R. Seepolt et O. Lorenz, SURVEILLANCE OF NUCLEAR-THERMOHYDRAULIC STABILITY IN BWR OPERATION, Nuclear Engineering and Design, 159(2-3), 1995, pp. 183-188
A concept of a survey of the nuclear-thermohydraulic stability during
operation of large modern boiling water reactors is presented. The con
cept incorporates detailed measurements of the stability boundary as w
ell as accompanying evaluations of the stability margin during the ope
rating reactor cycle. An automatic system to avoid unstable power flow
conditions by immediate control rod insertion is an additional elemen
t of the concept. The proper functioning of this system in a practical
event was demonstrated. Thus, inadvertent unstable reactor operating
conditions could be avoided in all completed cycles by means of reacto
r and core loading design together with the enforced surveillance conc
ept.