Authors & Affiliations

Cho J., Shin Y.-H., Lee S.G., Hwang I.S.
Seoul National University, Seoul, Republic of Korea


As coolant material for fast reactors, Lead-Bismuth Eutectic (LBE) coolant has many advantages; no production of hydrogen, no reaction with water and air, high capability of natural circulation, and negative void coefficients for small-sized core. On the other hand, the demand of fully-passive cooling SMRs (small modular reactors) is increasing worldwide. It is because SMRs are simpler, more standardized than current nuclear power plants, and safer with modular designs by factory fabrication. Also, they require smaller initial capital investment, and having shorter construction time. SMRs could be small enough to be transportable and used in isolated locations without advanced infrastructure and power grid, or could be clustered in a single site to provide a multi-module, large capacity power plant. Also fully-passive cooling without pump even in normal operation enhances the passive safety of nuclear power plants. Thus, the solution integrated by long-burning technology with LBE coolant and fullypassive SMRs can solve the current weaknesses of PWRs by burning nuclear waste, enhancing nuclear safety, and increasing nuclear economy. For the size of reactor power, the power of SMRs should be maximized to maximize the economy of the plant. Moreover, it is necessary to have a specific power level matching the specific demands of towns or sites that are either off-grid or on immature local grids, being right-sized for growing economies and infrastructures of developing countries. Thus, the maximized power level of SMRs should be estimated. However, flexibility of power is limited by land-transportable shipping size, material endurance, long-burning core neutronics, and accident conditions. The paper aims at developing the power maximization method for LBE-cooled SMRs with natural circulation satisfying the constraints including shipping size, material endurance, neutronics as well as safety under beyond Design Basis Events (DBEs).

long burning, fast reactor, lead-bismuth eutectic, small modular reactors, power maximization, natural circulation

Article Text (PDF)


UDC 621.039.5

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, issue 3:4, 2015