Russia hid details about nuclear accidents — here’s what we know

It’s no coincidence that many details of Chernobyl are still shrouded in mystery.

Since the Soviet Union began developing nuclear technology in 1943, Russia’s government has tried to keep the details about that meltdown and a handful of nuclear accidents quiet. In some cases, details haven’t emerged until decades later.

Some disasters, like Chernobyl, have been related to nuclear power, while others involved military tests or atomic bombs. One nuclear event was only detected after scientists observed radiation in the air.

Here’s what we know about a handful of those incidents.