TEPCO found radiation of 25 sieverts an hour on a duct, which connects reactor buildings and the 120-meter-tall ventilation pipe.
The estimated radiation level is the highest ever detected outside reactor buildings. People exposed to this level of radiation would die within 20 minutes.
The exhaust pipe in question was used to release radioactive gases following the outbreak of the accident 2 years ago.
TEPCO says radioactive substances could remain inside the pipes.
From NHK World
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