There is no end in sight to the accident at Tokyo Electric Power Company’s (TEPCO) Fukushima Daiichi Nuclear Power Station. No one knows what type of damage has occurred where inside the reactor and containment vessel. Each hour 100,000,000 becquerels of radioactive material continues to be released into the environment. On November 2 TEPCO discovered very small quantities of Xenon-133 and Xenon-135 at Fukushima Daiichi Unit 2. TEPCO asserts that this was caused by spontaneous fission not a prompt criticality, but the truth of the matter is still not clear. The reactor still has not been brought under control.
The combined capacity of TEPCO’s Fukushima Daiichi and Fukushima Daini Nuclear Power Stations is 9.1 GW, while the Kashiwazaki-Kariwa Nuclear Power Station (KK) has a total capacity of 8.2 GW. Of all this only KK Units 5 and 6, representing 2.46 GW, are operational. KK Units 5 and 6 are due to enter periodic inspections in January and March next year, respectively, so in March 2012 TEPCO will have no nuclear reactors in operation.
Even if Fukushima Daiichi and Daini are decommissioned, TEPCO still hopes to continue operating all its KK reactors, but that is also likely to be very difficult.
In July 2007 all seven KK reactors were shut down due to the Chuetsu-Oki Earthquake. Niigata Prefecture has three committees considering the technical pros and cons of restarting the reactors. Two of the committees are subcommittees of the other parent committee, which delivers judgments on the basis of the debate within the subcommittees.
The parent committee, the Technical Committee into Safety Management of Nuclear Power Plants in Niigata Prefecture (Technical Committee, 14 members), has met three times since the March 11 Great East Japan Earthquake, on May 19, June 21 and October 22. The Subcommittee into Earthquake and Ground Condition (6 members) has met twice, on August 11 (26th meeting) and August 30 (27th meeting), but the last time the Subcommittee into Equipment Integrity, Earthquake Resistance and Safety (8 members) met was its 51st meeting held on March 8, immediately before the Great East Japan Earthquake. It should quickly reconvene to consider the relevance of the earthquake-induced damage to the equipment and machinery of Fukushima Daiichi to the situation at KK.
Nuclear advocates have lost both map and compass
As a result of the March 11 Fukushima Daiichi nuclear earthquake disaster, the government’s standards for assessing the safety of nuclear power plants are in disarray. Faith in the people whose responsibility it was to assess nuclear safety has totally dissipated.
The government’s current position is that the safety of all Japan’s nuclear power plants will be judged on the basis of stress tests. However, there are problems with the Japanese stress tests in regard to both method and the fact that the assessment standard itself has not been determined. The Fukushima Daiichi accident still has not been brought under control and there are divergent views about the causes of the accident. In regard to Unit 1 at least, Mitsuhiko Tanaka’s interpretation that pipes were damaged as a result of the earthquake is more plausible than the “unpredictable tsunami”interpretation touted by TEPCO and the government. Under the current circumstances, it is impossible to establish assessment standards.
The Nuclear Industrial and Safety Agency will draw up a proposal after hearing the views of 11 experts. On October 28, Kansai Electric Power Company (KEPCO) submitted documents for Ohi-3, as the first cab of the rank. The first hearing was held on November 14. Many people at the hearing voiced the stark opinion that “there are flaws in the nuclear power plant safety review procedures.”
Redesign the Niigata Method
Niigata Prefecture’s two subcommittees engaged in serious debate, and did not simply accept whatever TEPCO told them. However, looking back, in light of the March 11 Fukushima Daiichi nuclear-earthquake disaster, the level of debate so far is probably insufficient to prevent accidents of this type occurring. It is no longer possible to avoid the redesign of these subcommittees and the Niigata method itself. I suspect that is the reason why the Subcommittee into Equipment Integrity, Earthquake Resistance and Safety has not reconvened since the disaster.
Allow me to explain briefly what this Niigata method is.The outcome of assessment committees and review committees established by the central government or prefectures had always been a foregone conclusion from the moment the committee members were selected. Niigata Prefecture established the Technical Committee after TEPCO cover-ups were revealed in 2002. The two subcommittees were subsequently established after the Chuetsu-Oki Earthquake. These two subcommittees both included among their members academics who took a critical position. This was quite extraordinary. To put it another way, Niigata Prefecture, host to the largest nuclear power station in the world, opened a chink, however small, in the defenses of Japan’s “nuclear village.”
But there were problems with the Niigata method, some of which are listed below, along with some pointers to the future.
1. Inadequate debate
The Technical Committee was not a forum for real debate. There were 14 members, but since they all had their own specialist fields, the arguments of the specialists in each field were accepted without debate among the members. Furthermore, the chairs of the two subcommittees, who were also members of the Technical Committee, presented the subcommittee debate in a formalistic manner, failing to correct misconceptions within the Technical Committee about the deliberations of the subcommittees.
2. Unreasonable “engineering judgments” by subcommittee chairs
All too often, when they should have given serious consideration to the debate within their subcommittees, the chairs leant their support to TEPCO, which simply reiterated its subjective “engineering judgments.” These “engineering judgments” were effectively conclusions that had no rational explanation. They were based on instincts built up over the years of what was within the bounds of predictability, and sometimes they could be wrong.
The reality was that there was little option but to rely on “engineering judgments” in the huge and complex structures that nuclear power plants are. For example, a huge number of parts are manufactured in factories, and when they are welded together at the nuclear power plant worksite they do not join up as shown on the blueprint. This is sometimes due to the skill of the workers. Now that we have experienced the huge disaster of March 11, we have learned the lesson that “engineering judgments” must not be relied upon for the grey areas that that cannot be scientifically measured. The subcommittee chairs cannot be too cautious in their facilitation. In light of March 11, the chairs must understand that they may have to take responsibility for their actions.
3. Include more critical members
Although critical academics participated in the Niigata method, they were in the minority. The membership should be at least 50-50. In fact, we need to realize that the time has come for critics to be in the majority.
4. A forum for local resident stakeholders
In the Niigata method the committee members were all academics. This has to be changed. It is essential that concerned residents be involved. They know the local ground condition and are familiar with the operating conditions of the nuclear power station from the time it was first established. It is simply not possible to assess nuclear safety and address residents’ concerns with a membership made up solely of experts from narrow fields. Furthermore, residents are primary stakeholders; if there is an accident they will be the victims.
In view of the above, rather than restarting the reactors, it is essential to establish a new system to thoroughly debate the future of KK, including the option of closing it down permanently. To summarize the above discussion:
1. The Niigata method should be redesigned with the full participation of residents of the local area and the wider prefecture citizenry.
2. The work of the secretariat should not be left to the Prefecture’s Nuclear Safety Response Section. A joint system should be established that includes residents of the local area and the wider prefecture citizenry.
The lessons of this tragedy must be fully learnt in order to prevent a Fukushima catastrophe happening in Niigata.
Yukio Yamaguchi (CNIC Co-director)