Six workers suffered significant burns on Wednesday at a Russian-backed nuclear power plant in southern India plagued by years of protests before its opening, reports said.

A hot water spill caused the accident at Kudankulam nuclear plant in Tamil Nadu state, which went into service in July 2013 after becoming the focus of safety and environmental concerns during its protracted development.

"Some maintenance work was going on when there was hot water spillage," plant director R. S. Sundar told the Press Trust of India news agency.

"Three of our employees and three contract workers suffered injuries," Sundar said.

After being given first aid, they were taken to hospital for treatment, he added.

There were no reports of leaked radiation or other serious problems.

Sundar dismissed Wednesday's incident as "small" and said there "was nothing to worry about".

India's NDTV news network said the maintenance workers had suffered 50 percent burns on their bodies.

Last week, India's Supreme Court dismissed a petition concerning the plant submitted by environmental activists, expressing satisfaction at steps taken by the government for safety.

The plant -- the plans for which were first drawn up in 1988 -- is designed to help meet a surging demand for electricity in Asia's third-largest economy where power blackouts are frequent. It employs more than 2,000 people.

The project forms part of India's hopes to achieve a 15-fold increase in nuclear power generation by 2030, according to state-run Nuclear Power Corp.