炉内構造物実証試験部（ＨＥＮＤＥＬ‐Ｔ２）による高温工学試験研究炉（ＨＴＴＲ）炉床部の冷却特性試験と解析

Abstract

An In-core Structure Test Section (HENDEL-T2) is a full scale simulation model of the core bottom structure of High Temperature Engineering Test Reactor (HTTR). Experimental studies on cooling performance of the core bottom structure were carried out by the use of the HENDEL-T2 to verify integrity of the metal structures. Experimental results showed that the temperature distribution of the core bottom structure was almost uniform in the circumferential direction. The temperatures of the metal structures were lower than the design temperatures. The heat transfer from the hot helium gas to the cold helium gas was negligibly small in the core bottom structure. The leakage flow of cold helium gas through the gaps of core bottom structure increased with the pressure difference between the hot and cold helium gases. However, there was no effect of the pressure difference on the temperature distribution of the core bottom structure in the circumferential direction. The detailed temperature distribution of the core bottom structure in HTTR was calculated by a three-dimensional thermal analysis code. Remarkably hot region in the core support plate could not be found in the analysis. The calculated temperatures of the metal structures for HTTR were lower than the design temperatures at the end of HTTR's life.