The nuclear reactor is expected to take another 24 hours to cool down.

Highlights Water leak in coolant system of nuclear reactor Workers safe, no radioactivity reported outside plant: officials Nuclear reactor in safe stage, is cooling down: officials

An emergency has been declared within the nuclear plant at Kakrapar in Gujarat after a major heavy water leak in a nuclear reactor. No worker has been exposed to radiation, said officials, adding that the employees remained sequestered till their shift ended, which is standard operating procedure for a crisis.The workers were allowed to go home after they had been counted and accounted for as officials checked to ensure that no radioactivity was reported outside the plant.Officials at India's nuclear operator, Nuclear Power Corporation of India Limited (NPCIL), told NDTV "The reactor has shut down safely and no radiation has leaked out". According to Nalinish Nagaich a senior official at NPCIL, no worker was stationed in the affected area.Officials said the safety checks and systems kicked in as intended for emergencies.The nuclear reactor is slowly cooling down and is in a "safe stage" confirmed Dr Sekhar Basu, Chairman of the Atomic Energy Commission.The heavy water leak affected the reactor's cooling system. If emergency cooling systems do not kick in after this sort of glitch, the temperature can rise so much that the core of the reactor can melt down completely.Heavy water, formed with a hydrogen isotope, is used in Indian reactors as a preferred cooling agent.