There has been a series of significant nuclear accidents over the past few years. To name a few, there was the Monju sodium leakage accident in December 1995, the Tokai reprocessing plant asphalt drum explosion accident in March 1997, and the JCO criticality accident in September 1999. On each occasion, the electric companies claimed that the nuclear power plants are operated with strict safety management. Since August 2002, however, Tokyo Electric Power Company (TEPCO), the largest electric utility in the nation and several other electric companies have plunged into a chain of scandals. On August 29 at 6 p.m., the Nuclear Industrial Safety Agency (NISA) announced at a press conference that TEPCO had falsified voluntary inspection reports and concealed it for many years. TEPCO admitted the stated facts at the press conference later in the same day. According to the agency, TEPCO has falsified the inspection records and attempted to hide cracks in reactor vessel shrouds in 13 units of the 17 nuclear power plants owned by TEPCO, including Fukushima I (6 reactors), Fukushima II (4 reactors), and Kashiwazaki-Kariwa (7 reactors). However, the agency maintained that there should be no problem regarding the safety of the nuclear power plants. Ironically, the safety assessment by the agency was based on TEPCOs calculation.The TEPCOs wrongdoings were exposed as a result of a whistle-blowing by a former engineer at General Electric International Inc. (GEII) in information given to the then Ministry of International Economy and Industry (MITI) (the former body of the Ministry of Economy, Trade and Industry, METI) on July 2000. The tip-offs revealed the falsification of inspection records regarding cracks in a steam dryer, as well as the attempt to hide the repair work for the cracks by the editing of video tapes. This insiders information was never taken seriously by the then MITI (after January 2001, the NISA took over administrative authority from the METI) and the case was left virtually untouched for two years. We needed a time to protect the status of the whistle-blower and we didnt know whether we had the right to investigate the case, said the agency after the press conference on August 29. On the contrary, it was found later that the METI leaked the whistle-blowers name to TEPCO, which clearly suggests the Ministry failed to support the person who blew the whistle on corporate corruption. While TEPCO had not taken any appropriate measures against the insiders tip-offs, it set up a special joint inspection group in conjunction with GEII on May 2002 to investigate the case, suspecting that there might be more falsification cases in the company.
It has been confirmed that there are 29 cases of falsification, which were related to damage in many parts of the reactor pressure vessel such as core shroud, jet pump, access hole cover, feed water spurger, on-core monitor housing and others. The NISA and the TEPCO published interim reports on September 13 and 17 respectively, which addressed the 29 suspected cases in more detail. Regarding the cracks detected in the core shroud, according to the report, they had been already found at Fukushima I Unit-1 and Unit-4 in 1993, where the cracks in the middle part of the shroud at Fukushima I Unit-2 in 1994 were reported officially as the first case. The magnitude of the cracks in Fukushima I Unit-2 turned out to be far greater and more serious than the ones announced by the official report. It has also become clear that reactors in Fukushima I Unit 1, 3, and 5 have cracks in each shroud, so the claim that no cracks were found in the core shrouds and that they were replaced as a preventive measure is completely false.
It is reported that cracks were found in the core shrouds of Fukushima II Unit 2, 3, and 4 and Kashiwazaki-Kariwa, 1 and 3, which is composed of the anti-stress collision crack material (SUS316L) after 10 years of their operation. It is now clear that there were more than 29 falsification scandals.
On September 20, other damage cover-ups in the re-circulation pipe system were revealed in TEPCOs eight nuclear reactors, as well as Onagawa Unit-1 of Tohoku Electric Power Company and Hamaoka Unit-1 of Chubu Electric Power Company. In addition, other cracks in the core shroud were found at Onagawa Unit-1, Hamaoka Unit-4, Tsuruga Unit-1 (Japan Atomic Power Co., Ltd), and Shimane Unit-1. As has been pointed out, this series of cover-ups showed the scandal was not merely TEPCOs particular problem but involved most of the nations electric companies (see map below).
Electric companies have made most data falsifications during voluntary inspection. There have been a growing number of damage cover-ups and data falsifications around 1994 when electric companies had started shortening the time for a periodical inspection having learned from the success experience in the U.S. In the same period, similar cracks were found in the core shroud of BWRs in many countries including the U.S., Sweden, Taiwan, Spain, and Germany, which have become serious issues in such countries. Although similar cases were also found in some of the reactors in Japan, electric companies only partially announced these accidents to the public.
Moreover, TEPCO falsified data from the containment vessel leak rate inspections conducted during periodical inspection at Fukushima I Unit-1by injecting compressed air into the containment vessel in order to pass the inspection. The falsification of containment vessel leak rate inspections at Fukushima I Unit-1 was revealed at the end of September, one month after the TEPCO scandal, and the TEPCO received the penalty of suspending the operation of Unit-1 for 12 months when it admitted the camouflage with the inspection report. However, it has been pointed out that a similar camouflage method during the inspections has been conducted in other units of the Fukushima II. Has the camouflage only been practiced in Fukushima I Unit-1?
The healthiness of Reactor Pressure Vessel (RPV)s head parts at PWRs should be another focal point. As mentioned earlier in this article, replacements of the core shroud were carried out as a preventive measure, which means to ensure the healthiness of the shroud, at Fukushima I-1, I-3, and I-5. However, TEPCO never reported to the agency that there were cracks in these shrouds. Several electric companies (Kansai Electric Power Co., Shikoku Electric Power Co., and Kyushu Electric Power Co.) have replaced their 11 units of reactor vessel head (all of them are PWRs) as a preventive measure. Did these reactor vessel heads have any defects at the replacements?
Although each electric power company submitted their interim survey reports on the scandal on November 15 according to NISAs request, the reports only addressed the history of voluntary inspections conducted for the past 3 years. What about the voluntary inspections conducted more than 3 years ago, or the examination records by inspection companies and the periodical inspections other than voluntary inspections? According to several sources, the then MITI has instructed electric companies to hide accident reports. Although NISA only accused TEPCO, it has never attempted to investigate the MITI itself. The TEPCO scandal only reflects the tip of the iceberg; the depth of the injustice by the electric companies and bureaucrats concerning nuclear power in Japan has not yet become fully resolved. However, the administrative body such as NISA is trying to adversely ease nuclear safety regulations despite the fact that failure in the regulation was the primary cause of the scandal.
In order to increase the availability factor of nuclear power plants, NISA has been preparing to simplify periodical inspection procedures. The agency is trying to introduce into nuclear safety regulation the so-called "safety allowance measure", which reflects the assessment of defects during operation. The proposed measure is intended to supplement the present technical standard, which defines the specifications of plant design and modification. The measure is intend to cut costs incurred by the maintenance of aged nuclear plants, and adoption of the standard should directly lead to lower the safety margin of nuclear reactor. Especially for aged nuclear power plants, more severe safety regulations should be established by applying the principle of preservation of order and public safety.
While the TEPCO scandal has had enormous societal impact, local governments of electric power source area, where they have been cooperating in the development of nuclear energy, rage at the scandal, realizing that they have been deceived, and their anger is ever stronger. Prior agreement on the Plu-thermal program was canceled not only by Fukushima prefecture, which has criticized the government nuclear policy, but also by Niigata prefecture. The Plu-thermal program has effectively come to an end. Then, there is no rationale for the plutonium use. What is Rokkasho reprocessing plant for, which has been constructed to start operation in 2005? We should abandon nuclear power, which is only maintained with falsification.
(Chihiro Kamisawa and Satoshi Fujino)
Map: The TEPCO scandal triggered the revelation of numerous damage cover-ups at the NPPs of other electric power companies. However, these cover-ups are only the tip of the iceberg. The scandal resulted in a setback for the Plu-thermal program (mixed oxide of uranium and plutonium fuel in LWR), which raised more questions about the reprocessing plant planned in operation 2005.
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