Convicted spy Christopher Boyce, apparently determined to die by fasting rather than spend the rest of his life behind bars, arrived last night at the Medical Center for Federal Prisoners.

"Nobody wants to die, but I don't want to go back to prison," Boyce said, according to his lawyer, William Dougherty. " . . . He's afraid if he goes back to prison he would die," Dougherty said.

Boyce was placed in an individual room in the hospital section of the prison and will be kept under close medical observation, officials said.

The transfer from a jail in Everett, Wash., was a "tactical move" that could allow Boyce to be force-fed without a court order, said Robert Christman, deputy U.S. marshal in Seattle.

Joe Crabtree, executive assistant to the warden, said doctors would examine Boyce thoroughly before deciding whether to force-feed him.

Boyce, 28, has refused to eat since he was recaptured in Port Angeles, Wash., Aug. 21, although he has been taking some liquids. A doctor who examined him Monday said he was in good condition.

Boyce was serving a 40-year sentence for selling details of secret U.S. satellite technology to the Soviets when he escaped from prison in Lompoc, Calif., 19 months ago.