On 24 March 1992, the number 3 power generating unit at the Leningrad Atomic Power Station in Sosnovyi Bor underwent an emergency shutdown. The plant suffered a steam leak, which spewed a total of some 3 thousand curies into the atmosphere.
On 24 March 1992, the number 1+2 power generating unit at the Leningrad Atomic Power Station
1+2=3, the number of the unit! I think the model got confused because it can't do addition