THE REACTIVITY EFFECT DUE TO NEUTRON STREAMING IN AN EMPTY TUBE

摘要

The critical size of a reactor is increased when neutrons can stream along an empty tube passing through the reactor. A perturbation method has been used to calculate the change in re¬production constant required compensating for streaming in an empty tube parallel to the axis of a right cylindrical reactor.nThe effect of removing moderator from tubes inserted in ZEEP has been measured for tubes with radii in the range 1 cm to 8 cm. After making minor corrections for effects other than streaming, the experimental results are in satisfactory agreement with the calculations. The reactor constants necessary in making the comparison were obtained from the change in critical size due to a known absorber which was placed at the lattice site in question.