Nuclear Reactor Dynamic Analysis

To investigate aspects of safety of control of a nuclear reactor system requires a method of analysis of the dynamic behaviour of the system following postulated disturbances or during particular operating conditions. The paper derives equations which indicate the dependence of reactor power dynamics on fundamental design parameters, the ‘reactivity’, and the delayed neutrons, for a static fuel thermal reactor, a static fuel fast reactor, and a circulating fuel thermal reactor. A method of analysis of component temperature variations is presented, with particular reference to a solid-fuel element, clad in a sheathing material, cooled on the outer surface by a flowing coolant. The coolant channel is formed in a solid moderator. A comparison of theory and experiment for the BEPO reactor shows a fair agreement, there being a maximum difference of 10 per cent at maximum power during a transient resulting from a sudden increase in reactivity of 200 × 10−5.