Tokai JCO Criticality Accident
Few Safety Improvements Seen Since JCO Accident
By Hideyuki Ban[CNIC] (Nuke Info Tokyo 80)
|On 30 Sep. 2000, a year after the JCO accident, about 110 people dressed in mourning clothes gathered in front of the Science and Technology Agency to remind the officials and the public of the accident and the victims who are still suffering physically, mentally, and economically. 400 people attended a symposium following this protest. The day was rapped up with a candle light procession through down town Tokyo. Similar protests and symposiums were held across the country.
A year has passed since the JCO criticality accident, but little improvement can be seen in the safety regulation of the nuclear industry.
This accident was a tremendous shock to Japan's nuclear power industry because in a single instant it destroyed the myth of safety that the industry had built over time. The conclusion of the report by the Accident Investigation Committee established by the Nuclear Safety Commission (NSC) says, "We must discard the 'myth of nuclear safety' and idealist slogans about 'absolute safety'." This shows that the NSC itself has abandoned the myth of safety. But some argue that the JCO accident did not occur in the generating sector, and that nuclear power plants would not have such accidents.
The myth of safety was backed by the industry's implementation of measures from a perspective that gave precedence to "accident prevention," which meant that accidents could be prevented if facilities were provided with engineered safety devices. But the JCO accident occurred where accidents supposedly couldn't. Its occurrence exposed the industry's flaws and showed that the accident had been bound to happen. Specific flaws included the lack of geometrical control on the precipitation tank, and no measures at all to prevent accident worsening. A major reason for this was the facility's flawed safety inspections, which are the responsibility of the NSC and of the Science and Technology Agency (STA), the government administrative agency in charge of the industry. Apparently STA had also neglected to check how the facility was being operated.
The NSC has made 103 proposals to the government and to the industry meant to prevent a reoccurrence, but all are symptomatic and leave doubts as to whether they can effectively prevent a repeat. In fact, one of the items changes the approach on accident prevention that has prevailed until now by saying that we must have a complete turnaround in perception, from "absolute safety" to "an assessment of safety based on risk criteria." This represents a switch from the previous philosophy of putting "accident prevention" before everything else to an approach based on preventing the worsening of accidents and mitigating their impacts. In other words, it introduces the doctrine of risk assessment. Such a change is hard to accept.
Some of the proposals are mere sugarcoating. One proposal to the government is to "perform a follow-up investigation taking into consideration matters like how people living near JCO have been taxed mentally," but in fact the exact opposite is being done. The Health Management Review Committee established by the NSC after the accident claims there is nothing to worry about because the exposure dose was under 200 mSv. It just emphasizes that the situation is safe, and does not lend an ear to what area residents have to say. What is more, JCO paid for only the first health diagnosis, leaving citizens to foot the bill even if they succumb to illness and have to see a doctor. The STA has recently added to its list of exposed people a number of delivery servicepeople, members of the press and others who were temporarily near JCO at the time of the accident and now claims that 667 people were exposed due to the accident. People in Tokaimura have formed a victims' association that is negotiating with the government and JCO for the issuance of accident victim IDs and coverage of medical expenses (See NIT No.77).
NSC's report on the accident therefore is too general and offers no hope of a solution. But through several revisions of laws, STA and NSC have somewhat improved measures for preventing accidents and the worsening of accidents.
Improvement of Nuclear Regulatory Law
Until recently, periodic inspections were only mandatory for nuclear power plants and reprocessing plants. All other nuclear-related facilities were not subject to periodic inspections and therefore, following the accident, periodic inspections were made mandatory at all nuclear facilities. However, periodic inspections would not have prevented the JCO accident. The accident was triggered by the deviation from normal procedures which was brought about under pressure to reduce cost by rationalizing the work process. This "inside manual" was prepared by the company itself. However, such manuals aren't in the criteria for periodic inspections. Similarly, the education of workers on radiation has been made mandatory as well, but the education manual stresses the safety of radiation instead of concentrating on the dangers of it.
Improvements of the NSC
NSC is responsible for keeping on eye on whether the controlling agency is properly conducting periodic inspections and other safety control measures. However, it will only be looking at documents and thus little is expected from this.
Two major improvements were made for the pre-operation safety review. First, manufacturing process has been included in the criteria for the safety review. Not only the facility but the use of it will be included in the evaluation as well. At JCO they were dissolving uranium with nitric acid to purify it, then made it into uranium powder, and following that were re-dissolving it. The process for that final re-dissolution was never made very clear, and a separate line for that process was never set up. The process was thus carried out with existing equipment. There should have been separate equipment for this process since the concentration of uranium was highly different. It will become easier to identify the insufficiency of equipment now since the manufacturing process has been included into the safety review. However, deviations carried out company-wide will be difficult to identify even with this new improvement. Wherever there is even a remote possibility of criticality, geometrical-control*, optimized to the specific conditions in each case, is a more secure and effective way to prevent criticality accidents than mass control and other controls, which are more prone to human error. Unfortunately, such regulation - where safety control is limited to geometrical-control - does not exist yet and even if it did the risk of human error would not be completely eliminated.
* The expression 'geometrical control' refers to control of the dimensions of the containers in which the fissile materials are held.
Following the fact that JCO was handling uranium concentrate to 18.8%, NSC has revised its safety review guidelines for nuclear-related facilities which handle uranium concentrated by 5~20%. The guideline requires facilities to come up with measures to prevent criticality. However, though the guideline has geometrical control as the basis for criticality prevention, it allows companies to rely on mass control by setting a limit to the amount to be handled when it is difficult to equip their equipment with geometrical control. But the JCO accident has taught us that we cannot rely on humans and that only physical geometrical control can prevent criticality. In addition, this new guideline will only apply to newly built facilities and not to the existing ones.
The enacting of the Law on Special Nuclear Disaster Countermeasures
Many were exposed due to the accident because there was a lack of measures to prevent further expansion of the accident and because the officials were slow in directing evacuation and other countermeasures. Since the accident exposed the serious weakness in disaster prevention and countermeasures, the Law on Special Nuclear Disaster Countermeasures was enacted in December 1999. The law has made it mandatory for companies to prepare an accident countermeasure plan and to set up a disaster countermeasure section. This is a welcomed improvement since such requirements were never made before. It also calls for the strengthening of the role of the central government and a speedy reaction by it during a nuclear disaster. However, this law requires countermeasures to be taken for the residents only when the radioactive leak has reached 10,000 times the normal reading. This is extremely insufficient from the view of preventing residents' exposure.
Though many improvements have been made or are in the process of being made, they are not enough. In the background of the accident was the intensifying of economic competition which led to the negligence of safety. It is expected that economic competition will further intensify. Such projections should force the government to further strengthen regulations and safety reviews/inspections. Safety culture alone cannot prevent accidents.
The JCO Criticality Accident Comprehensive Assessment Committee organized by CNIC and the Japan Congress Against A-and H-bombs released its final report in September 2000 and made seven suggestions to the NSC including demands for a reinvestigation of the accident and a commitment to take care of the residents' physical and emotional health. The committee also carried out research into the effects of the accident on the life of local residents. It was found through this field-research that 25% of the residents who were within 350 meters radius of JCO had experienced nausea, metallic tastes in their mouths, headaches, rashes, and many other symptoms after the accident. There has been no aftercare provided by the government. The accident is not over, and the care of exposed and affected residents are the upmost tasks to be seriously undertaken by the government.