"The fire occurred at around 8:30, when the submarine was being cut up," an Emergencies Ministry spokesman said. "As a result of the fire one person died, and another was injured."
"There was no nuclear reactor on the submarine," he said.
A large fire broke out in a section of the submarine while a flame-cutting torch was being used, the Zvezdochka plant's chief engineer Oleg Frolov said.
The fire seems to have been caused by diesel fuel igniting, he said.
The incident occurred during the dismantling process in the third section of the "Shchuka" submarine, classified by NATO as "Victor III."
"This year we plan to dismantle eight nuclear submarines at the factory.... Two have already been dismantled," Frolov said.
Such incidents are extremely rare during dismantling work, he said.
"In this case, one flame-cutting torch operator was working, while another was checking for fire safety," he said.
The submarine is not owned by the Russian Navy, First Class Captain Igor Dygalo said.
In July 2000, the submarine was decommissioned. Last year it was handed over to the Federal Agency for Nuclear Power, who then passed it to the Zvezdochka factory for dismantling, Dygalo said.
Investigations into the fire are underway.
