Graphite, Ceramics, and Ceramic Composites for High-Temperature Nuclear Power Systems

MRS Bulletin ◽  
2009 ◽  
Vol 34 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Jean-Pierre Bonal ◽  
Akira Kohyama ◽  
Jaap van der Laan ◽  
Lance L. Snead
Keyword(s):  
High Temperature ◽  
Power Systems ◽  
Nuclear Power ◽  
Material Selection ◽  
Reactor Core ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
Next Generation

AbstractThe age of nuclear power originated with the gas-cooled, graphite-moderated reactor in the 1940s. Although this reactor design had intrinsic safety features and enjoyed initial widespread use, gas-cooled reactor technology was supplanted by higher power density water-cooled systems in the 1960s. However, the next-generation reactors seek enhanced power conversion efficiency and the ability to produce hydrogen, best accomplished with high-temperature gas-cooled systems. Thus, international interest in gas-cooled reactor systems is reemerging. Although the materials systems of these reactors are fairly simple, the reactor environment, particularly its high temperatures and intense irradiation, present extreme challenges in terms of material selection and survivability. This article provides a brief review of materials issues and recent progress related to graphite and ceramic materials for application in gas-cooled nuclear reactor environments. Of particular interest are the drastic, irradiation-induced microstructural evolution and thermophysical property changes occurring as a result of energetic neutron irradiation, which significantly impact the performance and lifetime of much of the reactor core. For “nuclear” graphite, the performance and lifetime not only are closely related to the irradiation environment but also are dramatically affected by the specifics of the particular graphite: manufacturing process, graphitization temperature, composition (amount of coke, filler, etc., depending on where it was mined), and so on. Moreover, the extreme environmental challenges set down by this next generation of fission nuclear plants have driven the development and application of ceramic composites for critical components, pushing beyond upper temperature limits set by metallic alloys used in previous generations of nuclear reactors. The composite material systems of particular interest are continuous carbon-fiber composites and newly developed radiation-resistant silicon carbide fiber composites.

scholarly journals Nuclear policy-nuclear fuels for peaceful, safer co-generation and environmentally benign applications

2020 ◽  
Vol 9 (3) ◽  
pp. 724
Author(s):  
Syazwani Mohd Fadzil ◽  
Shafi Qureshi ◽  
Sekhar Basu ◽  
K. Kasturirangan ◽  
Anil Kakodkar ◽  
...  
Keyword(s):  
High Temperature ◽  
Nuclear Power ◽  
Reactor Core ◽  
Negative Temperature ◽  
Hydrogen Gas ◽  
Hydraulic Diameter ◽  
Nuclear Fuels ◽  
Spent Fuel ◽  
Fuel Temperature ◽  
Nuclear Policy

Here, safer nuclear fuels which can sustain in the high temperature and fluence environment of the reactor core are investigated to utilize nuclear energy peacefully. At Nuclear Fuel Complex in Hyderabad, nuclear fuels are being manufactured which are best suited for high temperature and fluence environment of the reactor core even in accidental scenarios. In this paper, nuclear fuels manufactured at NFC, Hyderabad are presented. The developed nuclear fuels have higher equivalent hydraulic diameter and breeding capability to produce U^233. Nuclear fuels having higher equivalent hydraulic diameter reduce the reactor core temperature substantially. These fuels have negative temperature coefficient of reactivity. Thus, in case of an accident, the fuel temperature never exceeds the safety limit. Therefore, the thermal heat available across the secondary of a heat exchanger can be utilized for different industrial processes. This allows the development of key technologies, such as safer co-generation of electricity and Hydrogen. The Three-Stage Indian Nuclear Power Program has been explained for nuclear disarmament. The product Hydrogen gas has been utilized in many ways for different applications. Moreover, the processing of iron ore with the energy obtained from the IHX secondary side, eliminates the burning of coals and CO2 emissions into the environment. Several radioisotopes have been developed for medical applications from spent fuel.  

Silicon carbide fibers and whiskers for ceramic matrix composites (review)

2021 ◽  
Vol 87 (8) ◽  
pp. 51-63
Author(s):  
A. M. Shestakov
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
High Temperature ◽  
Composite Materials ◽  
Ceramic Matrix Composites ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Silicon Compounds ◽  
Reinforcing Fillers ◽  
Operating Temperatures

An increase the operating temperature range of structural elements and aircraft assemblies is one of the main goals in developing advanced and new models of aerospace equipment to improve their technical characteristics. The most heat-loaded aircraft structures, such as a combustion chamber, high-pressure turbine segments, nozzle flaps with a controlled thrust vector, must have a long service life under conditions of high temperatures, an oxidizing environment, fuel combustion products, and variable mechanical and thermal loads. At the same time, modern Ti and Ni-based superalloys have reached the limits of their operating temperatures. The leading world aircraft manufacturers — General Electric (USA), Rolls-Royce High Temperature Composite Inc. (USA), Snecma Propulsion Solide (France) — actively conduct fundamental research in developing ceramic materials with high (1300 – 1600°C) and ultrahigh (2000 – 2500°C) operating temperatures. However, ceramic materials have a number of shortcomings attributed to the high brittleness and low crack resistance of monolithic ceramics. Moreover, manufacturing of complex configuration and large-sized ceramic parts faces serious difficulties. Nowadays, ceramic composite materials with a high-temperature matrix (e.g., based on ZrC-SiC) and reinforcing filler, an inorganic fiber, (e.g., silicon carbide) appeared most promising for operating temperatures above 1200°C and exhibited enhanced energy efficiency. Ceramic fibers based on silicon compounds possess excellent mechanical properties: the tensile strength more than 2 GPa, modulus of elasticity more than 200 GPa, and thermal resistance at a temperature above 800°C, thus making them an essential reinforcing component in metal and ceramic composites. This review is devoted to silicon carbide core fibers obtained by chemical vapor deposition of silicon carbide onto a tungsten or carbon core, which makes it possible to obtain fibers a 100 – 150 μm in diameter to be used in composites with a metal matrix. The coreless SiC-fibers with a diameter of 10 – 20 μm obtained by molding a polymer precursor from a melt and used mainly in ceramic composites are also considered. A comparative analysis of the phase composition, physical and mechanical properties and thermal-oxidative resistance of fibers obtained by different methods is presented. Whiskers (filamentary crystals) are also considered as reinforcing fillers for composite materials along with their properties and methods of production. The prospects of using different fibers and whiskers as reinforcing fillers for composites are discussed.

Obtaining of Graphene Structure Containing Ceramic Composites in High Temperature Vacuum Furnace

2017 ◽  
Vol 900 ◽  
pp. 101-104
Author(s):  
Natia Jalagonia ◽  
Fernand Marqui ◽  
Karlo Barbakadze ◽  
Ekaterine Sanaia ◽  
Guram Bokuchava ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
High Temperature ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Organic Binder ◽  
Vacuum Furnace ◽  
Natural Graphite ◽  
Equal Distribution ◽  
Oxide Layers ◽  
Homogenization Process

We have obtained ceramic composites containing graphene structure, where homogenization process of powdery composite was improved. At first, α-alumina was obtained from local row, which is cheap and available. The obtaining method was developed by our group. Graphene oxide was synthesized from natural graphite. Homogenization was carried out in nanomill with organic binder, which provides for equal distribution and separation of graphene oxide layers (Organic binder behaves as “scotch tape”) during grinding. Some characteristics of ceramic materials have been improved.

A Nodal Dynamic Model for Control System Simulation of the HTR-PM Reactor Core

2010 ◽  
Author(s):  
Zhe Dong ◽  
Xiaojin Huang ◽  
Liangju Zhang
Keyword(s):  
Control System ◽  
High Temperature ◽  
Power Distribution ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Reactor Core ◽  
Pebble Bed ◽  
Nodal Model ◽  
High Temperature Gas

The modular high-temperature gas-cooled nuclear reactor (MHTGR) is seen as one of the best candidates for the next generation of nuclear power plants. China began to research the MHTGR technology at the end of the 1970s, and a 10 MWth pebble-bed high temperature reactor HTR-10 has been built. On the basis of the design and operation of the HTR-10, the high temperature gas-cooled reactor pebble-bed module (HTR-PM) project is proposed. One of the main differences between the HTR-PM and HTR-10 is that the ratio of height to diameter corresponding to the core of the HTR-PM is much larger than that of the HTR-10. Therefore it is not proper to use the point kinetics based model for control system design and verification. Motivated by this, a nodal neutron kinetics model for the HTR-PM is derived, and the corresponding nodal thermal-hydraulic model is also established. This newly developed nodal model can reflect not only the total or average information but also the distribution information such as the power distribution as well. Numerical simulation results show that the static precision of the new core model is satisfactory, and the trend of the transient responses is consistent with physical rules.

scholarly journals Numerical investigation of advanced gas turbine combined cycle coupled with high-temperature nuclear reactor and cogeneration unit

2019 ◽  
Vol 128 ◽  
pp. 03005 ◽  
Author(s):  
Marek Jaszczur ◽  
Michal Dudek ◽  
Zygmunt Kolenda
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Power Systems ◽  
Gas Turbine ◽  
Nuclear Power ◽  
Coal Gasification ◽  
Nuclear Reactor ◽  
Combined Cycle ◽  
The European Union ◽  
Intergovernmental Panel

In the European Union by 2050, more than 80% of electricity should be generated using nongreenhousegases energy technology. Nuclear power systems share at present about 15% of the power market and thistechnology can be the backbone of a carbon-free European power system. Energy market transitions are similar to global pathways were analysed in the Intergovernmental Panel on Climate Change report. From a practical point of view currently, the most advanced and most effective technology for electricity generation is based on a gas turbine combined cycle. This technology in a normal way uses natural gas, synthesis gas from the coal gasification or crude oil processing products as the energy carriers but at the same time, such system emits sulphur oxides, nitrogen oxides, and CO2 to the environment. In thepresent paper, a thermodynamic analysis of environmentally friendly power plant with a high–temperature gas nuclear reactor and advanced configuration of gas turbine combined cycle technology is investigated. The presented analysis shows that it is possible to obtain for proposed thermalcycles an efficiency higher than 50% which is not only more than could be offered by traditional coal power plant but much more than can be proposed by any other nuclear technology.

Extending Transmitter Life and Mitigating Accident Risk Through the Use of Proven Sensor Technology

2011 ◽  
Author(s):  
Elias C. David ◽  
Frederick A. Marino
Keyword(s):  
High Temperature ◽  
Nuclear Power ◽  
Material Selection ◽  
Lessons Learned ◽  
Sensor Technology ◽  
Accident Risk ◽  
Plant Design ◽  
Steam Generation ◽  
Radiation Hardened ◽  
And Control

Pressure, level, and flow transmitters are an integral part of a nuclear power plant’s primary cooling and steam generation system. To function accurately within the plant design specifications, normal operating and event instances of a Gen III or IV plant environment these transmitters will need to possess rugged and long life characteristics. These transmitters need to be high temperature, radiation, and high shock resistant. Lessons learned from legacy plants show the need to be able to both monitor and control cooling processes throughout the lifespan of the plant in addition to operating during and after a Loss of Coolant Accident (LOCA) occurrence. LOCA requirements associated with some new power plant designs stipulate extended performance after exposure to a 425°F (221°C) and 65 psig (4.5 bar) environment. An alternative and proven technology utilizes a bellows and control spring that reacts to the changes in pressure along with a radiation hardened and high temperature resistant Linear Variable Differential Transformer (LVDT) that converts the bellows travel into a VAC output signal. The LVDT VAC output is then converted into a 4 −20mA output using a signal conditioner containing high temperature and radiation hardened components. LOCA testing, performed on pressure and differential pressure transducers of various ranges, has shown that with proper material selection for the bellows, control spring, LVDT, and pressure boundary components, these sensors can successfully withstand environmental profiles of up to 600°F (315°C) at 250 psig (17 bar) for 30 minutes and 230°F (110°C) at 5 psig (0.34 bar), submerged, for 30 days. Application data has shown that these types of sensors possess long term stability and accuracy, require no periodic maintenance, and can have a forty year life. In addition, high impact shock testing per specification MIL-S-901 shows that the bellow/spring/LVDT sensor can withstand greater than 50g’s shock and still continue to function within specification.

Research Challenges of Heat Transfer to Supercritical Fluids

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
X. Cheng ◽  
X. J. Liu
Keyword(s):  
Heat Transfer ◽  
Power Systems ◽  
Supercritical Fluids ◽  
Nuclear Power ◽  
Superconducting Magnets ◽  
Accurate Determination ◽  
Model Development ◽  
Experimental Studies ◽  
Reactor Core ◽  
Prediction Method

Supercritical fluids (SCFs) become more and more important in various engineering applications. In nuclear power systems, SCFs are considered as coolant of the reactor core such as the supercritical water-cooled reactor (SCWR), superconducting magnets and blankets in the fusion reactors, or as fluid in the energy conversion systems of the next generation nuclear reactors. Accurate determination of heat transfer and the temperature of the structural material (e.g., fuel rod cladding) is of crucial importance for the system design. Thus, extensive studies on heat transfer to SCFs have been carried out in the past five decades and are still ongoing worldwide. However, no breakthrough is recognized or expected in the near future. In this paper, the status, main challenges, and future R&D needs are briefly reviewed. Three aspects are taken into consideration, i.e., experimental studies, numerical analysis, and model development for the prediction of heat transfer coefficient (HTC). Several key challenges and also the important subjects of the future R&D needs are identified. They are (a) data base for turbulence quantities, (b) multisolution of wall temperature, (c) extensive Reynolds-averaged Navier–Stokes (ERANS) method, and (d) new prediction method for HTC.

scholarly journals Fabrication of low-density carbon-bonded carbon fiber composites with an Hf-based coating for high temperature applications

RSC Advances ◽  
2018 ◽  
Vol 8 (34) ◽  
pp. 19171-19180 ◽  
Author(s):  
Lin Xu ◽  
Wenbing Yang ◽  
Zhen Fan ◽  
Xingchao Li ◽  
Wei Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Carbon Fiber ◽  
Fiber Composites ◽  
Maximum Temperature ◽  
Carbon Fiber Composites ◽  
Low Density ◽  
Temperature Range ◽  
Ablation Resistance ◽  
Temperature Applications

A novel low-density CBCF composite with an Hf-based coating was designed and prepared, which exhibited a good ablation resistance at the maximum temperature range of 1616–2037 °C for 300 s.

Mechanical Behavior of High Temperature Hybrid Carbon Fiber/Titanium Laminates

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Christos G. Papakonstantinou ◽  
Konstantinos Katakalos
Keyword(s):  
High Temperature ◽  
Carbon Fiber ◽  
Elevated Temperatures ◽  
Pure Titanium ◽  
High Strength ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
High Modulus ◽  
Hybrid Laminates ◽  
The Individual

The aim of this paper was to investigate the tensile and flexural properties of hybrid laminates made with titanium sheets and high modulus carbon fiber composites. Grade II titanium was used, which exhibits great high-temperature performance and creep resistance, low weight, and high strength. An inorganic fireproof matrix, known as geopolymer, was used to fabricate the high modulus carbon fiber composites. Previous studies have shown that these composites are strong, durable, lightweight, and can exhibit excellent performance up to 400°C. In the present study, a number of specimens were tested in uniaxial tension and four-point bending after exposure at elevated temperatures. The results indicate that the addition of carbon fibers can reduce the weight and increase the stiffness of the pure titanium. Moreover, the hybrid laminates are stronger and stiffer than the sum of the individual strengths and stiffnesses of the parent materials. An important finding is that the interlaminar bond is strong, and as a result no delamination failures were observed.

Sign in / Sign up

Export Citation Format

Share Document