The first unit of India's Kudankulam Nuclear Power Plant was shut down when the emergency protection system was activated; there is no threat to safety, a source in the Indian nuclear industry told RIA Novosti Thursday.

"The emergency protection system of the first unit of Kudankulam nuclear power plant was activated. The tripping of the electricity grid mode operation triggered the activation of the reactor's emergency protection system and the transformer shutdown," the source told RIA Novosti about Wednesday's shutdown.

According to the source, the reactor equipment is in good condition and was working normally when the shutdown occurred. The quick activation of the system indicates the high reliability of the system. The source assured that the unit was equipped with the most advanced security measures and diagnostic systems.

"This event is not qualified as an accident. This is such an insignificant incident that it is not attributed to any level according to the IAEA International Nuclear Event Scale. It means that this event does not affect neither safety of the plant and its personnel, nor safety of the local population, environment and sea," Alexander Uvarov, an eminent Russian nuclear engineer told RIA Novosti Thursday.

Kudankulam's first unit started its commercial operation from December 31, 2014. It is currently the most powerful nuclear reactor in India with a maximum operating capacity of 1,000 MW.

Kundankulam power plant is being built in India's southern Tamil Nadu state with technical assistance from Russia, in accordance with the intergovernmental agreement made in 1988 and an addition to it made in 1988. Nuclear Power Corporation of India Ltd (NPCIL) contracted the project and operates the plant.