|Japanese military helicopters used large buckets yesterday to pick up sea water to drop onto the stricken Fukushima nuclear power plant. (Yomiuri Shimbun/AFP/Getty Images)|
A frantic effort to stem spread
Contamination highest within 19-mile radius
WASHINGTON — Frantic and increasingly unconventional attempts to stem bursts of radiation from the stricken Fukushima Daiichi nuclear plant in Japan yesterday did little to immediately ease fears of an ecological disaster at the plant, although US officials said the first readings from data-collection flights show that significant levels of contamination have not spread beyond the 19-mile range of top concern established by Japanese authorities.
The data were collected in the first use of the Aerial Measurement System, among the most sophisticated devices rushed to Japan by the Obama administration in an effort to help contain a nuclear crisis.
Three reactors have had at least partial meltdowns at the plant, where wisps of steam enveloped the stricken units this morning. Japanese and US officials believe a greater danger exists in the pools used to store spent nuclear fuel: Fuel rods in one pool were believed to be at least partially exposed, if not dry, and others were in danger. Without water, the rods could heat up and spew radiation.
It could take “possibly weeks’’ to get the complex under control, US Nuclear Regulatory Commission chairman Gregory Jazcko said.
The US data show ground-level fallout of harmful radioactive pollution in the immediate vicinity of the stricken plant — a different standard than the trace amounts of radioactive particles in an atmospheric plume now projected to cover a much broad er area.
While the findings were reassuring in the short term, the United States declined to back away from its warning to Americans to stay at least 50 miles from the plant, a far larger perimeter than the Japanese government has established.
President Obama affirmed the warning, saying in the Rose Garden that the decision was based on “a careful scientific evaluation’’ of the “substantial risk’’ to those near the plant. He also repeated that there was no expectation that the radioactive plume emitted by the plant would bring harmful levels of radiation to any part of the United States, including its territories in the Pacific.
He also called for a “comprehensive review’’ of the country’s nuclear plants.
In interviews, US officials said their biggest worry about the Japanese plant was that a frenetic series of efforts by the Japanese military to get water into four of the reactors there — including water cannons and helicopters that dumped water but appeared to largely miss their targets — showed few signs of working.
Another effort by the Japanese, to hook electric power back up to the plant, only began yesterday and was expected to take several days to complete — and even then it was unclear how the cooling systems, in reactor buildings battered by the tsunami and then torn apart by hydrogen explosions, would work, if at all.
“What you are seeing are desperate efforts — just throwing everything at it in hopes something will work,’’ said one US official with significant experience in nuclear matters, who would not speak for attribution. “Right now this is more prayer than plan.’’
After a day in which US and Japanese officials had radically different assessments of the danger of what is spewing from the plant, the two governments attempted yesterday to join forces. Specialists met in Tokyo to compare notes. The United States, with Japanese permission, began to put the intelligence-collection aircraft over the site, in hopes of gaining a view for Washington as well as its allies in Tokyo that did not rely on the announcements of officials from the Tokyo Electric Power Co.
Officials say they suspect that company has consistently underestimated the risk and moved too slowing to contain the damage.
Aircraft normally used to monitor North Korea’s nuclear weapons activities — a Global Hawk drone and U-2 spy planes — were flying missions over the reactor, trying to help the Japanese government map out its response to the quake, the tsunami, and now the nuclear disaster.
The official death toll from the disasters stood at 5,692 as of this morning, with 9,522 missing, the national police agency said.
Chopper crews flew missions of about 40 minutes each to limit their radiation exposure, passing over the reactor with loads of about 2,000 gallons of water. Another 9,000 gallons of water were blasted from military trucks with high-pressure sprayers used to extinguish fires at plane crashes, though the vehicles had to stay safely back from areas deemed to have too much radiation.
Special police units with water cannons that are designed as a crowd-control device were also tried, but they could not reach the targets from safe distances and had to pull back, said Yasuhiro Hashimoto, a spokesman for Japan’s nuclear safety agency.
In Washington, Obama made an unscheduled stop at the Japanese Embassy to sign a condolence book, writing, “My heart goes out to the people of Japan during this enormous tragedy.’’ He added: “Because of the strength and wisdom of its people, we know that Japan will recover, and indeed will emerge stronger than ever.’’
But before the recovery can begin, the nuclear plants must be brought under control. And so US officials were fixated on the temperature readings inside the three reactors, and at the spent fuel pools, looking for any signs that they were decreasing. So far they haven’t seen any, but on the website of the International Atomic Energy Agency, the UN nuclear watchdog, it was clear that there were no readings at all from some critical areas.
Part of the US effort is to identify the hot spots, something the Japanese have not been able to do in some cases.
Critical to that effort are the “pods’’ flown into Japan by the Air Force over the past day. Made for quick assessments of radiation emergencies, the Aerial Measuring System is an instrument pod that fits on a helicopter or fixed-wing aircraft to sample air and survey the land below. The information is used to produce colored maps of radiation exposure and contamination.
The sensors on the instrument pod are good at mapping radioactive isotopes, such as Cesium-137, which has been detected around the stricken Japanese complex and has a half-life of 30 years. Its radiation can alter cellular function, leading to an increased risk of cancer.
Cesium-137 mixes easily with water and is chemically similar to potassium. It thus mimics how potassium gets metabolized in the body and can enter through many foods, including milk. Cesium gets widely distributed in the body, and its concentrations are said to be higher in muscle tissues and lower in bones.
On Wednesday when the US Embassy in Tokyo, on advice from the Nuclear Regulatory Commission, told Americans to evacuate a radius of “approximately 50 miles’’ from the Fukushima plant, the recommendation was based on a specific calculation of risk of radioactive fallout in the affected area.
Yesterday, the State Department warned US citizens to consider leaving the country and offered voluntary evacuation to family members and dependents in the cities of Tokyo, Yokohama, and Nagoya.
The first flight left yesterday, with fewer than 100 people onboard, Undersecretary of State Patrick Kennedy said. Plans also call for airlifting several thousand family members of US armed forces personnel as well as nonessential staff stationed in Japan in the coming days.
Material from the Associated Press was used in this report.