Business has been slow at a Larsen & Toubro Ltd. factory in western India that makes parts for nuclear power plants. The Mumbai-based construction company opened the plant in 2012, hoping to profit from government plans to build more reactors in a country where more than 200 million people lack access to electricity. But most of the projects have gone nowhere, and L&T’s facility in Hazira is running at one-fifth of capacity. “That’s not the best use of resources,” says Senior Vice President Y.S. Trivedi.

L&T’s factory could soon be humming. On June 1, Indian Prime Minister Narendra Modi and Russian President Vladi