Nuclear Fusion Power Plants

Nuclear fusion, the process that powers the sun and the stars, is heralded as the ultimate energy source for the future of mankind. The promise of nuclear fusion to provide clean and safe energy, while having abundant fuel resources continues to drive global research and development. However, the goal of reaching so-called “breakeven” energy conditions, whereby the energy produced from a fusion reaction is greater than the energy put in, is yet to be demonstrated. It is the role of ITER, an international collaborative experimental reactor, to achieve breakeven conditions and to demonstrate technologies that will allow fusion to be realized as a viable energy source. However, with significant delays and cost overruns to ITER, there has been increased interest in the development of other fusion reactor concepts, particularly by private-sector start-ups, all of which are exploring the possibility of an accelerated route to fusion. This chapter gives a comprehensive overview of nuclear fusion science, and provides an account of current approaches and their progress towards the realization of future fusion energy power plants. The range of technical issues, associated technology development challenges and future commercial opportunities are explored, with a focus on magnetic confinement approaches

Low-carbon energy transition with the sun and forest: Solar-driven hydrogen production from biomass

森と太陽から水素を作る革新的プラント --あらゆる既知手法より少ないCO2排出量を実現--. 京都大学プレスリリース. 2021-12-24.There is a need to derive hydrogen from renewable sources, and the innovative stewardship of two natural resources, namely the Sun and forest, could provide a new pathway. This paper provides the first comparative analysis of solar-driven hydrogen production from environmental angles. A novel hydrogen production process proposed in this paper, named Solar-Driven Advanced Biomass Indirect-Gasification (SABI-Hydrogen), shows promise toward achieving continuous operation and scalability, the two key challenges to meet future energy needs. The calculated Global Warming Potential for 1 kg of solar-driven hydrogen production is 1.04 kg CO₂-eq/kg H₂, less than half of the current biomass gasification process which emits 2.67 kg CO₂-eq/kg H₂. Further, SABI-Hydrogen demonstrates the least-carbon intensive pathway among all current hydrogen production methods. Thus, solar-driven hydrogen production from biomass could lead to a sustainable supply, essential for a low-carbon energy transition

Are renewables as friendly to humans as to the environment?: A social life cycle assessment of renewable electricity

The adoption of renewable energy technologies in developing nations is recognized to have positive environmental impacts; however, what are their effects on the electricity supply chain workers? This article provides a quantitative analysis on this question through a relatively new framework called social life cycle assessment, taking Malaysia as a case example. Impact assessments by the authors show that electricity from renewables has greater adverse impacts on supply chain workers than the conventional electricity mix: Electricity production with biomass requires 127% longer labor hours per unit-electricity under the risk of human rights violations, while the solar photovoltaic requires 95% longer labor hours per unit-electricity. However, our assessment also indicates that renewables have less impacts per dollar-spent. In fact, the impact of solar photovoltaic would be 60% less than the conventional mix when it attains grid parity. The answer of “are renewables as friendly to humans as to the environment?” is “not-yet, but eventually.

Life-cycle assessment of hydrogen utilization in power generation: A systematic review of technological and methodological choices

Interest in reducing the greenhouse gas emissions from conventional power generation has increased the focus on the potential use of hydrogen to produce electricity. Numerous life-cycle assessment (LCA) studies of hydrogen-based power generation have been published. This study reviews the technological and methodological choices made in hydrogen-based power generation LCAs. A systematic review was chosen as the research method to achieve a comprehensive and minimally biased overview of hydrogen-based power generation LCAs. Relevant articles published between 2004 and 2021 were identified by searching the Scopus and Web of Science databases. Electrolysis from renewable energy resources was the most widely considered type of hydrogen production in the LCAs analyzed. Fuel cell technology was the most common conversion equipment used in hydrogen-based electricity LCAs. A significant number of scenarios examine the use of hydrogen for energy storage and co-generation purposes. Based on qualitative analysis, the methodological choices of LCAs vary between studies in terms of the functional units, allocations, system boundaries, and life-cycle impact assessment methods chosen. These discrepancies were likely to influence the value of the environmental impact results. The findings of the reviewed LCAs could provide an environmental profile of hydrogen-based electricity systems, identify hotspots, drive future research, define performance goals, and establish a baseline for their large-scale deployment

The Quiescent Intracluster Medium in the Core of the Perseus Cluster

Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July

Hitomi (ASTRO-H) X-ray Astronomy Satellite

The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E  >  2  keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month

Canon Law and Knighthood in Modern Times

One of the fascinating intersections of the Canon law and the modern society can be found in the catholic-founded dynastic orders of knighthood. The author conducted a comprehensive review of legal debates, both in the Canon law and in the international law, to provide readers with an up-to-date understanding on this developing topic. Six major views on the appointment of knights are extracted from the review. Then, a new interpretation is proposed, wherein the legitimacy to confer honours and the legitimacy of the orders of knighthood themselves have to be considered separately. Under this method of interpretation, the criterion to judge the legitimacy of an appointment of knight is both the jus honorum of the head of the family and the order of knighthood itself being legitimate. This article provides a unique perspective on how the Canon law affects an unexpected area of the modern society

Why do I like Schumann more than Chopin? A Physiological Analysis of Pianists' Affinities for Composers

Understanding students' physiological characteristics is essential in piano teaching. However, how can teachers in the field know what music suits their students physiologically? This paper explores a new theory in sport science called, "the Four-Stance Theory" to provide teachers with a simple yet practical method to understand students' physiological nature. A survey-based experiment with 20 research participants (10 male and 10 female pianists) was conducted. Research participants were physically tested for their physiological "Stance Types" to see if pianists' physiological characteristics can predict their preferences for certain composers' music. Chi-square tests of independence showed that Stance Type can indeed predict what type of composers they favor (p < .05); further, this simple 10-minute physical test could also predict what types of composer's works they feel most technically comfortable to perform (p < .01) and feel are easier to understand (p < .05). These results indicate that this remarkably simple method could effectively discern pianists' physiological nature and predict which composer's music suits them physiologically. The authors envision that this 10-minute test could be useful for bringing physiological preparedness to both teachers and students

A System Dynamics Study on the Prospect of Japanese Plutonium Balance

The authors conducted a quantitative reevaluation of the short-term Japanese plutonium balance forecast until 2040 with a new numeric model, in the aim of contributing to the policy making toward the stable US-Japan alliance as well as the East Asian region. The Japanese nuclear fuel cycle was replicated as a system dynamics model on Stella with officially available statistical data. The Monte Carlo method was used to estimate the range of the capacities Japanese nuclear power plants until 2040. The simulation results showed the peak accumulation of plutonium in Japan would be observed around 2025. This indicates that while the plutonium imbalance in Japan would be a point of concern for the next five years, the situation will likely mitigate. Consequently, even if lowering the capacity of Rokkasho reprocessing plant were to be possible, it would not make a significant difference if it takes more than five years. As a result, the authors conclude that if we were to hurry the resolution of the current Japanese plutonium imbalance issues, the Japanese government has to either consider to limit the restarting of NPPs to newer plants or to cut the operation rate of Rokkasho reprocessing plant from the first year