Dozens Hurt in Japan’s Worst Nuclear Accident

TOKYO —  Three Japanese workers were hospitalized with radiation poisoning today and 46 others suffered radioactive contamination after an uncontrolled nuclear reaction occurred Thursday at a uranium processing plant about 81 miles northeast of Tokyo. It was Japan’s worst civilian nuclear disaster.

Authorities said the nuclear fission reaction had been stopped today, but about 310,000 people living within a six-mile radius of the plant were ordered to stay indoors with their windows shut until officials were certain that the danger had passed. Japan’s Science and Technology Agency said radiation measured outside the plant had at one point reached 4,000 times the normal ambient level.

The accident prompted immediate calls for a thorough review of the nation’s spotty nuclear safety record as well as its controversial policy of pursuing plutonium-fueled fast-breeder nuclear reactors.

The accident in Tokaimura, in Ibaraki prefecture, occurred at 10:35 a.m. Thursday local time after workers at the privately owned JCO Co. plant, which processes uranium to make fuel for nuclear power plants, allegedly poured about 35.2 pounds of uranium solution into a tank designed to handle only 5.2 pounds.

Workers reported seeing a blue flash of light, and authorities said radioactive gas spewed into the atmosphere.

The dangerously high concentration of uranium triggered a fission reaction that officials scrambled for nearly 20 hours to control.

About 3 a.m. today, JCO officials began draining the cooling fluid inside the tank, Japanese media reported. The water had been helping to keep the reaction going by slowing neutrons produced by nuclear fission and thus making them able to split other atoms.

By 6:30 a.m., a sensor located on the second floor of the factory’s control tower registered no neutron emissions, said Atomic Safety Director Kenichi Hirose, a sign that the nuclear chain reaction had been halted.

Nevertheless, as an extra precaution, Science and Technology Agency officials announced at 9 a.m. that they were injecting a boric acid solution into the tank to quench any remaining reaction.

At least 160 people living within a quarter of a mile of the facility were evacuated Thursday afternoon. However, Ibaraki prefectural officials said they would investigate why JCO Co. employees had waited 58 minutes before informing local authorities, and nuclear safety critics questioned why the prefecture had waited until late afternoon to order an evacuation.

This morning, all 137 schools and kindergartens in the affected six-mile area were closed, post offices were shuttered, and train service through the area was halted, disrupting commuter trains from northeastern Japan to Tokyo’s Ueno station. Television stations broadcast warnings to residents to stay indoors with their windows shut, avoid using fans or air conditioners that would bring in air, keep their car windows shut if they absolutely had to drive, and avoid drinking well water or rainwater.

Agricultural and marine authorities told local residents not to harvest any produce or sea life while they checked for possible contamination.

“The rice harvest is almost over, but we are very worried about our vegetables being contaminated by the wind,” said Takashi Suzuki, head of Kanasugo-machi, a farming town about five miles from the site.

Prime Minister Keizo Obuchi postponed a reshuffle of his Cabinet scheduled for today as a number of different government task forces began investigating why the accident could have occurred and what kind of response would be needed.

“We may later be accused of overreacting, but we must put the safety of local residents first,” said Chief Cabinet Secretary Hiromu Nonaka.

There was no official word as to the prognosis for the three radiation victims, but a reporter for state-run NHK television warned that “we cannot be too optimistic” about their fate.

Two of the injured workers, Hisashi Ouchi, 35, and Masato Shinohara, 39, were drifting in and out of consciousness, suffering from nausea, diarrhea, abdominal pain, and plummeting white blood cell counts, doctors said. They were found to have between 150 and 260 times the normal amount of radiation in their bodies, and by this morning they had reportedly developed radiation burns.

The third worker, Yutaka Yokokawa, 54, had about 40 times the normal amount of radiation in his body but was able to walk out of the plant unassisted, was conscious, and appeared less severely injured, doctors said.

All three of the JCO employees were evacuated from the plant by helicopter Thursday to the National Institute for Radiological Science in Chiba prefecture, and then to a nearby hospital.

Dr. Hirohiko Tsuji said their injuries “could lead to a life-threatening situation and therefore we are doing our best to treat them.”

The 46 others who were injured included 33 plant employees, three from affiliated companies, three firefighters and seven people who were working at a nearby golf course.

Atsushi Sakurai, a longtime nuclear safety watchdog, said because the three workers were exposed to an unshielded fission reaction, they may have received more radiation than those at the 1986 Chernobyl nuclear disaster in Ukraine, where two plant workers were killed and at least 29 other people died later from radiation sickness. More than 200 others were hospitalized with injuries.

“They may have received as much radiation as the atomic bombing victims,” Sakurai said. He was referring to the 1945 U.S. bombing of Hiroshima and Nagasaki, which prompted Japan to surrender and ended World War II. Other experts concurred with that assessment.

The United States and Russia offered to send a joint emergency nuclear response team to help Japan, but Tokyo had not indicated whether it needed or would accept the aid. However, Japan did ask for information and research on dealing with nuclear disasters.

President Clinton expressed deep sympathy, saying, “This is going to be a very hard day for the people of Japan.”

Nuclear safety experts said the accident was wholly avoidable. “This is the kind of accident which should not have happened under any circumstances at a nuclear fuel facility,” said Tetsuo Iguchi, professor of nuclear engineering at Nagoya University. “I am extremely surprised.”

Iguchi said similar accidents occurred in the United States in the 1950s at atomic weapons facilities, but after the introduction of safety procedures in 1964, “criticality,” meaning a nuclear fission reaction, had not occurred at any fuel facility since.

But nuclear critics in the U.S. and Japan were not surprised by Thursday’s accident. They blamed lax safety standards and a dangerous complacency in the Japanese nuclear industry.

“It would never have occurred if they were following the [safety] manual,” Iguchi said.

Company officials admitted today that the workers, who were using British-made equipment to convert enriched uranium purchased in France into fuel pellets for use in Japanese reactors, had violated procedures in many ways.

In addition to pouring in too much uranium, they skipped a procedure to move the fluid to a holding tank, company officials said. They then poured the solution by hand into the tank, instead of transferring it by pipe as they were supposed to.

“It was a primitive mistake,” said Chief Cabinet Secretary Nonaka. However, he insisted that better-regulated nuclear power plants are safe.

This is a regulation-mad, law-abiding society, where ordinary citizens glare at jaywalkers, loudspeakers in subways ceaselessly broadcast safety announcements, and respect for protocol is often paralyzing. Activists said that it is precisely the assumption that such a primitive mistake would not happen in Japan that led to Thursday’s accident.

“That is a very unscientific attitude,” Masako Sawai, a researcher at the Citizens’ Nuclear Information Center in Tokyo. “They were not prepared for this kind of accident at all.”

She said regulation on fuel processing plants is much looser than at nuclear power plants.

A spokesman for the Science and Technology Agency said the incident had been rated a level 4 on the International Atomic Energy Agency’s seven-step scale. The Chernobyl nuclear plant meltdown rated a 7 on the IAEA scale, while Japan’s worst accident until now, a 1997 fire and explosion at a plutonium reprocessing plant, rated a 3.

The IAEA said it had been in touch with Japanese nuclear authorities today and that much of the information it had received early in the incident was “conflicting and very limited.” The IAEA said in a statement that it was formally requesting “authentic and verified official information” about the accident.

This accident was the latest in a series of explosions, fires, radiation leaks and falsified reports that have plagued this country’s nuclear power industry in recent years. Japan gets about 30% of its energy from nuclear power, but its atomic safety record and use of plutonium as fuel have been under fire from domestic and international environmentalists.

Greenpeace International, the environmental group, said that Thursday’s accident occurred less than 24 hours before the arrival of a shipment of “weapons-usable plutonium” destined for the Takahama nuclear power plant in Fukui prefecture.

The “accident at Tokaimura confirms our fears: The safety culture within Japan is in crisis and the use of dangerous plutonium in reactors here will only increase the probability of a nuclear catastrophe,” the group’s Shaun Burnie said.

The 1997 plutonium plant disaster also occurred in Tokaimura, where a large number of nuclear facilities are clustered, and 37 workers were exposed to small amounts of radiation.

In 1995, a massive coolant leak forced the closure of a fast-breeder reactor at Monju, in Western Japan. The government has announced plans to reopen the controversial facility, but a date has not been set.

In 1996, the town of Makimachi voted in a referendum not to allow construction of a nuclear power plant there. In 1997, public mistrust was further inflamed by disclosures of low-level radiation leaks at a two other sites. And in July of this year, a reactor at the Tsuruga nuclear power plant west of Tokyo was shut down after a massive leak of radioactive cooling water.

Times staff writers John J. Goldman in New York and Thomas H. Maugh II in Los Angeles contributed to this story.

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Past Nuclear Accidents

Major nuclear incidents during the past 40 years. Some have come to light only since the end of the Cold War.

Jan. 3, 1961: Three tecnicians die at a U.S. plant in Idaho Falls, Idaho, in an accident at an experimental reactor.

July 4, 1961: The captain and seven crew members die when radiation spreads through the Soviet Union’s first nuclear-powered submarine.

Oct. 5, 1966: The core of an experimental reactor near Detroit partly melts when a sodium cooling system fails.

March 28, 1979: America’s worst nuclear accident occurs at the Three Mile Island plant near Harrisburg, Pa. A partial meltdown of one of the reactors forces the evacuation of residnets after radioactive gas leaks into the atmosphere.

Aug. 7, 1979: Highly enriched uranium spews out of a top-secret nuclear fuel plant in Tennessee. About 1,000 people are contaiminated.

April 25, 1981: About 45 workers are exposed to radioactivity during repairs to a problem-ridden plant at Tsuruga, Japan.

Aug. 10, 1985: An explosion devastates the Shkotovo-22 ship repair facility that services Soviet navy nuclear-powered vessels. Ten people are killed, and many die later of radiation exposure.

Jan. 6, 1986: One worker dies, and 100 are injured at a plant in Oklahoma when a cylinder of nuclear material bursts after being improperly heated.

April 26, 1986: An explosion and fire at the Chernobyl nuclear plant spews radiation over much of Europe. Offically, 31 people die int he world’s worst nuclear accident.

Dec. 8, 1995: Two to 3 tons of sodium leak from secondary cooling system of Japan’s Monju prototype fast-breeder nuclear reactor in an accident.

March 11, 1997: A fire and explosion at the state-run Power Reactor and Nuclear Fuel Development Corp. reprocessing plant at Tokaimura contaminate at least 35 workers.

Sources: Reuters, Associated Press

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Radiation Effects

At least two plant-workers were exposed to potentially fatal radiation doses during the accident at a uranium processing facility in Japan. Officials said radiation levels outside the plant reached 4,000 times the normal level, enough to cause acute exposure symptoms, possibly even death.

Acute Exposure

Dozens in the area of the plant are at risk. A large, single dose of radiation can cause immediate and delayed effects, including:

Immediate: Radiation sickness symptoms, such as:

Vomiting and Diarrhea: occurs due to damage in cells that maintain intestinal intergrity.

Reduction in number of blood cells: results from damage to blood producing cells in the bone marrow.

Bleeding: occurs because damaged marrow cells cannot produce blood platelets that coagulate blood.

Delayed

Cataracts, temporary sterility, cancer, genetic damage.

Anemia and risk of infection due to loss of protective white blood cells.

Treatment: Antibiotics, blood transfusions and bone marrow transplants/

Fatal Dosage; At least two workers received doses of 800 rem, 600 rem is considered a potentially fatal dose.

Radiation Sources:

The average American receives 360 millirem (a measure of potential damage to a living organism) of radiation a year; 300 from natural sources such as the sun’s rays, rocks, soil, building materials and other background sources; 60 from medical / dental X-rays and consumer products.

Radon: largest source of radiation exposure in U.S. Radon trapped in homes accounts for 55% of radiation to which average American is exposed, about 200 millirem a year.

Cosmic rays: average person recives about 8% of his total exposure (28 millirem a year) from cosmic radiation from space.

Medical: average American receives about 15% of his exposure from X-rays and nuclear medicine procedures--average of 45 millirem a year.

Sources: Environmental Protection Agency; Radiation Effects Research Foundation; Researched by JULIE SHEER / Los Angeles Times