More debate needed over volcanoes

August 26, 2014

Experts want more debate on risks of volcanoes near nuclear plant

http://mainichi.jp/english/english/newsselect/news/20140826p2g00m0dm036000c.html

TOKYO (Kyodo) -- As Japan gets closer to the first restart of a nuclear plant under new tighter regulations, experts said Monday it is difficult to predict volcanic hazards and called for more debate on the risks of volcanic eruptions on facilities.

Last month, the Nuclear Regulation Authority said the risks of volcanic eruptions around the Sendai plant -- located in a region of active volcanic sites in southwestern Japan -- are negligible during its lifespan.

It was an effective safety nod based on its operator Kyushu Electric Power Co. continuing to monitor the state of volcanoes and taking appropriate measures if any signs of change are observed.

At Monday's expert panel meeting, however, scientists said there are no established ways to predict future volcanic eruptions, and even when signs of changes are noted, their interpretation is still open to debate.

"It is extremely difficult to predict the timing and the scale of massive volcanic eruptions" with current knowledge in volcanology, said Setsuya Nakada, professor at the Volcano Research Center of the Earthquake Research Institute at the University of Tokyo.

Another academic claimed the primary overseas study cited by Kyushu Electric and the NRA to support their arguments only covers a specific caldera volcano, and it cannot be generalized and applied to other volcanoes.

"It is extremely risky" to conclude that the possibility of volcanic eruptions around the Sendai complex is small enough "only on the basis of one study," said Toshitsugu Fujii, honorary professor of volcanology at the University of Tokyo.

The Sendai plant, on the island of Kyushu, is some 50 kilometers away from Mt. Sakurajima, an active volcano. There are a total of five calderas around the complex.

The odds of an eruption that give rise to a caldera, or a large crater formed by the collapse or explosion of a volcano, are said to be rather slim, but the potential damage could be devastating.

The NRA could order the operator to close down the plant or move fuels out in the event of emergency, but what measures should be taken on what criteria remains uncertain.

NRA Commissioner Kunihiko Shimazaki said at the meeting the regulator will "cope with the matter with responsibility."

On July 16, the NRA decision-making panel approved a draft report on the outcome of safety screenings on the Nos. 1 and 2 reactors at the Sendai nuclear station.

The regulator is expected to release the final version of the document possibly this month. The reactors would be the first among Japan's 48 idled commercial units to meet the new regulations introduced following the accident at the Fukushima Daiichi nuclear plant.

The two-unit Sendai plant is set to go back online after undergoing some other checks and once local consent has been obtained, but the restart is not expected before this winter.

The expert panel on volcanoes will continue discussion on how to monitor possible signs of volcanic hazards, but it will not affect the results of the safety screening, an NRA official said.

August 26, 2014(Mainichi Japan)

August 25, 2014

NRA safety plan over volcano eruptions questioned

Aug. 25, 2014 - Updated 13:43 UTC+2

http://www3.nhk.or.jp/nhkworld/english/news/20140825_32.html

Experts on volcanoes are posing questions about the safety guidelines of Japan's nuclear regulator in dealing with volcanic eruptions.

The Nuclear Regulation Authority, or NRA, guidelines require nuclear power plant operators to take specific actions if volcanic activity could affect operations. The actions include taking nuclear fuel out of the facilities.

The NRA approved a draft safety plan to restart two reactors at the Sendai Nuclear Power Plant which is located about 50 kilometers from an active volcano, Mt. Sakurajima, in Kagoshima Prefecture, southwestern Japan. The plant operated by the Kyushu Electric Power Company.

On Monday, the regulator held its first meeting with volcanologists. They discussed volcanic surveillance and criteria for determining eruption levels.

Volcano experts are raising doubts about the NRA's safety measures in dealing with eruptions. One scientist said there is usually advance warning of major eruptions. But he says it takes years to remove nuclear fuel and this would not leave enough time for removal. Another cited the absence of standards for determining what kind of phenomena indicate the possibility of a major volcanic eruption.

NRA Commissioner Kunihiko Shimazaki expressed his intention to undertake safety measures with a major eruption in mind.

NRA officials said the views of experts will be reflected in the safety measures. The officials added that Kyushu Electric will likely be required to undertake additional safety measures to restart its reactors at the Sendai plant.