Predicting Volcanoes a Risky Game for Japan’s Reactors


After the eruption of Mount Ontake on September 27, Japan’s Kyushu Electric Power Co. has announced plans to continue with the restart of its two Sendai reactors, which are located 50 km away from the still active volcano of Sakurajima. Those plans are meeting with local protest, which the utility company must theoretically overcome in order to go ahead with restart plans set for early 2015. Several media and scientific outlets have challenged the reactivation of Japan’s nuclear industry in light of Ontake’s eruption, which Japan’s scientific community failed to predict, and which has so far claimed the lives of more than 50 people.

On October 8, Kyushu Electric submitted an extension of its safety measures that were approved in September by the Nuclear Regulation Authority, which include more detail on plans to deal with a volcanic eruption near its Sendai plant. The September report already included provisions for a volcanic eruption, but the utility likely felt pressure to make more details of its plan public after last month’s eruption. Kyushu Electric says it will halt operations if researchers indicate a large eruption could occur and then will remove the nuclear fuel from the site, in a process that would take up to five years. The company will receive data on “seismic and tectonic observations” annually, and make that information available to the NRA. If the company deems a situation dangerous enough to warrant removal, company researchers would notify the president, who then would make a decision.

The troubling issue with this plan of action is that it has very little oversight built in, from the government or the NRA. While Kyushu Electric does offer to make its research available to the regulator, there is so far no mention of how the utility might be forced to reconcile itself with independent research, nor mention of the government’s ability to shut down the facility if it is deemed at risk. An additional concern is the company’s own admission that there is no set plan for the removal of fuel rods, should it prove necessary. A spokesperson said that the issue would be “considered when we are actually given orders to do so.”

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On October 9, residents living near the Sendai power plant met with NRA officials to voice their concerns with the potential restart. It was the first of five meetings that will be held by next Wednesday, and was attended by the governor of Kagoshima prefecture, Yuichiro Ito, as well as Satsumasendai’s mayor Hideo Iwakiri. There is so far no clear bar that Kyushu Electric must clear in order to have effectively gained the local communities’ consent. Ito maintains that approval is needed only from the prefectural government and the host city of Satsumasendai, yet two other nearby communities have formally petitioned the governor to seek their approval as well before consenting. To make matters less clear, the newly appointed Cabinet minister in charge of the industry, Yuko Obuchi, has said “obtaining consent from local communities is not a legal requisite for a restart.”

The remaining issue is the level of unpredictability still inherent in monitoring volcanic activity. Utilities like Kyushu Electric have stated that they would be able to detect an eruption large enough to endanger their reactors from any of the nearby volcanoes. The head of the NRA, Shunichi Tanaka, went even farther after nuclear concerns were raised following Mt Ontake, saying “it is unscientific to discuss different events at the same time.” While the level of an eruption on Mt Ontake’s scale might not threaten the Sendai plants, the head of Japan’s Meteorological Agency said this latest eruption was “beyond our ability to predict.”

Assuming that an eruption large enough to affect the Sendai plant would indeed be within the scientific community’s ability to discern, would they be able to detect it five years before it happened? The timeline for effective shutdown and the complete removal of potentially dangerous fissile material does not appear to conform with the still relatively unpredictable nature of volcanoes, or other catastrophic seismic activity. Determining what Kyushu Electric deems an acceptably low level of risk consequently remains unclear as well.

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