CRITICALITY ACCIDENT AT A URANIUM CONVERSION FACILITY
AT TOKAI-MURA, JAPAN


Second Death from JCO Criticality Accident
Reported by the CNIC (Citizens' Nuclear Information Center), Tokyo, 27 April 2000

Japan not to upgrade worst nuclear accident
The Japanese government decided to maintain the level 4 rating of the Tokai-mura accident
Reuters Japan, April 26, 2000

Japan Nuclear Co. Chief To Resign
New York Times, 15 February 2000
By The Associated Press

Nuclear guideline draft defines what emergency is
Japan Times, 9 February 2000

Asahi Glass, Mitsubishi Corp. to acquire BNFL subsidiary
Tokyo, February 7, 2000

Nuclear leak worse than first feared - More than 400 were exposed to radiation in Japan
The Guardian, wednesday February 2, 2000
By Jonathan Watts in Tokyo


THE "POST-ACCIDENT" MEASURES AND ISSUES

STA and several groups of independant scientists have carried out sampling around the JCO Tokai plant, mainly in the 350 m area zone. Radioactive fallout of cesium-137, iodine-131, strontium-91 and sodium-24 have been (extensively for sodium-24) confirmed.

The STA inspection of the JCO plant (which is legally prescribed) on 3 october 1999 was the very first one in 10 years to be carried out. It was also revealed that STA had conducted no site inspection either at Tokai Reprocessing Plant (operated by JNC) or at Rokkasho-mura Enrichment Plant (operated by JNFL) over six years. STA claims they were too busy.

On 4 October 1999, it is announced that various samples of a common local herb had been collected by citizens in the area on 2 October 1999, measured by the Research Reactor Institute of Kyoto University, were found contaminated with 23 to 54 Bq/kg Iodine-131.

The following is an overview of fission products detected within 3 km of the accident site. The figures were taken from newspapers and TV reports, and have been compiled by CNIC. (Citizens' Nuclear Information Center, Tokyo:
- strontium-91 : 0.021 Bq/m3 in air, 900 m southeast of the site
- strontium-91 (krypton-91) : unknown amount, location not specified
- iodine-131 : 54.7 Bq/kg from mugwort leaves, 100 m from the site
- iodine-133 (krypton-91) : unreported amount, 100 m from the site
- cesium-137 : unreported amount, 7 locations
- sodium-24 : 64 Bq/kg, 300 m west from the site
- sodium-24 : 1.7 Bq/kg, 3 km west from the site
- xenon-139 : from the vomit of the exposed workers
- krypton-91 : from the vomit of the exposed workers

The environmental group Greenpeace investigated materials from around the site -- including soil from around the accident site as well as salt (which is a neutron flow indicator) from the homes of local residents -- and concluded the government lifted its evacuation advisory too soon. According to Greenpeace, neutron radiation seems to have irradiated the environment at least 500 meters from the accident site, which would have reached a major nearby street and more than 170 homes as well as a golf course and farmland.

The mayor and the Governor of Ibaraki Prefecture jointly met the Prime Minister Obuchi on Monday (4 Oct). They firmly requested the suspension of JCO's operations, and also stated that new legislation to guarantee safety in nuclear plants should be introduced.

In the mean time the mayor of Tokai-mura issued an order of total suspension of the operation of JCO Tokai plant (all the work inside its Tokai facility) on the basis of the Safety Agreement between the company and the village administration. This is the first time in Japan in which a local government made use of this sanction power based on the nuclear safety agreement with a plant operator. It was also decided that the Tokai nuclear fuel reprocessing plant, of which the operation has been suspended since the March 1997 explosion and fire, would not restart for the time being. The reporcessing plant was about to restart. Its operator is Japan Nuclear Fuel Cycle Development Institute (JNC), former PNC.

On 6 October 1999, according to Kyodo News Agency, the Science and Technology Agency (STA) has decided to revoke the business license of JCO Co due to the "seriousness of the accident".

According to Reuters, on 6 October 1999, a police spokesman said that about 200 investigators raided JCO's headquarters in Tokyo and its office in Tokai-mura, searching for causes and responsibilities for the accident. It has been reported that STA and the Ibaraki Prefecture Police are involved in the investigations.

Kyodo quoted government sources as saying that the authorities have confirmed during their investigations that JCO had changed the government-approved procedure manual and used the illegal one as "standard procedure." JCO officials have admitted the firm illegally revised a government-approved manual to allow workers to use buckets instead of a pump to transfer a uranium solution to a tank. It has been revealed that the three JCO workers, who were hospitalized due to massive radiation exposure, had not been wearing their film badges to measure radiation dose. This is another serious violation of the safety regulations.

The responsability of the Tokai local government is also put into question since it did not conduct a nuclear emergency exercise for the last eight years.

  According to news reports, at the time of the accident, there was not even any hot line between the prefectural government and Tokaimura's town hall. Tokai officials had to rely on busy public telephone lines when they tried to obtain radiation monitoring data from the prefectural authorities after the accident.

The Government's emergency response headquarter has been resolved, and now a Nuclear Accident Investigation Committee is to be set up. The PM's office ordered an ad hoc inspection in all nuclear facilities, including power plants, all over Japan.

A number of public meetings and protest actions are being organized all over the country by NGOs, trade unions and concerned citizens.

The Tokai-mura uranium was of French military origin :
The uranium which originated the criticality accident at Tokaimura on 30 septembre was of French origin, confirmed JCO Co spokesman, Norimichi Mori, to the French daily Le Monde. French sources indicated that the 18,8% enriched uranium was exported in december 1997. The 420 kg of uranium had been enriched by COGEMA in its military enrichment plant in Pierrelatte (shut down in 1996). The deal had been organized by the German nuclear fuel broker NUKEM. COGEMA stressed directly after the accident that it had no agreement with JCO Co. In fact COGEMA's client is JNC Co, operator of the Joyo experimental fast breeder reactor, which subcontracted the conversion work to JCO.

According to insider reports, STA officials are going to rank the Tokai accident at Level 5 instead of Level 4 on the International Nuclear Event Scale (INES), in other words as severe as Three Mile Island accident 1979.

"While there may be some cracks, since we have not been able to enter the site, the plant does not appear to be destroyed from the outside," the STA told the IAEA. It added that it was not sure how much radiation may have escaped from the building.

The approach of spokesmen for the companies involved seemed similarly focused on the need to provide swift reassurance and emphasised the culpable role of workers without examining that of managers, even those on the spot, let alone those higher up in the JCO company and its parent corporation, Sumitomo Metal Mining.

The insurance program designed to cover damage from nuclear accidents is not likely to compensate people for lost sales of agricultural products because of the Tokaimura nuclear accident, sources said on thursday 4 october. Sales are expected to decline in Tokaimura and neighboring municipalities in Ibaraki Prefecture. Nor is the insurance program likely to cover the entire cost of other losses stemming from the nation's first accident involving nuclear criticality. These include losses related to the suspension of railroad services and temporary closure of private firms. The insurance system makes it mandatory for operators of nuclear facilities to buy insurance against possible accidents. Further, it allows the use of taxpayers' money--subject to Diet approval--to pay compensation if the responsible operator is not capable of paying for all damages, reported the daily Asahi Shimbun.

CNIC revised its estimation of the quantity of U-235 that underwent fission to "up to several tens of milligram of U-235". The Japanese Government's Nuclear Safety Commission (NSC), according to the daily Asahi, claims that the figure would be in the order of 0.001 mg (10E-6 grams).

NSC confirmed in an official report to the Government that the criticality in the Tokai accident continued for 17.5 hours; the judgement is based on neutron dose monitoring by different institutions.

The number of exposed people continues to increase, and reached 63 as of 9 October 1999.

Sumitomo Metal Mining company, of which JCO is a 100% subsidiary, now intends to totally withdraw from the nuclear fuel business. This means that quite a few of the Japanese nuclear reactors will have to find overseas suppliers for nuclear fuel assemblies (conventional uranium fuel). For instance, Kyushu Electric Power Company depends for 70% on JCO uranium fuel, and is severely affected by the suspension (and permanent shut down, which is now likely) of JCO operations.

The European Parliament voted for a total review of " all the nuclear facilities worlwide " by the IAEA. They require controls and check-up at the Tokaimura plant and ask the japanese officials for revised safety procedures. Hirofumi Nakasone, the new head of the Science and Technology Agency (STA) accepted IAEA experts to come to " increase transparency and recover international confidence."

On 14 October 1999, the visit of three IAEA experts in Japan comes a day after the Japanese Government admitted a ventilator at the plant had been mistakenly left operating for 12 days, allowing radioactive particles to leak into the atmosphere. The ventilator was only turned off on Monday 11 October 1999, three days after high levels of the radioactive substance iodine 131 were detected around the plant. Radiation levels at the accident site at Tokaimura are still dangerously high, so it is unclear how close the IAEA team will get.

Experts and scientists at a symposium held at Kyoto Seika University on 4 October 1999, said the government should be accountable for the nuclear accident at the uranium-processing plant in Tokai, Ibaraki Prefecture. They also expressed concern that the company as well as the government might be withholding information or releasing incorrect information about the nation's worst nuclear disaster. Seika University President Hajime Nakao said the fact that the country is continuing with plans to put the Joyo fast-breeder reactor back online makes him think that the government wants the ability to build nuclear arms.

As part of the reorganization of central government ministries and agencies, which will begin in 2001, the Nuclear Safety Commission (NSC) will operate under a newly created Cabinet office, with enhanced independence - being an advisory body, the NSC has no licensing authority - as will be the case with the Nuclear Energy Commission. The two commissions now belong to the Prime Minister's Office.

At a press conference on 15 october, JCO admitted that a " limited amount " (20 Bq/m3, twice the allowed quantity) of radioactive iodine-131 had been released into the atmosphere after the accident via the ventilation system of the building in which the criticality accident occurred. Prefecture and STA knew about the iodine release, but they took no measures considering the escaping quantity of radioactivity would be negligible. Concentrations of 0.04 Bq/m3 of I-131 were detected 50 m southwest of the building (the monitoring point is still within the JCO premises.)

One member of the first team who approached the building to take photographs of the pipe systems they were going to work on, according to a JCO statement, was initially dosed with 20 mSv. Now it is revealed that the workers wore 2-digit type neutron recorders (the meter is reset to "00" when the count is over 99). The "20 mSv" actually were 120 mSv (neutron plus gamma, mostly consisting of neutron dose.) The fact was reported by STA on 15 october 1999 to the accident investigation unit of NSC. In the same report, STA confirmed that the number of the exposed persons now reached 69. This figure does NOT include the general public who had stayed very close to the plant for over 5 hours in neutron shower before they were evacuated. Dr Komei Hosokawa of Saga-University estimates that some 100 to 150 people were significantly exposed to neutron radiation.

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Japan not to upgrade worst nuclear accident

The Japanese government decided to maintain the level 4 rating of the Tokai-mura accident

Reuters Japan, April 26, 2000

[posted 27 April 2000]

TOKYO - Japan has decided against upgrading its first fatal nuclear plant accident, sticking to a preliminary rating of "level four" rather than opting for the more serious level five.

A level five was assigned to the 1979 accident at Three Mile Island in the United States.

"We decided on level four for the final rating," a Science and Technology Agency official said on Tuesday.

The government had previously said the accident last September at a uranium processing plant plant in Tokai, 140 km (90 miles) northeast of Tokyo, might be upgraded to level five.

It occurred when workers put nearly eight times the proper amount of condensed uranium into a mixing tank, triggering a nuclear chain reaction.

Level four on the International Atomic Energy Agency's zero-to-seven International Nuclear Event Scale indicates the possibility of a fatal radiation leak at the accident site but no significant risk outside the plant, the official said.

The Soviet Union's Chernobyl accident in 1986, rated a level seven, was the worst nuclear power accident on record.

Tokyo University Hospital said on Monday that a 40-year-old worker exposed to heavy doses of radiation in the Tokai incident had slipped into serious condition.

"The patient's prognosis is uncertain after he suffered multiple organ failure," the hospital said in a statement. Another Tokai worker died as a result of the accident late last year, while a third who suffered heavy radiation exposure recovered and was released from hospital in December.

A total of 439 workers and residents were exposed to radiation as a result of the accident.

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Second Death from JCO Criticality Accident

Reported by the CNIC (Citizens' Nuclear Information Center), Tokyo, 27 April 2000

[posted 27 April 2000]

Mr. Masato Shinohara who was exposed to a lethal dose of radiation on 30 September, 1999 at JCO Co., the site of the criticality accident, died in the early morning of 27 April, 2000. According to the Science and Technology Agency's estimation, he was exposed to 6 - 10 gray-equivalent of radiation.

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Japan Nuclear Co. Chief To Resign

New York Times, 15 February 2000
By The Associated Press

TOKYO (AP) -- A top executive at a company closely linked to Japan's worst nuclear accident said Tuesday [15-02-2000] that he would resign to take responsibility for what happened.

Moriki Aoyagi, the president of Sumitomo Metal Mining Co., said he felt "socially and morally'' responsible for the Sept. 30 accident which killed one and left over 400 others exposed to radiation.

Sumitomo Metal Mining owns JCO Co., the operator of the fuel processing plant where three workers ignored regulations while mixing nitric acid and highly enriched uranium, setting off an uncontrolled atomic reaction.

Earlier this month, the government announced that it would repeal JCO's operating license, but that Sumitomo would have a chance to appeal the decision at a hearing in March.

Aoyagi said Tuesday [15 February] that the company planned to accept the decision.

Nuclear power officials have still not succeeded in regaining the trust of residents of Tokaimura, the town 70 miles northeast of Tokyo where the accident took place.

Seventy-eight percent of respondents said they felt nuclear plants were dangerous, against 62 percent who said they trusted nuclear facilities before the accident, according to a poll conducted by the town government cited Tuesday by Kyodo News.

The town polled 1,426 residents, and 546 replied.

JCO, which was set up in 1979 to process nuclear fuel, is owned 100 percent by Sumitomo Metal Mining, a leading Japanese comprehensive nonferrous metal company.

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Nuclear guideline draft defines what emergency is

Japan Times, 9 February 2000

A subcommittee of the Nuclear Safety Commission drew up guidelines Wednesday that include a requirement for operators of nuclear facilities to promptly inform local governments if monitors show gamma ray levels of 5 microsieverts per hour.

Under the guidelines, the government would set up a task force headed by the prime minister in the event radiation levels amount to 500 microsieverts per hour. One microsievert is a thousandth of a millisievert.

The guidelines would be utilized in the government's efforts to galvanize disaster prevention areas nationwide ahead of the implementation of new laws regarding nuclear safety that were enacted by the Diet in December.

Under Wednesday's guidelines, operators would have to notify local authorities if a monitoring device set up at the outermost point at a facility registers radiation of at least 5 microsieverts per hour for 10 minutes or more, or if two monitors pick up such radioactivity at the same time.

While this level is not harmful to humans, the new guidelines require prompt notification to authorities.

In addition, notification would also be required in the event unusual readings are picked up by monitors placed near vents as well as when problems that could lead to major disasters are detected.

If these new guidelines are applied to the September criticality accident at the JCO Co. uranium-processing plant in Tokai, Ibaraki Prefecture, notification would have been necessary immediately after the problem occurred.

With the 800 microsieverts detected in the emergency monitoring that ensued, a central government task force should have been set up swiftly after the disaster, which was triggered by workers who used a bucket to pour an unsafe amount of highly enriched uranium into a tank.

The latest revisions to nuclear safety legislation would have the central government, rather than local municipalities, play a major role in the event of nuclear disasters.

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Asahi Glass, Mitsubishi Corp. to acquire BNFL subsidiary

Tokyo, February 7, 2000

Asahi Glass Co. and Mitsubishi Corp. said Monday they have agreed with British Nuclear Fuels PLC (BNFL) to acquire all shares in BNFL's wholly owned subsidiary F2 Chemicals Ltd. Asahi Glass and the trading house will pay about 856 million yen ($8 million) to BNFL for the subsidiary, as part of a plan to strengthen their fluorinated fine chemicals business, officials of the two Japanese companies said.

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Nuclear leak worse than first feared - More than 400 were exposed to radiation in Japan.

The Guardian, February 2, 2000
By Jonathan Watts in Tokyo

Japan's worst nuclear accident exposed nearly five times as many people to radiation as wasoriginally thought, the government said yesterday.

The sharp upward revision of the impact of the uncontrolled chain reaction on September 30 is a fresh blow to public confidence in a nuclear industry that has suffered a series of accidents and cover-ups over the past few years.

Japan's science and technology agency revealed that 439 people were exposed to neutron rays during the 20 hours in which the nuclear fission took place at a uranium processing plant in Tokaimura, 80 miles northeast of Tokyo.

In its initial report, the agency said only 69 people were affected. The accident occurred when plant workers used buckets to mix nearly eight times the correct amount of condensed uranium.

According to the agency's revised figures, the resulting fission exposed 119 residents, plant workers and emergency service staff to more than one millisievert of radiation, which is the annual permissible level.

It is the first time that an accident in Japan has affected more than 100 people to such an extent.

One worker who battled to halt the chain reaction suffered as much as 38 millisieverts and ambulance crews who arrived without being told they were visiting a nuclear accident site were exposed to high levels of radiation.

The agency played down the health implications of its findings, saying that the risks of cancer only increased significantly with a dose of more than 50 millisieverts. It said the revised figures were higher because the later assessment included local residents.

"This makes the number look bigger than the original figures we reported," an agency official told reporters.

Anti-nuclear groups, however, said the data under played the seriousness of the accident.

"We still don't think this is an accurate figure. It doesn't include any people passing through the area at the time or those who were working in nearby fields," said Kazue Suzuki of Greenpeace Japan.

The average incidence of leukaemia is 0.66% in Japan. According to the International Commission of Radiological Protection, the risk increases by 0.05 points for every 10 millisieverts of exposure.

The new figures are likely to add to public concern about the safety of the nuclear industry. Since the chain reaction, several local governments have halted or cancelled nuclear energy projects.

In the atmosphere of increased safety consciousness, British Nuclear Fuels Ltd has lost contracts as a punishment for supplying reprocessed fuel with falsified safety data.

Health officials have offered to monitor 120 people affected by radiation.

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