Three years after new nuclear plant safety rules were adopted in the wake of the Fukushima nuclear disaster, work continues to evaluate whether plants meet the new requirements and can be restarted, while the requirements themselves face criticism as insufficient.
July 8 marks three years since the new, stricter rules came into force. The rules include stronger precautions against tsunami and earthquakes, and require electric utilities to prepare against large-scale disasters, which had previously been left to their own discretion.
So far applications for 26 reactors at 16 plants have been made to the Nuclear Regulation Authority (NRA) for the safety evaluations necessary for restart. Seven reactors at three plants have passed their safety evaluations, although only two reactors at Kyushu Electric Power Co.'s Sendai nuclear power plant in Kagoshima Prefecture have actually been reactivated so far.
Meanwhile, six reactors have been tabbed for decommissioning due to a law limiting reactor operations to 40 years that went into effect at the same time as the new regulations. Before the Fukushima disaster, there were 54 nuclear reactors in service in the country. However, there are now 42 reactors considered eligible for operation after 12 were slated for decommissioning -- the six aging reactors plus six more at the disaster-stricken Fukushima No. 1 nuclear plant.
Among the seven reactors at three plants that have passed safety evaluations under the new regulations, the No. 3 and 4 reactors at Kansai Electric Power Co.'s Takahama nuclear power plant in Fukui Prefecture that restarted in February this year had their operation suspended by a temporary injunction from the Otsu District Court in March. The No. 1 and 2 reactors are not planned to be restarted until October 2019 or later, so the only reactor with reactivation anticipated soon is the No. 3 reactor at Shikoku Electric Power Co.'s Ikata nuclear power plant in Ehime Prefecture.
Shunichi Tanaka, head of the NRA, calls the new nuclear regulations "the strictest in the world." At a July 6 press conference he said, "We are taking more than enough measures to make sure another disaster like the Fukushima one doesn't happen."
The possibility of terrorist attacks on nuclear plants remains an issue. In its March injunction the Otsu District Court cast doubt on preparations against large-scale terrorist attacks stipulated under the safety regulations, saying that they go "beyond the range of what safety regulations can cover." The new regulations require the installation of equipment to allow remote cooling of nuclear reactors in case of terrorist attacks, but there is a grace period, including for the already restarted Sendai plant reactors.
Kunihiko Shimazaki, a former NRA deputy chairman, spoke in June this year about the predicted earthquake levels at nuclear plant sites, saying that under the current calculation method earthquakes could be underestimated in some locations. He called on the NRA to redo the calculations with a new method, which could change the expected earthquake severity in some areas and affect what earthquake preparation measures are deemed necessary.
Additionally, the safety regulations do not require power utilities to create evacuation plans for residents nearby to nuclear reactors, raising another issue to be solved that is not covered by the reactivation requirements.
The International Atomic Energy Agency (IAEA) has, meanwhile, expressed doubts over the way safety checks are conducted after a plant's reactors have passed the safety evaluation and been reactivated. In an April IAEA report, the agency called for an improvement to the current situation of the NRA only checking on reactors once every quarter.
Muneo Morokuzu, former specially appointed professor of the University of Tokyo's Graduate School of Public Policy and an expert in nuclear regulations, says, "We have the fact that until now there were safety checks of little substance being done. First we have to improve the level of the safety check officers."