Sloshing Loads on the Head of an Annular Cylindrical Reactor Vessel

Abstract

The head of a cylindrical reactor vessel must be designed for earthquake-induced sloshing force if there is insufficient freeboard. Herein, a design-oriented calculation method is developed for base-and head-supported annular tanks, where the annulus separates the reactor vessel and its core barrel. Charts are provided to enable preliminary design calculations. Examples are presented to describe the calculations.

Keywords:

• Sloshing
• earthquake
• annular tanks
• reactor vessels

Acknowledgments

The information, data, or work presented herein was funded by the Advanced Research Projects Agency-Energy (ARPA-E) of the U.S. Department of Energy under award number DE-AR0000978. The views and opinions of the authors expressed herein do not necessarily state or reflect those of the U.S. government or any agency thereof. The authors thank Professor Phillipe Bardet of The George Washington University for providing his insights on the design of pressurized vessels for sloshing loadings.

Disclosure Statement

No potential conflict of interest was reported by the authors.

Notes

^a Table 1 in Tang et al.⁷ presents values of ${\alpha }_1$for a few values of k.

^b The damping ratio of 0.5% for the convective (sloshing) mode is a legacy value routinely assumed for analysis (Jaiswal et al.⁹). In practice, the damping ratio of the convective mode in an annular tank may be greater or smaller than 0.5% depending on the fluid used and the annulus width. A value of 0.5% is used in the example calculations.

^c The 0.5%-damped uniform hazard response spectrum is representative of a site in the central and eastern United States for a soft rock site and shaking with a return period of 5000 years. The 0.5%-damped response spectrum was derived from a 5%-damped spectrum using frequency-dependent scale factors per the U.S. Nuclear Regulatory Commission¹¹ that range between 1.56 at 0.1 Hz to 1.75 at 1 Hz.