Mitsubishi Heavy Industries and a subsidiary of Hitachi will separately develop next-generation nuclear reactors in what could be the first two projects in the government's recent policy shift to push nuclear energy.

Mitsubishi Heavy said Thursday it will develop with four major Japanese utilities an advanced light-water reactor, a new type of pressurized water reactor, or PWR, deemed safer than existing models. The company said it plans to put it into use in the mid-2030s.

The four power companies — Kansai Electric Power, Hokkaido Electric Power, Shikoku Electric Power and Kyushu Electric Power — all operate Mitsubishi Heavy reactors at their nuclear plants.