TWO GROUP THEORY OF CONTROL RODS IN A THERMAL REACTOR

Approximate formulas are obtained on two-group neutron diffusion theory for estimating the effectiveness of completely inserted cylindrical control rods which are sitaated parallel to the axis of a bare cylindrical reactor. It is assumed that the control rods are black to thermal neutrons but do not absorb neutrons of higher energies. The cases investigated include a central control rod, an excentric control rod, and a concentric ring of equally spaced control rods. (auth)