Natural Circulation and Integrated Layout Pressurized Water Reactor

A natural circulation and integrated layout PWR is here proposed by a preliminary feasibility study. Its main features are: low unit power and core power density, the same temperatures and pressures of current PWRs, no fuel melting scenario, passive protection systems, pressure suppression containment, long fuel cycle duration and no boron in the primary water. The power station can be designed for electrical power production (700 MWth - 225 MWe), or for combined electricity and heat production (200 MWth); this last solution seems viable even for urban siting. Here only the 225 MWe plant is described. The reactor startup is obtained by heating with a constant and low neutronic power, and a possible procedure is indicated and analyzed. The ATWS of a steam line break accident in hot standby conditions is studied by a suitable calculation program and the results are positive.