Decommissioning Japanese reactors

August 19, 2013

Stricter nuclear plant safety standards to force decommissioning of reactors

http://mainichi.jp/english/english/newsselect/news/20130819p2a00m0na012000c.html

The enforcement of stricter nuclear power safety standards in the wake of the Fukushima nuclear disaster has made it realistic that many reactors across the country must be decommissioned sooner or later.

Besides the No. 1 to 4 reactors at the disaster-hit Fukushima No. 1 Nuclear Power Plant, only three commercial nuclear reactors are currently undergoing procedures for decommissioning and dismantling. The three are the Tokai plant with an output of 166,000 kilowatts run by Japan Atomic Power Co. (JAPC), and the No. 1 and 2 reactors at Chubu Electric Power Co.'s Hamaoka plant with outputs of 540,000 and 840,000 kilowatts, respectively.

JAPC estimates that it will cost a total of 88.5 billion yen to decommission and dismantle its Tokai power station, while Chubu Electric Power foresees it will cost a combined 84.1 billion yen to decommission Hamaoka plant's No. 1 and 2 reactors, with the goal of completing the process by fiscal 2036.

However, the NRA enforced new safety standards in July this year to prevent catastrophic accidents involving nuclear plants, similar to that at the Fukushima No. 1 plant. Moreover, the government set the upper limit of the period of operation of each nuclear reactor at 40 years in principle.

The NRA's new safety standards stipulate that the most advanced safety measures must be implemented for existing reactors, requiring larger-scale remodeling for older reactors. Of the 50 commercial reactors across the country, 17, or about 30 percent, have been in operation for more than 30 years. Their operators will be forced to choose between drastically remodeling or decommissioning such aging reactors sooner or later.

It costs a huge amount of money to decommission and dismantle nuclear reactors. In 2007, the Economy, Trade and Industry Ministry estimated that it costs roughly 65.9 billion yen to decommission a boiling-water nuclear reactor like those at the crippled Fukushima plant and 59.7 billion yen to dismantle a pressurized-water reactor like many of those in western Japan. Moreover, the ministry estimated that 3 trillion yen would be needed to decommission all the reactors throughout the country.

Such being the case, the ministry is considering revising the system to use electricity charges to sufficiently cover costs of decommissioning nuclear reactors in anticipation that a large number of such reactors must be decommissioned at the same time under the stricter safety regulations.

In the meantime, the estimated expenses of decommissioning the crippled No. 1 to 4 reactors at the Fukushima No. 1 plant have been only snowballing. Plant operator Tokyo Electric Power Co. (TEPCO) has so far invested 957.9 billion yen on such efforts. However, there are no prospects for developing a method of treating radioactive water accumulating on the premises of the power station in the foreseeable future, and it will cost the utility a massive amount of money to develop new technology to recover and store melted nuclear fuel.

To cope with the challenge, the national government set up the International Research Institute for Nuclear Decommissioning (IRID) comprised of 17 nuclear plant operators including TEPCO earlier this month in an effort to shorten the time required to decommission a reactor, which currently takes up to 40 years.

Hajimu Yamana, president of the IRID, underscored the need to learn from overseas technology for decommissioning nuclear reactors.

"We can't tackle the challenge of decommissioning the Fukushima reactors without learning from the Three Mile Island and Chernobyl nuclear disasters as well as from Britain, which has broad experiences in decommissioning nuclear reactors," Yamana, also professor at Kyoto University Research Reactor Institute, told a news conference on Aug. 1.