National

Half of radiation monitors around Kagoshima plant not up to the job

Kyodo

About half of the monitoring posts around an active nuclear power plant in Kagoshima Prefecture are unable to detect the high radiation levels that would spark an immediate evacuation of residents.

Of 48 monitoring posts installed within 5 to 30 kilometers of Kyushu Electric Power Co.’s Sendai plant, 22 can only detect radiation levels of up to 80 microsieverts per hour — far lower than the 500 microsieverts per hour that would spark an immediate evacuation. The plant was restarted last year.

The government’s guidelines say residents within a 5-km radius of nuclear plants must evacuate immediately in the event of a severe accident, but that those living between 5 and 30 km of the site should take shelter first and then evacuate if a radiation dose of 500 microsieverts per hour is detected.

A Kagoshima Prefectural Government official said there is “no problem” with its monitoring, because the government will make a decision on any evacuation based on data from nearby devices that can measure high radiation levels, and portable measuring devices can also be used.

But of the 44 portable devices that the government can use, 30 can measure radiation levels of up to only 100 microsieverts per hour. Moreover, the government may be unable to use the devices at the locations it wants to, such as if an earthquake or other natural disaster were to sever roads and disrupt traffic.

The local government installed the 48 monitoring posts ahead of the restart of the No. 1 reactor at the Sendai plant last August, which became the nation’s first unit to be brought back online after stricter safety regulations were introduced following the 2011 Fukushima nuclear disaster.

Meanwhile, a newspaper reported Monday that Kyoto Prefecture has missed its own target for setting up monitoring posts around Kansai Electric Power Co.’s Takahama nuclear power plant in neighboring Fukui Prefecture.

The Asahi Shimbun said Kyoto Prefecture planned to set up monitoring posts at 41 locations, but as of the end of February, 27 monitoring posts were not in place.

This means the No. 3 reactor restarted operations in January without the ability in place to assess fully the fallout from an accident. The newspaper quoted the prefecture as saying it will set up the remaining 27 posts by the end of this month.

Takahama’s No. 3 reactor was halted after the Otsu District Court last week imposed a provisional injunction on its operation.