A newly discovered water leak at unit 1 and the approval of an ice wall to redirect groundwater were among the developments of note at Fukushima Daiichi this week.
Recent news related to the Tokyo Electric Power Co. plant severely damaged following Japan's 2011 earthquake and tsunami includes:
Leak Found Near Unit 1 Torus
For the first time, a remote survey on Wednesday identified a source of the water leaking from unit 1. Footage taken by a robot inspecting the unit's torus showed water leaking from an expansion joint connected to the primary containment vessel, according to Kyodo News and photos released by TEPCO. Saltwater used to cool the reactor might have corroded the joint, and it is unclear what proportion of the water escaping from the unit the leak accounts for. Earlier this month, a similar survey found a leak in an expansion joint near unit 3's main steam isolation valves. Leaks from the three reactors with core damage must be identified and fixed before their fuel can be removed.
Ice Wall Approved
After addressing objections related to ground settling and other uncertainties, Japanese regulators on Monday approved a plan to freeze soil around units 1 through 4. TEPCO adviser and former Chairman of the U.S. Nuclear Regulatory Commission Dale Klein recently expressed concerns that the untested system needed to be studied further before going into service. The Mainichi Daily News reported that Japan's Nuclear Regulation Authority and other agencies studied about 30 issues related to the plan and concluded ground settling beneath reactors and other possible effects should not preclude the start of construction next month.