Fresh water is now circulating through all three reactors
that were operating at the Fukushima Daiichi nuclear plant when a tsunami
caused a station blackout two weeks ago.
Japan’s Nuclear and Industrial Safety Agency reported
Tuesday that water injection at unit 3 had switched from a fire truck to a
motor-driven pump Monday, and that the reactor was being cooled by fresh water
the following day. Units at the plant that lost core cooling systems had been
regulated in part by trucks pumping seawater into them. Unit 1 also received
fresh water on Tuesday, and unit 2 has been circulating fresh water since
Sunday, according to NISA. The U.S. Navy has provided two large barges carrying
fresh water to the site.
While crews work to fix equipment to pump water within the
reactors, efforts continued to pump recently discovered radioactive water out
of tunnels and reactor buildings. Kyodo news reported late Tuesday that water
levels in unit 1’s lower floor had dropped by half.
Radiation readings in standing water around the plant vary
widely, but a measurement Saturday at unit 2 topped 1,000 millisieverts per hour.
High dose readings make repair work very difficult to manage, and priority has
been placed on removing standing water as fears mount that it will wash into
the sea. NISA reported late Tuesday that concentrations of radioactive iodine
3,355 times the legal limit were found in seawater near the plant, compared to
levels 1,850 times the limit recorded Saturday.
Chief Cabinet Secretary Yukio Edano said in a news
conference that engineers are discussing “every possibility” to control the
plant, Kyodo reported. He alluded to recent media reports that experts have been
studying ideas like covering units with a special cloth to reduce the amount of
radioactive particles that escape from the plant and using a tanker to collect
contaminated water.