News Updates, 4/4/11
TEPCO has identified a potential pathway by which water from Unit 2 may have been leaking into the Pacific Ocean. This pathway consists of a 20 cm crack in the concrete wall of a pit which holds electrical cables for the seawater intake pumps. Two efforts have been made to plug this crack, with limited success. The first was an attempt to pour fresh concrete over the breach, and the second made use of a polymer sealant. Crews are making use of tracer dyes in order to both track the flow of water out of the pit, and determine whether the repair is successful.
Efforts are additionally still underway to remove and store water from the basements of the reactor turbine buildings. In unit 2, storage space for this water is running low. As a result, the Japanese government has authorized the discharge of some 10,000 tons of low-level radioactivity water from its wastewater treatment facility, in order to make way for storage of the more highly radioactive water in unit 2’s turbine building basement. TEPCO also plans to release some 1,500 tons of similarly low-level radioactive water from Units 5 and 6, so that it does not damage vital safety equipment. The discharge was scheduled to begin at 7 PM JST.
While these numbers seem alarming, TEPCO has predicted that a person eating seaweed and fish from the waters immediately outside the plant every day for a year would receive a dose of just 0.6 mSv. The IAEA has asked for additional information on this planned discharge so that it may itself predict the impact on the environment.
The IAEA has reported the most recent results of tests on vegetables grown in Fukushima and neighboring prefectures. In 133 of 134 samples tested, radiation was either not detected or was detected at levels lower than regulatory limits. A single sample of mushrooms from Fukushima province exceeded regulatory limits on radioactive iodine and cesium. The IAEA is continuing its own program of air and water monitoring, in addition to that already being performed by TEPCO and MEXT.