Keisuke Okumura, Yoshiaki Oka, and Yuki Ishiwatari

Abstract The most fundamental evaluation quantity of the nuclear design calculation is the effective multiplication factor (kf and neutron flux distribution. The excess reactivity, control rod worth, reactivity coefficient, power distribution, etc. are undoubtedly inseparable from the nuclear design calculation. Some quan­tities among them can be derived by secondary calculations from the effective multiplication factor or neutron flux distribution. Section 2.1 treats the theory and mechanism to calculate the effective multiplication factor and neutron flux distri­bution in calculation programs (called codes). It is written by Keisuke Okumura.

The nuclear reactor calculation is classified broadly into the reactor core calcu­lation and the nuclear plant characteristics calculation. The former is done to clarify nuclear, thermal, or their composite properties. The latter is done to clarify dynamic and control properties, startup and stability, and safety by modeling pipes and valves of the coolant system, coolant pump, their control system, steam turbine and condenser, etc. connected with the reactor pressure vessel as well as the reactor core. The reactor core, plant dynamics, safety analysis and fuel rod analysis are described in Sect. 2.2. It is written by Yoshiaki Oka and Yuki Ishiwatari.