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Servo‐hydraulic shake tables are widely used for simulating earthquake shaking in a laboratory environment. Control procedures for shake‐table testing and the associated mathematical models are well documented. An evaluation of such models revealed nuances regarding actuator control, which led to the development of the simple, easy to implement, robust shake‐table controller described in this paper. This controller design recognizes that (i) differential pressure feedback in actuator control is highly beneficial in reducing the consequences of hydraulic‐related nonlinearities and other modeling uncertainties, (ii) the bandwidth over which differential pressure feedback is useful is limited by the sampling frequency of the chosen digital controller, (iii) a linear model predicts shake‐table response with high fidelity across a broad frequency range for a carefully chosen differential pressure gain and a sufficiently large controller sampling frequency, and (iv) shake‐table transfer functions derived from such a linear model are highly effective in designing a feedforward controller. Further, and perhaps most importantly, the controller utilizes real‐time feedback of the reaction force from the test article to account for table‐test article interaction. The three clear advantages of the proposed shake‐table controller are (i) the test‐article dynamics are decoupled from the control design, (ii) the need for offline/online iterative tuning, which is often ground motion‐ and test article‐specific, is minimized, and (iii) control procedures for shake tables can be standardized, all of which are validated in this paper through a series of experiments performed on a uniaxial hydraulic shake table.

The nuclear industry is currently at a severe economic disadvantage, mainly due to the extremely large capital costs involved constructing in new nuclear power plants. Recent nuclear constructions have seen large cost overruns and schedule delays, making the nuclear sector less attractive to investors. Advanced reactor concepts currently under development in the United States are striving to improve the economics of nuclear power primarily by using passive and 'walk-away' safe technologies. The recently published report, 'Future of Nuclear Energy in a Carbon-Constrained World' (Buongiorno et al., 2018) by the Massachusetts Institute of Technology Energy Institute (MIT EI) has shown that a significant contributor to the capital cost of NPPs is the 'civil works' i.e., the construction of the balance of plant (BoP: all SSCs except those involved in power generation, e.g., reactor vessel) such as the buildings, containment dome, foundation, etc., which amount to almost half of the overnight capital cost. It also suggests that using advanced construction technologies such as seismic isolation and high-performance concrete to significantly reduce the capital costs of advanced reactors. It is therefore imperative that innovations in advanced reactors are not only in the reactor technology, but also in the design, procurement, and construction of the balance of plant and in the civil works. This report demonstrates the application of two cost-cutting solutions on generic advanced reactor designs. These solutions include, (1) seismic base isolation, and (2) risk-and cost-based seismic design optimization including seismic isolation of individual components. Capital cost (USD millions) Seismic risk Initial, unoptimized, and not seismically isolated 99.20 5.16 x 10-5 Optimized, without including component seismic isolation 83.22 4.92 x 10-5 Optimized, including component seismic isolation 78.61 4.86 x 10-5