Small Modular Reactor Thermal Performance Improvement With Addition of a High Temperature Gas Reactor Superheater

2014 ◽  
Author(s):  
Paul J. Marotta ◽  
Basil N. Antar
Keyword(s):  
Heat Flux ◽  
High Temperature ◽  
Power Output ◽  
Thermal Source ◽  
Steam Quality ◽  
Two Phase ◽  
Small Modular Reactor ◽  
Axial Heat ◽  
Thermal Phenomena ◽  
High Temperature Gas

Reheating steam from a Small Modular Reactor (SMR) is explored in order to increase efficiency and power output. A thermal source in the form of a High Temperature Gas Reactor (HTGR) is considered. Engineering challenges include proof-of-principle, reactor sizing, evaluation, and feasibility. The proposed thermodynamic process modifications have been evaluated for a range of inlet steam quality conditions. The evaluation of the steam tube dimensions and number of optimal tubes have been calculated utilizing the so-called Log Mean Temperature Difference method. Subsequently, the performance of the steam tubes was further analyzed within a RELAP5 model to investigate two phase boiling flow thermal phenomena. Detailed calculations include a non-uniform axial heat flux distribution based on published results for the tri-structural isotropic fuel system (TRISO). Non-uniform axial heat flux served as the non-uniform heat source boundary condition in the computer model for the High Temperature Gas Reactor. The work shows that the proposed modifications are not only feasible but also show significant improvement for power output in the amount of over 50%, and increase of the power cycle efficiency of over 14%.

scholarly journals A Parametrical Study on Convective Heat Transfer between High-Temperature Gas and Regenerative Cooling Panel

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1784
Author(s):  
Jiangyu Hu ◽  
Ning Wang ◽  
Jin Zhou ◽  
Yu Pan
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Temperature ◽  
Thermal Protection ◽  
Flow Direction ◽  
Heated Surface ◽  
Heat Transfer Process ◽  
Cocurrent Flow ◽  
Regenerative Cooling ◽  
High Temperature Gas

Thermal protection is still one of the key challenges for successful scramjet operations. In this study, the three-dimensional coupled heat transfer between high-temperature gas and regenerative cooling panel with kerosene of supercritical pressure flowing in the cooling channels was numerically investigated to reveal the fundamental characteristics of regenerative cooling as well as its influencing factors. The SST k-ω turbulence model with low-Reynolds-number correction provided by the pressure-based solver of Fluent 19.2 is adopted for simulation. It was found that the heat flux of the gas heated surface is in the order of 106 W/m2, and it declines along the flow direction of gas due to the development of boundary layer. Compared with cocurrent flow, the temperature peak of the gas heated surface in counter flow is much higher. The temperature and heat flux of the gas heated surface both rises with the static pressure and total temperature of gas. The heat flux of the gas heated surface increases with the mass flow rate of kerosene, and it hardly changes with the pressure of kerosene. Results herein could help to understand the real heat transfer process of regenerative cooling and guide the design of thermal protection systems.

Small Modular Reactors: Learning From the Past

2021 ◽  
Author(s):  
Esam Hussein
Keyword(s):  
High Temperature ◽  
Pressurized Water Reactors ◽  
Nuclear Technology ◽  
Pressurized Water ◽  
The Past ◽  
Canadian Experience ◽  
Small Modular Reactor ◽  
Technology Experience ◽  
Water Reactors ◽  
High Temperature Gas

Abstract Most emerging small modular reactor (SMR) designs resemble older reactors that were designed in the early days of the nuclear technology. Experience with operating these old reactors can contribute to the licensing of new SMRs, by showing that some safety concepts were already proven, and their viability was demonstrated. This paper shows examples of older reactors in each of the reemerging SMR concepts of integrated pressurized water reactors, high temperature gas cooled reactors, molten salt reactors, and liquid metal cooled fast reactors. The Canadian experience with the WR-1 organic cooled reactor is also discussed to examine whether it can inform the development on an organic cooled SMR.

The AOK-TFR analysis of high temperature gas–solid two-phase flow

2016 ◽  
Vol 70 ◽  
pp. 236-245 ◽  
Author(s):  
Hong-Wei Li ◽  
Tao Li ◽  
Hao Guo ◽  
Malcolm Shepler
Keyword(s):  
High Temperature ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
High Temperature Gas

scholarly journals Reactor performance and safety characteristics of two-phase composite moderator concepts for modular high temperature gas cooled reactors

2020 ◽  
Vol 368 ◽  
pp. 110824
Author(s):  
Edward M. Duchnowski ◽  
Robert F. Kile ◽  
Lance L. Snead ◽  
Jason R. Trelewicz ◽  
Nicholas R. Brown
Keyword(s):  
High Temperature ◽  
Reactor Performance ◽  
Two Phase ◽  
High Temperature Gas

Goals, Requirements, and Design Implications for the Advanced High-Temperature Reactor

2006 ◽  
Author(s):  
Charles W. Forsberg
Keyword(s):  
High Temperature ◽  
Power Output ◽  
Nuclear Power ◽  
Heat Removal ◽  
Security Requirements ◽  
Electricity Production ◽  
Plant Design ◽  
High Temperature Reactor ◽  
High Temperature Gas ◽  
Electrical Output

The Advanced High-Temperature Reactor (AHTR), also called the liquid-salt-cooled Very High-Temperature Reactor (LS-VHTR), is a new reactor concept that has been under development for several years. The AHTR combines four existing technologies to create a new reactor option: graphite-matrix, coated-particle fuels (the same fuel as used in high-temperature gas-cooled reactors); a liquid-fluoride-salt coolant with a boiling point near 1400°C; plant designs and decay-heat-removal safety systems similar to those in sodium-cooled fast reactors; and a helium or nitrogen Brayton power cycle. This paper describes the basis for the selection of goals and requirements, the preliminary goals and requirements, and some of the design implications. For electricity production, the draft AHTR goals include peak coolant temperatures between 700 and 800°C and a maximum power output of about 4000 MW(t), for an electrical output of ∼2000 MW(e). The electrical output matches that expected for a large advanced light-water reactor (ALWR) built in 2025. Plant capital cost per kilowatt electric is to be at least one-third less than those for ALWRs with the long-term potential to significantly exceed this goal. For hydrogen production, the peak temperatures may be as high as 950°C, with a power output of 2400 MW(t). The safety goals are to equal or surpass those of the modular high-temperature gas-cooled reactor with a beyond-design-basis accident capability to withstand large system and structural failures (vessel failure, etc.) without significant fuel failure or off-site radionuclide releases. These safety goals may eliminate the technical need for evacuation zones and reduce security requirements and significantly exceed the safety goals of ALWRs. The plant design should enable economic dry cooling to make possible wider nuclear-power-plant siting options. Uranium consumption is to be less than that for a LWR, with major improvements in repository performance and nonproliferation characteristics.

scholarly journals RESULTS OF A PHENOMENA IDENTIFICATION AND RANKING TABLE (PIRT) EXERCISE FOR A SEVERE ACCIDENT IN A SMALL MODULAR HIGH-TEMPERATURE GAS-COOLED REACTOR

2019 ◽  
Vol 8 (2) ◽  
pp. 159-169
Author(s):  
David William Hummel ◽  
Yu-Shan Chin ◽  
Andrew Prudil ◽  
Anthony Williams ◽  
Eugene Masala ◽  
...  
Keyword(s):  
High Temperature ◽  
Current Knowledge ◽  
Safety Analysis ◽  
Severe Accident ◽  
Specific Interest ◽  
Worst Case ◽  
Severe Accidents ◽  
Small Modular Reactor ◽  
Physical Phenomena ◽  
High Temperature Gas

Canada has attracted specific interest from developers of nonwater-cooled small modular reactor (SMR) technologies, including concepts based on high-temperature gas-cooled reactors (HTGRs). It is anticipated that some research and development (R&D) will be necessary to support safety analysis and licensing of these reactors in Canada. The Phenomena Identification and Ranking Table (PIRT) process is a formalized method in which a panel of experts identifies which physical phenomena are most relevant to the reactor safety analysis and how well understood these phenomena are. The PIRT process is thus a tool to assess current knowledge levels and (or) predictive capabilities of models, thus providing direction to a focused R&D program. This paper summarizes the results of a PIRT process performed by a panel of experts at Canadian Nuclear Laboratories for a limiting or “worst-case” accident scenario at a generic HTGR-type SMR. Suggestions are given regarding the highest priority R&D items to support severe accidents analysis of these reactors.

Analysis and design of a high temperature gas gap with tunable heat flux based on He-Ar mixture

2019 ◽  
Vol 157 ◽  
pp. 113677
Author(s):  
Mingyang Ma ◽  
Wenfeng Liang ◽  
Shumiao Wang ◽  
Zhongxiong Bai ◽  
Qilin Xie
Keyword(s):  
Heat Flux ◽  
High Temperature ◽  
Analysis And Design ◽  
Gas Gap ◽  
High Temperature Gas

An Environmental Wet Cell For High Voltage Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 18-19
Author(s):  
N.J. Tighe ◽  
H.M. Flower ◽  
P.R. Swann
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Image Quality ◽  
Inelastic Scattering ◽  
High Voltage ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Environmental Cell ◽  
Water Saturated ◽  
High Temperature Gas

A differentially pumped environmental cell has been developed for use in the AEI EM7 million volt microscope. In the initial version the column of gas traversed by the beam was 5.5mm. This permited inclusion of a tilting hot stage in the cell for investigating high temperature gas-specimen reactions. In order to examine specimens in the wet state it was found that a pressure of approximately 400 torr of water saturated helium was needed around the specimen to prevent dehydration. Inelastic scattering by the water resulted in a sharp loss of image quality. Therefore a modified cell with an ‘airgap’ of only 1.5mm has been constructed. The shorter electron path through the gas permits examination of specimens at the necessary pressure of moist helium; the specimen can still be tilted about the side entry rod axis by ±7°C to obtain stereopairs.

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