Reactor physics on STACY heterogeneous core with light water moderator, 2; Evaluation of nuclear characteristics and reactivity

Izawa, Kazuhiko ; Miyoshi, Yoshinori; Aoyama, Yasuo; Sono, Hiroki ; Ogawa, Kazuhiko ; Yanagisawa, Hiroshi 

Prior to modification of STACY, neutronic characteristics are analyzed to contribute the safety design and regulation. The analyzed items are reactivity coefficients (temperature and void ratio), kinetic parameter (prompt neutron lifetime and effective delayed neutron fraction), and reactor shutdown margin. In the analyses, a Monte Carlo code, MVP, and a neutron transport code system, DANTSYS, have been used with an evaluated nuclear data library, JENDL-3.3.