The No. 2 reactor at the Onagawa Nuclear Power Station straddling the town of Onagawa and the city of Ishinomaki, both in northeast Japan's Miyagi Prefecture, has resumed operating in the first restart of a nuclear power plant damaged in the 2011 Great East Japan Earthquake. Constant reviews of safety measures and evacuation plans are crucial.

The Tohoku Electric Power Co. plant grounds sank by about 1 meter due to the quake that locally measured a lower 6 on the 7-point Japanese seismic intensity scale. While its elevated location helped it avoid a direct tsunami impact, seawater flowed into underground channels, damaging equipment in the No. 2 reactor. Fortunately, a catastrophic accident such as the one at the Fukushima Daiichi Nuclear Power Station was averted.

Tohoku Electric has since improved earthquake resistance and tsunami countermeasures, clearing inspections by the Nuclear Regulation Authority (NRA) in 2020. Local governments, including that of Miyagi Prefecture, later approved the restart.

Since the 2011 disaster, no nuclear plants in eastern Japan had been turned back online. The government has promoted restarts on the grounds of addressing power shortages. However, the Sanriku coast on the Pacific has seen large earthquakes throughout history. There's no room for negligence in preparing for a "multiple disaster" scenario involving both natural disasters and nuclear accidents.

On the Sea of Japan coast's Noto Peninsula, home to Hokuriku Electric Power Co.'s Shika Nuclear Power Station, a powerful New Year's Day earthquake caused houses to collapse and disrupted roads, underscoring the challenges of evacuating or sheltering at home or elsewhere to avoid radiation exposure.

The Onagawa plant's location complicates evacuation efforts due to its rugged, ria coastline on a peninsula facing the Pacific Ocean. Scattered settlements on few plains are also vulnerable to isolation -- a situation similar to that of the Noto Peninsula.

Following the Noto Peninsula quake, the NRA began reviewing shelter-in-place policies. However, their interim report did not address the issues of making houses better equipped to resist tremors or how to respond to road disruptions, citing these as outside its purview.

The Noto Peninsula was additionally hit by heavy rains this September. Risks of disasters are rising in the country. If authorities are to seek local residents' understanding for reactor restarts, relevant government ministries and agencies must work together on measures to address multiple disasters.

Chugoku Electric Power Co.'s Shimane Nuclear Power Station, expected to restart in December, is the only plant in Japan located in a prefectural capital. Despite this, concerns remain that adequate evacuation measures are not yet in place for many residents.

While nuclear safety measures have been enhanced, complacency is dangerous. The role for the national government, local authorities and power companies is to heed the lessons of the Great East Japan Earthquake and take all necessary precautions to protect lives.