CRP-2B (Crisis Relocation Program 2B) is a hypothetical scenario of nuclear war between the United States and the Soviet Union that was created in 1976 by the Federal Emergency Management Agency. It involved the detonation of 1444 weapons, with a yield of 6559 megatonnes, and projected a death toll of between 85 and 125 megadeaths.
The program was referred to as a "study", but in fact it was the product of a computer simulation. It was also the source of an 80% survival rate figure that was quoted by many people in the years afterwards. The 80% survival rate was an initial assumption, built into the parameters of the computer simulation by its designers. But as the program came to be a "study", so the survival rate figure came to be the "finding" of the study.
Charles F. Estes Jr., director of strategic police at the Office of the Undersecretary of Defence for Policy, stated:
It was assumed at the outset that 80 percent of the population of hypothesized target areas would in fact have been evacuated and would survive. […] [T]his was an entering assumption rather than one of the study's analytically derived findings. […] It is importance to note that the survivability assumptions […] of the computer model were derived from opinions of interested civil defense program managers, academics, and contractor personnel These opinions were obtained through the use of accepted opinion survey techniques.
This 80% figure was quoted in the 1980s by U.S. congressmen and other officials.