Japan’s Nuclear Regulation Authority (NRA) this June approved 20-year license extensions for the aging Takahama 1 and 2 reactors, a first for the power-strapped country that has been conflicted about the future of its nuclear power plants since the Fukushima Daiichi catastrophe in 2011.
A regulatory system established in the aftermath of Fukushima limits the operating lives of Japanese nuclear units to 40 years, though it allows a one-time extension of no more than 20 years. The NRA’s approval to allow the 40-year-old Takahama 1 and 39-year-old Takahama 2 to operate an additional 20 years was carried out as an “extraordinary case.” Kansai Electric Power Co., which owns the two 826-MW reactors, filed applications for the extensions in April 2015, as well as for its 826-MW Mihama 3 reactor in November 2015, saying that they were “important” for its business.
Under its revised long-term energy plan, Japan anticipates getting between 20% and 22% of its total generated electricity from nuclear power by 2030, and industry groups like the Japan Atomic Industrial Forum have argued that the lifetime extensions will be integral to meeting that target.
Four of the nation’s nuclear power plants idled after Fukushima have so far cleared the new regulatory standards required to resume operations, but only Sendai 1 and 2, which are owned and operated by Kyushu Electric Power Co., are online. Kansai started up its Takahama 3 reactor on January 29 and Takahama 4 on February 26, but it took Unit 4 offline just three days later following a “main transformer/generator internal failure” (Figure 1). It was then forced to halt operations at Unit 3 on March 10 after Japan’s Otsu District Court issued a temporary injunction against the operation of both reactors because, the court said, the safety of the units could not be guaranteed. On July 12, Otsu District Court Judge Yoshihiko Yamamoto rejected Kansai’s request to lift the injunction. Kansai now says that—though it has filed to appeal the court’s decision to the Osaka High Court—it will begin removing nuclear fuel from the reactor cores.
Meanwhile, applications for 22 more nuclear plant restarts have been filed with the NRA. According to a 2017 economic and energy outlook released by the Institute of Energy Economics of Japan (IEEJ) in late July, at least 12 nuclear power plants should be restarted next year. The research group notes, however, that those projections are clouded by a number of issues, including court judgments and local agreements. That uncertainty could come at a significant cost to the nation, it added.
“Because of the judicial ruling that ceased operations at the Takahama Unit No. 3 and 4, it is important to analyse the effect of stopping operations of nuclear power plants from a local point of view,” the IEEJ’s outlook says. “As a rule, if one nuclear plant with the capacity of 1 MW stops operation for one year in an area where annual demand is about 100 TWh, total fossil fuel costs increase by [$594 million] and the energy-related [carbon dioxide] emissions increases by 4 Mt-CO2 (7% increase for the local emissions). The average electricity unit cost will increase by [$3.96/MWh] (1.8% rise of the average power unit price).”
—Sonal Patel, associate editor