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Nyt om atomkraftulykken i Japan
den 30. september 99.

E-mail afsendt fra Japan 1. oktober (de nyeste mails ligger først i rækkefølgen)

Fri Oct 1 17:13:43 1999
Date: Fri, 1 Oct 1999 23:07:48 (lokal tid) +0900
From: hosokawk@cc.saga-u.ac.jp (Hosokawk)
Subject: MagpieNews #991001e (accident-10th report)

Magpie Country Nukes Headliner
nuclear issues news brief from Japan

Criticality accident at Tokai uranium processing plant



1 October 1999

Red Cross Japan has decided to send experts of the Nagasaki Atomic Bomb Hospital to Tokai to assist medical staff there.

The team consists of doctors, a radiologist, and specialized nurses. The Nagasaki A-Bomb Hospital has long-standing experience in treating radiation-exposed hibakusha patients.

We have reported the number of those exposed to the radiation during the JCO Tokai accident. Readers are reminded that the figure only refers to those who were on site or in direct vicinity to the site.

The latest figure of 49 include 39 JCO staff (including subcontract workers), 3 ambulance staff and 7 construction workers, who were unlucky enough to be at work in certain renovation in the commercial golf course directly adjacent to the JCO plant.

The figure DOES NOT include the workers who did a self-sacrificing job (or simply told to do so in ignorance?!) of the vulve control and the pipe destruction operation (discharging the coolant water and thus discouraging the chain reactions) earlier this morning around 4am, 1 Oct 99, successfully reversing the nuclear criticality. We don't have specific dose data of these operators. According to a reliable indenpendent source of information, which has not yet been double-checked for confirmation though, a site operator who at a later stage in the same morning (around 8:30am) poured boron water into the solution tank in question had as much as 91.2mSv, almost twice the 50mSv annual dose limit of radiation workers.

The figure DOES NOT include, either, the members of the general public around the JCO plant who may well have been exposed to abnormally high atmospheric radiation.

Fri Oct 1 16:26:57 1999
Date: Fri, 1 Oct 1999 22:24:17 (lokal tid) +0900
From: hosokawk@cc.saga-u.ac.jp (Hosokawk)
Subject: MagpieNews #991001d (accident-9th report)

Magpie Country Nukes Headliner
nuclear issues news brief from Japan

Criticality accident at Tokai uranium processing plant



1 October 1999

The Minister of Foreign Affairs, Mr Kohmura, requested USA and Russia to send an expert team to Japan in order to help domestic staff deal with the situaton and investigate into the cause of the accident. US secretary of Department of Energy (DOE), who was happened to be in Moscow, replied that they were willing to prepare.

The Fishery Federations of Ibaragi, which is the umbrella body of fishery unions in the Prefecture, issued a temporary ban on coastal fishing activities for an unspecified period. They will have a head-of-unions meeting tommorrow to consider further measures.

Tokai Village and Naka Town agricultural cooperatives recalled the agricultural products which they had shipped to Tsukiji (the Tokyo Central Food Market). The ban on harvesting in the region continues.

Fukui Prefecture (in west Japan), which has 15 reactors in their jurisdiction, decided to send their administrative staff equipped with monitoring devices to Tokai in order to carry out an independent investigaion.

Self Defence Force has its special decontamination unit vehicle standing by at the Mito Red Cross Hospital.

More than 4,500 people visited hospitals in Ibaraki Prefecture for radiological screening and physical check up. Although no ascertained case of rad contamination has been detected, a mood of panic dominates.

There were several ascertained cases of contamination among the 350m-radius refugees. They claim no health anormalities, however. Medical check-up is going on.

Fri Oct 1 16:07:23 1999
Date: Fri, 1 Oct 1999 22:04:01 (lokal tid) +0900
From: hosokawk@cc.saga-u.ac.jp (Hosokawk)
Subject: MagpieNews #991001c (accident-8th report)

Magpie Country Nukes Headliner
nuclear issues news brief from Japan

Criticality accident at Tokai uranium processing plant



1 October 1999

Some readers queried about the relationship between JCO company and Sumitomo. Well, JCO is a subsidiary of the Sumitomo Metalic Mining Company. ("JCO, Inc." and "JCO & Co., Ltd." are one and the same. It's simply a matter of translation.)

It is one of the only two companies, along with Mitsubishi Nuclear Fuel Co., Ltd., which produce nuclear reactor fuel in Japan. Mitsubishi specializes in PWR fuel, while JCO manufactures nuke fuel for BWR, PWR, and FBR.

A likely reason why the JCO workers mistook the amount of uranium, causing the unreversible criticality, was that they might have used a check sheet for BWR or PWR when actually handling FBR fuel material.

The uranium pin for the FBR Joyo fuel assemblies has 19% of fissile U-235 (with the criticality control mass of 2.4kg) whereas light-water reactors (either BWR or PWR) utilizes low-enriched uranium, i.e. 3 to 5% of fissile U-235 (with the criticality control mass of around 16kg). The latter amount seems to have been mistakenly poured into the nitrate solution in the Tokai accident. If that is the case, it is unbelievably silly and careless deed.

At a press conference at 9am this morning (1 Oct), JCO officials admitted that the workers had handled the uranium nitrate solution "in a manner that was incompatible with safety regulations". For some reason, they did not use the mechanical system which would have controlled the concentration of U-235, but handled the material manually.

This explanation supplied by the company is just very hard to believe primafacie. A more complicated reasons involving combined breaches of the safety regulations are suspect.


The following queries was put up on NukeNet:

"Their earlier report [of the BBC news in London] shows a hole in the roof and describes this current accident. http://news.bbc.co.uk/hi/english/world/asia-pacific/newsid_461000/461446.stm

But, the most recent BBC report makes no mention of an explosion or a hole.

No one else has reported an explosion including news crews in Japan."

Well, apparently there was no such "explosion". We don't know how such piece of information ran through. Australian Broadcasting Corporation (ABC) copied the BBC story (understandably giving a shock to a number of our Aussie mates!)

The absence of an "explosion" by no means alleviates the seriousness of the accident. The unreversible criticality lasted for 20 hours! Nobody was able to control it, or even to physically approach the site of the event!


At 8am (1 Oct), the closure of the Joban Highway, which runs very close to the accident site, was lifted. Railways are still suspending services.

At around 3pm (1 Oct), the sheltering advice (virtually an order) for the general public residing within the 10km radius of the plant site was cancelled by the Chief Cabinet Secretary, Mr Nonaka, representing the Government's emergency responce headquarter, according to the advise of the Nuclear Safety Commission (NSC) who scrutinized the updated radiation monitoring results.


The two victims in critical conditions at NIRS hospital are now suffering from further decrease of lymphocytes --- less than 1% (the normal level is around 40%), rendering an extreme vulnerability to fatal infections. An edema of the lungs is also likely in one of the patients.

It is now apparent that they suffer mainly from external exposure to high neutron and gamma radiation, rather than internal exposure.

Principal treatments tried so far include various drip infusions, steroid medication, and dosage of a uranium antidote.

Radiological doctors are now considering bone marrow transplantation in a slight hope of saving their lives.


At 22:00 tonight (1 Oct), the evacuation of 350m radius area is not yet lifted.



The name of the Prefecture (something like a province or state, but enjoying much less political power than US/Australian states or Canadian provinces do) in which Tokai Village is located is "Ibaraki", rather than "Ibaragi" as reported earlier. The Japanese people would pronounce it either way, but the Prefectural authority has "Ibaraki" as the official romanization.

Fri Oct 1 12:27:07 1999
Date: Fri, 1 Oct 1999 18:01:18 (lokal tid) +0900
From: hosokawk@cc.saga-u.ac.jp (Hosokawk)
Subject: MagpieNews #991001b (accident-7th report)

Magpie Country Nukes Headliner
nuclear issues news brief from Japan

Criticality accident at Tokai uranium processing plant



1 October 1999

Number of those exposed to radiation now reached 49.

Worst ever record of injury in the history of nuclear criticality accident worldwide.

Those hospitalized are still in serious conditions.

In earlier MagpieNews report, it was reported that the dose estimate was 1Sv(=1,000mSv).

This was wrong.

The estimate is at around 8Sv (=8,000mSv).

Yes, it is a lethal dose.

The dose is equivalent or even worse than that of the ground zero at Nagasaki or Hiroshima.

Doctors are working hard to save their lives.

The 10km radius warning to stay indoors was lifted by the Government's emergency responce headquarter (yet to be confirmed by the Prefectural authorities). But the evacuees of 350m radius are told to keep taking refuge.

More info will be sent in two hours time (at around 8pm Japan time). Sorry, I must go right now.

Fri Oct 1 02:15:33 1999
Date: Fri, 1 Oct 1999 08:22:45 (lokal tid) +0900
From: hosokawk@cc.saga-u.ac.jp (Hosokawk)
Subject: MagpieNews #991001 (accident-6th report)

Magpie Country Nukes Headliner
nuclear issues news brief from Japan


Criticality accident at Tokai uranium processing plant


1 October 1999

***All the time and date indications in this report are Japanese Standard Time (JST), which is 9 hours ahead of GST.

At 5pm yesterday (30 September), the radiation counts on the edge of the JCO Tokai uranium processing plant premises remain around 4mSv/h level; it slightly went down to 3.3mSv/h at around 2am (1 October). STA experts estimate that the uncontrolled criticality still continues, or at least it is being repeated intermittently.

The accident is provisionally estimated at Level 4 on INES. IAEA officials claimed that there had been no notification from the Japanese Government. Any nuclear accident above Level 2 should be immediately reported to IAEA.

Chief Cabinet Secretary, Mr Nonaka, said that we are faced with an unprecedented crisis of the nation.

Prime Minister, Mr Obuchi, decided to postpone the reshufflement of his Cabinet that had been proposed for today (1 October).

Ibaraki Prefecture issued an official advice that all the residents within the 10km-radius of the site of the accident should remain indoors until further notice. Affected population is over 310,000. Yes, this is a densely populated area.

The 10km radius area include all the Tokai Village (Tokai-mura) districts and parts of Mito City, Hitachi City, Hitachi-Ohta City, Hitachi-Naka City, Naka Town, Urigura Town, Ohmiya Town and Kanasagoh Town.

People who had voluntarily took refuge to any downwind refuge point were advised to take further refuge, leaving the downwind area. A case of external contamination was detected among the evacuees.

Self Defence Force (SDF, i.e. Army) is being mobilized to control traffic and the public peace. SDF's Chemical Protection Unit has also been called to stand by at Katsuta SDF Base.

All the 135 schools within the 10km area will be closed on 1 October.

All the roads within 1km radius around the JCO plant have been closed. No traffic except emergency vehicles is allowed there.

Japan Railways (JR) is suspending all the train service between Mito and Hitachi stations. Ibaraki Traffics (Ibaraki Kohtsuh), the dominant bus company in the region, has decided to suspend all the services in the 10km area.

Japan Highway Services has closed the Mito/Hitachiminami-Ohta section of the Joban Highway, which connects Tokyo and the Tokai region.

The Prefecture is advising farmers in the Tokai-Naka region not to harvest until safety of the land is confirmed. Rice harvest in the region has almost been finished, and it is the sweet potato harvest time now.

All the Hitach factories in the Tokai-Mito area decided to suspend their operations, with 8,700 workers laid-by.

Tokai Village suspended taking drinking water from Kuji River for fear of radioactive contamination. The water is now supplied from Naka River, which is well far away and is therefore unlikely to be contaminated.

All the 50 post offices in the area will be closed for the day.

Major courier services, such as Kuroneko Yamato and others, will suspend their services today.


It was revealed that JCO had mentioned the possibility of a criticality accident in their first notification of the event to the Ibaraki prefectural administration at 11:15am yesterday (30 September), and that JCO had requested evacuataion of the general public around the plant in their 3rd notification at 12:19 the same day. The accident started 10:35am. The actual advice to the residents was issued at 13:25.


The number of the JCO workers exposed to radiation now reached 27, included the three who had been hospitalized earlier.


According to STA, JCO staff tried to get rid of the cooling water circulation around the uranium solution tank in which the criticality is suspected to be taking place. It is suspected that the water reflects neutrons inwards, helping the chain reactions to be maintained. The work started at 2:58am. Due to high level of radiation, workers had to take 3-minute turns in order to do the vulve.

(Later, at 6am press conference, STA revealed that the vulve work failed to discharge the warter and they had to destroy the coolant pipes to take the water out.)

The Marine Safety Agency's Region-3 headquarter in Yokohama issued a warning to the vessels entering the waters off Tokai coast.

Resource and Energy Agency of the Ministry of International Trade and Industry (MITI) established an emergency office to deal with the Tokai accident and sent 14 expert staff members to the site.

Ministry of Agriculture, Forestry and Fishery also set up their emergency office in order to investigate radioactive contamination of food products.

Prefectural Police now has a 3,000-membered emergency responce group to control the state of affairs.

In a press conference held at 3:30am this morning (1 October), the Ibaraki Prefecture advised the residents as follows:

*Stay indoors. Shut all the windows and switch ventilations off.

*In case of travelling in cars for unavoidable circumstances, keep all the windows of the car shut and avoid using the ventilation fan.

*Tap water is safe, because the source of water supply has been changed.

*Do not drink bore water or rain water.

Local governments are preparing to distribute iodine tablets.

At 5:40am (1 Oct) press conference, STA admitted there was a possibility of expanding the evacuation area (350m radius at the moment) if the situation is not improved. STA said that the radiation monitored at the JCO site had reached 18mSv/h (neutron) and 20mSv/h (gamma).

At 7am, STA declared that the criticality no longer continued. They had poured boron water into the tank, successfully breaking the chain reactions.

Neutron monitors on site now indicate rapid decrease of radiation level.

Number of the exposed workers has now reached 33, including three ambulance staff. The two of the hospitalized three seem to have had extremely high exposure of probably more than 1Sv (=1,000mSv).

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Sidst opdateret 12. oktober 1999