Replacement of Hamaoka Reactors 1 and 2 Nuke Info Tokyo No. 128

On December 22, the Board of Directors of Chubu Electric Power Company decided that it would terminate operations at Hamaoka Reactors No. 1 (540 MW, BWR) and No. 2 (840 MW, BWR) and replace them with a new Reactor No. 6 (1,400 MW, ABWR). (Hamaoka Nuclear Power Plant is located in Omaezaki City in Shizuoka Prefecture.) This is the first ever replacement plan in Japan. The Board also decided that the spent fuel from the spent fuel pools of Units 1 and 2 should be removed and placed in a common dry storage facility to be built onsite for all the plants.

Cartoon by Shoji Takagi

On the same day, Chubu Electric informed the Minister of Economy, Trade and Industry of its plan to close down Units 1 and 2, requested Omaezaki City and the six local fishing cooperatives to allow construction of a sixth reactor, and sought the cooperation of the neighboring two cities and Shizuoka Prefecture.

In its press release Chubu Electric emphasized that rationalization on economic grounds was the reason. It denies strongly that it is closing down the reactors because of aging. Chubu Electric emphasizes this point because it has been telling local governments and others that, given a life span for nuclear reactors of 60 years, these reactors are in the prime of life. Unit 1 commenced operation in March 1976, making it nearly 33 years old, while Unit 2 commenced operation in November 1978, making it just 30. In regard to seismic safety, Chubu Electric concludes, on the basis of its own seismic motion estimate of 1,000 Gal, that reconstruction of major equipment is not necessary.

Nevertheless, Chubu Electric decided in January 2005 to carry out work to increase the seismic resistance leeway of all five reactors. Work on Units 3, 4 and 5 was completed by March 2008. Chubu Electric estimates that the work on Units 1 and 2 would cost over 300 billion yen and take over ten years to complete and that the investment would not be recovered until 2028.

Rather than spend all that money to upgrade Units 1 and 2, which would have less than 20 years left to operate when the work is completed, it makes more economic sense to build a new reactor, which would become operational at about the same time anyway. Besides which, the extra 1,400 MW will not be needed for the next 10 years or so.

However, Chubu Electric’s emphasis on economic rationality and its refusal to admit that safety is an issue only increased the distrust of the local people. The fact that it went ahead with work to increase the seismic resistance of Units 3 to 5, while postponing work on Units 1 and 2 suggests that at the time it was already thinking of closing Units 1 and 2.

At the time when it made its decision on the seismic resistance work, Unit 1 had already been shut down for four years since an explosion in November 2001 ruptured piping in the Emergency Core Cooling System. Unit 2 had been closed down for a year since February 2004, because of the discovery of cracks in the shroud during a periodic inspection. In December 2004 leaks from cracks in a shared exhaust stack were discovered. It was judged that the stack would have to be replaced. As repair costs kept rising, it should have been clear that the plants would not last 60 years.

Was the estimated 300 billion yen plus assigned for upgrading seismic resistance an indication of the extent of the seismic safety problems, or was Chubu Electric looking for an excuse to close down the plants? Was it trying to inflate the cost by opting to go so far as to replace the base mats of the two units? (The base mats of the other three units were not replaced.) In either case, the real issue was safety.

That is why the mayors and the heads of the municipal authorities of Omaezaki and the surrounding cities welcomed the decision to close down Units 1 and 2, even though they complained about the lack of consultation. On the other hand, it seems that they will not readily agree to the construction of Unit 6 or the spent fuel dry storage facility. In anyone’s eyes, in the absence of growth in electricity demand, building a new plant right over the center of the anticipated Tokai Earthquake will be seen as a risky venture. The local population is also unhappy that another plant might be built at Hamaoka to make up for the failure of Chubu Electric’s plans to build nuclear power plants at Ashihama and Suzu.

Another concern raised by the local people, Mayor Kakegawa, and also in an editorial in the Shizuoka Shimbun is the way decommissioning and rebuild, which are both major projects in their own right, are being sold as a package deal. They are saying that Chubu Electric should wait until the local people have accepted that the decommissioning proposal is safe. Chubu Electric’s plan is that Unit 6 will begin operating by 2018, or a couple of years thereafter, but at that stage Units 1 and 2 would either still be standing, or in the process of being dismantled.

It has been pointed out that the cost of decommissioning will exceed the approximately 48 billion yen set aside for the purpose. Chubu Electric announced that it will take a loss disposition of 155 billion yen for the accounting period ending March 2009 owing to the shutdown of Reactors 1 and 2. Besides decommissioning costs, this includes around 50 billion yen for disposal of unused fuel and around 57 billion yen for lost depreciation of fixed assets. Kazuhiro Matsubara, head of Chubu Electric’s accounts division, is quoted in the December 24 edition of the Nikkei Shimbun as saying that this figure could change, depending on how the decommissioning plan actually turns out in practice. The author of the article, Taro Matsushita, makes the following point: “The fact is that it is impossible to be sure of the time required for decommissioning. If the scale of the decommissioning work exceeds predictions, it could put pressure on [the company’s] performance.” Aptly said, considering that these will be the first reactors to be decommissioned in Japan.

The reason why decommissioning and new build are being sold as a package is that without the prospect of a new reactor, decommissioning alone would punch a hole in the rationale for the government’s nuclear energy policy. One feels some sympathy for Chubu Electric on this point. Along with Tokyo Electric and Kansai Electric, Chubu Electric is referred to as one of the big three power companies (Chuo Sansha). As such, Chubu Electric’s President could potentially become the Chairman of the Federation of Electric Power Companies. It would, therefore, be an embarrassment if the percentage of nuclear in Chubu Electric’s generation capacity were to fall. Seen in this light, even if it doesn’t really want to build a sixth reactor, perhaps Chubu Electric had little choice but to offer the decommissioning of Units 1 and 2 and the construction of Unit 6 as a package.

This also suggests that other utilities wishing to close down reactors due to aging might offer decommissioning as a package deal with new construction. There are currently 17 reactors in Japan that have been operating for more than 30 years. The oldest, Tsuruga-1 (BWR, 357 MW), will be 40 years old in 2010, when it is due to be decommissioned. However, the next oldest, Mihama-1 (PWR, 340), which began commercial operations 8 months after Tsuruga-1, had its life extended to 60 years and is not scheduled to close down until 2030. Hamaoka-1 is the tenth oldest reactor, while Hamaoka-2 is the seventeenth oldest, so there are quite a few reactors that are older.

Another perspective on the package deal approach is that it was intended to reduce the impact of the proposal for a dry storage facility. This facility will have a capacity of 700 tons of uranium and it is proposed that it begin receiving spent fuel in 2016. It is supposed to take spent fuel from the spent fuel pools of Reactors 1 and 2, but in that case 2016 will be too late. It appears that Chubu Electric wants to take advantage of this opportunity to build a storage facility for the longer-term future.

Whatever way you look at it, the Hamaoka reactor replacement plan is anything but transparent.

Baku Nishio (CNIC Co-Director)