Updated 4:15 p.m. ET | In a last-ditch effort to avert a nuclear meltdown, officials in Japan flooded a nuclear reactor with seawater on Saturday, the New York Times reported. Japan’s chief cabinet secretary, Yukio Edano, said Tokyo Electric Power workers also added boric acid to the containment vessel to poison the nuclear chain reaction.
Meanwhile, an American nuclear expert released a statement critical of the Japanese response to the nuclear emergencies. Peter Bradford, former member of the U.S. Nuclear Regulatory Commission:
An early tipoff that Japanese authorities felt that events at Fukushima were very serious was the ordering of an evacuation within a couple of hours of the earthquake. Though the area was small and the evacuation was called “precautionary,” the fact is that ordering several thousand more people into motion during the immediate aftermath of a major earthquake and tsunami is something that no government would do if it could possibly help it. Neither Three Mile Island nor Chernobyl were accompanied by natural disasters. Even then, authorities were loathe to evacuate, in part because evacuations are themselves dangerous and in part because they are admissions of a major failure.
Dr. Ira Helfand, a broad member of the Physicians for Social Responsibility, assessed the health risks involved with damaged reactors:
It is not known how much radiation has been or will ultimately be released from the damaged Daiichi nuclear reactor in Japan, but as found by the National Academy Sciences, any exposure to radiation increases a person’s risk of cancer. No one, including the plant’s operators, can say what is going to happen, and potentially millions of people are in harm’s way. The Japanese government should be preparing for the worst-case scenario. After one year of operation, a commercial nuclear reactor contains 1000 times as much radioactivity as was released by the Hiroshima bomb. From a public health perspective, the most important isotopes are short-lived isotopes of iodine (like Iodine-131), Cesium-137, Strontium-90, and possibly Plutonium-239. Radioactive iodine caused thousands of cases of thyroid cancer in children after the Chernobyl accident. Cesium and strontium cause a number of different kinds of cancer and remain dangerous for hundreds of years; plutonium causes lung cancer as well as other types of cancer and remains deadly for hundreds of thousands of years.
But the World Health Organization’s Gregory Hartl tamped down fears of a great risk to public health:
“At this moment it appears to be the case that the public health risk is probably quite low,” he said, quoted Al Jazeera English. “We understand radiation that has escaped from the plant is very small in amount.”
The French Nuclear Safety Authority said that any radioactive pollution from the Fukushima nuclear power plant blast would will likely blow out over the Pacific Ocean, thanks to favorable winds, according to Al Jazeera.
Also, Google is releasing satellite imagery from after Friday’s quake.
Original post, 10 a.m. ET | An explosion at a nuclear power plant in Japan Saturday rattled nerves and raised concerns about leaking radiation as the country races to assess the scope of devastation from dual disasters of an 8.9-magnitude earthquake and powerful tsunami.
The explosion rocked a building that houses a nuclear reactor at the Fukushima Daiichi plant, 150 miles north of Tokyo. The cause of the blast remains unclear.
Earlier, Japan declared states of emergency — the first in its history for a nuclear situation — for five reactors at two plants after the units lost cooling ability due to power outages following the powerful quake. Thousands of residents who live near the facilities were evacuated.
Japanese government official Yukio Edano told The Associated Press that the the metal container sheltering a nuclear reactor was not affected by an explosion that destroyed the building housing it. He also said radiation levels were not increasing outside the plant, although an evacuation zone had been doubled to 12 miles.
The cooling system must continually pump water from a large pond that surrounds the core through a set of towers that keep the water at a safe temperature. Otherwise, the water will boil off, the fuel rods will melt, and there is a possibility that radioactive material will escape from the reactor’s containment dome — a so-called meltdown.
“We are now trying to analyze what is behind the explosion,” said Edano as reported by the AP. “We ask everyone to take action to secure safety.”
Before the explosion, operators had detected eight times the normal radiation levels outside the facility.
Meanwhile, the full scale of destruction in northern Japan from the earthquake and tsunami is still being absorbed. The twin disasters have left 574 people dead by official count, although local media reports said at least 1,300 people may have been killed, according to the AP.
Staggering numbers of people are still missing and have been evacuated. According to The Washington Post:
Roughly 9,500 in Minamisanriku — a town of 17,000 in Miyagi Prefecture — remain missing or unaccounted for, according to the Kyodo news agency, citing local government officials. As of Saturday evening, police said that 621 were confirmed dead, with thousands more missing. More than 210,000 had been evacuated.
Prime Minister Naoto Kan said 50,000 troops joined rescue and recovery efforts, aided by boats and helicopters.
From our NewsHour report Friday:
Weekend coverage: Stay with The Rundown this weekend for more coverage of the aftermath in Japan. Also for latest developments, check out coverage from the BBC, Al Jazeera English, NHK World, the Los Angeles Times and The New York Times’ The Lede blog.