The 21 century coe program: COE-INES “innovative nuclear energy systems for sustainable development of the world”

In the year 2002 and 2003 the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) started the “Priority Assistance for the Formation of Worldwide Renowned Centers of Research — The 21st Century Center of Excellence (COE) Program”, which is planned to continue for 5 years.

A program proposed by Tokyo Institute of Technology “Innovative Nuclear Energy Systems for Sustainable Development of the World” simply called as COE-INES was selected as only one program in nuclear engineering field.

The program consists of research, education and international collaboration. The research will be performed on the innovative nuclear energy systems, which include innovative nuclear reactors and innovative fuel cycles. The research on innovative nuclear reactors does not cover only reactor design studies but also its utilization systems such as hydrogen production. Both free thinking and overall vision are taken on the research. They are stressed on education also.

In the education program (COE-INES Captainship Program) by integrating research with education, we will foster creative researchers and engineers. The program also provides lectures at the professional engineer level, and also various opportunities to cultivate internationalism.

We believe these ideas are occupied by many scientists in various countries. Then we have a plan to promote the international collaboration for research and education on innovative nuclear energy systems.     

Synergistic hydrogen production by nuclear-heated steam reforming of fossil fuels

Processes and technologies to produce hydrogen synergistically by the nuclear-heated steam reforming reaction of fossil fuels are reviewed. Formulas of chemical reactions, required heats for reactions, saving of fuel consumption, reduction of carbon dioxide emission, and possible processes are investigated for such fossil fuels as natural gas, petroleum and coal.

In this investigation, examined are the steam reforming processes using the “membrane reformer” and adopting the recirculation of reaction products in a closed loop configuration. The recirculation-type membrane reformer process is considered to be the most advantageous among various synergistic hydrogen production processes. Typical merits of this process are; nuclear heat supply at medium temperature around 550°C, compact plant size and membrane area for hydrogen production, efficient conversion of a feed fossil fuel, appreciable reduction of carbon dioxide emission, high purity hydrogen without any additional process, and ease of separating carbon dioxide for future sequestration requirements.

The synergistic hydrogen production using fossil fuels and nuclear energy can be an effective solution in this century for the world which has to use fossil fuels to some extent, according to various estimates of global energy supply, while reducing carbon dioxide emission.     

A few comments based on Nuclear Physics

The workshop and symposium on “Accelerator-Driven Sub-Critical Reactor System and Nuclear Physics” were held in March 2000 at KEK (Tsukuba) and in October 2000 at Niigata University during the Autumn Meeting of the Japan Physical Society. This was the first joint meeting between the Japanese nuclear physics community members and the Japanese Atomic Energy Society members. About 150 participants working in various fields, such as nuclear physics, reactor physics, reactor engineering, and nuclear power plants in industries discussed the problems related to the nuclear transmutation. Young students also participated in the meetings. Based on the comments in these meetings and on my personal research experience on nuclear physics at university I would like to make a few comments in considering the energy problem in the 21^st century.     

Hydrogen and its relationship with nuclear energy

In broad terms it is estimated that the world will need 17 TW of additional primary energy to meet its needs by 2050. Much of this growth in energy demand will take place in developing countries. Wind, biomass, solar, nuclear and coal will all compete to fill this gap as oil market share declines. Economics, environmental issues, and public acceptance elements of sustainable development goals will be as important as the engineering issues of efficiency and reliability in this competition.

Nuclear power is increasingly recognized as a principal contender to provide economic, “carbon free” electricity for the grid, but it does not directly provide a transportation fuel as flexible as is gasoline. Nuclear-produced hydrogen might help to fill this transportation fuel gap. This presentation will discuss the processes for manufacture of hydrogen from nuclear heat, and the integration of nuclear-produced hydrogen into the transportation fuel system – in part via synergies with traditional oil, natural gas and coal, and/or synergies with nontraditional shale and tar sands. We will discuss the nuclear hydrogen system as we expect it to appear in 2050 and will discuss some of processes that will provide a pathway to creating that system.     

Role of nuclear energy in environment, economy, and energy issues of the 21st century – Growing energy demand in Asia and role of nuclear

The economic growth of recent Asia is rapid, and the GDP and the energy consumption growth rate are about 8–10% in China and India. The energy consumption forecast of Asia in this century was estimated based on the GDP growth rate by Goldman Sachs. As a result, about twice in India and Association of South East Asian Nations (ASEAN) and about 1.5 times in China of SRES B (Special Report on Emission Scenarios) are forecasted. The simulation was done by Grape Code to analyze the impact of energy increase in Asia. As for the nuclear plant in Asia, it is expected 1500 GWe in 2050 and 2000 GWe in 2100, in the case of the environmental constrain. To achieve this nuclear utilization, there are two important aspects, technically and institutionally.

A. Development of the CANDLE core and/or the Breed and Burn core.

B. The establishment of the stable nuclear fuel supply system like “Asian nuclear fuel supply organization”.

High and very high temperature reactor research for multipurpose energy applications

Ten years ago, the European High Temperature Reactor (HTR) Technology Network (HTR-TN) launched a programme for developing HTR Technology, which expanded so far through 4 successive Euratom Framework Programmes. Many projects have been performed - in particular the RAPHAEL project in the 6th Euratom Framework Programme and presently ARCHER in the 7th - in line with the Network strategy that identified cogeneration of process heat and power as the main specific mission of HTR. HTR can indeed address the growing energy needs of industry presently fully relying on fossil fuel combustion with a CO₂-lean generation technology, thanks to its high operating temperature and to its unique flexibility obtained from its large thermal inertia and its low power.Relying on the legacy of the former European leadership in HTR technology, this programme has addressed specific developments required for industrial process heat applications and for increasing HTR performances (higher temperatures and fuel burn-up). Decisive achievements have been obtained concerning fuel manufacturing and irradiation behaviour, key components and their materials, safety, computer code validation and specific HTR waste (fuel and graphite) management. Key experiments have been performed or are still ongoing: irradiation of graphite, fuel and vessel materials and the corresponding post-irradiation examinations, safety tests and isotopic analyses; thermal-hydraulic tests of an Intermediate Heat Exchanger mock-up in helium; air ingress experiments for a block type core, etc. Through Euratom participation in the Generation IV International Forum (GIF), these achievements contribute to international cooperation.HTR-TN strategy has been recently integrated by the “Sustainable Nuclear Energy Technology Platform” (SNE-TP) as one of the 3 “pillars” of its global nuclear strategy. It is also in line with the orientations and the timing of the “Strategic Energy Technology Plan (SET-Plan)” for the development of CO₂-lean energy technologies, and thus strengthens the nuclear option in a future European energy mix.Nuclear cogeneration for industrial process heat applications is a major innovation and a major challenge, requiring large-scale demonstration to prove its industrial viability. To enable demonstration, it is necessary not only to develop an appropriate nuclear heat source, but also to develop coupling technologies and to adapt industrial processes to the coupling with a HTR. This requires a close partnership between the conventional and the nuclear technology holders as the base of a Nuclear Cogeneration Industrial Initiative.Recently the project EUROPAIRS initiated by HTR-TN together with process heat user industries has set the bases of such a strategic partnership.     

Progress in “COE-INES”

In the year 2002 and 2003, the Japanese Ministry of Education, Culture, Sports, Science and Technology started the “ The 21st Century Center of Excellence (COE) Program”, which is planned to continue for 5 years. A program proposed by Tokyo Institute of Technology “Innovative Nuclear Energy Systems for Sustainable Development of the World” simply called as COE-INES was selected as only one program in nuclear engineering field. The program consists of four main activities: research, education, society and internationalism. The research will be performed on the innovative nuclear energy systems, which include innovative nuclear reactors and innovative fuel cycles. Both free thinking and overall vision are taken on the research, and stressed on education also. In the education, COE-INES Captainship Program is promoted by integrating research with education, and we will foster creative researchers and engineers. Society is also a very important issue for nuclear energy. We try to coevolve nuclear energy with society and to strive towards the fulfillment of SR as well as to research innovative nuclear energy systems. We believe these ideas are occupied by many scientists in various countries. Then we are promoting the international collaboration for research and education on innovative nuclear energy systems.     

Inherently safe containments for nuclear power plants

Nuclear energy cannot be avoided in the near future. To regain public acceptance the safety of nuclear power plants has to be increased. Consequently, feasibility studies have been carried out for a containment proposal for future pressurized water reactors which will keep people unharmed even in the case of severe nuclear accidents under the assumption “all that can go wrong, will go wrong”. The main features of the design concept are a core melt cooling and retention device, a passively acting cooling system to remove the decay heat and a double-wall containment which is able to withstand high static and dynamic internal pressures due to hydrogen detonation. Internal structures are designed to resist extreme loadings resulting from various accident scenarios including in-vessel steam explosion and vessel failure under high system pressure.     

Nuclear energy strategy in the environment of utility business deregulation

Nuclear power has contributed to the reduction and stabilization of electricity rate in Japan. However, its economic competitiveness has been eroding since mid 80's. Deregulation is hitting nuclear power just at the time its competitiveness is declining, and it poses a threat to drive short-sighted market orientation and precludes long term focus on achieving a balance between “environmental agenda” and “competitiveness in market”. Lowering the electricity rate is one of the important agenda to improve the nation's industrial competitiveness in the global market. However, it will be very difficult to win the competition of gas and oil prices with other developed countries in Europe and North America due to a handicap of long transportation distance. Only nuclear power and natural energy have no relation to such a handicap of economic distance from resources. Without securing economic superiority of those energy sources, Japan will not be able to clear the handicap of energy costs. The Japanese utilities are trying hard to regain the competitive edge of nuclear power. We have established short-term strategies for both existing and new LWRs as well as a long-term strategy for technological development. With these strategies we will be able to regain the competitiveness of nuclear power.     

Importance of nuclear generation in the struggles to reduce CO2 emission at Kansai Electric Power Co.

It has been pointed out in recent years that the potential impacts of global warming has been becoming more and more serious because of the rapid increase of anthropogenic CO₂ emission.

Japan's annual CO₂ emissions (fiscal 1994) amounted to 343 million tons of carbon. Although CO₂ emissions caused by fossil-fuel power generation accounted for 29.4% of total, on a sector basis, those directly from the energy conversion sector accounted for only 7.7%. Most CO₂ emissions (21.7% of total) resulted from electric power use in the industrial, commercial and domestic sectors. Thus, the reduction of CO₂ emissions caused by the use of electricity is a nationwide subject.

Understanding that both supply side and demand side approaches are necessary, Kansai Electric has been deploying “New ERA Strategy” as a comprehensive strategy to seek a potential for CO₂ reduction more broadly and deeply. Among a number of action items are the promotion of nuclear power generation, and improvement of overall energy efficiency, besides such demand side measures as leveling off the peak load.

The effectiveness of action items of the New ERA Strategy was evaluated in terms of CO₂ reduction. As a result, estimated CO₂ reduction related to nuclear power amounted to 88% of the total for fiscal 1995 in comparison with 1990, and that expected in 2000 is 84%. These results reconfirm that nuclear power is always the key to practical CO₂ reduction at present and in the future.

Comparison with candidate technology alternatives revealed that photovoltaic power generation needed 7 times greater rated capacity and 280 times larger area than nuclear power, so it is not realistic as a central power station alternative. The comparison also clarified that if wind power stations were constructed at all feasible sites in the Kansai region, they would not be a viable alternative to a single nuclear unit from CO₂ reduction viewpoint.     

The severe accident mitigation concept and the design measures for core melt retention of the European Pressurized Reactor (EPR)

For the mitigation of severe accidents, the European Pressurized Water Reactor (EPR) has adopted and improved the defense-in-depth approaches of its predecessors, the French “N4” and the German “Konvoi” plants. Beyond the corresponding evolutionary changes, the EPR includes a new, 4th level of defense-in-depth that is aimed at limiting the consequences of a postulated severe accident with core melting. It involves a strengthening of the confinement function and the avoidance of large early releases. The latter requires the prevention of scenarios and events that can result in high loads on the containment, e.g., a failure of the Reactor Pressure Vessel (RPV) at high internal pressure. This is achieved by dedicated design measures.

The paper gives an short overview of the general concept and the strategies for: primary circuit depressurization, H₂ mitigation and the avoidance of energetic Fuel Coolant Interactions (FCIs). It then describes, in detail, the conceptual solution for the stabilization and long-term cooling of the molten core.

The EPR melt retention strategy supports itself on the use of an ex-vessel core catcher located in a compartment lateral to the pit. The related spatial and functional separation isolates the core catcher from the various loads during RPV failure and, at the same time, avoids risks resulting from an unintended initiation of the system during power operation.

Within the core catcher, the melt will be passively flooded with water from the Internal Refueling Water Storage Tank (IRWST). Due to the effective cooling of the melt from all sides a stable state will be reached within hours and complete solidification of the melt is achieved after a few days. The core catcher can optionally be supplied by the Containment Heat Removal System (CHRS). In this active mode of operation, the water levels inside spreading compartment and reactor pit rise and the pools become subcooled, so further steaming is avoided. This results in a depressurization of the containment in the long-term.     

The Stuttgart positron beam, its performance and recent experiments

A monoenergetic MeV positron (e⁺) beam, with a flux at present of 6 × 10⁴ e⁺/s in the energy range of 0.5 to 6.5 MeV, has been installed at the Stuttgart Pelletron accelerator. The stabilization and the absolute calibration of the energy E is monitored by a Ge detector with real-time feedback; a relative energy stability of ΔE/E 10⁻⁴ is obtained. So far, e⁺e⁻ scattering and annihilation-in-flight experiments for investigating the low-energy e⁺e⁻ interaction as well as β⁺ γ positron lifetime measurements in condensed matter have been performed. The advantages of the β⁺ γ method compared to the conventional γγ coincidence technique have been demonstrated. Recently, triple-coincidence positron “age-momentum correlation” measurements have been carried out on fused quartz. A brief account is given on the development of a “positron clock” aiming at a substantial improvement of the time resolution of the β⁺ γ positron lifetime measurements.     

Condition telemonitoring and diagnosis of power plants using web technology

The monitoring and diagnostic systems currently installed in power plants generally supply information for control room displays and for on-site personnel. Telemonitoring is also frequently used. In this case, relevant diagnostic data are transmitted remotely to a special laboratory for analysis using highly specialized equipment and software.

The appearance of the terms “Monitoring” and “Diagnosis” alongside the term “Web Technology” in the title of this paper does not mean that remote access to diagnostic systems over the Internet is being presented here as a simple extension of the existing situation.

Condition telemonitoring and diagnosis based on Web technology is a new departure in diagnostic system design philosophy. It is the technology used to integrate diagnostic systems into a customer's IT infrastructure (Intranet or Internet).

Siemens has started to use Web-based condition telemonitoring and diagnosis in some power plants (nuclear and fossil-fueled) to provide a global source of specialist support.     

Global electrification and nuclear power: Toward sustainable growth in the new millennium

The new millennium will present daunting challenges for the world community: how to sustain prosperity while preserving the global environment in the presence of increasing world population. Science and technology hold the keys to resolving this well-publicized “tri-lemma” of balancing economy and environment under the increasing burden of population growth.

Technologies have been developing rapidly in recent years and their impact is being felt in every corner of the global community. It is expected that the process will only accelerate and expand in the new millennium. This, together with people's aspirations for better life, will put enormous demands on energy production. Thus, energy and environment will remain two poles of a central global issue in the new century. Electricity's role in mitigating environmental degradation is well known and global electrification promises the best hope for achieving globally sustainable growth. The question is then how to produce energy that can generate electricity harmoniously with environment. Nuclear power offers the best answer, as it is one of the few non-carbon sources that can produce electricity in significant quantity.

In examining the big picture of global priorities for the new millennium, the role of electrification and nuclear power is brought to the fore in the context of globally sustainable growth, and a strategic roadmap for revival of nuclear option is proposed.     

Low-energy unstable nuclear beam channel “SLOW” at the RIKEN ring cyclotron

A new type of low-energy radioactive nuclear beam channel “SLOW” has been constructed at the RIKEN ring cyclotron facility, intended not only for the study of emission mechanisms of various low-energy radioactive as well as stable isotope ions from a characterized surface of the primary target, but also for the generation of useful radioactive ion beams for surface-physics studies of the secondary target.

In the commissioning experiment of the SLOW beam channel, the reaction products of a heavy-ion induced nuclear reaction have been observed after surface ionization at a hot tungsten target.     

Optimal space-energy splitting in MCNP with the DSA

The DSA theory is based on the possibility to obtain exact explicit expressions for the dependence of the second moment and calculation time on the splitting parameters. This allows the automatic optimization of the splitting parameters by “learning” the problem's bulk parameters from which the problem depended coefficients of the quality function (second moment ^* time) are constructed.

The above procedure was exploited to implement an automatic optimization of the splitting parameters in the MCNP code. This was done in a number of steps. Firstly only spatial surface splitting was considered. In this step, the major obstacle has been the truncation of an infinite series of “products” of “surface path's” leading from the source to the detector. The encouraging results of the first phase led to the inclusion of full space/energy phase space splitting.     

Progress for on-line acoustic emission monitoring of cracks in reactor systems

This paper reviews accomplishments and planned tasks for the NRC-sponsored research program concerned with “Acoustic Emission/Flaw Relationships for Inservice Monitoring of Nuclear Reactor Pressure Boundaries”. The objective of the acoustic emission (AE) monitoring program is to develop and validate the use of AE methods for continuous surveillance of reactor pressure boundaries to detect flaw growth. Topics discussed include testing AE monitoring on reactors, refinement of an AE signal identification relationship, study of slow crack growth rate effects on AE generation, and activity to produce an ASTM standard for AE monitoring and to gain ASME code acceptance of AE monitoring.     

Coal gasification with heat from high temperature reactors: Objectives and status of the project “Prototype Plant for Nuclear Process Heat (PNP)”

It is by now fairly widely known that the high temperature reactor (HTR) is a unique nuclear energy source which can supply heat at temperatures up to 1000°C for application in chemical processes, for which previously exclusively combustion heat sources have been used. With the HTR, it is possible to apply nuclear energy not only for electrical power production but also for the synthesis of liquid or gaseous energy carriers. Nuclear coal gasification appears most promising as the first step for the demonstration and industrial application of nuclear process heat technology in the Federal Republic of Germany. Reactor manufacturers and coal mining companies in co-operation with the Nuclear Research Center at Jülich established a joint project in 1975 for the development of an HTR with a coolant outlet temperature of 950°C, for the development and testing of nuclear coal gasification, for the detailed engineering of a prototype plant consisting of an HTR and gasification plant and finally for the construction and operation of this prototype plant for nuclear process heat (PNP). This contribution describes the status of the PNP-Project and the scope for future development.     

Structure and optical properties of sapphire implanted with boron at room temperature and 1000 °C

Many previous studies of ion-implanted sapphire have used gas-forming light ions or heavier metallic cations. In this study, boron (10¹⁷ cm⁻², 150 keV) was implanted in c-axis crystals at room temperature, 500 and 1000 °C as part of a continuing study of cascade density and “chemical” effects on the structure of sapphire. Rutherford backscattering-ion channeling (RBS-C) of the RT samples indicated little residual disorder in the Al-sublattice to a depth of 50–75 nm but almost random scattering at the depth of peak damage energy deposition. The transmission electron micrographs contain “black-spot” damage features. The residual disorder is much less at all depths for samples implanted at 1000 °C. The TEM photographs show a coarse “black-spot damage” microstructure. The optical absorption at 205 nm is much greater than for samples implanted with C, N, or Fe under similar conditions.