On control of reactor shutdown involving minimal xenon poisoning.
An application of the theory of dynamic programming to the control of reactor shutdown involving minimal xenon poisoning. After a high-flux thermal nuclear reactor is shut down, the con- centration of fission product xenon may rise for many hours as a result of the decay of fission product iodine into xenon-135. This results in reactor poisoning and may, with consequent loss of efficiency, postpone the time at which the reactor may be restarted. This poisoning may be minimized by carefully controlling the rate at which the neutron flux is decreased during the shut-down operation. The study shows how dynamic programming, assisted by high-speed digital computers with large memories, determines optimal control in this situation.