Achievement of Reactor-Outlet Coolant Temperature of 950.DEG.C. in HTTR

TLDR

A high‑temperature gas‑cooled reactor (HTGR) is attractive for its ability to produce high‑temperature helium and its inherent safety features. This report presents the results of the HTTR’s high‑temperature test operation. During the final rise‑to‑power phase, reactor characteristics and performance were confirmed and operations monitored to demonstrate safety and stability. The HTTR achieved 30 MW and a reactor‑outlet coolant temperature of 950 °C, enabling high‑temperature gas‑turbine power generation, hydrogen production, and broader HTGR applications beyond electricity generation.

Abstract

A High Temperature Gas-cooled Reactor (HTGR) is particularly attractive due to its capability of producing high-temperature helium gas and to its inherent safety characteristics. The High Temperature Engineering Test Reactor (HTTR), which is the first HTGR in Japan, achieved its rated thermal power of 30 MW and reactor-outlet coolant temperature of 950°C on 19 April 2004. During the high-temperature test operation which is the final phase of the rise-to-power tests, reactor characteristics and reactor performance were confirmed, and reactor operations were monitored to demonstrate the safety and stability of operation. The reactor-outlet coolant temperature of 950°C makes it possible to extend high-temperature gas-cooled reactor use beyond the field of electric power. Also, highly effective power generation with a high-temperature gas turbine becomes possible, as does hydrogen production from water. The achievement of 950°C will be a major contribution to the actualization of producing hydrogen from water using the high-temperature gas-cooled reactors. This report describes the results of the high-temperature test operation of the HTTR.