We offer to your attention a preprint “The Cycle Changing of Dynamics of the IBR-2M Pulsed Reactor” P13-2021-11 published by the JINR Publishing Department. The authors are Pepelyshev Yu. N., Sumkhuu D.

It is shown that in the IBR-2M reactor by the end of the reactor cycle, changes in dynamics are observed associated with a strong weakening of the fast power feedback (PFB), as a result of which the reactor becomes oscillatory unstable. When the reactor is shut down, negative changes in dynamics disappear and the stability of the reactor is restored. Thus, the reactor undergoes cyclic changes in the oscillatory instability. The correlation between a fast PFB and a slow PFB is experimentally observed, which makes it possible to almost completely eliminate the cyclic component of instability by changing the control mode of rods of the control system.

Sent to the Nuclear Engineering and Design journal.

The investigation has been performed at the Frank Laboratory of Neutron Physics JINR.

Read the full version (in Russian)