Available from: NC State University Archives

Publicly-accessible

URL: http://www.lib.ncsu.edu/archives/etext/engineering/reactor/murray/

Nuclear Reactor Digitization Project

Raymond L. Murray Reactor Project Notebook

The relation between excess reactivity and period (e-folding time) is
given by the inhour equation

where τ

The half-lives and yields for delayed neutrons in each group are
available.

that γ

f = 0.0086 and τp = 135 x 10-6 seconds. Theoretically τp = 1/VΣa, thus,
considering only fissionable material we have the ratio of the

tor

τ

We have, then, for the inhour equation

A plot of this is attached to the original report. With an excess
reactivity at 20°C of 0.0157, which is the calculated value for the

Reactor

be used in the design of the c

eontraol amplifiers.

cc: Members of the Reactor Committee

Physical Review, 73, 111 (1948).