FLNP seminar

01-16-2025 15:00 Conference hall (bldg. 42, 3rd floor)

"Theoretical calculation of the IBR-2M reactor dynamic parameters"

E. Shabalin (speaker), A. Verkhoglyadov, M. Podlesny, Hasan Ahmed, Ya. Vdovin, I. Kushnir, V. Verkhoglyadova.

As is known, the IBR-2M reactor exhibits oscillatory instability at a power of 1.5-2 MW. At present, the reactor dynamics forecast for the near future is carried out by extrapolating the observed trend of the MER (power effect of reactivity) change using a black box model. However, without knowing the real physical nature of the feedback, it is impossible to take technical or administrative measures to guarantee safe operation of the reactor for a long time.

At one time, the physicists of SNIIKZ were given the task of making a substantiated calculation of the IBR-2M feedback, using modern programs for thermomechanical and neutronic problems in three-dimensional real geometry. This work has been completed by now. The main results are as:

Three components of the “power-reactivity” feedback were identified, and their parameters were obtained with satisfactory accuracy.

Three components of the feedback do not coincide with those previously assumed on the basis of the three-exponential model of dynamics, and two of them have nonexponential character.

The obtained results are used in the created dynamics of a pulsed reactor.