CANDU-Like Features in Emerging Small Modular Reactor Designs

2021 ◽  
Author(s):  
Esam Hussein
Keyword(s):  
Heavy Water ◽  
Operating Experience ◽  
Heat Sinks ◽  
Candu Reactors ◽  
Small Modular Reactor ◽  
Large Heat ◽  
Reactor Shutdown ◽  
To Receive

Abstract Several small modular reactor (SMR) designs are emerging, but only the CANDU Small Modular Reactor and a couple of Indian designs incorporate the familiar features of the larger CANDU-reactors. This paper shows that while the CANDU concept did not seem to receive wider attention among SMR designers, it has influenced a few. The paper discusses how the CANDU operating experience can aid in the construction and operation of some SMRs. For example, the concept of passive reactor shutdown by draining the moderator, which was utilized in the early Pickering A units, is adopted in the Copenhagen Atomics Waste Burner; a molten slat (LiF-ThF$ _4 $) heavy-water moderated reactor. The heavy-water and lithium in this salt produce tritium and can benefit from the CANDU experience in handling tritium. The online refueling of CANDU reactors, their large heat sinks and seamless configuration are also reflected in SMR designs.

scholarly journals Where does India find heavy water for Candu reactors?

Nature ◽  
1988 ◽  
Vol 333 (6171) ◽  
pp. 288-288
Author(s):  
K. S. Jayaraman
Keyword(s):  
Heavy Water ◽  
Candu Reactors

scholarly journals Small Modular Reactor Control Room Workstation Demonstration

2019 ◽  
Vol 63 (1) ◽  
pp. 479-480
Author(s):  
Jessica Stevens ◽  
Kevin LaFerriere ◽  
Ryan Flamand NuScale
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Operating Experience ◽  
Nuclear Regulatory Commission ◽  
Lessons Learned ◽  
Agile Development ◽  
Control Room ◽  
Small Modular Reactor ◽  
Regulatory Commission

A control room simulator was designed to model the operation of a NuScale small modular reactor (SMR) nuclear power plant and provide enough fidelity to perform staffing validation studies for Nuscale’s Nuclear Regulatory Commission Design Certification Application. The simulator serves as a simulated control room with work stations to mimic the operation of an SMR module, turbine generator, and support systems using a proprietary human system interface (HSI) software package. The simulator, which includes all HSI screens, was designed by a team of Human Factors and Plant Operations staff to capitalize on best practices, lessons learned, and operating experience using the Agile development process. Finally, the design process included the development of plant operating procedures and training material as well as a training platform for future plant operators at an SMR nuclear power plant.

Deuterium Ingress at the Rolled Joints in CANDU Reactors: Where Does it Comefrom and How Can It be Reduced?

2020 ◽  
Author(s):  
Scott Langille ◽  
Christopher Coleman ◽  
Glenn McRae
Keyword(s):  
Stainless Steel ◽  
Heat Transport ◽  
Heavy Water ◽  
Nuclear Reactors ◽  
Hydrogen Isotopes ◽  
Operating Principle ◽  
Small Scale ◽  
Candu Reactors ◽  
Pressure Tubes

Abstract Simple, small-scale, experiments demonstrate the high deuterium concentrations found in the zirconium pressure tubes at CANDU rolled joints comes from the initial as-received protium in stainless-steel end fittings exchanging with deuterium before being gettered by the zirconium. We propose to reduce the concentration of hydrogen isotopes at the ends of pressure tubes in heavy-water nuclear reactors with yttrium getters placed in the outer regions of the stainless-steel end fittings away from the heat-transport heavy water. Simple, small-scale, experiments demonstrate the operating principle showing that yttrium can getter hydrogen isotopes from the zirconium through the stainless steel.

scholarly journals The Feasibility of Multidimensional CFD Applied to Calandria System in the Moderator of CANDU-6 PHWR Using Commercial and Open-Source Codes

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Hyoung Tae Kim ◽  
Se-Myong Chang ◽  
Jong-Hyeon Shin ◽  
Yong Gwon Kim
Keyword(s):  
Open Source ◽  
Heavy Water ◽  
Numerical Models ◽  
Three Dimensional ◽  
Hydrothermal Systems ◽  
Candu Reactors ◽  
Source Codes ◽  
Ansys Cfx ◽  
Heavy Water Reactor ◽  
Water Reactors

The moderator system of CANDU, a prototype of PHWR (pressurized heavy-water reactor), has been modeled in multidimension for the computation based on CFD (computational fluid dynamics) technique. Three CFD codes are tested in modeled hydrothermal systems of heavy-water reactors. Commercial codes, COMSOL Multiphysics and ANSYS-CFX with OpenFOAM, an open-source code, are introduced for the various simplified and practical problems. All the implemented computational codes are tested for a benchmark problem of STERN laboratory experiment with a precise modeling of tubes, compared with each other as well as the measured data and a porous model based on the experimental correlation of pressure drop. Also the effect of turbulence model is discussed for these low Reynolds number flows. As a result, they are shown to be successful for the analysis of three-dimensional numerical models related to the calandria system of CANDU reactors.

Operating Experience With Mechanical Seals in Reactor Shutdown Cooling Pumps

2009 ◽  
Author(s):  
G. Staniewski ◽  
A. Keshavarz ◽  
W. J. Ferguson
Keyword(s):  
High Pressure ◽  
Nuclear Reactor ◽  
Cooling System ◽  
Operating Experience ◽  
Normal Operation ◽  
Mechanical Seals ◽  
Reactor Inlet ◽  
Start Up ◽  
Service Water ◽  
Reactor Shutdown

The CANDU nuclear reactor has a dedicated shutdown cooling system (SDC) to remove heat from the primary heat transport system and transfer it to the high pressure service water open system. There are four individual SDC circuits, each connected to one of the four quadrants of the reactor. The four circuits are independent and each of them consists of one SDC pump and one heat exchanger. When the reactor is within normal operation, all four SDC loops are isolated but kept pressurized to the reactor inlet header of 9.7 MPa (1410 psi) and warmed up to 93°C. During reactor shutdown condition and at reactor start-up operation, the SDC pumps are in-service. They operate in several different configurations and are exposed to a number of different pressure conditions. This paper will present typical failures of the seal components.

Nanocarpets Decorating the Walls of Microchannels

2009 ◽  
Author(s):  
Yildiz Bayazitoglu ◽  
Jami F. Tullius
Keyword(s):  
Heat Transfer ◽  
Surface Area ◽  
Electronic Devices ◽  
Volume Ratio ◽  
Heat Transfer Surface ◽  
Heat Sinks ◽  
Additional Increase ◽  
Boltzmann Equations ◽  
Large Heat ◽  
Micro Systems

Without the appropriate cooling, the operating temperature of electronic devices and micro systems could reach values where the components lose their physical integrity, and the proper functioning would cease. In response to this demand, many techniques have been studied and developed such as laser drilled cavities, heat sinks, micro fins, etc. but have still not been able to reach an adequate cooling performance necessary for the components to operate properly. Because of the large heat transfer surface area to volume ratio, microchannels cooled with gas or liquid coolant have been shown to be strong prospects. By lining the walls for the microchannel with nanocarpets — fins, pins, etc. that varies the roughness of the surface — it can alter the effect of the microchannel performance. Carbon nanotubes have extremely high thermal conductivities and they also can be made to have an additional increase in the wall heat transfer surface area. The use of approximated Boltzmann equations, Molecular Dynamics, and Computational Fluid Dynamics to model the heat flow in nanostructured surface microchannels, and also the nanotstructure-fluid interface will be reviewed. The explanation of important interactions, heat transport phenomena, the numerical experimentations related to effect of nanotube length, the nanotube type, the spacing of the nanotubes, and their staggered pattern, and their other physical and material properties in relation to the fluid flow properties within the microchannels will be discussed.

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