Development of transportable capsule version of Peacer design

Based on earlier large- and medium-scale burner designs of PEACER (Proliferation-resistant, Environment-friendly, Accident-tolerant, Continual and Economical Reactor), a small proliferation-resistant transportable power capsules designated as PASCAR has been developed by capitalizing on outstanding natural circulation and chemically stability of lead-bismuth eutectic (LBE) coolant. This class of design employs an integral reactor capsule including a core of U-TRU-Zr-alloy fuel rods in open-square lattice and in-vessel steam generators with no pump. A capsule can deliver a reference thermal power of 100 MW cooled by LBE with a power conversion efficiency of 35%. The elimination of primary pump and the utilization of advanced structural materials as well as optimized hot-leg temperature enable continual operations for a period of 20 years with an initial loading of core with less 20% of fissile element concentration. The natural circulation capability leading to uncompromised accident-tolerance and the corrosion-resistance of materials to ensure up to 60 years of capsule design life are demonstrated with the help of HELIOS experiments and multi-dimensional computer simulations. To eliminate loss of coolant events, a double-wall reactor vessel has been employed, and the entire capsule is to be placed on a monolithic underground foundation through overhung supports with three dimensional seismic isolations. To cope with hypothetical core damage accidents, fully-passive and fail-safe designs are installed including double containments, buoyancy-driven second shutdown system, reactor vessel air cooling system, melting core distribution system and emergency battery power supply. At the end of its core-life, the core module with the inner reactor vessel will be replaced with a pristine module while the spent module is transported to one of nearby multi-national fuel cycle centers in a lead-shielded cask for rebuilding. In addition to electricity generation, the modular power capsule can be used for local heating, hydrogen generation and desalination as well as research and demonstration of nuclear transmutation technology. Design descriptions and assessment findings on proliferation- resistance, accident-tolerance and economical viability of the power capsule as well as demonstration concept with associated fuel cycle are presented herein. (authors)