Kinetic calculations were made to show that subcritical accelerator driven devices are robust and stable. The calculations show that large changes in reactivity that would lead to an uncontrollable excursion in a reactor would lead only to a new power lev...

Kinetic calculations were made to show that subcritical accelerator driven devices are robust and stable. The calculations show that large changes in reactivity that would lead to an uncontrollable excursion in a reactor would lead only to a new power level in a subcritical device. Calculations ...

Kinetic calculations were made to show that subcritical accelerator driven devices are robust and stable. The calculations show that large changes in reactivity that would lead to an uncontrollable excursion in a reactor would lead only to a new power level in subcritical device. Calculations ...

A series of basic experiments for an accelerator driven subcritical reactor (ADSR) has been performed at the Kyoto University Critical Assembly (KUCA) by combining a critical assembly with a Cockcroft-Walton type accelerator in view of a future plan to establish a new neutron source for research. By injecting 14 ...

Thermal neutron reactor (LWR), fast neutron reactor (FBR), accelerator- driven subcritical system have been studied as the potential transmutation devices. Oxide fuel is considered in LWR and metal, oxide, and nitride fuels are studied in FBR. In accelera...

Fissile fuel can be produced at a high rate using an accelerator-driven Pu-fueled subcritical fast reactor which avoids encountering a shortage of Pu during a high growth rate in the production of nuclear energy. Furthermore, the necessity of the early in...

For the Thermophysical analysis of the Accelerator Driven Systems (ADS) an simplified model of ADS core was used. The neutron flux was calculated by means of diffusion theory for subcritical homogeneous reactor with an external neutron source. From this result the distribution of the heat sources was found and next ...

Various transmutation concepts such as PWR, LMR, Accelerator Driven Subcritical Reactor, are under investigation. A study to decide which option is the optimum among three concepts has been performed in this project. In addition, various computer code sys...

Hybrid reactors (Accelerator Driven Sub-critical Systems, ADS), coupling an accelerator with a target and a sub-critical reactor, could simultaneously burn minor actinides and transmute long-lived fission products, while producing a consistent amount of electrical energy. A ...

Accelerator-driven systems for fissile materials production have been proposed and studied since the early 1950s. Recent advances in beam power levels for small accelerators have raised the possibility that such use could be feasible for a potential proliferator. The objective of this study is to review the state of technology development for accelerator-driven spallation ...

Study of a small accelerator-driven subcritical research reactor in the Vin?a Institute of Nuclear Sciences was initiated in 1999. The idea was to extract a beam of medium-energy protons or deuterons from the TESLA accelerator installation, and to transport and inject it into the reactor. The ...

The operation of the accelerator driven reactor with subcritical condition provides a more flexible choice of the reactor materials and of design parameters. A deep subcriticality is chosen sometime from the analysis of point kinetics. When a large ...

The TRiga Accelerator-Driven Experiment (TRADE), to be performed in the TRIGA reactor of the ENEA-Casaccia Centre in Italy, consists of the coupling of an external proton accelerator to a target to be installed in the central channel of the reactor scrammed to subcriticality. This pilot experiment, aimed at a ...

Thorium cycle subcritical reactor driven by 800MeV protons delivered by flux coupled superconducting stack of cyclotrons can operate as a sealed unit for up to 7 years and is stable against melt-down. Small, low power units with minimum security and small crew of operators are perfect candidates for powering remote small towns. The ...

Linear accelerator breeders (LAB) could be used to produce fissile fuel in two modes, either with fuel reprocessing or without fuel reprocessing. With fuel reprocessing, the fissile would be separated from the target and refabricated into a fuel element for use in a burner power reactor. Without reprocessing, the fissile material would be produced in-situ, either in a fresh ...

Experiments were performed at the Nuclear Engineering Teaching Laboratory (NETL) in 2005 and 2006 in which a 20 MeV linear electron accelerator operating as a photoneutron source was coupled to the TRIGA (Training, Research, Isotope production, General Atomics) Mark II research reactor at the University of Texas at Austin (UT) to simulate the operation and characteristics of a ...

In recent years, there has been an increasing worldwide interest in accelerator driven systems (ADS) due to their perceived superior safety characteristics and their potential for burning actinides and long-lived fission products. Indian interest in ADS has an additional dimension, which is related to our planned large-scale thorium utilization for future ...

The proposal presents a PLUTONIUM BASED ENERGY AMPLIFIER TESTING CONCEPT which employs a plutonium subcritical assembly and a 660 MeV proton accelerator, operating in the the JINR (Dubna, Russia). To make the present conceptual design of the Plutonium Energy Amplifier we have chosen a nominal unit capacity of 20 kW (thermal). This corresponds to the multiplication coefficient ...

Since 1991, the CEA has studied the physics of hybrid systems, involving a sub-critical reactor coupled with an accelerator. These studies have provided information on the potential of hybrid systems to transmute actinides and, long lived fission products. The potential of such a system remains to be proven, specifically in terms of the physical ...

The paper present results of Monte Carlo modeling of an Experimental Accelerator Driven System (ADS), which employs a subcritical assembly and a 660 MeV proton accelerator operating at the Laboratory of Nuclear Problems of the Joint Institute for Nuclear Research in Dubna. The mix of oxides PuO2+UO2 MOX fuel designed for the ...

Subcritical nuclear reactors driven by intense neutron sources can be very suitable tools for nuclear waste transmutation, particularly in the case of minor actinides with very low fractions of delayed neutrons. A proper control of these systems needs to know at every time the absolute value of the reactor ...

The purpose of this paper is to compare the safety characteristics of an accelerator driven metal-fueled fast system to a critical core on a consistent basis to determine how these characteristics are affected solely by subcriticality of the system. To accomplish this, an accelerator proton beam/tungsten neutron source model is ...

The purpose of this paper is to compare the safety characteristics of an accelerator driven metal fueled fast system to a critical core on a consistent basis to determine how these characteristics are affected solely by subcritically of the system. To accomplish this an accelerator proton beam/tungsten neutron source model is ...

Fissile fuel can be produced at a high rate using an accelerator driven Pu fueled fast reactor operated at deep subcriticality; this approach avoids encountering a shortage of Pu during a high rate of growth in the production of nuclear energy. Slightly reducing the acceleration field minimizes the tripping of the ...

The purpose of this paper is to compare the safety characteristics of an accelerator driven metal fueled fast system to a critical core on a consistent basis to determine how these characteristics are affected solely by subcritically of the system. To acc...

The application of thermal-spectrum molten-salt reactors and accelerator-driven subcritical systems to the destruction of weapons-return plutonium is considered from the perspective of deriving the maximum societal benefit. The enhancement of electric power production from burning the fertile fuel {sup 232}Th with the plutonium is evaluated. Also the ...

Accelerator driven transmutation technology (ADTT) is a promising way toward liquidation of spent nuclear fuel, nuclear wastes and weapon grade Pu. The ADTT facility comprises a high current (proton) accelerator supplying a sub-critical reactor assembly with spallation neutrons. The reactor ...

The Los Alamos National Laboratory (LANL) is involved in the analysis of many different types of nuclear systems. The nuclear systems that we have analyzed have included subcritical accelerator driven systems for the transmutation of waste, fusion systems, critical experiment systems, and space propulsion and power systems. We have ...

A demonstration facility for Accelerator Driven Systems has been proposed to be constructed at the Joint Institute of Nuclear Research in Dubna. The Subcritical Assembly in Dubna project proposes to couple an existing proton accelerator of 660 MeV and 1 ?A current with a specially designed U-Pu MOX subcritical ...

To study control and safety of accelerator driven nuclear systems, a one point kinetic model was developed and programed. It deals with fast transients as a function of reactivity insertion. Doppler feedback, and the intensity of an external neutron source. The model allows for a simultaneous calculation of an equivalent critical ...

The most challenging issue to realize an accelerator for an Accelerator Driven Sub-critical Reactor system (ADSR) is the handling of high intensity beam�more than 1 mA. For such an application, FFAG is one of most promising candidates. To take advantage of the FFAG as a high intensity accelerator, efficient ...

We describe the power production process in Accelerator Driven Sub-critical systems employing Thorium-232 and Uranium-238 as fuel and examine the demands on the power of the accelerator required.

We describe the power production process in Accelerator Driven Sub-critical systems employing Thorium-232 and Uranium-238 as fuel and examine the demands on the power of the accelerator required.

It is desirable to have only a small reactivity change in the large burn-up of a solid fuel fast reactor, so that the number of replacements or shuffling of the fuel can be reduced, and plant factor accordingly increased. Also, this reduces the number of control rods needed for the change in burn-up reactivity. In subcritical operation, power controlled by ...

A means of transmuting key long-lived nuclear wastes, primarily the minor actinides (Np, Am, Cm) and iodine, using a hybrid proton accelerator and sub-critical lattice, is proposed. By partitioning the components of the light water reactor (LWR) spent fuel and by transmuting key elements, such as the plutonium, the minor actinides, and a few of the ...

Subcritical Assembly in Dubna (SAD), a project funded by the International Science and Technology Centre, driven in collaboration with many European partners, may become the first Accelerator Driven Subcritical experiment coupling an existing proton accelerator of 660 MeV with a compact MQX-fuelled ...

We seek to develop accelerator-driven subcritical (ADS) nuclear power stations operating at more than 5 to 10 GW in an inherently safe region below criticality, generating no greenhouse gases, producing minimal nuclear waste and no byproducts that are useful to rogue nations or terrorists, incinerating waste from conventional nuclear ...

An experimental neutron source facility has been developed for producing medical isotopes, training young nuclear professionals, providing capability for performing reactor physics, material research, and basic science experiments. It uses a driven subcritical assembly with an electron accelerator. The neutrons driving the subcritical ...

The Reactor Accelerator Coupling Experiments (RACE) are a set of neutron source driven subcritical experiments under temperature feedback conditions. These experiments will involve coupling an accelerator driven neutron source to a TRIGA reactor system in a subcritical ...

Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a ...

Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a ...

Transmutation of nuclear wastes (Minor Actinides and Long-Lived Fission Products) remains an important option to reduce the burden of high-level waste on final waste disposal in deep geological structures. Accelerator-Driven Systems (ADS) are considered as possible candidates to perform transmutation due to their subcritical operation mode that eliminates ...

TRASCO-ADS is a national funded program in which INFN, ENEA, and Italian industries work on the design of an accelerator driven subcritical system for nuclear waste transmutation. TRASCO is the Italian acronym for Transmutation (TRAsmutazione) of Waste (SCOrie). One of the most critical aspects in the design of an ...

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The major goal has been to develop accelerator transmutation of waste (ATW) system designs that will thoroughly and rapidly transmute nuclear waste, including plutonium from dismantled weapons and spent reactor fuel, while ...

Nuclear systems under study in the Los Alamos Accelerator-Driven Transmutation Technology program (ADTT) will allow the destruction of nuclear spent fuel and weapons-return plutonium, as well as the production of nuclear energy from the thorium cycle, without a long-lived radioactive waste stream. The subcritical systems proposed represent a radical ...

Power supply is a key issue for China's further economic development. To meet the needs of our economic growth in the next century, the part of nuclear energy in the total newly increased power supply must become larger. However, the present nuclear power stations dominated by the PWR in the world are facing some troubles. Recently, a new concept, called ADS (Accelerator ...

Nuclear systems under study in the Los Alamos Accelerator-Driven Transmutation Technology program (ADTT) will allow the destruction of nuclear spent fuel and weapons-return plutonium, as well as the production of nuclear energy from the thorium cycle, without a long-lived radioactive waste stream. The subcritical systems proposed represent a radical ...

Steady development in SRF accelerator technology combined with the success of large scale installations such as CEBAF at Jefferson Laboratory and the SNS Linac at ORNL gives credibility to the concept of very high average power CW machines for light sources or Proton drivers. Such machines would be powerful tools for discovery science in themselves but could also pave the way to reliable cost ...

Steady development in SRF accelerator technology combined with the success of large scale installations such as CEBAF at Jefferson Laboratory and the SNS Linac at ORNL gives credibility to the concept of very high average power CW machines for light sources or Proton drivers. Such machines would be powerful tools for discovery science in themselves but could also pave the way to reliable cost ...

Accelerator driven nuclear transmutation system has been pursued to have a clue to the solution of high-level radioactive waste management. The concept consists of super conducting linac, sub-critical reactor and the beam window. Reference model is set up to 800MW thermal power by using 1.5GeV proton beams with ...

The YALINA-Booster experiments and analyses are part of the collaboration between Argonne National Laboratory of USA and the Joint Institute for Power & Nuclear Research - SOSNY of Belarus for studying the physics of accelerator driven systems for nuclear...

Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and e...

An apparatus and method is described for transmuting higher actinides, plutonium and selected fission products in a liquid-fuel subcritical assembly. Uranium may also be enriched, thereby providing new fuel for use in conventional nuclear power plants. An accelerator provides the additional neutrons required to perform the processes. The size of the accelerator needed to ...

SCK.CEN, the Belgian Nuclear Research Centre, in partnership with IBA s.a., Ion Beam Applications, is designing an ADS prototype, MYRRHA, and is conducting an associated R&D programme. The project focuses primarily on research on structural materials, nuclear fuel, liquid metals and associated aspects, on subcritical reactor physics and subsequently on ...

The coupling between an accelerator, a spallation target and a subcritical core has been studied for the first time at SCK�CEN in collaboration with Ion Beam Applications (IBA, Louvain-la-Neuve) in the frame of the ADONIS project (1995-1997). ADONIS was a small irradiation facility, based on the ADS concept, having a dedicated objective to produce radioisotopes for medical ...

In order to operate accelerator driven subcritical system safely, it is necessary to monitor the subcriticality in real-time. In this paper, we propose a highly accurate real-time subcriticality-monitoring system by combining the existing multiple measurement techniques, a number of neutron ...

This document is complementary to a document produced by Prof. Salvatores on ''The Physics of Transmutation in Critical or Subcritical Reactors and the Impact on the Fuel Cycle''. In that document, Salvatores describes the fundamental of transmutation, through basic physics properties and general parametric studies. In ...

Since thorium is an abundant fertile material, there is hope for the thorium-cycle fuels for an accelerator driven subcritical system (ADS). The ADS utilizes neutrons, which are generated by high-energy protons of giga-electron-volt-grade, but cross sections for the interaction of high-energy particles are not available for use in ...

This paper describes principles of Accelerator-Driven Transmutation of Nuclear Wastes (ATW) and gives some flavour of the most important topics which are today under investigations in many countries. An assessment of the potential impact of ATW on a future of nuclear energy is also given. Nuclear reactors based on self-sustained fission reactions --- after spectacular ...

The TRADE project (TRiga Accelerator Driven Experiment), to be performed at the existing TRIGA reactor at ENEA Casaccia, has been proposed as a validation of the accelerator-driven system (ADS) concept. TRADE will be the first experiment in which the three main components of an ADS--the accelerator, spallation target and ...

Los Alamos National Laboratory has led the development of accelerator-driven transmutation of waste (ATW) to provide an alternative technological solution to the disposition of nuclear waste. While ATW will not eliminate the need for a high-level waste repository, it offers a new technology option for altering the nature of nuclear waste and enhancing the capability of a repository. The basic ...

Within the framework of the neutronic characterization of the TRIGA RC-1 reactor in support to the TRADE (TRiga Accelerator Driven Experiment) program, the interpretation of the subcriticality level measurements performed in static regime during the TRADE In-Pile experimental program is presented. Different levels ...

As part of the effort to investigate the use of an electron accelerator driven system for TRU transmutation, the effects of TRU distributions in the core on transmuter system performance was examined in this paper. The system performance examined includes the transmutation and system power efficiency and changes in power peaking. The transmutation benefits ...

In the recently completed RACE Project of the AFCI, accelerator-driven subcritical systems (ADS) experiments were conducted to develop technology of coupling accelerators to nuclear reactors. In these experiments electron accelerators induced photon-neutron reactions in heavy-metal targets to initiate fission reactions in ADS. Although ...

Evaluated data are adjusted on experimental measurements using nuclear reaction models. Among these data, those concerning alpha-particle interactions on light nuclei are not well known, although crucial for neutron emission problems via ({alpha},n) processes in nuclear fuels (oxide, carbide, nitride). Examples of applications are reprocessing, packaging and storage of radioactive waste, and ...

Studies have shown that the repository long-term radiological risk is from the long-lived transuranics and the fission products Tc-99 and I-129, thermal loading concerns arise mainly form the short-lived fission products Sr-90 and Cs-137. In relation to the disposition of nuclear waste, ATW is expected to accomplish the following: (1) destroy over 99.9% of the actinides; (2) destroy over 99.9% of ...

ATW destroys virtually all the plutonium and higher actinides without reprocessing the spent fuel in a way that could lead to weapons material diversion. An ATW facility consists of three major elements: (1) a high-power proton linear accelerator; (2) a pyrochemical spent fuel treatment i waste cleanup system; (3) a liquid lead-bismuth cooled burner that produces and utilizes an intense ...

There are many possible applications for the non-scaling Fixed Field Alternating Gradient (NS-FFAG): accelerating non-relativistic ions, ion cancer therapy, proton drivers, accelerator driven subcritical reactors, heavy radioactive ions, recirculating linacs, and etc. They are confronted with two significant ...

The Accelerator Driven Test Facility (ADTF) is being developed as a reactor concepts test bed for transmutation of nuclear waste. A 13.3 mA continuous-wave (CW) proton beam will be accelerated to 600 MeV and impinged on a spallation target. The subsequent neutron shower is used to create a nuclear reaction within a ...

Neutron yield and energy production in a very large, practically infinite, uranium and thorium target-blocks irradiated by protons with energies in the range 0.1-2 GeV are studied by Monte Carlo method. Though the comparison of uranium and thorium targets shows that the neutron yield in the latter is 30-40 % less and the energy gain is approximatelly two times smaller, ...

As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The ...

As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The ...

A particle accelerator-driven spallation target and corresponding blanket region are proposed for the ultimate disposition of weapons-grade plutonium being retired from excess nuclear weapons in the US and Russia. The highly fissile plutonium is contained within .25 to .5 cm diameter silicon-carbide coated graphite beads, which are cooled by helium, within the slightly ...

Since 1998, SCK*CEN, in partnership with IBA s.a. and many European research laboratories, is designing a multipurpose accelerator driven system (ADS) for Research and Development (R&D) applications-MYRRHA-and is conducting an associated R&D support programme. MYRRHA is an ADS under development at Mol in Belgium and is aiming to serve as a basis ...

Fissioning surplus weapons-grade plutonium (WG-Pu) in a reactor is an effective means of rendering this stockpile non-weapons useable. In addition the enormous energy content of the plutonium is released by the fission process and can be captured to produce valuable electric power. While no fission option has been identified that can accomplish the destruction of more than ...

A review is presented on reactor physics experiments using subcritical systems. Experimental facilities and techniques are described, and the correlations of theory and experiments are discussed. Some of the interesting pulsed neutron experiments utilizing subcritical systems are also discussed. (auth)

Partitioning and Transmutation (P&T) of Minor Actinides (MAs) and Long-Lived Fission Products (LLFP) arising out of the back-end of the fuel cycle would be one of the key-steps in any future sustainable nuclear fuel cycle. Pyro-chemical separation methods would form a critical stage of P&T by recovering long-lived elements and thus reducing the environmental impact by the back-end of the ...

The Backward Theory of Feynman- and Rossi-Alpha Methods with Multiple Emission Sources I. P�zsit October 26, 1998 Accepted February 3, 1999 Abstract � The Feynman- and Rossi-alpha formulas are calculated accelerator-driven subcritical systems (ADS), such as the energy amplifier. The Feynman- and Rossi

A novel, highly compact, fusion neutron source (CNS) based on a coaxial electrostatic accelerator is under development at the Lawrence Berkeley National Laboratory. This source is designed to generate up to approx. 10(sup 12) D-D n/s. This source intensit...

High intensity proton accelerators have two important applications in China in recent years: Accelerator Driven Sub-critical System for nuclear waste transmutation and China Spallation Neutron Source. This paper focuses on the R&D activities of the key technology of high intensity proton accelerators in China, including the normal ...

Developments of new reactor designs for the utilization of thorium, such as the Advanced Heavy Water Reactor, especially demand creation of new nuclear data for all the isotopes of the thorium fuel cycle. Improved nuclear data are essential to support new initiatives such as the international project on innovative nuclear reactors and ...

The beam entry window and container for a liquid lead spallation target will be exposed to high fluxes of protons and neutrons that are both higher in magnitude and energy than have been experienced in proton accelerators and fission reactors, as well as ...

This paper identifies the basic safety functions in nuclear reactor design, and the safety design issues for accelerator-driven subcritical reactors.

Kharkov Institute of Physics and Technology (KIPT) of Ukraine has a plan to construct an accelerator driven subcritical assembly. The main functions of the subcritical assembly are the medical isotope production, neutron thereby, and the support of the Ukraine nuclear industry. Reactor physics ...

A description is given of the University of Florida subcritical assembly. Reactor operation and control are discussed with respect to engineering training, Experiments for the determination of radiation hazards are given. (C.J.G.)

... USING A SMALL SUBCRITICAL REACTOR. Corporate Author : Personal Author(s) : BOUCHEY ,GD ; GAGE,SJ. Report Date : MAR 1971. ...

Accelerator driven systems (ADS) are aimed at incineration of long living radioactive isotopes of spent nuclear reactor fuel, thus providing a solution for nuclear waste utilization. The idea is to couple a subcritical nuclear reactor with a high-energy proton accelerator. Protons interacting ...

The main challenge in nuclear fuel cycle closure is the reduction of the potential radiotoxicity of spent LWR nuclear fuel, or the length of time in which that potential hazard exists. Partitioning and accelerator-based transmutation in combination with geological disposal can lead to an acceptable societal solution for the nuclear spent fuel management problem. Nuclear fuel seems ideally suited ...

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an experimental neutron source facility based on the use of an electron accelerator driven subcritical (ADS) facility [1]. The facility uses the existing electron ...

An Accelerator Driven System (ADS) for transmutation of nuclear waste typically requires a 600 MeV - 1 GeV accelerator delivering a proton flux of a few mA for demonstrators, and a few tens of mA for large industrial systems. This high power accelerator requires an exceptional reliability: because of the induced thermal stress to the ...

Different reactivity determination methods have been investigated, based on experiments performed at the subcritical assembly Yalina in Minsk, Belarus. The development of techniques for on-line monitoring of the reactivity level in a future accelerator-driven system (ADS) is of major importance for safe operation. Since an ADS is operating in a ...

A long-term strategy based on existing technological, ecological, economical, and geopolitical realities is urgently needed to develop a sustainable energy economy, which should be designed with adaptability to unpredicted changes in any of these aspects. While only a highly diverse energy portfolio and conservation can ultimately guarantee optimum sustainability, based on a comparison of current ...

Programme A. Nuclear Power Subprogramme A.4 Technology Development for Advanced Reactor Lines. Project A.4.02: Technology advances in fast reactors and accelerator driven systems CRP Title: Analysis and Materials Technologies Subprogramme B.2 Nuclear Power Reactor Fuel Engineering Project ...

Nuclear waste from commercial power plants contains large quantities of plutonium, other fissionable actinides, and long-lived fission products that are potential proliferation concerns and create challenges for the long-term storage. Different strategies for dealing with nuclear waste are being followed by various countries because of their geologic situations and their views on nuclear energy, ...

The thermo-physical properties of Heavy Liquid Metals (Pb and Pb-Bi Eutectic) such as the low melting and high boiling temperatures, the chemical inertness in direct contact with typical reactor coolants, makes HLMs to relevant candidates as core coolant of critical and sub-critical nuclear systems. In addition the high neutron yield obtained by proton ...

This report describes methods in which an accelerator can be used to increase the safety and neutron economy of a power reactor and transmutor of long-lived radioactive wastes, such as minor actinides and fission products, by providing neutrons for its subcritical operation. Instead of the rather large subcriticality of k=0.9--0.95 ...

Recent measurements at Sandia Laboratories have demonstrated that a laser gas excited solely by fission products can be made to lase. This paper explores the concept of a subcritical nuclear driven laser (NDL) system excited by a fast pulse reactor of the...

... The numerical evaluation of the theoretical variance/mean ratio of the neutron population in the subcritical condition of the AFFRI-TRIGA reactor is ...

as a supercritical state) or decreasing (also known as a subcritical state) the rate of nuclear reaction. Schematic of nuclear reactor, circa 1956. ...

in a subcritical reactor with a source (Bell and Glasstone, 1970). Consider the neutron noise induced in position r

Plutonium recycle in fast reactors, as well as utilization/transmutation of minor actinides and long-lived fission products in hybrid reactor systems (e.g. accelerator driven systems, ADS) offer promising nuclear fuel backend management options. Several R&D programs in various IAEA Member States are actively ...

The Czech Republic is almost the only country in the central Europe which continues with the construction of nuclear power reactors. Its small territory and dense population causes public worries concerning the disposal of the spent nuclear fuel. The Czech nuclear scientists and the power companies and the nuclear industries are therefore looking for alterative solutions. The ...

This article presents the different activity of Ingot niobium in BARC. BARC is developing a technology for the accelerator driven subcritical system (ADSS) that will be mainly utilized for the transmutation of nuclear waste and enrichment of U233. Design and development of superconducting medium velocity cavity has been taken up as a ...

Design and development of superconducting (SC) cavity having {beta}{sub g}>0.42 has been taken up as a part of the accelerator driven subcritical system project. An input coupler is designed for the SC, elliptical cavity operating at 1.056 GHz, using the Kroll-Yu method. The evaluation procedure is optimized and the method has ...

The management of long-lived high-level waste, such as minor actinides (MA) and long-lived fission products (LLFP), is one of the most important issues to be solved for the utilization of the nuclear fission energy. The transmutation project of the radioactive wastes based on an accelerator driven sub-critical (ADS) system is very ...

The YALINA-Booster experiments and analyses are part of the collaboration between Argonne National Laboratory of USA and the Joint Institute for Power & Nuclear Research - SOSNY of Belarus for studying the physics of accelerator driven systems for nuclear energy applications using low enriched uranium. The YALINA-Booster ...

The KEMA sub-critical suspension reactor is provided with three safety rods of boron carbide which are suspended from electromagnets. The operation and performance of these safely rods are discussed. (Reactor Centrum Nederland)

The nuclear design and safety analyses for the Fusion Transmutation of Waste Reactor (FTWR) are described. The advantages of sub-critical operation for nuclear stability and safety are illustrated.

tubetype fuel elements aiming at the construction of a subcritical unit employing the internal thermal column of an Argonaut reactor as a source. The results confirmed the feasibility of the use of natural UO/sub 2/ for the proposed arrangement as long as one has a strong source or a subcritical unit diameter greater than 100 ...

Subcritical source-driven noise measurements are simultaneous Rossia and randomly pulsed neutron measurements that provide measured quantities that can be related to the subcritical neutron multiplication factor. In fact, subcritical source-driven noise measurements should be performed in lieu of Rossia measurements because of the ...

Kinetics of a zero power reactor with particular reference to PURNIMA are discussed for step and ramp reactivity inputs. Computations of waiting time, reactor power, instantaneous reactor period etc. are made in subcritical, critical and supercritical dom...

ABS>A subcritical assembly of natural uranium and ordinary water was constructed at Haverford College as an educational instrument. Many of its parameters were determined; their theoretical calculation and experimental measurement are discussed (auth)

The design, construction, and operation of a sub-critical assembly, intended for college teaching of reactor physics and of associated nuclear phenomena, are described. (W.D.M.)

S>For the determination of the neutron lifetime of a highly subcritical reactor, the Rossi alpha method is used. The distribution of the Intervals of the pulses that were produced by a neutron counter installed in the reactor was measured with a time analyzer. The neutron lifetime of a reactor (the ...

The mathematical formulation of the subcritical reactor with extraneous sources is presented in detail. The solutions are presented for a two-group approximation including epithermal fission and the relationship to the usual critical reactor problem is discussed. Application of the equations to an arbitrarily complicated ...

An elementary theory is used to describe the time behavior of a subcritical, critical, and supercritical reactor when an external source is put near it. Neutron absorption by the source is considered. Experiments performed at the Sorin swimming-pool reactor confirm the theoretical predictions. Criteria for better positioning ...

It is shown that absolute reactivities can be measured with good accuracy from the transient behavior of a subcritical nuclear reactor. The method is characterized by the application of step functions (either in neutron source strength or in reactivity) and by the observation of a time lag of the integrated reactor power. Simple ...

The growing stockpile of nuclear waste constitutes a severe challenge for the mankind for more than hundred thousand years. To reduce the radiotoxicity of the nuclear waste, the Accelerator Driven System (ADS) has been proposed. One of the most important issues of ADSs technology is the choice of the appropriate neutron spectrum for the transmutation of ...

that high pressure operation is necessary to ensure heat removal. Typically fast helium-cooled reactors the radial power peaking factor. At beginning of life ~BOL!, the reflector is loaded with boron carbide for reactivity loss, boron carbide absorber assemblies in the reflector are replaced with steel pin assemblies

Transmutation is a worldwide promising and feasible technology for significant reduction of the amount, and thereby, the long-term radiotoxicity of highly radioactive wastes produced by the operation of nuclear power plants such as light water reactors. Plutonium, minor actinides and long-live fission products can be transmuted in an Accelerator ...

Recent advances in accelerator technology have led to the practical realization of high-power beams. When coupled with high-power spallation target technology, these systems offer a more environmentally-friendly method of producing neutrons than reactors. We will focus our attention here on the application of spallation technology to the Accelerator Production of Tritium ...

From FY 02-05 IAC has been a part of the DOE Advanced Fuel Cycle Initiative and its predecessor organization Advanced Accelerator Applications. In the IAC program effort has been divided into three parts; Student Research, Accelerator Driven Nuclear Research and Materials Science. Within the three parts specific research and development activities have ...

Historically, subcritical accelerator-driven systems have been called electronuclear devices. Interest in these devices has been revived for numerous nuclear applications, such as boron neutron capture therapy, accelerator transmutation of waste (ATW), and accelerator-based conversion (ABC). The latter systems are being investigated at Los Alamos National ...

Use of subcritical source multiplication measurements during refueling has been investigated as a possible replacement for out-of-reactor subcriticality measurements formerly made on fresh HFIR fuel elements at the ORNL Critical Experiment Facility. These measurements have been used in the past for preparation of estimated critical rod ...

The YALINA facility is a zero-power, sub-critical assembly driven by a conventional neutron generator. It was conceived, constructed, and put into operation at the Radiation Physics and Chemistry Problems Institute of the National Academy of Sciences of Belarus located in Minsk-Sosny, Belarus. This facility was conceived for the purpose of investigating the static and dynamic ...

A design concept and the performance characteristics for a fusion transmutation of waste reactor (FTWR)-a sub-critical fast reactor driven by a tokamak fusion neutron source-are presented. A FTWR, operating with Keff

The goals of this investigation were: (1) to develop a single specimen method for determining the onset of sub-critical crack growth, and (2) to characterize the influence of sub-critical crack growth on the fracture toughness of ferritic materials used i...

BS>The expression for the reactor period T as a function of the multiplication factor in subcritical state (i.e., before attaining k/sub eff/ = 1) was found. It is possible to prepare T(k) diagrams in order to gage the reactivity meter and the reactor periodmeter. (auth)

The possibility of in-service growth of sub-critical defects in a PWR reactor pressure vessel to a critical size which could result in vessel failure was addressed in both the 1976 and 1982 reports of the Light Water Reactor Study Group (LWRSG), under the...

The schemes of jet gas and liquid targets as well as the gastargets with a solid phase dispersion are introduced to use to receive the neutrons admitted to a subcritical reactor core. The possible variants of target position in the reactor are considered, target characteristics are calculated. The authors pay a great attention to the ...

An accelerator can be used to increase the safety and neutron economy of a power reactor and transmuter of long-lived radioactive wastes, such as minor actinides and fission products, by providing neutrons for its subcritical operation. Instead of the rather large subcriticality of k=0.9-0.95 which we originally proposed for such a ...

... are made for an assumed reactor size, and source strength, S sub x, graphite moderator, and varying pressure and enrichments of UF6 fuel. ...

A new concept termed ADAPT for the rapid and virtually complete burning of plutonium is described. ADAPT employs a high current CW linear accelerator (linac) to generate neutrons in a lead/D.0 target. The neutrons are then absorbed in a surrounding subcritical (K{sub eff} {approximately} 0.95) blanket assembly, that holds small ({approximately} 0.5 cm diameter) graphite beads ...

A new concept; termed ADAPT; for the rapid and virtually complete burning of plutonium is described. ADAPT employs a high current CW linear accelerator (linac) to generate neutrons in a lead/D2O target. The neutrons are then absorbed in a surrounding subcritical (Keff{approx}0.95) blanket assembly, that holds small ({approx}0.5 cm diameter) graphite beads containing the ...

Within the scope of the Accelerator Driven System (ADS) concept for nuclear waste management applications, the burnup uncertainty estimates due to uncertainty in the activation cross sections (XSs) are important regarding both the safety and the efficiency of the waste burning process. We have applied both sensitivity analysis and Monte Carlo methodology ...

Within the scope of the Accelerator Driven System (ADS) concept for nuclear waste management applications, the burnup uncertainty estimates due to uncertainty in the activation cross sections (XSs) are important regarding both the safety and the efficiency of the waste burning process. We have applied both sensitivity analysis and Monte Carlo methodology ...

A small scale experiment is described that will demonstrate many of the aspects of accelerator-driven transmutation technology. This experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator and will be located in the Area-A experimental hall. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by ...

A small scale experiment is described that will demonstrate many of the aspects of accelerator-driven transmutation technology. This experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator and will be located in the Area-A experimental hall. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by ...

This work intends to be a starting point for the extension of the TRANSURANUS fuel rod performance code to the modelling of the T91 steel, which is designed to be the cladding material in LBE (lead-bismuth eutectic) accelerator-driven systems (ADS). On the basis of the experimental data available in the recent literature on LBE and T91, a preliminary modelling of the T91 ...

For breeding plutonium in a thermal reactor, the reactor system must have a central reactor stage and one or more outer reactor stages, wherein the central reactor stage is operated in a super-critical state emitting thermal neutrons and the outer stages are operated in a ...

Recent measurements at Sandia Laboratories demonstrated that a laser gas excited solely by fission products can be made to laser. The concept is explored of a subcritical nuclear driven laser (NDL) system excited by a fast pulse reactor of the Godiva type. A neutronics analysis, presented for a NDL system used with the SPR II/SPR III pulse ...

Transmutation of minor actinides and fission products using proton accelerators has many advantages over a transmutor operated in a critical condition. The energy required for this transmutation can be reduced by multiplying the spallation neutrons in a subcritical assembly surrounding the spallation target. The authors have studied the relation between the energy requirements ...

In the thesis an absolute measurements technique for the subcriticality determination is presented. The ADS is a hybrid system where a subcritical system is fed by a proton accelerator. There are different proposals to define an ADS, one is to use plutonium and minor actinides from power plants waste as fuel to be transmuted into non radioactive isotopes ...

The types of Italian reactors include teaching reactors, research reactors, and power reactors. Brief descriptions are given of the following: Ispra-I, Avogagro RS-1, Cesnef Constanza, RC-1, AGIP, RTS-1, Latina, Senn, Selni, PRO, and subcritical reactors. The ...

The Merlin research reactor is a light water-moderated reactor using highly enriched uranium fuel. A subcritical facility was buiit and is described for the experimental determination of the critical masses of the reactor before the reactor is made critical. The critical mass ...

A relatively inexpensive reactor for the specific purpose of testing a sub-critical portion of another reactor under conditions that would exist during actual operation is discussed. It is concluded that an engineering tool for reactor development work that bridges the present gap between exponential and ...

The 300-MWe power unit based on an experimental-demonstration two-circuit 700-MWt reactor installation with lead coolant is briefly described. The thermal process diagram of the secondary coolant circuit for the subcritical steam conditions 17 MPa and 505�C at the outlet from steam generators is presented.

The numerical evaluation of the theoretical variance/mean ratio of the neutron population in the subcritical condition of the AFFRI-TRIGA reactor is given for (1) the case of no delayed neutron group; and (3) the case of six delayed neutron groups. The Co...

The principal results of a series of design scoping studies of sub-critical fast transmutation reactors (based on the nuclear and processing technology being developed in the USDoE Generation IV, Advanced Fuel Cycle and Next Generation Nuclear Plant programs) coupled with a tokamak fusion neutron source (based on the ITER design basis physics and ...

Accelerator reliability corresponding to a very low frequency of beam interrupts is an important new accelerator requirement for accelerator-driven subcritical reactor systems. In this paper we review typical accelerator-reliability requirements and discuss possible methods for meeting these goals with superconducting proton-linac technology.

Construction and research progress at the Atomic Energy Establishment, Winfrith Heath, is surveyed. Eight subcritical assemblies, some transferred from Harwell and others recently constructed, are described. Designs of the zero- energy reactors developed for studies of neutron behavior in graphite systems are discussed. A 10-kw graphite-moderated ...

A subcritical fast reactor, fueled with Pu, is described. Calculations and experimental measurements of neutron flux and gamma dose rates near the bare core face are reported, as well as the core temperature increase eaused by Pu alpha and gamma heating. (auth)

This study was carried out to model and analyze the YALINA-Booster facility, of the Joint Institute for Power and Nuclear Research of Belarus, with the long term objective of advancing the utilization of accelerator driven systems for the incineration of nuclear waste. The YALINA-Booster facility is a subcritical assembly, driven by an ...

A collaborative experimental research program has been established between industry and university partners to evaluate the subcritical behavior of fresh and spent highly enriched fuel assemblies at the University of Missouri Research Reactor (MURR). This proposed program will involve a series of subcritical measurements using the Oak ...

Research is reported on fracture mechanics analyses and investigations, effect of high temperature primary reactor water on subcritical crack growth of reactor vessel steels, investigations of irradiated materials, pressure vessel investigations, and thermal shock investigations. (FS)

The use of a computer program, Maintenance Information and Control (MIAC), at the Savannah River Laboratory (SRL) assists a small operating staff in maintaining three research reactors and a subcritical facility. The program schedules and defines preventi...

Lessons from the Chernobyl accident are summarized. The evolution of traditional nuclear reactor design, including new projects such as subcritical assemblies controlled by an external beam of particles (neutrons and protons) is presented. The Feoktistov reactor and the possibility of its realization are discussed.

SRS reactor charges are designed to ensure the reactor remains subcritical during chargeback and shutdown conditions. Calculations have recently been performed to determine the shutdown k{sub eff} for the K-14 charge. This document discusses the results and uncertainties.

Methods and equipment employed in determining and contrdiling temperatures and fuel concentrations in the Annheim suspension reactor are deecribed. Diagrams and flow charts are included. (D.E.B.)

A cooling system in which a hot nonstationary fuel pellet core is transported via gravity to a perpetually cooled subcritical catchment is modeled. The core fuel mass is suspended by the upward flowing coolant, similar to the concept in fluidized bed reactors.

A wholly mechanical compact control device is designed for automatically rendering the core of a fission reactor subcritical in response to core temperatures in excess of the design operating temperature limit. The control device comprises an expansible bellows interposed between the base of a channel in a reactor core and the ...

The US policy on the disposition of weapons and commercial plutonium by geologic storage is examined and compared with destruction in reactors or accelerator-driven systems. The close coupling with Russian weapons plutonium is considered. Strong emphasis is placed on the preference by terrorists and rogue states for commercial plutonium over weapons plutonium for fast and ...

With the rapid development of particle accelerator technologies during the Strategic Defense Initiative (SDI) of the 1980s and the severe institutional and political challenges faced by the nuclear reactor community, there has been increasing interest in the use of particle accelerators to fulfill some nuclear missions in the US and abroad. This paper describes the enabling ...

The impact of a number of current and future nuclear systems on global plutonium inventories is assessed under realistic forecasts of nuclear power growth. Advanced systems, such as those employing Accelerator Driven Transmutation Technologies (ADTT) and liquid metal reactors, show significant promise for meeting future plutonium ...

Liquid lead and lead-bismuth have drawn the attention as one of the candidate coolants of the fast breeder reactors (FBRs), and the accelerator driven transmutation systems (ADSs). In order to use the coolant to the systems, the physical and chemical characteristics of the heavy metals are necessary. This plan has been proposed for the ...

A flux-coupled stack of superconducting isochronous cyclotrons could be used to drive thorium-cycle fission power. The 800 MeV proton beams produce fast neutrons through spallation, then the fast neutrons transmute the thorium into uranium and drive fission. The thorium reactor would provide GW electric power, eat its own long-lived waste, run for 7 years between core ...

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an electron accelerator driven subcritical (ADS) facility, using the KIPT electron accelerator. The neutron source of the subcritical assembly is ...

A methodology for the neutronics design of space power reactors is presented. This methodology involves balancing the competing requirements of having sufficient excess reactivity for the desired lifetime, keeping the reactor subcritical at launch and during submersion accidents, and providing sufficient control over the lifetime of ...

A resurgence in use of nuclear power is now underway worldwide. However due to the shutdown of many university research reactors , student laboratories must rely more heavily on use of sub-critical assemblies. Here a driven sub-critical is described that uses a cylindrical Inertial Electrostatic Confinement (IEC) device to provide a ...

Subcritical source-driven noise measurements are simultaneous Rossi-{alpha} and randomly pulsed neutron measurements that provide measured quantities that can be related to the subcritical neutron multiplication factor. In fact, subcritical source-driven noise measurements should be performed in lieu of Rossi-{alpha} measurements ...

A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod ...

A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod ...

A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod ...

The current status of molten salt reactor development is discussed with reference to the experience from the Oak Ridge Molten Salt Reactor Experiment. Assessment of the future for this reactor system is reviewed with consideration of both advantages and disadvantages. Application of this concept to ADTT ...

Some years ago, within the framework of the study for the International Thermonuclear Experimental Reactor (ITER), ENEA assessed the RELAP5 code capability to simulate Helium cooled systems on the experimental data provided by the helium facility HEFUS3 (Brasimone, Italy). This activity allowed acquiring a certain experience on the limits and capabilities of the code that, in ...

The actinide management has become a key issue in nuclear energy. Recovering and fissioning transuranium elements reduce the long-term proliferation risks and the environmental burden. The better way of waste management will be made by system symbiosis: a combination of light-water reactor and fast reactor and/or accelerator-driven ...

A conceptual design development of an accelerator-driven subcritical facility has been carried out in the preparation of a joint activity with Kharkov Institute of Physics and Technology of Ukraine. The main functions of the facility are the medical isotope production and the support of the Ukraine nuclear industry. An electron accelerator is considered to drive the ...

Studies in nuclear energy and transmutation of radioactive waste require neutron data for conceptual and performance studies, to determine the viability of advanced ideas such as an Accelerator Driven System and to fix the safety margins of any new concepts. IRMM's neutron data-measurement program addresses data needs associated with ...

Studies in nuclear energy and transmutation of radioactive waste require neutron data for conceptual and performance studies, to determine the viability of advanced ideas such as an Accelerator Driven System and to fix the safety margins of any new concepts. IRMM's neutron data-measurement program addresses data needs associated with ...

While the potential hazards posed by large particle accelerator driven spallation targets are greatly reduced in comparison to nuclear reactors capable of similar neutron production levels, they are significant, and require a safety-by-design approach to ensure there is little likelihood of accidental releases of target materials. Most ...

In the FUTURE Program, the development and application of fertile-free fuels for Accelerator Driven Transmuters (ADTs) has been advanced. To assess the reactor performance and safety behavior of an ADT with so-called dedicated fuels, various transient cases for an 800 MW-class Pb/Bi-cooled ADT were investigated using the SIMMER-III ...

The reactor design based on pare calculation from fundamental cross sections is still in an unsatisfactory state. Integral data tsken from critical or subcritical experfments form a much better basis. This type of experiment has wide applications particularly to the uniform multiplying medium itself as well as to the investigation of all kinds of ...

Fissile fuel can be produced at a high rate using an accelerator-driven Pu-fueled subcritical fast reactor which avoids encountering a shortage of Pu during a high growth rate in the production of nuclear energy. Furthermore, the necessity of the early introduction of the fast reactor can be moderated. Subcritical ...

A series of 9 nuclear reactor simulation experiments were developed to be performed on an analog computer. Analog computer and nuclear reactor fundamentals are discussed. Experimental procedure is outlined. The experiments include: introduction to the computer; reactor analysis, effect of delayed neutrons; ...

At the National Science Centre, Kharkiv Institute of Physics and Technology (NSC KIPT) the possibility of creating an installation with a subcritical reactor driven by an electron accelerator is examined. To obtain the maximal stream of neutrons from a neutron-producing target at a minimal density of energy emission, the electron energy should be in the ...

'A series of subcritical noise measurements were performed on fresh and spent University of Missouri Research Reactor fuel assemblies. These experimental measurements were performed for the purposes of providing benchmark quality data for validating transport theory computer codes and nuclear cross-section data used to perform criticality safety ...

ABS>Research and development progress is reported on water-cooled reactors, liquid metal-cooled reactors, general reactor technology, plutonium recycle, advance systems research and development, and nuclear safety. Topics covered include the EBWR, BORAX-V, EBR-I, EBR-II, FARET, applied reactor physics, ...

A method of determining the reactivity of far-subcritical systems from neutron noise power spectral density measurements with /sup 252/Cf has previously been tested in fast reactor critical assemblies: a mockup of the Fast Flux Test Facility reactor and a uranium metal sphere. Calculations indicated that this measurement was feasible ...

subcritical configuration based in TRIGA-ADS project which consists of coupling a 1 MW TRIGA reactor1 A NOVEL MICROMEGAS DETECTOR FOR IN-CORE NUCLEAR REACTOR NEUTRON FLUX MEASUREMENTS S. ANDRIAMONJE Talence Cedex, France Future fast nuclear reactors designed for energy production and transmutation

Use of the MIT-SNL Period-Generated Minimum Time Control Laws for the automated increase of neutronic power from subcritical conditions has recently been demonstrated. The use of these laws is advantageous because they provide the speed at which a control...

The design, construction, and use of a subcritical assembly, intended for college teaching of reactor physics and of associated nuclear phenomena, are described. The report is written as a short cumulative progress report on the assumption that it may be of more value than status reports describing the work done in successive periods. (W.D.M.)

The potential utilization of near-term tokamak test reactors for nuclear radiation damage evaluation and hardening programs is examined. Physical layouts of the irradiation modules and methods of neutron spectrum tailoring are described. Tokamak fusion generators provide much larger test volume and can give more faithful spectral simulations of thermonuclear threat ...

The potential to incinerate minor actinides (MA) in a sub-critical accelerator-driven system (ADS) is a subject of study in several countries where nuclear power plants are present. The performance of the MYRRHA experimental ADS, as to the transmutation of Am and Cm in the inert matrix fuel (IMF) samples consisting of 40 vol.% (Cm0.1Am0.5Pu0.4)O1.88 fuel ...

Faced with a backlog of nuclear waste and weapons plutonium, as well as an ever-increasing public concern about safety and environmental issues associated with conventional nuclear reactors, many countries are studying new, accelerator-driven technologies that hold the promise of providing safe and effective solutions to these problems. Proposed projects ...

I suggest that an accelerator can be used to increase the safety and neutron economy of a power reactor and transmutor of the long-lived radioactive wastes, such as minor actinides and fission products, by providing the neutrons for its subcritical operation.

The methods for measuring radiation are shortly reviewed. The instrumentation for neutron flux measurement is classified into out-of-core and in-core instrumentation. The out-of-core instrumentation monitors the operational range from the subcritical reac...

The neutron source strength associated with fuel irradiated in the FFTF reactor is important in determining the reactivity of the core when it is shut down or being refueled. The monitoring of subcritical reactivity for FFTF will be done with the Modified...

The literature on the relations of parameters obtained in various types of assemblies is surveyed. The emphasis is placed on experimental results obtained in thermal systems and on problems raised by the existing data. 135 references. (J.R.D.)

Based on the comparison between experimental data and numerical results for the growth of GaAs from TMGa, it was shown that 3D simulations are necessary to simulate rectangular CVD reactors even when operated under subcritical (Ra) conditions. The importa...

Jul 5, 2007 ... This Direct-Drive Gas-Cooled Reactor (DDG) is designed to be subcritical ... Nuclear Power Plants (ICAPP) 2003, 4-7 May 2003, Cordoba, Spain ...