Supercritical CO2 Direct Cycle Gas Fast Reactor (SC-GFR) Concept

Supercritical CO2 Direct Cycle Gas Fast Reactor (SC-GFR) Concept PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 55

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Book Description
This report describes the supercritical carbon dioxide (S-CO2) direct cycle gas fast reactor (SC-GFR) concept. The SC-GFR reactor concept was developed to determine the feasibility of a right size reactor (RSR) type concept using S-CO2 as the working fluid in a direct cycle fast reactor. Scoping analyses were performed for a 200 to 400 MWth reactor and an S-CO2 Brayton cycle. Although a significant amount of work is still required, this type of reactor concept maintains some potentially significant advantages over ideal gas-cooled systems and liquid metal-cooled systems. The analyses presented in this report show that a relatively small long-life reactor core could be developed that maintains decay heat removal by natural circulation. The concept is based largely on the Advanced Gas Reactor (AGR) commercial power plants operated in the United Kingdom and other GFR concepts.

Supercritical CO2 Direct Cycle Gas Fast Reactor (SC-GFR) Concept

Supercritical CO2 Direct Cycle Gas Fast Reactor (SC-GFR) Concept PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 55

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Book Description
This report describes the supercritical carbon dioxide (S-CO2) direct cycle gas fast reactor (SC-GFR) concept. The SC-GFR reactor concept was developed to determine the feasibility of a right size reactor (RSR) type concept using S-CO2 as the working fluid in a direct cycle fast reactor. Scoping analyses were performed for a 200 to 400 MWth reactor and an S-CO2 Brayton cycle. Although a significant amount of work is still required, this type of reactor concept maintains some potentially significant advantages over ideal gas-cooled systems and liquid metal-cooled systems. The analyses presented in this report show that a relatively small long-life reactor core could be developed that maintains decay heat removal by natural circulation. The concept is based largely on the Advanced Gas Reactor (AGR) commercial power plants operated in the United Kingdom and other GFR concepts.

Optimized, Competitive Supercritical-CO2 Cycle GFR for Gen IV Service

Optimized, Competitive Supercritical-CO2 Cycle GFR for Gen IV Service PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
An overall plant design was developed for a gas-cooled fast reactor employing a direct supercritical Brayton power conversion system. The most important findings were that (1) the concept could be capital-cost competitive, but startup fuel cycle costs are penalized by the low core power density, specified in large part to satisfy the goal of significatn post-accident passive natural convection cooling; (2) active decay heat removal is preferable as the first line of defense, with passive performance in a backup role; (3) an innovative tube-in-duct fuel assembly, vented to the primpary coolant, appears to be practicable; and (4) use of the S-Co2 GFR to support hydrogen production is a synergistic application, since sufficient energy can be recuperated from the product H2 and 02 to allow the electrolysis cell to run 250 C hotter than the reactor coolant, and the water boilers can be used for reactor decay heat removal. Increasing core poer density is identified as the top priority for future work on GFRs of this type.

Reactor Physics Design of Supercritical CO2-cooled Fast Reactors

Reactor Physics Design of Supercritical CO2-cooled Fast Reactors PDF Author: Michael Alexander Pope
Publisher:
ISBN:
Category :
Languages : en
Pages : 140

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Book Description
(Cont.) Overall, present work confirmed that the S-CO2-cooled GFR concept has promising characteristics and a sufficiently broad opion space such that a safe and competitive design could be developed in future work with considerably less than $1 void reactivity and a controllable [delta]k due to burnup.

Gas-Cooled Fast Reactor (GFR) Decay Heat Removal Concepts

Gas-Cooled Fast Reactor (GFR) Decay Heat Removal Concepts PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Current research and development on the Gas-Cooled Fast Reactor (GFR) has focused on the design of safety systems that will remove the decay heat during accident conditions, ion irradiations of candidate ceramic materials, joining studies of oxide dispersion strengthened alloys; and within the Advanced Fuel Cycle Initiative (AFCI) the fabrication of carbide fuels and ceramic fuel matrix materials, development of non-halide precursor low density and high density ceramic coatings, and neutron irradiation of candidate ceramic fuel matrix and metallic materials. The vast majority of this work has focused on the reference design for the GFR: a helium-cooled, direct power conversion system that will operate with an outlet temperature of 850oC at 7 MPa. In addition to the work being performed in the United States, seven international partners under the Generation IV International Forum (GIF) have identified their interest in participating in research related to the development of the GFR. These are Euratom (European Commission), France, Japan, South Africa, South Korea, Switzerland, and the United Kingdom. Of these, Euratom (including the United Kingdom), France, and Japan have active research activities with respect to the GFR. The research includes GFR design and safety, and fuels/in-core materials/fuel cycle projects. This report is a compilation of work performed on decay heat removal systems for a 2400 MWt GFR during this fiscal year (FY05).

Improving Fuel Cycle Design and Safety Characteristics of a Gas Cooled Fast Reactor

Improving Fuel Cycle Design and Safety Characteristics of a Gas Cooled Fast Reactor PDF Author: Willem Frederik Geert van Rooijen
Publisher: IOS Press
ISBN: 9781586036966
Category : Technology & Engineering
Languages : en
Pages : 160

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Book Description
The Generation IV Forum is an international nuclear energy research initiative aimed at developing the fourth generation of nuclear reactors, envisaged to enter service halfway the 21st century. One of the Generation IV reactor systems is the Gas Cooled Fast Reactor (GCFR), the subject of study in this thesis. The Generation IV reactor concepts should improve all aspects of nuclear power generation. Within Generation IV, the GCFR concept specifically targets sustainability of nuclear power generation. The Gas Cooled Fast Reactor core power density is high in comparison to other gas cooled reactor concepts. Like all nuclear reactors, the GCFR produces decay heat after shut down, which has to be transported out of the reactor under all circumstances. The layout of the primary system therefore focuses on using natural convection Decay Heat Removal (DHR) where possible, with a large coolant fraction in the core to reduce friction losses.

Thermal Hydraulic Design of a 2400 MW T̳h̳ Direct Supercritical CO2-cooled Fast Reactor

Thermal Hydraulic Design of a 2400 MW T̳h̳ Direct Supercritical CO2-cooled Fast Reactor PDF Author: Michael Alexander Pope
Publisher:
ISBN:
Category :
Languages : en
Pages : 244

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Book Description
(cont.) The loss of external load (LOEL) event is analyzed and a bypass valve scheme is recommended which prevents shaft overspeed and excessive core coolant mass flow rate. A large dry pressurized water reactor (PWR) containment building having a free volume of 70,000 m3 and a peak design pressure of 6 bar is selected for this design based on a 100 in2 cold duct break. During this same loss of coolant accident (LOCA), the depressurization time is shown to be in excess of 10 minutes. No action need be taken by the SCS/ECS blowers before this time in order to prevent core damage. After this time, a total blower power less than 90 kW is sufficient to cool the core out to 10,000 seconds. A loss of flow (LOF) transient in which a PCS loop is instantaneously isolated and no mitigating action is taken (i.e. no reactor scram) is also shown not to cause core damage. It is concluded that a large S-CO2 cooled GFR coupled to a supercritical Brayton power conversion system can withstand the thermal hydraulic challenges posed by the usual menu of severe accident scenarios.

Initial Requirements for Gas-Cooled Fast Reactor (GFR) System Design, Performance, and Safety Analysis Models

Initial Requirements for Gas-Cooled Fast Reactor (GFR) System Design, Performance, and Safety Analysis Models PDF Author: Kevan D. Weaver
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The gas-cooled fast reactor (GFR) was chosen as one of the Generation IV nuclear reactor systems to be developed based on its excellent potential for sustainability through reduction of the volume and radio toxicity of both its own fuel and other spent nuclear fuel, and for extending/utilizing uranium resources orders of magnitude beyond what the current open fuel cycle can realize. In addition, energy conversion at high thermal efficiency is possible with the current designs being considered, thus increasing the economic benefit of the GFR. However, research and development challenges include the ability to use passive decay heat removal systems during accident conditions, survivability of fuels and in-core materials under extremetemperatures and radiation, and economical and efficient fuel cycle processes. Nevertheless, the GFR was chosen as one of only six Generation IV systems to be pursued based on its ability tomeet the Generation IV goals in sustainability, economics, safety and reliability, proliferation resistance and physical protection.

Analysis of Supercritical CO2 Cycle Control Strategies and Dynamic Response for Generation IV Reactors

Analysis of Supercritical CO2 Cycle Control Strategies and Dynamic Response for Generation IV Reactors PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The analysis of specific control strategies and dynamic behavior of the supercritical carbon dioxide (S-CO2) Brayton cycle has been extended to the two reactor types selected for continued development under the Generation IV Nuclear Energy Systems Initiative; namely, the Very High Temperature Reactor (VHTR) and the Sodium-Cooled Fast Reactor (SFR). Direct application of the standard S-CO2 recompression cycle to the VHTR was found to be challenging because of the mismatch in the temperature drop of the He gaseous reactor coolant through the He-to-CO2 reactor heat exchanger (RHX) versus the temperature rise of the CO2 through the RHX. The reference VHTR features a large temperature drop of 450 C between the assumed core outlet and inlet temperatures of 850 and 400 C, respectively. This large temperature difference is an essential feature of the VHTR enabling a lower He flow rate reducing the required core velocities and pressure drop. In contrast, the standard recompression S-CO2 cycle wants to operate with a temperature rise through the RHX of about 150 C reflecting the temperature drop as the CO2 expands from 20 MPa to 7.4 MPa in the turbine and the fact that the cycle is highly recuperated such that the CO2 entering the RHX is effectively preheated. Because of this mismatch, direct application of the standard recompression cycle results in a relatively poor cycle efficiency of 44.9%. However, two approaches have been identified by which the S-CO2 cycle can be successfully adapted to the VHTR and the benefits of the S-CO2 cycle, especially a significant gain in cycle efficiency, can be realized. The first approach involves the use of three separate cascaded S-CO2 cycles. Each S-CO2 cycle is coupled to the VHTR through its own He-to-CO2 RHX in which the He temperature is reduced by 150 C. The three respective cycles have efficiencies of 54, 50, and 44%, respectively, resulting in a net cycle efficiency of 49.3 %. The other approach involves reducing the minimum cycle pressure significantly below the critical pressure such that the temperature drop in the turbine is increased while the minimum cycle temperature is maintained above the critical temperature to prevent the formation of a liquid phase. The latter approach also involves the addition of a precooler and a third compressor before the main compressor to retain the benefits of compression near the critical point with the main compressor. For a minimum cycle pressure of 1 MPa, a cycle efficiency of 49.5% is achieved. Either approach opens up the door to applying the SCO2 cycle to the VHTR. In contrast, the SFR system typically has a core outlet-inlet temperature difference of about 150 C such that the standard recompression cycle is ideally suited for direct application to the SFR. The ANL Plant Dynamics Code has been modified for application to the VHTR and SFR when the reactor side dynamic behavior is calculated with another system level computer code such as SAS4A/SYSSYS-1 in the SFR case. The key modification involves modeling heat exchange in the RHX, accepting time dependent tabular input from the reactor code, and generating time dependent tabular input to the reactor code such that both the reactor and S-CO2 cycle sides can be calculated in a convergent iterative scheme. This approach retains the modeling benefits provided by the detailed reactor system level code and can be applied to any reactor system type incorporating a S-CO2 cycle. This approach was applied to the particular calculation of a scram scenario for a SFR in which the main and intermediate sodium pumps are not tripped and the generator is not disconnected from the electrical grid in order to enhance heat removal from the reactor system thereby enhancing the cooldown rate of the Na-to-CO2 RHX. The reactor side is calculated with SAS4A/SASSYS-1 while the S-CO2 cycle is calculated with the Plant Dynamics Code with a number of iterations over a timescale of 500 seconds. It is found that the RHX undergoes a maximum cooldown rate of ≈ -0.3 C/s. The Plant Dynamics Code was also modified to decrease its running time by replacing the compressible flow form of the momentum equation with an incompressible flow equation for use inside of the cooler or recuperators where the CO2 has a compressibility similar to that of a liquid. Appendices provide a quasi-static control strategy for a SFR as well as the self-adaptive linear function fitting algorithm developed to produce the tabular data for input to the reactor code and Plant Dynamics Code from the detailed output of the other code.

Gas-cooled Fast Reactor

Gas-cooled Fast Reactor PDF Author:
Publisher:
ISBN:
Category : Gas cooled reactors
Languages : en
Pages : 1

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Book Description


Handbook of Generation IV Nuclear Reactors

Handbook of Generation IV Nuclear Reactors PDF Author: Igor Pioro
Publisher: Woodhead Publishing
ISBN: 0128226536
Category : Technology & Engineering
Languages : en
Pages : 1112

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Book Description
Handbook of Generation IV Nuclear Reactors, Second Edition is a fully revised and updated comprehensive resource on the latest research and advances in generation IV nuclear reactor concepts. Editor Igor Pioro and his team of expert contributors have updated every chapter to reflect advances in the field since the first edition published in 2016. The book teaches the reader about available technologies, future prospects and the feasibility of each concept presented, equipping them users with a strong skillset which they can apply to their own work and research. Provides a fully updated, revised and comprehensive handbook dedicated entirely to generation IV nuclear reactors Includes new trends and developments since the first publication, as well as brand new case studies and appendices Covers the latest research, developments and design information surrounding generation IV nuclear reactors