From 2011 to 2017 these units underwent significant safety upgrades to enhance their resistance against extreme environmental impacts such as earthquakes and tsunamis.

In 2014, Chubu Electric submitted an application to resume power generation, but the review by the Nuclear Regulation Authority has been progressing slowly, and is still ongoing as of 2024.

[5] Sand hills of up to 15 m height have provided defence against a tsunami of up to 8 m high until 2012, when Hamaoka was equipped with a concrete sea barrier.

[8] Hamaoka is built directly over the subduction zone near the junction of two tectonic plates, and a major Tōkai earthquake was said in 2004 to be overdue.

[5][12] After the earthquake, units 1 and 2 were considered too vulnerable and would have required expensive safety upgrades to meet new seismic standards to continue operation.

Thus, Prime Minister Naoto Kan requested on May 6, 2011 the plant be shut down to avoid a possible repeat of the Fukushima accident.

Kan said that considering the unique location of the Hamaoka plant, the operator must draw up and implement mid-to-long-term plans to ensure the reactors can withstand the projected Tōkai earthquake and any triggered tsunami.

In July 2011, a mayor in Shizuoka Prefecture and a group of residents filed a lawsuit seeking the decommissioning of the reactors at the Hamaoka nuclear power plant permanently, without success.

The barrier would also be 10 meters taller than the highest waves expected in the area in the event of 3 major earthquakes occurring at the same time.

In particular, additional gas turbine generators were installed on high ground for emergency electric supply of cooling equipment.

Ground and supports for pipes and cables had to be reinforced for earthquake resistance, outdoor equipment was secured against object impacts during tornadoes.

[24] In Omaezaki city, restarting or decommissioning the Hamaoka nuclear power plant became a big issue in campaigning for the 15 April 2012 mayoral election.

Of three candidates, the sitting mayor Shigeo Ishihara was willing to grant a restart, after consultation with the city residents and taking into account the "lessons learned form the Fukushima crisis", if he were re-elected for a third term.

[30] The Kishida administration, which governs Japan since 2021 has expressed its devotion to bring as many nuclear reactors back to the grid as possible.