In 2018 three Russian scientists were arrested at a top-secret nuclear warhead facility in Sarov for using one of Russia's most powerful supercomputers to mine bitcoin

The Federal Nuclear Center of Sarov in Nizhny Novgorod is where the USSR's first nuclear warhead was manufactured under Joseph Stalin, in a time when the secret town of Sarov was not marked on Soviet maps. Today, it is a top-secret facility surrounded by barbed wire and a no-man's-land where the "All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF)" program is carried out.

These scientists have access to one of Russia's fastest supercomputers, which runs at 1 petaflop, or 1 quadrillion calculations per second.

In early 2018, three scientists were arrested for allegedly using this supercomputer to mine bitcoin. The computer was supposed to be disconnected from the internet for security reasons, and the facility's security department was eventually able to detect the internet connection that the researchers were using when mining. They were caught and handed over to the FSB.

According to Interfax, court documents show that they mined mostly at night between May and September of 2017, and caused $17,700 in "damages" (I assume this means power consumption, but it's unclear).

One of the three, Andrei Rybkin, was sentenced to 3 years and 3 months in a penal colony. Another, Andrei Shatokhin, was given a suspended sentence of 4 years. The third was fined an amount of rubles roughly equivalent to $7,000 USD.

It is not known how much bitcoin they mined.

BBC

Washington Post

I also used Interfax and The Moscow Times as sources, but linking them seemed to be getting my post auto-deleted.