A STATUS REPORT ON REACTIVITY COEFFICIENTS IN FAST REACTORS AND METHODS OF INVESTIGATING THEIR EFFECTS ON REACTOR STABILITY

BS>Methods for predicting the stability of fast reactors in the presence of both positive and negative reactivity coefficients are surveyed. Experimental methods of determining reactor stability are reviewed: excursion, transient, and oscillator. Sources of reactivity coefficients are discussed for both zero power and nonzero power operation. Representative reactivity coefficient values are presented, and positive coefficients due to Doppler effect, fuel bowing, and sodium coolant expansion are discussed. (D.L.C.