Tokaimura (Japan's Sep. 30, 1999) Nuclear Accident:
It's Causes, Health & Environmental Effects

Freshman Seminar:  Technology & Environment
Professor Najmedin Meshkati
Fall 1999
University of Southern California

The Tokaimura Report

 --The Criticality Accident—
  --The Response of JCO Co. and Government Agencies—
 --The Lax Safety Standards and Illegal Procedures at the Tokaimura Plant—
 --The Response of Governmental Agencies in the Aftermath of the Accident—
 --The Employees and Others Exposed to Radiation—
--The Rating of the Accident Based on the International Atomic Energy Agency (IAEA)--
--IAEA’s Preliminary Report on the Tokaimura Accident (released November 26, 1999)--
--Financial Repercussions—

The following students contributed to this section of the paper:

Bernice Algeria
Brian Clifford
Aerospace Engineering
Joseph Deato
Louie Huang
Electrical Engineering

 The Criticality Accident

    On Thursday, September 30, the worst nuclear accident Japan has faced in its history of utilizing nuclear power happened in Tokaimura, approximately 87 miles northwest of Tokyo.  The accident occurred around 1030 hours (local time) when employees of JCO Co., the company which operates the plant, poured 35 pounds of uranium into a purification tank containing nitric acid, instead of the 5.2 pounds normally used (French, New York Times).  What followed was a flash of blue light inside the plant as the result of what has been called a nuclear fission chain reaction.  The Tokyo Electric Power Company rushed 880 pounds of sodium borate to the plant to absorb the radiation emitted, but the workers had difficulty getting close to the processing tank (French). The workers then reentered the facility and crushed the water pipes leading to the tank where the criticality accident was occurring, thus allowing the water to drain.  This eventually allowed the nuclear reaction to subside.  (For more in-depth analysis of the accident, please refer to the American Nuclear Society’s page on the Tokaimura Accident)

 The Response of JCO Co. and Governmental Agencies

    During the accident, JCO and the nuclear monitoring agencies of the government exhibited a lack of decisiveness.  JCO took 61 minutes to notify the Japanese prefecture authorities about the accident.  The company faxed the notification instead of calling the authorities directly (Efron, Rietman, Los Angeles Times).  In addition, it took the company two hours after the incident occurred to ask the village authorities to issue an order for evacuation. Furthermore, the village authorities took another hour to actually issue the order (BBC).  A possible explanation is the failure of the prefecture government to immediately read the report sent by a prefecture monitoring station stating the unusually high levels of radiation detected three minutes after the accident, because “because no one [in the prefecture government] bothered to look at the computer screen” (Efron, October 8, 1999).  Moreover, when the Atomic Energy Research Institute monitoring station, located about 3/4 of a mile from the plant, recorded neutron radiation levels at 0.26 microsieverts, around 20 times the normal level, the employees at the station did nothing and simply regarded the reading as "background noise" (Efron, October 8, 1999).  Twelve hours after the incident, the prefecture finally declared a major emergency in the area (Efron, October 2, 1999).  Around 630 hours (local time) the next day, the reaction finally ended.  The reaction generated an estimated 22.5 kilowatt-hours, “enough to power a one-kilowatt electrical appliance for more than 22 hours” (The Daily Yomiuri, November 5, 1999).

The Lax Safety Standards and Illegal Procedures of the Tokaimura Plant

    According to a Los Angeles Times article, “[t]he Kyodo News Service said it had obtained documents showing that, when JCO applied to the government for permission to build the Tokaimura plant in 1993, it said that ‘there was no need to prepare for a possible criticality accident’ because the company would take the appropriate preventive measures.  According to the news service, JCO assured the government that a criticality accident wouldn't occur ‘because the amount of nuclear substance would be limited according to its density, then weighed to confirm that its mass was within safety guidelines’” (Efron, Rietman). This fact is further compounded by the admission of company officials to the allegations of its usage of an ‘illegal manual,’ which advocated the use of the illegal shortcut, that has caused the recent strings of accidents in the plant for the past seven or eight years (Tolbert, Washington Post).  The shortcuts recommended the use of stainless steel buckets to move and mix the uranium manually instead of utilizing complex machines that were specifically designed for such tasks.  According to Valerie L. Putman, “Before the accident, supervisor(s) and, possibly, manager(s) directed personnel to accelerate [the nuclear fuel] processing further.  Apparently, workers were directed to use the buckets, overbatch [processing two “orders” for nuclear fuel into one process in order to save time and increase profits], and possibly, skip other steps.  Workers might also have decided to skip more steps than their oral directions specified” (Putman).  In addition, the company also under-trained their employees working at the Tokaimura plant.  According to Kenzo Koshijima, the head of the nuclear fuel processing plant, “The company trains new employees on safety for one week but teaches nothing about the dangers of a self-sustaining nuclear reaction” (Kyodo News Service, October 15, 1999).

    The company also failed to install basic defensive measures, such as alarms or high walls, to alert and protect the neighboring residential area.  This omission can be blamed for the failure of the company to detect a ventilator which was spewing radioactive iodine, which can cause thyroid disease, at double the legal limit a week later after the accident (Chicago Tribune).  These cost-cutting measures undertaken by the company clearly undermined the safety of its employees and the populace of Tokaimura.

The Response of Governmental Agencies in the Aftermath of the Accident

    How was JCO allowed to run a nuclear facility with such blatant disregard for safety?  The Government and independent agencies must assume some responsibility for the accident at the Tokaimura plant because they allowed JCO to slip through the cracks.  In fact, the Nuclear Safety Commission’s investigative committee placed the blame for the accident on the Science and Technology Agency for “failing to uncover illegal procedures” (Kyodo News Service, November 5, 1999).  As a result of this condemnation, "the top bureaucrat at the Science and Technology Agency, Toshios Okazaki, recently submitted his resignation.  He offered no explanation" (Reitman).  Furthermore, the JCO plant is not the only nuclear facility with lax nuclear safety standards.  According to a report released by the Japanese Labour Ministry completed after the Tokaimura accident, 15 of 17 nuclear facilities, none involving power plants, failed to meet many health and safety regulations (CBNET).  In fact, 9 out of the 15 violated the Industrial Safety and Health Law (CBNET).

    In the light of the accusations of neglect on the government's part, the government has responded by conducting investigations on the operations of JCO and its nuclear facilities.  In response to the accident, the Japanese government has launched a large-scale investigation with around 200 police officers involved.  The investigation included multiple raids on JCO offices in Ibaraki and Tokyo.  A top official of the Ministry of International Trade and Industry (MITI) said the accident was serious enough to lead Japan to reconsider its nuclear power policy.  The accident's repercussions are important since Japan operates 51 nuclear power plants (French) which produces a third of the nation's energy needs (Tolbert).  Thus, it can be deduced that Japan is highly dependent on nuclear energy to fuel its activities.

    In the wake of the accident, the Science and Technology Agency and the MITI have agreed on the main issues of legislation that would help deal with and prevent nuclear disasters (BBC).  The new legislation includes calls for periodic inspections of all nuclear facilities, improved communications, and training and instruction for employees about nuclear safety.  Another "bill would empower the prime minister to declare a state of emergency and set up emergency headquarters near accident sites, a role now carried out by local authorities" (Reitman).  In addition, "[a]nother bill would require nuclear-related facilities to conduct the same safety checks as nuclear power plants.  It also would require employees to report any illegal procedures to chiefs of related agencies or ministries" (Reitman).

The Employees and Others Exposed To Radiation

    Initial reports list 35 people as exposed to radiation, three of them seriously injured, and 300,000 local residents were ordered to stay indoors (French).  A later report suggested that 63 people have been identified as having been exposed, including 14 workers who entered the plant briefly in an attempt to halt the nuclear reaction, and the three involved in the accident (Tolbert).  Two employees remain hospitalized (Tolbert).  As many as 83 people have been recorded as being exposed to radiation in other reports (Kyodo News Service, November 5, 1999).  The most severely injured workers were exposed to radiation on the order of 700,000 millirems; by comparison, people in this country are exposed to about 260 millirems per year from a combination of natural and man-made sources (Lochner, Contra Costa Times).  The three workers involved with mixing the uranium, which led to the nuclear accident, were exposed to the largest amounts of radiation.  The three workers, Yutaka Yokokawa, Masato Shinohara, and Hisashi Ouchi were exposed to radiation amounts of 3, 8, and 17 sieverts respectively (Malaysian National News Agency, October 11, 1999).  They showed serious symptoms, which included “vomiting, diarrhea, difficulty in maintaining consciousness, a high white-cell count (25,000) and fever,” of radiation (JAIF, 32).  Shinohara has received an umbilical cord blood transplant while Ouchi has received two peripheral blood stem cell transplants (Putman).  The “response” workers reportedly received the next highest doses of radiation, which were less than 0.1 sieverts each (Putman).  The environmental group Greenpeace sent a group of investigators, and their report reveals that the number of people exposed to radiation was higher than government estimated (Tolbert).  It is being reported that 100 millisieverts of radiation covered locations 100 meters from the accident site caused by neutrons being emitted from the plant (The Daily Yomiuri, November 5, 1999).  The data collected on the neutron radiation leads some experts to believe that “a phenomenon called ‘prompt criticality’, a rapid nuclear fission reaction often found in nuclear explosions” may have occurred (BBC).  “Prompt criticality…is reached when nuclear fission energy is released in the one 1,000th of a second. It is believed to be impossible to control.” (BBC).

The Rating of the Accident Based on the International Atomic Energy Agency (IAEA)

    The preliminary rating of the accident on the IAEA's International Nuclear Event Scale, was 4 (Coleman, Associated Press).  (For comparison, to acquire the rating of 7, the highest rating on the scale, an accident will have to be similar to the one which occurred in Chernobyl)  However, as data on the accident became available, there have been serious discussions and reports on the possibility of raising the accident rating to 5 (Coleman).  On October 8, 1999, it was formally announced that the rating will be upgraded.   The fact that the reaction lasted for 17 to 20 hours was enough to raise the accident rating from level 4 to 5 on the IAEA's International Nuclear Event Scale of 7 (Tolbert).

IAEA’s Preliminary Report on the Tokaimura Accident (released November 26, 1999)

    The IAEA published a report on the accident on November 26, 1999.  “The information presented here [in the report] derives primarily from source materials provided by Japanese authorities and institutes [pp. 1-25], corroborated to the extent possible by means of interviews conducted by the team with key officials and experts [pp. 26-28], and observations and measurements made by the team [p. 29]” (IAEA, p. 2).  The Secretariat team obtained their data by organizing “a fact finding mission to Tokaimura from 13 to 17 October 1999" (IAEA, Foreword).

    The IAEA’s report continually reiterates the organization’s conclusion that the accident presented no significant off-site risk (IAEA, Foreword).  This conclusion relies primarily on the fact that “[t]he [Secretariat] team was able to confirm independently that there was no apparent damage to the structural integrity of the JCO conversion building, in particular that the roof appeared to be intact, and that gamma dose rate levels outside the JCO site were normal (IAEA, p. 32).  Thus, the IAEA purports that most of the harmful radiation were contained within the site of the accident (IAEA, Foreword).

    Furthermore, the document also cites the data gained from the samples which were taken from the vicinity of the plant through within Tokaimura’s town limits and were then tested for various forms of radiation.  The samples tested included both potable and non-potable water, various agricultural products like vegetables, poultry and seafood, and soil samples (IAEA, p. 24).  According to the IAEA, the results of these sampling studies show that there were no abnormal radiation levels present in the samples taken (IAEA, p. 24).

    In addition, the report also states that appropriate emergency procedures were undertaken during and after the accident.  The report carefully outlines the sequence of actions taken, which clearly project an orderly procession of actions to counteract the effects of the criticality accident (IAEA, pp. 27-28).

    On the other hand, it is apparent that the IAEA does not recognize the fact that prior to the release of the study, the rating of the accident was upgraded to the rating of 5 on the IAEA’s INES Scale (Tolbert, October 8, 1999).  The IAEA completely ignores the implications of the change in the Tokaimura accident’s rating.  The report fails to address the fact that unusually high levels of radiation were obtained by monitoring stations not situated in the immediate vicinity of the plant (Efron, October 8, 1999).  Therefore, the radiation actually reached areas farther than JCO’s compound.  As a result, it is rational to assume that radiation actually affected the surrounding areas away from to the plant’s confines to a certain degree.

    Moreover, the issue of the integrity and validity of the data used to produce the report surfaces.  For example, the report states that “[a]fter 7 October, measurements were made of the concentration of [radioactive] iodine in air at the exhaust of the building ventilation system [which was discussed previously] and at the site boundary" (IAEA, p. 24).  This finding is utilized to show that even though the ventilation system operated from the time of the accident through October 7 (Chicago Tribune), the air which flowed from the vents did not transport radioactive iodine into the outside environment (IAEA, p. 24).  However, it is apparent that this test was conducted a week after the accident occurred.  Thus, the measurements for radioactive iodine will naturally be lower since the criticality accident has already stopped.  Therefore, the pertinence of this test is highly questionable.

    Another issue which arises is the lack of specific information on when the tests were actually conducted.  By stating that the tests were “conducted immediately after the accident,” (IAEA, p. 24) the background information like the actual time and date of the test’s completion which are vital in determining the validity of the data produced by these tests, were not provided.  As a result, the validity of the data obtained is highly suspect.

Financial Repercussions

    The immediate financial repercussions of the nuclear accident in Tokaimura have not been apparent. Around 400 families and a local farms products company have asked for the operator of the plant to pay them an amount number over 650 million Yen, roughly 6.5 million Dollars (Kyodo News Service, October, 19, 1999).  The farmers have received cancellations for their products and the farmers fear future losses.  Also, the Ibaraki prefectural federation of processed marine products cooperatives has also called on JCO Co. to compensate it with nearly 600 million Yen for its losses incurred after the accident (The Daily Yomiuri, October 22, 1999).  The people living in the Ibaraki Prefecture of Japan, where Tokaimura is located, need this money to survive and keep their businesses operating.  However, the threat of increased future financial losses loom, since orders for products from the Tokaimura region have been canceled, even for products made before the accident.  The financial costs of the Tokaimura accident will take years to surface.  Moreover, the costs for future problems directly associated with the Japanese accident will expose the true damage it has inflicted on Japan.

    It is undeniable that nuclear facilities should be operated under maximum security and extremist caution.  Nuclear power is of such a tremendous force that shortcuts cannot be made without incurring fierce penalties.  Japan relies upon the nuclear power industry to produce 37% of the nation’s energy (Farley, Reitman).  Therefore, it is imperative that the Japanese Government improve its methods of monitoring the nation’s nuclear facilities and enforcing the regulations of maintaining and operating such facilities, if it hopes to have a far better chance of preventing accidents, like Tokaimura, and disasters, like Chernobyl, from occurring again.
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