into the basement levels, it can still be located by installing [muon] sensors in underground holes, the scientists said.
Kyodo News, Jan. 23, 2014: The condition of the melted nuclear fuel remains unknown […] “The (cosmic ray) measurement system can be installed easily,” said team member Hidekazu Kakuno, associate professor at Tokyo Metropolitan University. “We are ready to use it at the Fukushima Daiichi plant if TEPCO cooperates.”
RT, Jan. 23, 2014: [Fumihiko Takasaki, a researcher at the High Energy Accelerator Research Organisation] claims that TEPCO has not yet officially confirmed that it will use the technology it is being offered.