On August 29 last year, an announcement was made about the long-term cover-up regarding cracks in the reactor shroud. Over the following year numerous horrifying facts have been revealed one after another.

The fragility of BWR technology

The first incident involved hiding cracks in the reactor shroud. This was followed by the discovery that Tokyo Electric Power Co. (TEPCO) had also found cracks in the recirculation piping system, but had failed to report them. Then, there was the cover-up of the results of the leak rate inspection test for the containment vessel. During this series of cover-ups, a so-called "defects standard" was approved despite the fact that there had been insufficient debate in the Diet. The "defects standard" allows nuclear reactors in which cracks have been found to continue to operate if they meet certain standards.

The first official announcement of cracks found in a reactor shroud was made for Fukushima II-3 in July 2001. After that TEPCO ordered a full inspection of its reactors, but, TEPCO continued to report, "no problems have been found" until they announced damage found in Kashiwazaki-Kariwa No.3 last August.

A pipe rupture in the recirculation system could possibly lead to a Loss of Coolant Accident (LOCA), so it is the most important component of the system. Previously, 25% of the pipe's welded line was required to be inspected every 10 years by Ultrasonic Test (UT). After many defects were found, the inspection term was reduced to every 5 years, and the area of inspection has been extended to 100% of the welded line. This represents an eight-fold increase in the number of tests. It was also found that some cracks which had been measured as 2mm using the UT inspection were actually more than 10 mm depth. This suggested that there was a problem concerning the accuracy of the inspection method. The recirculation pipe was excluded from the subject of the "defect standard" and now if any signs of cracks are detected, relevant parts will be replaced. Under the former inspection standard, cracks up to a depth of one third of the pipe's material thickness were considered to be "no problems detected."

The inspection and replacement of the recirculation pipe is made in a small space inside the containment vessel, where inspection workers are constantly exposed to a large amount of radiation. There are only enough inspection workers in the plant makers such as Toshiba and Hitachi to comply with the former inspection standards. As a consequence, it is hardly possible to carry out a thorough inspection for each plant. A large amount of radiation exposure is inevitable during the inspection and replacement of the recirculation pipes. While TEPCO claimed that the irradiated components had been cleaned before the operation, it was reported that a total of 0.3 person-Sv were recorded over 68 inspections and 0.7 person-Sv over the replacement of 6 parts of the recirculation pipe system at Kashiwazaki-Kariwa No.4 (1.2 person-Sv if the planning and preparatory procedures are also included). The highest rate for an individual worker was 8.6mSv during the inspection process and 7.8mSv during the parts replacement process, both of which exceeded the standard for workers' compensation for leukemia (i.e. 5mSv). The cracks in both the reactor shroud and the recirculation pump were found in the SUS316L "improved crack-resistant stainless material," which was jointly developed by the electric power companies and the plant makers. Since the cause of the cracks is unknown, there is no way to take any counter-measures.

No Sign of Regret from the Government and Electric Power Companies

Concerning the maintenance of the reactor shroud, the Nuclear and Industrial Safety Agency (NISA) adopted the "defect standard" approach and allowed the reactors to be restarted. It said, "the material used to constitute the whole system can withstand at least 5 years while it has cracks. Power companies should carefully monitor the cracks and continue operating." For the first time, NISA and the electric power companies stated that the "shroud is not an important component" to ease the anxiety of the public.

From the end of last March, TEPCO and NISA have held several local public meetings in Kashiwazaki-Kariwa. In the midst of all this it was revealed that TEPCO gave beer gift coupons (about 7,000 yen equivalent) to the Mayor and to local assembly members who are in favor of TEPCO to celebrate their election victory. In addition, the company has routinely distributed seasonal gifts to local influential people. It says it intends to continue this custom. TEPCO says, "We apologize. We will try our best to regain your trust." However, this is only lip service. The company's characteristic manner of trampling on the public's moral sensibilities remains unchanged.

Has Local Government Changed?

The Governor of Fukushima Prefecture got to the crux of the matter when he said, "This is a serious accident which shakes to the foundations the public's trust in the safety of nuclear power. Of course the electric companies should be held responsible for what they did, but a great deal of the blame also lies with the government" and "The problem is in the government's bulldozer approach to implementing nuclear policy, regardless of the wishes of the local people." On the other hand, Niigata Prefecture, which has shown its trust in TEPCO for many years, feeling that it had been betrayed, requested TEPCO to stop operation and make a full investigation, but in the end, it gave in in the face of TEPCO's "power shortage" campaign. Nevertheless, thanks to the public support for our claim, the regional governments demanded that all welding lines of the recirculation pipes be inspected, and on September 9 TEPCO reluctantly announced that it would do so. The net result is that the Prefectural Administrations of both Fukushima and Niigata have grown more distrustful of TEPCO.

It will be worth watching how the attitudes of both Prefectures change when considering the future of the relationship between the central government and local municipalities. However, in the case of the councils of the local villages where the facilities are located, they have behaved as if they were company representatives announcing their approval to restart the reactors. In Fukushima the first speech at the reopening ceremony was made by the head of the local government, in Kashiwazaki Kariwa it was the Mayor. It would seem that they are more interested in money than safety.

All Japan Council of Local Governments with Atomic Power Stations--an organization to help support local governments solve issues arising from the presence of nuclear power plants--is promoting a "Spent Nuclear Fuel Tax" scheme. Revenue from the fixed property value tax on nuclear power plants has been decreasing sharply. The Council maintains that the income from subsidies will not be enough to provide for the facilities they need, so they need a "Spent Nuclear Fuel Tax." The Federation of Electric Power Companies (FEPCO) and the Ministry of Economy, Trade and Industry (METI) resisted, claiming that "electric power companies already contribute their fair share to the local areas, that they carry a heavier tax burden than other industries and that it will amount to double counting because the Prefectures already levy a 'Nuclear Fuel Tax' on nuclear fuel." But on August 1, influenced by the recent scandals, TEPCO agreed to pay the "Spent Nuclear Fuel Tax." Kashiwazaki City will tax the spent fuels stored at the reactor site from October and Sendai City in Kagoshima Prefecture will levy the tax from next April.

(Kazuyuki Takemoto*)

*Member of The Coalition Against the Kashiwazaki Nuclear Power Plant and a Board member of Citizens' Nuclear Information Center

Return to NIT 97 Contents