Grant: NSERC/NRCan/AECL Generation IV Energy Technologies Program

Here we propose to analyze the nuclear safety performance of the SCWR, a Generation IV nuclear system, based on the following two considerations: excellence in safety and reliability and a very low likelihood and degree of reactor core damage. Because the SCWR is a nuclear system, its general behavior is controlled by reactor physics, which is used to predict the population of neutrons in the core with time as well as the changes in reactivity resulting from variation in the core properties. These changes may take place as the reactor operates and their impact on the reactor safety must be assessed. One must also minimize the likelihood of core damage that could result from postulated accident scenarios. This implies selecting a fuel configuration that will make the coolant void and power reactivity coefficients negative while optimizing fuel consumption. Finally, the efficiency of the reactivity control mechanism and shutdown systems for operation conditions or during accident scenarios must also be assessed since they play an important role to ensure the safety of the reactor. Our research program is aimed at characterizing the safety parameters of the SCWR using the chain of reactor physics codes DRAGON (an industry standard toolset (IST) code of the Canadian nuclear industry for lattice cell calculation) and DONJON (a finite reactor diffusion code). It will consist of three parts. We will first generalize the CANDU simulation procedures to the SCWR problem and compute the various safety related parameters associated with the SCWR. Then we will refine these reference models in such a way that environment dependent DRAGON simulations are taken into account in DONJON. Finally we will optimize the SCWR design towards higher safety and improved fuel consumption starting with the fuel and reactivity control devices. We will also perform a series of optimization studies from which we will propose a refueling procedure (maximize fuel burnup) as well as locations for the reactivity control mechanisms and neutron detector (optimized for effectiveness) in the core.