A magnitude 7.4 aftershock hit northeastern Japan April 7—raising fears of a deepening of the crisis at the stricken Fukushima nuclear plant. Tokyo Electric Power Co. (TEPCO) reported no serious incidents as a result of the aftershock. But Ed Lyman, a nuclear safety expert at the Union of Concerned Scientists told the LA Times' Ecocentric blog: "The damage that has been done to date by the earthquake and tsunami has degraded the plant's ability to withstand ground motion, so you have more chance of a containment breach with the next earthquake. The conditions at the plant are so fragile, it can't really stand many more challenges."

A second attempt to stop radioactive water leaking into the Pacific ocean at the Fukushima nuclear plant by using paper and sawdust bound with a chemical compound failed April 4. Engineers are now resorting to a third plan: building mounds of silt around the reactor to filter radioactive particles. (Daily Mail, April 4) Officials in Fukushima prefecture have launched an emergency program to measure radiation levels in school playgrounds. More than 1,400 schools and nurseries will be tested over two days amid growing anxiety among local parents. Officials say there should be no risk to children if they stay outside a 30-kilometer evacuation zone. (BBC News, April 4) Efforts to protect Tokyo’s water supply from radiation have led to a run on Indonesian coconut husks. Granulated charcoal made of the husks is used in Tokyo area treatment plants. Prices for the absorbent carbon material have jumped 44% since the disaster started. (Bloomberg, April 4)

From the central committee of the Movement for Democratic Socialism (MDS), Tokyo, March 27:

Let us struggle for democratic reconstruction of eastern Japan, and for the total abolishment of nuclear power plants!
More than two weeks have passed since March 11th gigantic earthquake that hit eastern Japan. The death toll is increasing even now, reaching almost thirty thousand to include those who are still unknown whether safe or not. MDS extends our deepest condolences to all the victims in this disaster. Particularly, Fukushima Daiichi nuclear power plant poses a serious issue as it continues to deteriorate its radioactive contamination. In Fukushima as well as in neighboring prefectures, shipments of vegetables and raw milk have been suspended since higher level of radioactive substance was detected from them. Tap water contaminated by radioactive iodine has expanded to encompass the Tokyo Metropolitan area.

South Korean environmental activists staged an anti-nuclear rally on March 28, marking the 32nd anniversary of the Three Mile Island nuclear accident in Pennsylvania. Dozens of protesters wearing white masks gathered in downtown Seoul and denounced their government's nuclear development plans. Said protest leader Kim Hae-jung: "Today is the 32nd anniversary of the Three Mile Island nuclear plant accident, and it's been 17 days since the nuclear tragedy broke out in Japan. We're here to urge our government to change its plan to expand nuclear plants and to inform people of the danger of nuclear plants." South Korea has 21 nuclear power plants, with seven more under construction, and another 11 planned. (NTD-TV, March 28)

Tokyo Electric Power Co. (TEPCO), operator of Japan's stricken Fukushima Dai-ichi nuclear plant, said April 2 that highly radioactive water is leaking directly into the ocean, which may help explain high levels of radioactivity in seawater off the coast. The water is coming from an 8-inch (20-centimeter) crack that was found in the concrete pit holding power cables near reactor Number 2, with the radiation level measured at 1,000 milli-sieverts an hour. The annual limit of radiation exposure allowed for Fukushima workers is 250 milli-sieverts. Efforts to seal the crack by pumping in concrete have failed to slow the flow of water into the ocean. TEPCO officials said they will next try using a polymer—a type of quick-setting plastic. The tainted water is pooled up some 10 to 20 centimeters high at the bottom of the pit. (LAT, Kyodo News, April 2)

Seawater near Japan's stricken Fukushima Dai-ichi nuclear power plant shows significantly higher levels of radioactive iodine than in recent days, Japan's nuclear safety agency reported March 30. Hidehiko Nishiyama, deputy director general of the Nuclear and Industrial Safety Agency, said that seawater collected about 300 yards from the Fukushima Dai-ichi plant was found to contain iodine 131 at 3,355 times the safety standard, the highest levels reported so far. Meanwhile, Tokyo Electric Power Co. (TEPCO), operator of the plant, acknowledged for the first time that at least reactors 1 through 4 of the six-reactor complex will have to be written off. (NYT, March 31) A US engineer who helped install reactors at Fukushima, speaking anonymously to the Scandinavian environmental NGO Bellona, said he believes the radioactive core in reactor Number 2 may have melted through the bottom of its containment vessel and on to a concrete floor—a development that would pose a grave risk to soil and groundwater. (Bellona, March 31)

Plutonium has been found in soil at various points in and around Japan's stricken Fukushima Dai-ichi nuclear complex, officials of the Tokyo Electric Power Co. (TEPCO) admitted March 28. TEPCO vice president Sakae Muto told journalists at the company's latest briefing that test results showing the plutonium came from samples taken last week—while of course insisting that the contamination poses no threat to the public. The plutonium presumably comes from partially-melted MOX fuel from reactor Number 3. (Reuters, DC Bureau, March 28)

Sharply elevated radiation at the Fukushima Dai-ichi nuclear complex on March 27 forced an emergency evacuation of of the Number 2 unit. The concerns began when a worker attempting to measure radiation levels of water puddles there saw the reading on his dosimeter jump beyond 1 sievert per hour, the highest reading. Michiaki Furukawa, a nuclear chemist and board member of the Citizens’ Nuclear Information Center, a Tokyo watchdog group, said exposure to 1 sievert of radiation would induce nausea and vomiting, while levels between 3 to 5 sieverts an hour could be lethal. Yukio Edano, the Japanese government’s top spokesman, told a press briefing that it appeared the radioactive puddles had developed when the No. 2 unit’s fuel rods were exposed to air but that "we don’t at this time believe they are melting. We’re confident that we are able to keep them cool." (NYT, March 28)