Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injectors (9) System Outline and Endurance Test of Low-Pressure Steam Injectors

摘要

A Steam Injector (SI) is a simple, compact and passive pump and also acts as a high-performance direct-contact compact heater. This provides SI with capability to serve also as a direct-contact feedwater heater that heats up feedwater by using extracted steam from the turbine. We are developing technology for "Innovative Simplified Nuclear Power Plants" in order to further improve the economy and safety of nuclear power plants. Our technology development aims to significantly simplify equipment and reduce physical quantities by applying "High-Efficiency SI", which are applicable to a wide range of operation regimes beyond the performance and applicable range of existing SIs and enables unprecedented multistage and parallel operation, to the low-pressure feedwater heaters and Emergency Core Cooling Systems (ECCS) of nuclear power plants, as well as achieve high inherent safety to prevent severe accidents by keeping the core covered with water (a Severe Accident-Free Concept). The innovative-simplified nuclear power plant consists of a simplified feedwater heating system, a passive core injection system and a passive containment cooling system. This report describes the results of the endurance and performance tests of low-pressure SIs for feedwater heaters with Jet-deaerator and core injection system. A part of this report are fruits of research which is carried out by Tokyo Electric Power Company (TEPCO), Toshiba, and 7 Universities in Japan, funded from the Ministry of Economy, Trade and Industry (METI) of Japan as the national public research-funded program.