A Modal-Based Reduced-Order Model of BWR Out-of-Phase Instabilities

BWR Parametric Sensitivity Effect of Regional Mode Instability on Stability Boundary

“…One is a qualitative approach with a three-dimensional nonlinear dynamics model to simulate the phenomenon and to evaluate the neutronic flux amplitude distribution, then to build up the detection ability of the oscillation (Muto etal.,1990;Takigawa, 1987). The other approach developed is defined as a qualitative or quasi-quantitative study with reduced-order model, by which to explaining the mechanisms of regional mode (Hashimoto, 1993;Turso, 1997).…”

Monitoring and Control Research Using a University Reactor and SBWR Test-Loop

“…Furthermore, out-of-phase instability characteristics were incorporated in the HRS by using a modalkinetics formulation [6,8] and simulation of parallel boiling channels. The modal kinetics model is given as a set of four equations for the amplitudes of the fundamental mode n 0 and the first harmonic n 1 :…”

Models and Stability Analysis of Boiling Water Reactors

“…Here and everywhere below, we retain the subscript j q 5 on all terms in order t o clearly distinguish between the overall average temperature of the fuel rod Taug(t) in the channel used in Eq. (20), and the average temperature of the fuel rod in each of the two axial regions The pellet surface temperature deviation can be evaluated in two different wayseither directly from the expression for the pellet temperature [Eq. (go)] by evaluating it at T = rp to give or by relating it to the average quantity Oavg,jd(t) defined in Eq.…”