TY - JOUR
T1 - A dynamic model of a passively cooled small modular reactor for controller design purposes
AU - Arda, Samet E.
AU - Holbert, Keith
N1 - Funding Information:
To support U.S.-based SMR projects, the Department of Energy (DOE) launched an initiative called the SMR Licensing Technical Support Program in March 2012 and two separate industry groups headed by Babcock & Wilcox (B&W) and NuScale Power received funding under 6-year cost-share public–private partnerships ( DOE, 2015 ). The first DOE sponsored design, B&W's mPower, is an integral reactor with an output of 530 MWth. Net electricity generation changes according to type of condenser cooling employed. mPower is expected to produce 180 MWe when evaporative cooling is utilized whereas deploying an air-cooled unit reduces the electrical output to 155 MW. The reactor coolant flow rate relies on forced circulation by eight internal coolant pumps ( Halfinger and Haggerty, 2012 ). The second design, the Nuscale SMR, is smaller than mPower in terms of electrical output with the capability of generating 45 MWe. The NuScale SMR is based on the Multi-Application Small Light Water Reactor (MASLWR) concept which was developed by a consortium including Idaho National Laboratory and Oregon State University under a DOE-sponsored project ( Reyes and Lorenzini, 2010; Liu and Fan, 2014 ).
Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2015/5/22
Y1 - 2015/5/22
N2 - An analytical dynamic model for a passively cooled small modular reactor (SMR) is developed using a state-variable lumped parameter approach. Reactor power is represented by the generation time formulation of the point kinetics equations with a single combined neutron precursor group. The heat transfer process in the core is described via an overall heat transfer coefficient by defining two coolant lumps paired to a single fuel lump. In addition, a thermal-hydraulics model for single-phase natural circulation is incorporated. For the helical-coil steam generator, a moving-boundary model including subcooled, two-phase, and superheated regions is utilized. Finally, the hot leg riser and downcomer regions are expressed by first-order lags. The performance of the overall system described by ordinary differential equations (ODEs) is evaluated by the Simulink dynamic environment and directly using a MATLAB ODE solver recommended for stiff systems. Simulation results based on NuScale SMR design data show that the initial steady-state values for 100% power are within range of the design data and the model can predict the system dynamics due to typical perturbations, e.g., control rod movement and change in feedwater mass flow rate and temperature. The model developed in this work can be utilized as a foundation for designing and testing a suitable control algorithm for reactor thermal power.
AB - An analytical dynamic model for a passively cooled small modular reactor (SMR) is developed using a state-variable lumped parameter approach. Reactor power is represented by the generation time formulation of the point kinetics equations with a single combined neutron precursor group. The heat transfer process in the core is described via an overall heat transfer coefficient by defining two coolant lumps paired to a single fuel lump. In addition, a thermal-hydraulics model for single-phase natural circulation is incorporated. For the helical-coil steam generator, a moving-boundary model including subcooled, two-phase, and superheated regions is utilized. Finally, the hot leg riser and downcomer regions are expressed by first-order lags. The performance of the overall system described by ordinary differential equations (ODEs) is evaluated by the Simulink dynamic environment and directly using a MATLAB ODE solver recommended for stiff systems. Simulation results based on NuScale SMR design data show that the initial steady-state values for 100% power are within range of the design data and the model can predict the system dynamics due to typical perturbations, e.g., control rod movement and change in feedwater mass flow rate and temperature. The model developed in this work can be utilized as a foundation for designing and testing a suitable control algorithm for reactor thermal power.
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U2 - 10.1016/j.nucengdes.2015.04.026
DO - 10.1016/j.nucengdes.2015.04.026
M3 - Article
AN - SCOPUS:84929573092
SN - 0029-5493
VL - 289
SP - 218
EP - 230
JO - Nuclear Engineering and Design
JF - Nuclear Engineering and Design
ER -