S. Ukai et al., DEVELOPMENT OF COMPUTER CODE SAFFRON FOR EVALUATING BREACHED PIN PERFORMANCE IN FBRS, Journal of Nuclear Science and Technology, 31(7), 1994, pp. 662-670
In order to evaluate the breached pin behavior in FBR, the breached pi
n performance analysis code SAFFRON was developed. Based on the result
s of run-beyond-cladding-breach test in EBR-II as a collaborative prog
ram between PNC and U.S. DOE, the following behaviors were taken into
cosideration; fuel sodium reaction product (FSRP) formation, resultant
fuel expansion, breach extension of cladding and release of delayed n
eutron precursors into the coolant. Using 3-dimensional elastic analys
es by finite element method, breached pin diameter increase is adequat
ely predicted with the reduced Young's modulus of the breached fuel. T
he delayed neutron signal response in on-line diagnosis was evaluated
in relation to the growth of FSRP and breached area enlargement.