In a move aimed at preventing hydrogen explosions similar to those at the nuclear plant in Fukushima,Japan,Indian scientists have designed a device to convert the gas into water before it can explode. Hydrogen can be highly explosive when it comes in contact with oxygen but the hydrogen recombiner,designed by the Nuclear Power Corporation of India Limited (NPCIL) and the Bhabha Atomic Research Centre (BARC),works on a principle that helps the gas combine with atmospheric oxygen and turn into water vapour. The device is ready for testing. The NPCIL aims to install it all 20 plants across the country as part of several steps being taken to safeguard Indias reactors in the aftermath of the nuclear crisis in Japan,where the explosions had blown the roof off the reactor building and sent radioactive substances into the atmosphere. The earthquake in Japan had shut the reactors down automatically. These were cooling down but due to the tsunami,the plant lost all power supply,leading to a breakdown in the core cooling process. The water in the reactor evaporated,escaped and eventually reacted with zirconium,generating hydrogen. The gas escaped into the the reactor building,leading to the explosions. The explosions at Fukushima were all hydrogen explosions. We will soon install hundreds of hydrogen recombiners in each of our 20 operating plants. It will soon be tested, S Dharne,associate director of NPCIL,told The Indian Express. The tests will enable us to ascertain the efficiency of the system. Based on the feedback,we will make modifications,if required. Subsequently,production will start. They will be fitted inside the inner containment of the nuclear power plant. We will assume the worst-case scenario for each of the plants and will accordingly decide the number of recombiners for each plant, he said. Experts say hydrogen gas in high concentration is explosive when it comes in contact with oxygen. A hydrogen recombiner has a catalyst that enables the combination with atmospheric oxygen. When such equipment is fitted inside the plant,the chance of an explosion is reduced substantially, Dharne said. The NPCIL had set up four task-forces to revisit the 20 nuclear plants operating in India and conduct safety audits. Last month,it submitted a consolidated report to the Department of Atomic Energy (DAE). Besides the recombiner,several other measures are being implemented. These include initiation of an automatic reactor shutdown on sensing seismic activity and putting mobile power units beyond the reach of a tsunami. Other steps being planned involve stationing mobile pump units at all plants,and additional shore protection measures across coastal units that involve building a thick wall to absorb the impact of a possible tsunami. We have instructed NPCIL to start working on some of their suggestions. Once the AERB (Atomic Energy Regulatory Board) submits its report,there will be some regulatory stipulations that NPCIL will have to comply with, said Srikumar Banerjee,chairman of the Atomic Energy Commission and DAE secretary.
