The Modular High-Temperature Reactor

Science and Technology of Nuclear Installations

Pan

Song

et al. 2017

The modular high temperature gas-cooled reactor (MHTGR) is a typical small modular reactor (SMR) with inherent safety feature. Due to its high reactor outlet coolant temperature, the MHTGR can be applied not only for electricity production but also as a heat source for industrial complexes. Through multimodular scheme, that is, the superheated steam flows produced by multiple MHTGR-based nuclear supplying system (NSSS) modules combined together to drive a common thermal load, the inherent safety feature of MHTGR is applicable to large-scale nuclear plants at any desired power ratings. Since the plant power control technique of traditional single-modular nuclear plants cannot be directly applied to the multimodular plants, it is necessary to develop the power control method of multimodular plants, where dynamical modeling, control design, and performance verification are three main aspects of developing plant control method. In this paper, the study in the power control for two-modular HTR-PM plant is summarized, and the verification results based on numerical simulation are given. The simulation results in the cases of plant power step and ramp show that the plant control characteristics are satisfactory.

Section: Thermal Hydraulicsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dynamic Modeling and Control Characteristics of the Two-Modular HTR-PM Nuclear Plant

Science and Technology of Nuclear Installations

Pan

Song

et al. 2017

“…The coatings surrounding the particle kernel produce a robust fuel form by acting as the containment boundary for radioactive material. The crucial inherent safety feature is guaranteed by the low power density and the slim shape of the reactor core [1][2][3], which makes the MHTGR meet and exceed current nuclear standards in reliability, waste management and safety. Moreover, the MHTGR can provide heat for industrial process at temperatures from 700 to 950 °C, which opens a door for a wider range of commercial applications than that of current light water reactors operating near 300 °C.…”

Section: Open Accessmentioning

confidence: 99%

Dynamic Output Feedback Power-Level Control for the MHTGR Based On Iterative Damping Assignment

2012

Energies

Because of its strong inherent safety features and high outlet temperature, the modular high temperature gas-cooled nuclear reactor (MHTGR) is already seen as the central part of the next generation of nuclear plants. Such power plants are being considered for industrial applications with a wide range of power levels, and thus power-level control is an important technique for their efficient and stable operation. Stimulated by the high regulation performance provided by nonlinear controllers, a novel dynamic output-feedback nonlinear power-level regulator is developed in this paper based on the technique of iterative damping assignment (IDA). This control strategy can provide the L 2 disturbance attenuation performance under modeling uncertainty or exterior disturbance, and can also guarantee the globally asymptotic closed-loop stability without uncertainty and disturbance. This newly built control strategy is then applied to the power-level regulation of the HTR-PM plant, and numerical simulation results show both the feasibility and high performance of this newly-built control strategy. Furthermore, the relationship between the values of the parameters and the performance of this controller is not only illustrated numerically but also analyzed theoretically.

“…Due to the low power density and large heat capacity, some SMRs even have the inherent safety feature which is the most advanced feature of these SMR-based plants relative to those conventional nuclear plants and also prevents these SMRs from the hazards of core-melting, radiological release and loss of coolant accident (LOCA) [3,4]. Due to the ability of offering simpler, safer and standardized modular design by factory-building, less initial capital investment, and shorter construction period, SMRs have been viewed by International Atomic Energy Agency (IAEA) as a developing trend of nuclear energy.…”

Section: Introductionmentioning

confidence: 99%

Model-Free Coordinated Control for MHTGR-Based Nuclear Steam Supply Systems

2016

Energies

Abstract:The modular high temperature gas-cooled reactor (MHTGR) is a typical small modular reactor (SMR) that offers simpler, standardized and safer modular design by being factory built, requiring smaller initial capital investment, and having a shorter construction period. Thanks to its small size, the MHTGRs could be beneficial in providing electric power to remote areas that are deficient in transmission or distribution and in generating local power for large population centers. Based on the multi-modular operation scheme, the inherent safety feature of the MHTGRs can be applicable to large nuclear plants of any desired power rating. The MHTGR-based nuclear steam supplying system (NSSS) is constituted by an MHTGR, a side-by-side arranged helical-coil once-through steam generator (OTSG) and some connecting pipes. Due to the side-by-side arrangement, there is a tight coupling effect between the MHTGR and OTSG. Moreover, there always exists the parameter perturbation of the NSSSs. Thus, it is meaningful to study the model-free coordinated control of MHTGR-based NSSSs for safe, stable, robust and efficient operation. In this paper, a new model-free coordinated control strategy that regulates the nuclear power, MHTGR outlet helium temperature and OTSG outlet overheated steam temperature by properly adjusting the control rod position, helium flowrate and feed-water flowrate is established for the MHTGR-based NSSSs. Sufficient conditions for the globally asymptotic closed-loop stability is given. Finally, numerical simulation results in the cases of large range power decrease and increase illustrate the satisfactory performance of this newly-developed model-free coordinated NSSS control law.