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AP1000 passive containment cooling system water storage tank (PCCWST) is set at the top of a shield building. Its function is to hold the water which will flow by gravity to help cool the containment vessel in the highly unlikely event of an emergency – one of the AP1000 plant’s innovative passive safety systems. The huge amount of water may pose a threat to the integrity of the shield building during an earthquake. In this paper, both modal characteristics and transient response of a scaled elevated water tank model were studied by a shaking table experiment. The acceleration of the supporting structure and displacement of water sloshing were recorded under transient loading. Four numerical models were built, including two-mass equivalent model, single lumped-mass model, and finite element models using Fluid30 and Fluid80 elements. The advantages and disadvantages of different numerical methods were discussed. Moreover, finite element (FE) models of AP1000 shield building were established considering the fluid–structure interaction (FSI) effect. The sloshing phenomenon in PCCWST under resonant three-cycle sine (RTCS) wave and seismic loading was studied. The response of shield building under seismic loading was also studied. The results showed that the maximum von Mises stress occurred at the corner of the air inlet. The shaking table experiment can provide a benchmark for seismic response of an elevated water tank. The FE model of shield building may help improve the design of the AP1000 and CAP1400 in the future. [ABSTRACT FROM AUTHOR]

This study is motivated by a lack of information regarding the seismic analysis and design of AP1000 passive containment cooling system water storage tank (PCCWST). The major challenge faced in this specific type of fluid–structure interaction (FSI) problem is the estimation of the forces associated with the hydrodynamic pressure. In this paper, an equivalent mechanical model for the water tank of PCCWST was developed regarding the hydrodynamic pressure. Parameters of this newly-developed mechanical model, which was evaluated by finite element method (FEM), were given in chart form as functions of geometrical parameters including ratio of inner and outer tank radii, tank bottom’s inclination angle, and tank height. The values of impulsive mass were compared between the proposed model and the cylindrical tanks reported in the literature when their inclination angle approaches zero. The agreement shown by this comparison confirmed the validity of the proposed mechanical model. Shaking table experiments of a scaled PCCWST were also carried out to verify the feasibility of the proposed model. Finally, the transient response of PCCWST subjected to horizontal ground excitation was provided to illustrate the application of the proposed model. Therefore, the study shows that the equivalent mechanical model can provide an effective method for the design of PCCWST. [ABSTRACT FROM AUTHOR]

• OH/H 2 O content increases by ∼100–200 ppm in H+ irradiated plagioclase. • Structural water including Type I H 2 O and Type II H 2 O is formed by H+ irradiation. • Most OH/H 2 O desorbs at the highest temperatures (130 °C) on the lunar surface. Determining the characteristics and thermal stability of solar wind-produced OH/H 2 O is critical to understanding the formation and migration of water on the lunar surface. In this study, terrestrial plagioclase (An 50−53) was used as a lunar analogue and was irradiated with 5 keV H+ at a fluence of ∼1×1017 H+/cm2. The irradiated plagioclase was characterized via Fourier transform infrared spectroscopy, nanoscale secondary ion mass spectrometry, Raman spectroscopy, and transmission electron microscopy. The thermal stability of OH/H 2 O in the irradiated plagioclase was investigated via heating experiments. Our results reveal (1) a ∼100–200 ppm increase in the water content of the irradiated plagioclase; (2) structural hydrous species formation in the plagioclase through H+ implantation, including Type I H 2 O (∼2.75 μm) and Type II H 2 O (∼2.90 μm); and (3) the escape of much of the OH/H 2 O formed by H+ implantation at a temperature equivalent to the highest temperature on the lunar surface. The results of this study can improve our understanding of OH/H 2 O thermal stability on the lunar surface and provide a baseline for the interpretation of remote sensing observations. [ABSTRACT FROM AUTHOR]