FINAL ICONE17-75007 ANALYSIS OF FIV CHARACTERISTICS ON A COAXIAL DOUBLE-TUBE TYPE HOT GAS DUCT FOR THE VHTR

ABSTRACT The Very High Temperature Gas Cooled Reactor (VHTR) has been selected as a high energy heat source of the order of 950℃ for nuclear hydrogen generation, which can produce hydrogen from water or natural gas. A primary hot gas duct (HGD) as a coaxial double-tube type cross vessel is a key component connecting the reactor pressure vessel and the intermediate heat exchanger in a VHTR. In this study, a structural sizing methodology for the primary HGD of a VHTR is suggested in order to modulate a flow-induced vibration (FIV). And as an example, a structural sizing of a horizontal HGD with a coaxial double-tube structure was carried out using the suggested method. These activities include a decision of the geometric dimensions, a selection of the material, and a evaluation of the strength of the coaxial double-tube type cross vessel components. Also in order to compare the FIV characteristics of the proposed design cases, a fluid-structure interaction (FSI) analysis on a quarter part of the HGD was carried out using the ADINA code. INTRODUCTION The Very High Temperature Gas Cooled Reactor (VHTR) has been selected as a high energy heat source for nuclear hydrogen generation, which can produce hydrogen from heat and water by using a thermo-chemical process or from heat, water, and natural gas by steam reformer technology or using a high temperature electrolysis of steam. The nuclear hydrogen system being researched at KAERI is planning to produce hydrogen in the order of 950℃ by using nuclear energy and a thermo-chemical process. Helium gas is tentatively considered as the choice for the coolant of the nuclear hydrogen system since it is an inert gas, with no affinity to a chemical or nuclear activity; therefore the transport of radioactivity in the primary circuit of the nuclear hydrogen system is minimal under a normal operation. Moreover, its gaseous nature avoids the problems related to a phase change and water-metal reactions and therefore improves its safety. A hot gas duct (HGD) is a key component connecting the reactor pressure vessel and the intermediate heat exchanger (IHX) in a VHTR as shown i

Titanium Plate Fixation for a Dehisced Sternum Following Coronary Artery Bypass Grafting: A Case Report

Sternal dehiscence is one of the most troublesome complications following cardiac surgery. Treatment failure and consequent lethal results are very common, even with all the efforts to resolve sternal dehiscence such as removal of infectious tissue, muscle flap interposition, and sternal rewiring. We report on a case of sternal osteomyelitis following coronary artery bypass grafting that was successfully treated with wide sternal resection, titanium plate fixation, and pectoralis muscle flap interposition

Follicular Dendritic Cell Sarcoma of the Tonsil

Follicular dendritic cell sarcoma (FDCS) is unusual, and those with an extranodal origin in the head and neck region are extremely rare. To date, no cases of tumors featuring the characteristics of follicular dendritic cells were reported in Korea. We report a new case of FDCS of the tonsils in a 65-year-old man. A diagnostic tonsillectomy was performed. Based on histopathologic and immunohistochemical findings, the patient was diagnosed with FDCS. Adjuvant radiotherapy was performed due to a high mitotic count. The patient survived with a 2-year disease free period. The differential diagnosis of a tonsillar mass must include FDCS. In cases in which FDCS is suspected on histopathologic examination, an immunohistochemical study is essential for the diagnosi

Batalin-Tyutin Quantization of the Self-Dual Massive Theory in Three Dimensions

We quantize the self-dual massive theory by using the Batalin-Tyutin Hamiltonian method, which systematically embeds second class constraint system into first class one in the extended phase space by introducing the new fields. Through this analysis we obtain simultaneously the St\"uckelberg scalar term related to the explicit gauge-breaking effect and the new type of Wess-Zumino action related to the Chern-Simons term.Comment: 17 pages, SOGANG-HEP 191/9

Expression of the RERG Gene is Gender-Dependent in Hepatocellular Carcinoma and Regulated by Histone Deacetyltransferases

Ras-related, estrogen-regulated, and growth-inhibitory gene (RERG) is a novel gene that was first reported in breast cancer. However, the functions of RERG are largely unknown in other tumor types. In this study, RERG expression was analyzed in hepatocellular carcinomas of human patients using reverse transcriptase PCR analysis. In addition, the possible regulation of RERG expression by histone deacetyltransferases (HDACs) was studied in several cell lines. Interestingly, the expression of RERG gene was increased in hepatocellular carcinoma (HCC) of male patients (57.9%) but decreased in HCC of females (87.5%) comparison with paired peri-tumoral tissues. Moreover, RERG gene expression was increased in murine hepatoma Hepa1-6 cells, human breast tumor MDA-MB-231 cells, and mouse normal fibroblast NIH3T3 cells after treated by HDAC inhibitor, trichostatin A. Our results suggest that RERG may function in a gender-dependent manner in hepatic tumorigenesis and that the expression of this gene may be regulated by an HDAC-related signaling pathway