China
Africa
Explore chapters and articles related to this topic
Political and Regulatory Aspects of Energy and Environment
Published in Anco S. Blazev, Power Generation and the Environment, 2021
At 4 a.m., failure in the non-nuclear, secondary cooling system was followed by a stuck-open pilot-operated relief valve in the cooling primary system. The problem was not corrected on time, so large amounts of nuclear reactor coolant were allowed to escape.
Hydrodynamic Journal and Thrust Bearings
Published in Maurice L. Adams, Bearings, 2018
Tilting-pad bearings, often referred to as pivoted-pad bearings, made their early appearance in the 1950s to optimize the load-carrying capacity of hydrodynamic thrust bearings. That is reported in the early pioneering development work by Abramowitz (1955, 1956) and Raimondi (1960). Prominent machinery types quick to employ tilting-pad thrust bearings (TPTB) were (1) vertical canned-motor PWR nuclear reactor coolant pumps for submarines and early-generation commercial PWR nuclear power plants (see Figures 7.26–7.29), and (2) large power plant steam turbine generator sets (see Figure 7.2). Subsequently, TPTBs are now extensively employed on many other types of rotating machinery. A TPTP is illustrated in Figure 7.43.
Nuclear Power Plant Accidents
Published in B.S. Dhillon, Safety, Reliability, Human Factors, and Human Error in Nuclear Power Plants, 2017
The accident started with failures occurring in the nonnuclear secondary system, followed by a stuck-open, pilot-operated relief valve of the primary system that allowed very large quantities of nuclear reactor coolant to escape. The mechanical failures were compounded by the power plant operators' initial failure to clearly recognize the condition as a loss-of-coolant accident due to improper training and human factors, such as human-computer interaction design oversights concerning ambiguous control room indicators in the user interface of the power plant. More clearly, a hidden indicator light led to an operator to override the reactor's automatic emergency cooling system because the operator in question wrongly believed there was too much coolant water in the reactor, which was causing the steam pressure release [8].
Coolant Channel Design for Additively Manufactured Reactor Cores
Published in Nuclear Science and Engineering, 2022
Justin Weinmeister, Casey J. Jesse, Prashant Jain, Brian J. Ade, Danny Schappel
During a workshop for technologies to accelerate nuclear energy deployment for noncarbon-emitting energy, additive manufacturing (AM) was identified as one of the key enabling technologies for its potential to reduce cost, reduce part count, and increase the part complexity of nuclear reactors.aSee tcr.ornl.gov. These part changes ultimately allow a reactor design that is cheaper, faster to build, and more efficient. Following the workshop, the Transformational Challenge Reactor (TCR) program1 was begun by the U.S. Department of Energy’s (DOE’s) Office of Nuclear Energy to demonstrate advanced technologies for advanced reactors. Included in the TCR design was a core that featured AM fuel forms. These forms marked a sharp departure from traditional nuclear reactor coolant channel shapes because of the design freedom afforded by AM. This work describes the design process for the TCR coolant channels, with particular emphasis on feedback from rapid prototyping and optimization over a larger-than-traditional parameter space, to help inform future thermofluidic designs for advanced reactors.
Turbulent convective heat transfer behavior of supercritical water flowing upward in 2 × 2 rod bundle channels with various spacers
Published in Numerical Heat Transfer, Part A: Applications, 2022
Xin Li, Gongnan Xie, Hangfei Duan, Sandra K. S. Boetcher
The supercritical water-cooled reactor (SCWR), the only water-cooled reactor among six Generation IV nuclear energy systems [1], has received a lot of attention for the advantages of higher thermal efficiency, simplified system, smaller size, and lower capital costs [2–4]. Supercritical water is used as the nuclear reactor coolant in SCWR systems, which results in special flow and heat transfer behaviors in cooling channels. For the purpose of achieving higher thermal efficiency and security of nuclear reactor systems, the design of a cooling channel in a reactor core is vitally important [5]. Over the past decade, heat transfer characteristics of supercritical water [6–9], configurations of rod bundle channel [10], and heat transfer enhancement technologies [11,12] have been investigated.
An Insight into Processing and Properties of Smart Carbon Nanotubes Reinforced Nanocomposites
Published in Smart Science, 2022
Nand Jee Kanu, Saurabh Bapat, Harshad Deodhar, Eva Gupta, Gyanendra Kumar Singh, Umesh Kumar Vates, Girish C. Verma, Vivek Pandey
In reality, Radushkevich and Lukyanovich [12] deserve credit for discovering that carbon filaments may be hollow and have a nanometer-sized diameter, i.e., for discovering carbon nanotubes. Because TEM resolution was limited in the nanometer range at the time, the arrangement of graphenes in the nanotube walls could not be discriminated. It is not critical to know when the different MWCNT textures (concentric, herringbone, bamboo, and platelet) were discovered, but diffraction investigations revealed that most of them were discovered early on. It is true that vapor-grown carbon filaments have long piqued people’s curiosity. ‘Filamentary development of graphite … has just been found again,’ Hillert and Lange wrote in 1958 [13].; 15 years later, Baker et al. [14] stated that ‘interest in catalytic breakdown of hydrocarbons on metallic surfaces … has lately grown more active’ (i.e., which created carbon nano-filaments). However, none of these repeated ‘rediscoveries’ of carbon filament interest have had the same effect as the 1991 Iijima publication in NATURE [7]. This is due to a variety of factors. One is that material scientists have long studied carbon filaments and nanotubes, with the objective of understanding the growth principles so that they might prevent them from forming in coal and steel production, as well as in nuclear reactor coolant channels. The second explanation is more general, and it has to do with science’s degree of maturity (which is the consequence of a collection of favorable conditions, such as possessing the proper materials, as well as associated theory, research instruments, scientific minds, etc.) which was unable to truly think ‘nano’. As a result, the undeniable huge impact of the 1991 Iijima paper was due to a perfect storm of favorable factors: a high-quality paper, a top-rank journal read by all types of scientists, including those involved in basic research and fundamental physics, a boost from its connection to a previous worldwide research hit (fullerenes), and a fully mature scientific audience ready to surf on SWCNTs/MWCNTs.