Evaluation on fretting wear of heat-transfer tubes of Primary Sodium Mechanical Pump installed in IHX Component (3); Vibration Analysis Model and 1/4-Scale Vibration Test Equipment

Kisohara, Naoyuki ; Soman, Yoshindo; Nishiguchi, Yohei; Konomura, Mamoru

The conceptual design study of sodium-cooled FBRs is in progress in the "Feasibility Study on Commercialized Fast Reactor Cycle Systems (F/S)". In this plant system design, a primary sodium pump are placed into an intermediate heat exchanger (IHX) and these two components are installed in one vessel to reduce plant construction cost. The primary sodium pump is located in the center of IHX tube bundle and this pump-IHX component includes primary/secondary sodium flow shrouds, pump-IHX boundary shroud and bellows. Although the pump and IHX are installed in the same vessel, these two components are structurally separated, because they are connected through a bellows and their weights are supported by different floors. However, the vibration caused by pump rotation has possibility to induce the vibration of heat transfer tubes via sodium and it leads the tubes to fretting wear against their support plates. Therefore, the tube fretting wear has been evaluated by both a simple beam vibration analysis model and a detailed shell vibration analysis model. Since the pump-IHX component consists of many different parts such as shrouds and tube bundle, analysis tools cannot reveal the vibration phenomena precisely. Then the analysis model requires to be validated by vibration tests. A 1/4-scale vibration test equipment of the whole pump-IHX component has been planned to confirm the occurrence and transmission of vibration. This test equipment is precisely minimized based on the actual pump-IHX component structure except the tube bundle. Acceleration sensors are installed on the shrouds to measure beam and shell vibration phenomena, and the signal will be used to reveal vibration modes and pump response properties. The fabrication of the test equipment was completed in FY2002 except the pump. In FY2003 the vibration tests are being executed by using electromagnetic vibrator instead of the pump. In FY2005, the pump will be settled into the test equipment, and the vibration tes