Fission Plants Research Articles

International Relations Ingredients in Utopia: An Analysis of Callenbach’s Ecotopia

This research paper aims to investigate the ingredients of international relations in Ernest Callenbach’s utopian novel Ecotopia (1975). First, this paper analyses the concepts of Utopia and International Relations. Then, it explains and finds out that Ecotopia, an earth-friendly place that has seceded from the U.S. for about two decades because of its involvement in nature degradation activities, has cut off its relations with the U.S., but Ecotopia is not isolated from the rest of the world. The U.S. sends William Weston, a top international affairs reporter, and the protagonist, to make eroded diplomatic relations with Ecotopia amicable. But he finds Ecotopia as a live-worth place and decides to live there permanently. Ecotopia has established relations with other nations politically, economically as well as culturally. Except with the U.S., Ecotopia is involved in importing iron from other nations and exporting cultural artifacts to them. Ecotopian Government has applied a deterrence policy with the U.S., so it has run nuclear fission plants though such projects are against the ethics of a utopian nation. Ecotopians blame America for being an imperialist nation and waging wars against different nations. They believe that big nations must secede further into small nations so that they can manage their natural resources making them earth-friendly. This research concludes that a utopian work also includes different ingredients of international relations.

Failure mode and reliability study for dynamic confinement and conditioning of the IFMIF-DONES radiological areas

The reference engineering design of the IFMIF-DONES nuclear Heating, Ventilation, and Air Conditioning system (HVAC) has been analyzed in terms of potential failure modes and consequences as well as life-cycle reliability and availability. The HVAC system performs the safety function of preventing lithium fire and uncontrolled releases of radioactive materials from the radiological areas. The results of the Reliability, Availability, Maintainability and Inspectability (RAMI) analysis are of high practical importance for future activities on the system optimization and safety demonstration. This paper proposes a unified approach to the Failure Mode and Effects Analysis (FMEA) that can be applied to the plant systems evaluation in terms of the failure frequency, severity, and detectability. The reliability and availability calculation has been performed for two sets of data, the U.S. NRC collection representing the industry standards of fission power plants, and the fusion-specific data gathered from several sources and integrated by Monte Carlo-based method. Inherent availability of above 99.4% has been reached for the HVAC system based on the fusion-specific data. The use of reliability data from the commercial fission plants increased the system availability to nearly 99.8%, thus indicating the potential for allocation of higher availability requirements to the HVAC functions.

What Would Happen to a Fusion Power Plant in the Case of Plasma Disruption? A Dynamic Model Simulation

It is a widespread view in the fusion community that steady-state, water-cooled fusion power plants can utilize the power generation systems of conventional pressurized water reactor (PWR) fission plants as is. However, what would happen to a fusion power plant in the case of plasma disruption? The authors constructed a dynamic simulation model of a water-cooled ceramic breeder blanket fusion power plant model on Modelica language [300.0-MW(electric) electrical output/1138-MW(thermal) fusion output] and evaluated the applicability of a PWR power generation system. Simulation results suggest that while the PWR system would function as intended during steady-state operation, the conventional system may not be able to cope with a sudden loss of energy influx in the event of plasma disruption without modification: The PWR system’s steam generator experienced a water overflow in less than 150 s from the plasma disruption.

Potential contribution of fusion power generation to low-carbon development under the Paris Agreement and associated uncertainties

Fusion energy has abundant resources, does not exhibit nuclear runaway, and it has zero-carbon emissions. Long-term strategies for fusion energy development will become critically important to promote future DEMOnstration Fusion Reactor (DEMO) projects by another largescale investment and gain social acceptance. This paper assessed the potential contribution of fusion power generation to low-carbon development, which is prescribed in the Paris Agreement, under the combination of different uncertainties of future socioeconomic development, probability of the 2 °C target, and development of commercial fusion power plants. Global negative CO2 emission in 2100 by drastic decarbonization of energy systems was required to achieve the 2 °C target, and fusion power plants were expected to be installed in the latter half of the 21st century mainly in countries with limited potentials of zero-emission energy sources, such as Japan, Korea, and Turkey, for cost-efficient climate change mitigation. If inexpensive power plants could be developed by enhanced R&D and advanced design in DEMO projects or if the establishment of fission plants in the future is low, fusion power generation will also be deployed in the EU28, India, and China. Further cost reduction by innovative design and alternative concepts are also essential to diffuse fusion plants in zero-emission resource-rich countries.

CFD modelling of the CIRCE facility

CIRCE is a test facility designed and realized by the Italian agency ENEA to support the heavy liquid metal technology for nuclear fission plants. Within the H2020 projects SESAME and MYRTE, various experiments are performed in this facility, using two different heat exchangers (namely ICE and HERO), resembling nominal operation and accident scenarios of a Liquid Metal Fast Reactor (LMFR). Simultaneously, within these projects different thermal-hydraulics models of CIRCE are created to gain experience in the modelling of such a facility and to help future development of LMFRs. At NRG and CRS4, CFD models of CIRCE in the two different configurations are created. The present paper describes the steps taken to create these models. Results obtained with the models are, where possible, compared with experimental results, both for steady-state and transient conditions. For the steady-states, generally good agreement is found. The main features of the stratification forming in the pool are recovered, though they appear quite sensitive to the local heat balance. The transient simulation performed recovers some of the main features of the experiment, however excessive cooling is found. The causes of discrepancies found between numerical and experimental results are currently under investigation.

Estimation of Tritium and Dust Source Term in European DEMOnstration Fusion Reactor During Accident Scenarios

The safety features of the future nuclear fusion reactors are one of the key issues for their attractiveness if compared with the fission plants. In fusion devices, accidents with high release of radioactive materials have low probabilities because the most part of abnormal transients lead to passive plasma shutdown. It does not mean that radiological source terms such tritium and activated dust are not generated and released, but their inventory does not increase during abnormal events. Therefore, the source term inventory has to be assessed during normal operation and traced when accidents occur. For this reason, a study for qualification and quantification of the tritium and dust source term (DTS) was established with the aim to understand their production, deposition, and penetration in the vacuum vessel (VV) and in the breeding blanket (BB). The main concern is source term release during the main accident scenarios to comply with a future licensing process. In case of abnormal event scenarios, the source term inventory involved in the release changes and requires a different confinement approach and mitigation. For the estimation of the source term in the DEMOnstration Fusion Power Station (DEMO), a methodology was developed. The methodology scales the tritium and DTS inside the VV from the International Thermonuclear Experimental Reactor, the European Power Plant Conceptual Study, and reports the tritium generated inside the breeder blanket from data quantified in other studies for DEMO. In this article, the methodology was updated and tritium and DTS for DEMO 2016 design were estimated. Moreover, the tritium and dust release pathways were highlighted according to different accidental scenarios. These results were obtained for all blanket concepts, which are analyzing in the ongoing DEMO EUROFusion project. The values estimated in this article will be used in the safety analyses to evaluate releases or to quantify the operational limits starting from values postulated in International Thermonuclear Experimental Reactor.

Historical Fission Plant Availability and the Operation Goal for a Fusion DEMO

As fusion researchers look toward the future, there have been discussions on what the plant operation goals should be for a demonstration fusion power plant (DEMO). The U.S. Research Needs Workshop (ReNeW) in 2009 stated that power producers (the companies owning power plants) could not expect an ultimate fusion power plant availability of 80% or more if a DEMO reactor cannot demonstrate a 50% or higher availability. The ReNeW panel also stated that achieving 50% availability with a DEMO plant would be a huge accomplishment. Other recent DEMO design studies have given goals for plant availability as well. This technical note presents historical plant availability values of new technology fission power plants to compare fission achievements with the suggested goals for fusion DEMO plant designs. Demonstration fission plants that met or exceeded 40% average annual availability were generally considered to be successful. These data help to support the goal values that have been put forward in various studies.

NANO ENERGY

We live in a world that although saves energy by developing software however still consume an increasing amount of energy annually. Major energy crises world have caused the repeated political crises, economic, industrial, social, religious, and even military. While fossil energy issue is threatened with exhaustion and the nuclear fission is totally unfriendly, we are at the time when humanity must find new energies, alternative, renewable, sustainable, cost-effective, non-hazardous. Besides solar, wind, hydro, geothermal, tidal, present work comes to propose and other new alternative energy type nano. In turn it proposes the nuclear fusion energy, energy produced from matter and antimatter, and energy produced using high power lasers. After 1950, began to appear nuclear fission plants. The fission energy was a necessary evil. In this mode it stretched the oil life, avoiding an energy crisis. Even so, the energy obtained from oil represents about 66% of all energy used. At this rate of use of oil, it will be consumed in about 40 years. Today, the production of energy obtained by nuclear fusion is not yet perfect prepared. But time passes quickly. We must rush to implement of the additional sources of energy already known, but and find new energy sources. In these circumstances this paper comes to proposing possible new energy sources. The movement of an electron around the atomic nucleus has today a great importance in many engineering fields. Electronics, aeronautics, micro and nanotechnology, electrical engineering, optics, lasers, nuclear power, computing, equipment and automation, telecommunications, genetic engineering, bioengineering, special processing, modern welding, robotics, energy and electromagnetic wave field is today only a few of the many applications of electronic engineering. This paper presents shortly in the last chap. a new and original relation which calculates the radius with that the electron is running around the atomic nucleus. For a Bohr energetically level (n=a constant value), one determines now two energetically below levels, which form an electronic layer. The author realizes by this a new atomic model, or a new quantum theory, which explains the existence of electron-clouds without spin, and promises, that application, construction of some high-energy laser.

GREEN ENERGY TO PROTECTING THE ENVIRONMENT/ ENERGIA VERDE PARA PROTEGER O MEIO AMBIENTE

After 1950, began to appear nuclear fission plants. The fission energy was a necessary evil. In this mode it stretched the oil life, avoiding an energy crisis. Even so, the energy obtained from oil represents about 60% of all energy used. At this rate of use of oil, it will be consumed in about 60 years. Today, the production of energy obtained by nuclear fusion is not yet perfect prepared. But time passes quickly. We must rush to implement of the additional sources of energy already known, but and find new energy sources. Green energy in 2010-2015 managed a spectacular growth worldwide of about 5%. The most difficult obstacle met in worldwide was the inconstant green energy produced.

Dear Clarice

Dear Clarice Adrienne Celt (bio) Click for larger view View full resolution © Quinn Dombrowski, CC BY-SA 2.0 via Flickr YOU ARE THE LAST PERSON I EXPECT to be interested in my explanations and confessions, and yet you’re the only person I can think of to address them to. As I write, I imagine the ballet of reactions on your face; that familiar mix of—forgive me—envy and disgust. Exhaustion. I imagine each upcurled lip and puckered brow, and feel them play out across my own features. You know we made identical faces at one another, always. It was our only real common ground as sisters: being so different that we responded to one another in exactly the same baffled way. [End Page 113] So I’m sending you these pages, because I know you’ll be compelled to read them all the way through, by your parallel senses of duty and dread. Not a compliment, but not an insult either, whatever you may think. I’m grateful for the chance to offer someone what I feel to be the whole truth. THE INTERNET WAS, OF COURSE, INSUFFERABLE in the days that followed the event. All the social media outlets and special-interest blogs were flooded with some version of this sentiment: “I’m so happy I got to visit France before all this happened. It was a lifelong dream, and le château de Versailles will live forever in my heart. #blessed” Or alternatively: “Those socialist elitist fucks had it coming. You want to eat snails? Well, you’re asking for something bad to happen. Just my opinion.” Or even: “You all know the government is behind this, right? It’s a systematic depopulation program, and we’re next. You’ll see.” Not one of these people had any idea what they were talking about. But that was to be expected, really. We’re the ones who should’ve known. OUR PROJECT, AS I’M SURE YOU’RE AWARE BY NOW, was called the Cooperative International Thermonuclear Reactor Assessment, CITRA for short. “Cooperative” because it was built and funded by a number of different international agencies. “Assessment” because, in the early stages, it was unclear when, if ever, it would work.1 The other pieces, I think even you can figure out. Fusion energy was still a pie-in-the-sky proposition back then, but we were cocky—no surprise to you, I’m sure—and convinced ourselves that we could transform our theories into reality by sheer will. The world needed a safe alternative to gas, coal, and oil—and we would give it to them. No more exhaust fumes, no more fission plants blowing good country people to kingdom come. It wasn’t easy, though. There was no room for error. We couldn’t afford even a millimeter of discrepancy between the plans and the product. Like anything so precise, CITRA at work was worthy of awe. The force of the reaction could only be contained within a subzero vacuum, supported by powerful electromagnets. It was hotter than any natural phenomenon on Earth. It was a small terrestrial star. BUT I’M FORGETTING—or, as you’d more likely say, ignoring—you. The things that fill each of us with awe are not the same, are they? Always, you loved the Pentecost, the long hand of God. The descent of the Holy Spirit onto the body of the Earth. We both preferred to love things that the other [End Page 114] could not understand. So when I speak of CITRA, I know I risk boring you. Me and my scientific mumbo-jumbo, the kind of talk that was over your head and beneath your concern. After seven years, and a promise of confession, I don’t mean to be so disappointing. I want to hold your attention, Clarice, I really do—after all, these may be my last words. And I think there’s a way. The personal, you always said. The personal, and the providential. Dancing in our bedroom slippers, singing at the top of our lungs—to you, the point wasn’t to annoy our parents into sending us to summer camp...

Design related aspects in advanced nuclear fission plants

Important issues to be considered for design of future reactors are: extrapolation of stress rupture data, creep–fatigue, negligible creep, damage monitoring. The paper highlights some new developments taking examples from a martensitic steel (mod 9% Cr), oxide dispersion strengthened (ODS) steels and nickel-base superalloys. Traditional approaches to extrapolation of (thermal) stress rupture data like Larson–Miller Parameter or Monkman–Grant rule seem to be valid concepts also for advanced reactors. However, a significant influence of cyclic softening on creep rates and stress rupture data can be expected as shown for grade 91. This is particularly true for creep–fatigue interactions. Based on cyclic stress–strain behaviour it is also possible to get very good life-time predictions under creep–fatigue with a strain range separation (inelastic fatigue and creep ranges) technique which could replace the currently used linear life fraction rule. Results from in-beam irradiation creep reveal no significant influence of dispersoid size. It can be assumed that irradiation creep is a matrix property. Finally it is shown that micro-sample testing of exposed material could be used as an advanced method for damage assessment in future nuclear power plants.

Extracting Minerals from Seawater: An Energy Analysis

The concept of recovering minerals from seawater has been proposed as a way of counteracting the gradual depletion of conventional mineral ores. Seawater contains large amounts of dissolved ions and the four most concentrated metal ones (Na, Mg, Ca, K) are being commercially extracted today. However, all the other metal ions exist at much lower concentrations. This paper reports an estimate of the feasibility of the extraction of these metal ions on the basis of the energy needed. In most cases, the result is that extraction in amounts comparable to the present production from land mines would be impossible because of the very large amount of energy needed. This conclusion holds also for uranium as fuel for the present generation of nuclear fission plants. Nevertheless, in a few cases, mainly lithium, extraction from seawater could provide amounts of metals sufficient for closing the cycle of metal use in the economy, provided that an increased level of recycling can be attained.

NUCLEAR ENERGY MATERIALS PREDICTION: APPLICATION OF THE MULTI-SCALE MODELLING PARADIGM

The safe and reliable performance of fusion and fission plants depends on the choice of suitable materials and an assessment of long-term materials degradation. These materials are degraded by their exposure to extreme conditions; it is necessary, therefore, to address the issue of long-term damage evolution of materials under service exposure in advanced plants. The empirical approach to the study of structural materials and fuels is reaching its limit when used to define and extrapolate new materials, new environments, or new operating conditions due to a lack of knowledge of the basic principles and mechanisms present. Materials designed for future Gen IV systems require significant innovation for the new environments that the materials will be exposed to. Thus, it is a challenge to understand the materials more precisely and to go far beyond the current empirical design methodology. Breakthrough technology is being achieved with the incorporation in design codes of a fundamental understanding of the properties of materials. This paper discusses the multi-scale, multicode computations and multi-dimensional modelling undertaken to understand the mechanical properties of these materials. Such an approach is envisaged to probe beyond currently possible approaches to become a predictive tool in estimating the mechanical properties and lifetimes of materials.

Microcharacterization of Damage in Materials for Advanced Nuclear Fission Plants

Miniature and sub-miniature samples were used for determination of mechanical properties of materials for advanced fission plants. Results from indentation and focused ion beam prepared micro-samples, punch tests and thin strip (irradiation) creep tests are shown. The results allow conclusions concerning materials damage. Irradiation damage profiles were determined with indentation. Results from micro-pillar tests showed a good agreement with results from conventional samples in case of oxide dispersion strengthened steels. Thin strip irradiation creep experiments revealed a negligible influence of dispersoid size/distribution on creep rates. Punch tests of fibre reinforced materials showed consistent results which still need quantitative analysis.

Occupational Injury Rate Estimates in Magnetic Fusion Experiments

In nuclear facilities, there are two primary aspects of occupational safety. The first aspect is radiological safety, which has rightly been treated in detail in nuclear facilities. Radiological exposure data have been collected from the existing tokamaks to serve as forecasts for ITER radiation safety. The second aspect of occupational safety, “traditional” industrial safety, must also be considered for a complete occupational safety program. Industrial safety data on occupational injury rates from the JET and TFTR tokamaks, three accelerators, and U.S. nuclear fission plants have been collected to set industrial safety goals for the ITER operations staff. The results of this occupational safety data collection and analysis activity are presented here. The data show that an annual lost workday case rate of 0.3 incidents per 100 workers is a conceivable goal for ITER operations.

Materials Modeling - a key for the Design of Advanced High Temperature Reactor Components

The safe and reliable performance of advanced fission plants is dependent on the choice of suitable materials and assessment of long-term materials degradation. These materials are degraded by their exposure to high temperatures, irradiation and a corrosive environment, therefore it is necessary to address the issue of long term damage evolution of materials under service exposure in advanced plants. A higher confidence in life-time assessments of these materials requires an understanding of the related physical phenomena on a range of scales from the microscopic level of single defect damage effects all the way up to macroscopic effects. To understand the many different phenomena present, such a study needs to encompass broad time and length scales starting from atomistic descriptions of primary damage formation and ending with a description of bulk property behaviour at the continuum limit. This paper discusses the multi-scale, multi-code simulations and multi-dimensional validation experiments undertaken to understand the mechanical properties of these materials. Such a multiscale modelling and experimental approach is envisaged and will probe beyond currently possible approaches to become a predictive tool in estimating lifetimes and mechanical properties of materials.

On the path to fusion energy

There is a need to develop alternate energy sources in the coming century because fossil fuels will become depleted and their use may lead to global climate change. Inertial fusion can become such an energy source, but significant progress must be made before its promise is realized. The high-density approach to inertial fusion suggested by Nuckolls et al. leads reaction chambers compatible with civilian power production. Methods to achieve the good control of hydrodynamic stability and implosion symmetry required to achieve these high fuel densities will be discussed. Fast Ignition, a technique that achieves fusion ignition by igniting fusion fuel after it is assembled, will be described along with its gain curves. Fusion costs of energy for conventional hotspot ignition will be compared with those of Fast Ignition and their capital costs compared with advanced fission plants. Finally, techniques that may improve possible Fast Ignition gains by an order of magnitude and reduce driver scales by an order of magnitude below conventional ignition requirements are described.

On the path to fusion energy

There is a need to develop alternate energy sources in the coming century because fossil fuels will become depleted and their use may lead to global climate change. Inertial fusion can become such an energy source, but significant progress must be made before its promise is realized. The high-density approach to inertial fusion suggested by Nuckolls, et al., leads to reactors compatible with civilian power production. Methods to achieve the good control ofhydrodynamic stability (adiabat shaping) and implosion symmetry required to achieve these high fuel densities will be discussed. Examples of symmetry control for targets driven by Z-pinches or heavy ion beams are given. Fast Ignition, a technique that achieves fusion ignition by igniting fusion fuel after it is assembled, will be described along with its gain curves. Fusion costs of energy for conventional hotspot ignition will be compared with those of Fast Ignition and their capital costs compared with advanced fission plants. Finally, techniques that may improve possible Fast Ignition gains by an order of magnitude and reduce driver scales by an order of magnitude below conventional ignition requirements are described. If these innovations are successful, the fusion specific capital costs can be reduced below 10% of the balance of plant.

Synergies between FNT developments and advanced nuclear fission technologies

The development of future fusion power plants will face similar development issues as future generation of fission plants in order to achieve the goals of technical feasibility and operability. Except for plasma physics, the major challenges for fusion reactors are in the areas of materials development for the heat source structures (plasma facing material for fusion and materials for the fission core) and design of cooling systems for high efficiencies. Helium cooling systems have been proposed for both future fusion plants and advanced fission reactors, in particular those for GEN IV programme. They offer the potential of high efficiencies in combination with advanced high-temperature resistant materials. Therefore, synergies for fusion and fission reactor development could be realized for development in these two areas. For example, the testing of major components of the helium cooling systems for the two power plant systems, as well as the non-nuclear testing of materials, could be possible within common test loops in which different test sections will have to be integrated. The identification of possible synergies in the relevant R&D programmes should be endorsed to minimise the development effort for future power plants. However, the assumed time schedules for the realisation of future fusion and fission reactors have to be taken into account.

Ex-vessel break in ITER divertor cooling loop analysis with the ECART code

A hypothetical double-ended pipe rupture in the ex-vessel section of the International Thermonuclear Experimental Reactor (ITER) divertor primary heat transfer system during pulse operation has been assessed using the nuclear source term ECART code. That code was originally designed and validated for traditional nuclear power plant safety analyses, and has been internationally recognized as a relevant nuclear source term codes for nuclear fission plants. It permits the simulation of chemical reactions and transport of radioactive gases and aerosols under two-phase flow transients in generic flow systems, using a built-in thermal–hydraulic model. A comparison with the results given in ITER Generic Site Safety Report, obtained using a thermal–hydraulic system code (ATHENA), a containment code (INTRA) and an aerosol transportation code (NAUA), in a sequential way, is also presented and discussed.