“…where ν is fission neutron multiplicity, and X 0 is the reference (steady-state) 135 Xe concentration. Space-time oscillations of the 135 Xe concentration, imprecisely also referred to simply as "xenon oscillations", are a well-known phenomenon which might also occur during or after other, nonload-following, transients (Gyorey, 1962;Lellouche, 1962;Randall and John, 1962;Shotkin and Abernathy, 1963;Christie and Poncelet, 1973;Bauer and Poncelet, 1974;El-Bassioni and Poncelet, 1974;Onega and Kisner, 1978;Schulz and Lee, 1980;Kobayashi and Yoshikuni, 1982;Moon and Han, 1982;Teachman and Onega, 10.3389/fenrg.2023.1111357 1983; Gondal and Axford, 1986;Berkan et al, 1991;Alten and Danofsky, 1993;Shimazu, 1995;Tiwari et al, 1996;Song and Cho, 1997;Song et al, 1999;Domingos et al, 2003;Marseguerra et al, 2003;Obaidurrahman and Doshi, 2011;Chang, 2016;Pradhan et al, 2016;Zarei et al, 2016). Whereas principles regarding the neutron kinetics are the same for the load-following operations, the objective functions for the control methods differ-typically, axial offsets of the thermal power density, 135 Xe and 135 I concentrations are observed.…”