Japan’s Nuclear and Industrial Safety Agency has hinted that it could encase the Fukushima nuclear plants in concrete, as in the Chernobyl incident, if the situation deteriorates drastically.

The agency on Friday said that it is focusing on cooling the reactors down, but it is aware of the Chernobyl option.

In 1986, the Soviet Union encased the entire reactor in Chernobyl, including the debris and contaminants, in concrete to stop the leakage of radiation seven months after the incident.