The fusion-fission hybrid

International Nuclear Information System (INIS)

Teller, E.

1985-01-01

As the history of the development of fusion energy shows, a sustained controlled fusion reaction is much more difficult to produce than rapid uncontrolled release of fusion energy. Currently, the ''magnetic bottle'' technique shows sufficient progress that it might applied for the commercial fuel production of /sup 233/U, suitable for use in fission reactors, by developing a fusion-fission hybrid. Such a device would consist of a fusion chamber core surrounded by a region containing cladded uranium pellets cooled by helium, with lithium salts also present to produce tritium to refuel the fusion process. Successful development of this hybrid might be possible within 10 y, and would provide both experience and funds for further development of controlled fusion energy

Fusion technology development: role of fusion facility upgrades and fission test reactors

International Nuclear Information System (INIS)

Hsu, P.Y.; Deis, G.A.; Longhurst, G.R.; Miller, L.G.; Schmunk, R.E.

1983-01-01

The near term national fusion program is unlikely to follow the aggressive logic of the Fusion Engineering Act of 1980. Faced with level budgets, a large, new fusion facility with an engineering thrust is unlikely in the near future. Within the fusion community the idea of upgrading the existing machines (TFTR, MFTF-B) is being considered to partially mitigate the lack of a design data base to ready the nation to launch an aggressive, mission-oriented fusion program with the goal of power production. This paper examines the cost/benefit issues of using fusion upgrades to develop the technology data base which will be required to support the design and construction of the next generation of fusion machines. The extent of usefulness of the nation's fission test reactors will be examined vis-a-vis the mission of the fusion upgrades. The authors show that while fission neutrons will provide a useful test environment in terms of bulk heating and tritium breeding on a submodule scale, they can play only a supporting role in designing the integrated whole modules and systems to be used in a nuclear fusion machine

Fusion technology development: role of fusion facility upgrades and fission test reactors

International Nuclear Information System (INIS)

Hsu, P.Y.; Deis, G.A.; Miller, L.G.; Longhurst, G.R.; Schmunk, R.E.

1983-01-01

The near term national fusion program is unlikely to follow the aggressive logic of the Fusion Engineering Act of 1980. Faced with level budgets, a large, new fusion facility with an engineering thrust is unlikely in the near future. Within the fusion community the idea of upgrading the existing machines (TFTR, MFTF-B) is being considered to partially mitigate the lack of a design data base to ready the nation to launch an aggressive, mission-oriented fusion program with the goal of power production. This paper examines the cost/benefit issues of using fusion upgrades to develop the technology data base which will be required to support the design and construction of the next generation of fusion machines. The extent of usefulness of the nation's fission test reactors will be examined vis-a-vis the mission of the fusion upgrades. We will show that while fission neutrons will provide a useful test environment in terms of bulk heating and tritium breeding on a submodule scale, they can play only a supporting role in designing the integrated whole modules and systems to be used in a nuclear fusion machine

Perspective on the fusion-fission energy concept

International Nuclear Information System (INIS)

Liikala, R.C.; Perry, R.T.; Teofilo, V.L.

1978-01-01

A concept which has potential for near-term application in the electric power sector of our energy economy is combining fusion and fission technology. The fusion-fission system, called a hybrid, is distinguished from its pure fusion counterpart by incorporation of fertile materials (uranium or thorium) in the blanket region of a fusion machine. The neutrons produced by the fusion process can be used to generate energy through fission events in the blanket or produce fuel for fission reactors through capture events in the fertile material. The performance requirements of the fusion component of hybrids is perceived as being less stringent than those for pure fusion electric power plants. The performance requirements for the fission component of hybrids is perceived as having been demonstrated or could be demonstrated with a modest investment of research and development funds. This paper presents our insights and observations of this concept in the context of why and where it might fit into the picture of meeting our future energy needs. A bibliography of hybrid research is given

Hybrid fission-fusion nuclear reactors

International Nuclear Information System (INIS)

Zucchetti, Massimo

2011-01-01

A fusion-fission hybrid could contribute to all components of nuclear power - fuel supply, electricity production, and waste management. The idea of the fusion-fission hybrid is many decades old. Several ideas, both new and revisited, have been investigated by hybrid proponents. These ideas appear to have attractive features, but they require various levels of advances in plasma science and fusion and nuclear technology. As a first step towards the development of hybrid reactors, fusion neutron sources can be considered as an option. Compact high-field tokamaks can be a candidate for being the neutron source in a fission-fusion hybrid, essentially due to their design characteristics, such as compact dimensions, high magnetic field, flexibility of operation. This study presents the development of a tokamak neutron source for a material testing facility using an Ignitor-based concept. The computed values show the potential of this neutron-rich device for fusion materials testing. Some full-power months of operation are sufficient to obtain relevant radiation damage values in terms of dpa. (Author)

Neutronic calculation and cross section sensitivity analysis of the Livermore mirror fusion/fission hybrid reactor blanket

International Nuclear Information System (INIS)

Ku, L.P.; Price, W.G. Jr.

1977-08-01

The neutronic calculation for the Livermore mirror fusion/fission hybrid reactor blanket was performed using the PPPL cross section library. Significant differences were found in the tritium breeding and plutonium production in comparison to the results of the LLL calculation. The cross section sensitivity study for tritium breeding indicates that the response is sensitive to the cross section of 238 U in the neighborhood of 14 MeV and 1 MeV. The response is also sensitive to the cross sections of iron in the vicinity of 14 MeV near the first wall. Neutron transport in the resonance region is not important in this reactor model

Fusion-fission of superheavy nuclei at low excitation energies

International Nuclear Information System (INIS)

Itkis, M.G.; Oganesyan, Yu.Ts.; Kozulin, E.M.

2000-01-01

The process of fusion-fission of superheavy nuclei with Z = 102 -122 formed in the reactions with 22 Ne, 26 Mg, 48 Ca, 58 Fe and 86 Kr ions at energies near and below the Coulomb barrier has been studied. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR) using a time-of-flight spectrometer of fission fragments CORSET and a neutron multi-detector DEMON. As a result of the experiments, mass and energy distributions of fission fragments, fission and quasi-fission cross sections, multiplicities of neutrons and gamma-rays and their dependence on the mechanism of formation and decay of compound superheavy systems have been studied

Neutron emission as a probe of fusion-fission and quasi-fission dynamics

International Nuclear Information System (INIS)

Hinde, D.J.

1991-01-01

Pre- and post scission neutron yeilds have been measured as a function of projectile mass, compound nucleus fissility, and fission mass-split and total kinetic energy (TKE) for 27 fusion-fission and quasi-fission reactions induced by beams of 16,18 O, 40 Ar and 64 Ni. A new method of interpretation of experimental pre-scission neutron multiplicities ν-pre and mean kinetic energies ε ν allows the extraction of fission time scales with much less uncertainty than previously, all fusion-fission results being consistent with a dynamical time scale of (35±15) x 10 -21 s for symmetric fission. All reactions show that ν-pre falls quite rapidly with increasing mass-asymmetry; evidence is presented that for fusion-fission reactions this is partly due to a reduction of the dynamical fission time scale with mass-asymmetry. For quasi-fission, the data indicate that the pre-scission multiplicity and mean neutron kinetic energy are very sensitive to the final mass-asymmetry, but that the time scale is virtually independent of mass-asymmetry. It is concluded that for fusion-fission there is no dependence of ν-pre on TKE, whilst for 64 Ni-induced quasi-fission reactions, a strong increase of ν-pre with decreasing TKE is observed, probably largely caused by neutron emission during the acceleration time of the fission fragments in these fast reactions. Interpretation of post-scission multiplicities in terms of fragment excitation energies leads to deduced time scales consistent with those determined from the pre-scission data. 54 refs., 17 tabs., 25 figs

Integral tests of coupled multigroup neutron and gamma cross sections with fission and fusion sources

International Nuclear Information System (INIS)

Schriewer, J.; Hehn, G.; Mattes, M.; Pfister, G.; Keinert, J.

1978-01-01

Calculations were made for different benchmark experiments in order to test the coupled multigroup neutron and gamma library EURLIB-3 with 100 neutron groups and 20 gamma groups. In cooperation with EURATOM, Ispra, we produced this shielding library recently from ENDF/B-IV data for application in fission and fusion technology. Integral checks were performed for natural lithium, carbon, oxygen, and iron. Since iron is the most important structural material in nuclear technology, we started with calculations of iron benchmark experiments. Most of them are integral experiments of INR, Karlsruhe, but comparisons were also done with benchmark experiments from USA and Japan. For the experiments with fission sources we got satisfying results. All details of the resonances cannot be checked with flux measurements and multigroup cross sections used. But some averaged resonance behaviour of the measured and calculated fluxes can be compared and checked within the error limits given. We get greater differences in the calculations of benchmark experiments with 14 MeV neutron sources. For iron the group cross sections of EURLIB-3 produce an underestimation of the neutron flux in a broad energy region below the source energy. The conclusion is that the energy degradation by inelastic scattering is too strong. For fusion application the anisotropy of the inelastic scatter process must be taken into account, which isn't done by the processing codes at present. If this effect isn't enough, additional corrections have to be applied to the inelastic cross sections of iron in ENDF/B-IV. (author)

Proceedings of the Second Fusion-Fission Energy Systems Review Meeting

Energy Technology Data Exchange (ETDEWEB)

None

1977-11-02

The agenda of the meeting was developed to address, in turn, the following major areas: specific problem areas in nuclear energy systems for application of fusion-fission concepts; current and proposed fusion-fission programs in response to the identified problem areas; target costs and projected benefits associated with fusion-fission energy systems; and technical problems associated with the development of fusion-fission concepts. The greatest emphasis was placed on the characteristics of and problems, associated with fuel producing fusion-fission hybrid reactors.

Axisymmetric Magnetic Mirror Fusion-Fission Hybrid

Energy Technology Data Exchange (ETDEWEB)

Moir, R. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martovetsky, N. N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Molvik, A. W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ryutov, D. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simonen, T. C. [Univ. of California, Berkeley, CA (United States)

2011-05-13

The achieved performance of the gas dynamic trap version of magnetic mirrors and today’s technology we believe are sufficient with modest further efforts for a neutron source for material testing (Q=P_fusion/P_input~0.1). The performance needed for commercial power production requires considerable further advances to achieve the necessary high Q>>10. An early application of the mirror, requiring intermediate performance and intermediate values of Q~1 are the hybrid applications. The Axisymmetric Mirror has a number of attractive features as a driver for a fusion-fission hybrid system: geometrical simplicity, inherently steady-state operation, and the presence of the natural divertors in the form of end tanks. This level of physics performance has the virtue of low risk and only modest R&D needed and its simplicity promises economy advantages. Operation at Q~1 allows for relatively low electron temperatures, in the range of 4 keV, for the DT injection energy ~ 80 keV. A simple mirror with the plasma diameter of 1 m and mirror-to-mirror length of 35 m is discussed. Simple circular superconducting coils are based on today’s technology. The positive ion neutral beams are similar to existing units but designed for steady state. A brief qualitative discussion of three groups of physics issues is presented: axial heat loss, MHD stability in the axisymmetric geometry, microstability of sloshing ions. Burning fission reactor wastes by fissioning actinides (transuranics: Pu, Np, Am, Cm, .. or just minor actinides: Np, Am, Cm, …) in the hybrid will multiply fusion’s energy by a factor of ~10 or more and diminish the Q needed to less than 1 to overcome the cost of recirculating power for good economics. The economic value of destroying actinides by fissioning is rather low based on either the cost of long-term storage or even deep geologic disposal so most of the revenues of hybrids will come from electrical power. Hybrids that obtain revenues from

The LOFA analysis of fusion-fission hybrid reactor

International Nuclear Information System (INIS)

Yu, Z.-C.; Xie, H.

2014-01-01

The fusion-fission hybrid energy reactor can produce energy, breed nuclear fuel, and handle the nuclear waste, etc, with the fusion neutron source striking the subcritical blanket. The passive safety system, consisting of passive residual heat removal system, passive safety injection system and automatic depressurization system, was adopted into the fusion-fission hybrid energy reactor in this paper. Modeling and nodalization of primary loop, passive core cooling system and partial secondary loop of the fusion-fission hybrid energy reactor using RELAP5 were conducted and LOFA (Loss of Flow Accident) was analyzed. The results of key transient parameters indicated that the PRHRs could mitigate the accidental consequence of LOFA effectively. It is also concluded that it is feasible to apply the passive safety system concept to fusion-fission hybrid energy reactor. (author)

Fusion-fission dynamics

International Nuclear Information System (INIS)

Blocki, J.; Planeta, R.; Brzychczyk, J.; Grotowski, K.

1992-01-01

Classical dynamical calculations of the heavy ion induced fission processes have been performed for the reactions 40 Ar+ 141 Pr, 20 Ne+ 165 Ho and 12 C+ 175 Lu leading to the iridium like nucleus. As a result prescission lifetimes were obtained and compared with the experimental values. The comparison between the calculated and experimental lifetimes indicates that the one-body dissipation picture is much more relevant in describing the fusion-fission dynamics than the two-body one. (orig.)

Pulsed fission/fusion hybrid engines

International Nuclear Information System (INIS)

Hudson, G.C.

1979-01-01

Research into high-thrust, high-specific impulse rocket engines using energy from nuclear reactions which has been conducted at this organization will be discussed. The engines are all conceptual in nature, yet are within the realization of conventional or near-term technology. The engine concepts under study at Foundation, Inc. are designed to obviate or minimize these negative effects of the ORION scheme. By using non-chemical triggers to initiate a non-breakeven fusion reaction at the core of a target composed of both fission and fusion fuel, it should be possible to employ the fusion neutrons thus produced to begin a fission reaction in U-235 or Pu-239. Since the density of the target can be increased by as much as a factor of 250 through compression of the pellet, the amount of fission material necessary to produce a critical mass can be greatly reduced. (This also means that the amount of fission products produced for a giventhrust level is also reduced from the ORION levels.) Coupling this eeffect to the large number of 14 MeV fusion neutrons produced early in the compression process and subsequently to the heating of some additional fusion fuel surrounding the critical mass leads to the very efficient burnup of the target. This insures both high yield from the target as well as low cost per MJ energy released. Finally, the use of such small pellets allows the scale of the energy released to be tailored to a level usable in rocket engines of a few tens of tons thrust level. (orig.) [de

Hemi-fused structure mediates and controls fusion and fission in live cells.

Science.gov (United States)

Zhao, Wei-Dong; Hamid, Edaeni; Shin, Wonchul; Wen, Peter J; Krystofiak, Evan S; Villarreal, Seth A; Chiang, Hsueh-Cheng; Kachar, Bechara; Wu, Ling-Gang

2016-06-23

Membrane fusion and fission are vital for eukaryotic life. For three decades, it has been proposed that fusion is mediated by fusion between the proximal leaflets of two bilayers (hemi-fusion) to produce a hemi-fused structure, followed by fusion between the distal leaflets, whereas fission is via hemi-fission, which also produces a hemi-fused structure, followed by full fission. This hypothesis remained unsupported owing to the lack of observation of hemi-fusion or hemi-fission in live cells. A competing fusion hypothesis involving protein-lined pore formation has also been proposed. Here we report the observation of a hemi-fused Ω-shaped structure in live neuroendocrine chromaffin cells and pancreatic β-cells, visualized using confocal and super-resolution stimulated emission depletion microscopy. This structure is generated from fusion pore opening or closure (fission) at the plasma membrane. Unexpectedly, the transition to full fusion or fission is determined by competition between fusion and calcium/dynamin-dependent fission mechanisms, and is notably slow (seconds to tens of seconds) in a substantial fraction of the events. These results provide key missing evidence in support of the hemi-fusion and hemi-fission hypothesis in live cells, and reveal the hemi-fused intermediate as a key structure controlling fusion and fission, as fusion and fission mechanisms compete to determine the transition to fusion or fission.

New approach to description of fusion-fission dynamics in super-heavy element formation

International Nuclear Information System (INIS)

Zagrebaev, V.I.

2002-01-01

A new mechanism of the fusion-fission process for a heavy nuclear system is proposed, which takes place in the (A 1 , A 2 ) space, where A 1 and A 2 are two nuclei, surrounded by a certain number of shared nucleons ΔA. The nuclei A 1 and A 2 gradually lose (or acquire) their individualities with increasing (or decreasing) a number of collectivized nucleons ΔA. The driving potential in the (A 1 , A 2 ) space is derived, which allows the calculation of both the probability of the compound nucleus formation and the mass distribution of fission and quasi-fission fragments in heavy ion fusion reactions. The cross sections of super-heavy element formation in the 'hot' and 'cold' fusion reactions have been calculated up to Z CN =118. (author)

Number-Theory in Nuclear-Physics in Number-Theory: Non-Primality Factorization As Fission VS. Primality As Fusion; Composites' Islands of INstability: Feshbach-Resonances?

Science.gov (United States)

Siegel, Edward

2011-10-01

Numbers: primality/indivisibility/non-factorization versus compositeness/divisibility /factor-ization, often in tandem but not always, provocatively close analogy to nuclear-physics: (2 + 1)=(fusion)=3; (3+1)=(fission)=4[=2 × 2]; (4+1)=(fusion)=5; (5 +1)=(fission)=6[=2 × 3]; (6 + 1)=(fusion)=7; (7+1)=(fission)=8[= 2 × 4 = 2 × 2 × 2]; (8 + 1) =(non: fission nor fusion)= 9[=3 × 3]; then ONLY composites' Islands of fusion-INstability: 8, 9, 10; then 14, 15, 16,... Could inter-digit Feshbach-resonances exist??? Applications to: quantum-information/computing non-Shore factorization, millennium-problem Riemann-hypotheses proof as Goodkin BEC intersection with graph-theory ``short-cut'' method: Rayleigh(1870)-Polya(1922)-``Anderson'' (1958)-localization, Goldbach-conjecture, financial auditing/accounting as quantum-statistical-physics;... abound!!!

Neutron dosimetry for radiation damage in fission and fusion reactors

International Nuclear Information System (INIS)

Smith, D.L.

1979-01-01

The properties of materials subjected to the intense neutron radiation fields characteristic of fission power reactors or proposed fusion energy devices is a field of extensive current research. These investigations seek important information relevant to the safety and economics of nuclear energy. In high-level radiation environments, neutron metrology is accomplished predominantly with passive techniques which require detailed knowledge about many nuclear reactions. The quality of neutron dosimetry has increased noticeably during the past decade owing to the availability of new data and evaluations for both integral and differential cross sections, better quantitative understanding of radioactive decay processes, improvements in radiation detection technology, and the development of reliable spectrum unfolding procedures. However, there are problems caused by the persistence of serious integral-differential discrepancies for several important reactions. There is a need to further develop the data base for exothermic and low-threshold reactions needed in thermal and fast-fission dosimetry, and for high-threshold reactions needed in fusion-energy dosimetry. The unsatisfied data requirements for fission reactor dosimetry appear to be relatively modest and well defined, while the needs for fusion are extensive and less well defined because of the immature state of fusion technology. These various data requirements are examined with the goal of providing suggestions for continued dosimetry-related nuclear data research

LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative

DEFF Research Database (Denmark)

Verones, Francesca; Bare, Jane; Bulle, Cécile

2017-01-01

of these efforts, a dedicated task force focused on addressing several LCIA cross-cutting issues as aspects spanning several impact categories, including spatiotemporal aspects, reference states, normalization and weighting, and uncertainty assessment. Here, findings of the cross-cutting issues task force...... are presented along with an update of the existing UNEP-SETAC LCIA emission-to-damage framework. Specific recommendations are provided with respect to metrics for human health (Disability Adjusted Life Years, DALY) and ecosystem quality (Potentially Disappeared Fraction of species, PDF). Additionally, we stress...

Regulatory aspects of fusion power-lessons from fission plants

International Nuclear Information System (INIS)

Natalizio, A.; Brunnader, H.; Sood, S.K.

1993-01-01

Experience from fission reactors has shown the regulatory process for licensing a nuclear facility to be legalistic, lengthy, unpredictable, and costly. This experience also indicates that much of the regulatory debate is focused on safety margins, that is, the smaller the safety margins the bigger the regulatory debate and the greater the amount of proof required to satisfy the regulatory. Such experience suggests that caution and prudence guide the development of a regulatory regime for fusion reactors. Fusion has intrinsic safety and environmental advantages over fission, which should alleviate significantly, or even eliminate, the regulatory problems associated with fission. The absence of a criticality concern and the absence of fission products preclude a Chernobyl type accident from occurring in a fusion reactor. Although in a fusion reactor there are large inventories of radioactive products that can be mobilized, the total quantity is orders of magnitude smaller than in fission power reactors. The bulk of the radioactivity in a fusion reactor is either activation products in steel structures, or tritium fuel supplies safely stored in the form of a metal tritide in storage beds. The quantity of tritium that can be mobilized under accident conditions is much less than ten million curies. This compares very favorably with a fission product inventory greater than ten billion curies in a fission power reactor. Furthermore, in a fission reactor, all of the reactivity is contained in a steel vessel that is pressurized to about 150 atmospheres, whereas in a fusion reactor, the inventory of radioactive material is dispersed in different areas of the plant, such that it is improbable that a single event could give rise to the release of the entire inventory to the environment. With such significant intrinsic safety advantages there is no a priori need to make fusion requirements/regulations more demanding and more stringent than fission

Burn-up calculation of fusion-fission hybrid reactor using thorium cycle

International Nuclear Information System (INIS)

Shido, S.; Matsunaka, M.; Kondo, K.; Murata, I.; Yamamoto, Y.

2006-01-01

A burn-up calculation system has been developed to estimate performance of blanket in a fusion-fission hybrid reactor which is a fusion reactor with a blanket region containing nuclear fuel. In this system, neutron flux is calculated by MCNP4B and then burn-up calculation is performed by ORIGEN2. The cross-section library for ORIGEN2 is made from the calculated neutron flux and evaluated nuclear data. The 3-dimensional ITER model was used as a base fusion reactor. The nuclear fuel (reprocessed plutonium as the fission materials mixed with thorium as the fertile materials), transmutation materials (minor actinides and long-lived fission products) and tritium breeder were loaded into the blanket. Performances of gas-cooled and water-cooled blankets were compared with each other. As a result, the proposed reactor can meet the requirement for TBP and power density. As far as nuclear waste incineration is concerned, the gas-cooled blanket has advantages. On the other hand, the water cooled-blanket is suited to energy production. (author)

Study on fission blanket fuel cycling of a fusion-fission hybrid energy generation system

International Nuclear Information System (INIS)

Zhou, Z.; Yang, Y.; Xu, H.

2011-01-01

This paper presents a preliminary study on neutron physics characteristics of a light water cooled fission blanket for a new type subcritical fusion-fission hybrid reactor aiming at electric power generation with low technical limits of fission fuel. The major objective is to study the fission fuel cycling performance in the blanket, which may possess significant impacts on the feasibility of the new concept of fusion-fission hybrid reactor with a high energy gain (M) and tritium breeding ratio (TBR). The COUPLE2 code developed by the Institute of Nuclear and New Energy Technology of Tsinghua University is employed to simulate the neutronic behaviour in the blanket. COUPLE2 combines the particle transport code MCNPX with the fuel depletion code ORIGEN2. The code calculation results show that soft neutron spectrum can yield M > 20 while maintaining TBR >1.15 and the conversion ratio of fissile materials CR > 1 in a reasonably long refuelling cycle (>five years). The preliminary results also indicate that it is rather promising to design a high-performance light water cooled fission blanket of fusion-fission hybrid reactor for electric power generation by directly loading natural or depleted uranium if an ITER-scale tokamak fusion neutron source is achievable.

Updated comparison of economics of fusion reactors with advanced fission reactors

International Nuclear Information System (INIS)

Delene, J.G.

1990-01-01

The projected cost of electricity (COE) for fusion is compared with that from current and advanced nuclear fission and coal-fired plants. Fusion cost models were adjusted for consistency with advanced fission plants and the calculational methodology and cost factors follow guidelines recommended for cost comparisons of advanced fission reactors. The results show COEs of about 59--74 mills/kWh for the fusion designs considered. In comparison, COEs for future fission reactors are estimated to be in the 43--54 mills/kWh range with coal-fired plant COEs of about 53--69 mills/kWh ($2--3/GJ coal). The principal cost driver for the fusion plants relative to fission plants is the fusion island cost. Although the estimated COEs for fusion are greater than those for fission or coal, the costs are not so high as to preclude fusion's competitiveness as a safe and environmentally sound alternative

Nuclear fission and neutron-induced fission cross-sections

Energy Technology Data Exchange (ETDEWEB)

James, G.D.; Lynn, J.E.; Michaudon, A.; Rowlands, J.; de Saussure, G.

1981-01-01

A general presentation of current knowledge of the fission process is given with emphasis on the low energy fission of actinide nuclei and neutron induced fission. The need for and the required accuracy of fission cross section data in nuclear energy programs are discussed. A summary is given of the steps involved in fission cross section measurement and the range of available techniques. Methods of fission detection are described with emphasis on energy dependent changed and detector efficiency. Examples of cross section measurements are given and data reduction is discussed. The calculation of fission cross sections is discussed and relevant nuclear theory including the formation and decay of compound nuclei and energy level density is introduced. A description of a practical computation of fission cross sections is given.

Genetically Controlled Fusion, Exocytosis and Fission of Artificial Vesicles

DEFF Research Database (Denmark)

Bönzli, Eva; Hadorn, Maik; De Lucrezia, Davide

if a special class of viral proteins, termed fusogenic peptides, were added to the external medium. In the present work, we intend to develop genetically controlled fusion, fission and exocytosis of vesicles by the synthesis of peptides within vesicles. First, we enclosed synthesized peptides in vesicles...... to induce in a next step fusion of adjacent vesicles, fission and exocytosis of nested vesicles. Second, we will replace the peptides by an enclosed cell-free expression system to internally synthesize fusion peptides. To control the gene expression, different mechanisms are available, e.g. addition...... fusion, fission and exocytosis....

Neutronics of Laser Fission-Fusion Systems

International Nuclear Information System (INIS)

Velarde, G.

1976-01-01

Neutronics of Fission-Fusion microsystems inertially confined by Lasers are analysed by transport calculation, both stationary (DTF, TIHOC) and time dependent (TDA, TIHEX), discussing the results obtained for the basic parameters of the fission process (multiplication factor, neutron generation time and Rossi-∞). (Author) 14 refs

Neutronics of Laser Fission-Fusion Systems

Energy Technology Data Exchange (ETDEWEB)

Velarde, G

1976-07-01

Neutronics of Fission-Fusion microsystems inertially confined by Lasers are analysed by transport calculation, both stationary (DTF, TIHOC) and time dependent (TDA, TIHEX), discussing the results obtained for the basic parameters of the fission process (multiplication factor, neutron generation time and Rossi-{infinity}). (Author) 14 refs.

Aqueous cutting fluid for machining fissionable materials

Science.gov (United States)

Duerksen, Walter K.; Googin, John M.; Napier, Jr., Bradley

1984-01-01

The present invention is directed to a cutting fluid for machining fissionable material. The cutting fluid is formed of glycol, water and boron compound in an adequate concentration for effective neutron attenuation so as to inhibit criticality incidents during machining.

Fusion-fission dynamics and perspectives of future experiments

International Nuclear Information System (INIS)

Zagrebaev, V.I.; Itkis, M.G.; Oganessian, Yu.Ts.

2003-01-01

The paper is focused on reaction dynamics of superheavy-nucleus formation and decay at beam energies near the Coulomb barrier. The aim is to review the things we have learned from recent experiments on fusion-fission reactions leading to the formation of compound nuclei with Z ≥ 102 and from their extensive theoretical analysis. Major attention is paid to the dynamics of formation of very heavy compound nuclei taking place in strong competition with the process of fast fission (quasifission). The choice of collective degrees of freedom playing a fundamental role and finding the multidimensional driving potential and the corresponding dynamic equation regulating the whole process are discussed. A possibility of deriving the fission barriers of superheavy nuclei directly from performed experiments is of particular interest here. In conclusion, the results of a detailed theoretical analysis of available experimental data on the 'cold' and 'hot' fusion-fission reactions are presented. Perspectives of future experiments are discussed along with additional theoretical studies in this field needed for deeper understanding of the fusion-fission processes of very heavy nuclear systems

Fusion-fission dynamics

International Nuclear Information System (INIS)

Blocki, J.; Planeta, R.; Brzychczyk, J.; Grotowski, K.

1991-04-01

Classical dynamical calculations of the heavy ion induced fission process for the reactions 40 Ar+ 141 Pr, 20 Ne+ 165 Ho and 12 C+ 175 Lu leading to the iridium like nucleus have been performed. As a result prescission lifetimes were obtained and compared with the experimental values. The agreement between the calculated and experimental lifetimes indicates that the one-body dissipation picture is much more relevant in describing the fusion-fission dynamics than the two-body one. Somewhat bigger calculated times than the experimental ones in case of the C+Lu reaction at 16 MeV/nucleon may be a signal on the energy range applicability of the one-body dissipation model. (author)

Measurement and analysis of 14 MeV neutron-induced double-differential neutron emission cross sections needed for fission and fusion reactor technology

International Nuclear Information System (INIS)

Wang Dahai.

1990-10-01

The main objectives of this IAEA Co-ordinated Research Programme are to improve the data on 14 MeV neutron-induced double-differential neutron emission cross sections for materials needed for fission and fusion reactor technology. This report summarizes the conclusions and recommendations which were agreed by all participants during the Second Research Co-ordination Meeting

Influence of differences in the proton and neutron distributions on nuclear fusion and fission; Infuence de la difference entre les distributions de protons et de neutrons dans le noyau sur les processus de fusion et de fission

Energy Technology Data Exchange (ETDEWEB)

Dobrowolski, A

2006-04-15

This thesis work is centred on some essential ingredients of a theoretical description of the reaction dynamics of the nuclear fusion and fission process, such as the interaction potential between projectile and target nuclei for fusion and the deformation energy landscape in a multidimensional space for the fission process. We have in particular evaluated the importance of the difference between the neutron and proton density distributions on these 2 processes. The fusion potential between the two interacting nuclei is obtained through the nucleon densities, determined in a self-consistent way through semiclassical density variational calculations for a given effective nucleon-nucleon effective interaction of the Skyrme type. These fusion barriers can then be used in a Langevin formalism to evaluation fusion cross sections. For the fission process it turns out to be essential to allow for the large variety of shapes which appear between the nuclear ground state and the the scission configuration. We show that a shape parametrisation taking into account elongation, as well as possible neck formation, left-right asymmetry and non-axiality allows a precise description of this phenomena in the framework of the macroscopic-microscopic approach. We are thus able to enrich the expression of the liquid-drop type energy through a term which describes the variation of the nuclear energy due to a deformation difference between the proton and neutron distribution. The resulting reduction of the fission barriers is only of the order of one MeV but this can easily cause a change in the fission cross-section by an order of magnitude and thus plays a capital role for the stability of super-heavy of exotic nuclei. (author)

1978 source book for fusion--fission hybrid systems. Executive summary

International Nuclear Information System (INIS)

Crowley, J.H.; Pavlenco, G.F.; Kaminski, R.S.

1978-12-01

The 1978 Source Book for Fusion--Fission Hybrid Systems was prepared by United Engineers and Constructors Inc. for the U.S. Department of Energy and the Electric Power Research Institute. It reviews the current status of fusion--fission hybrid reactors, and presents the prevailing views of members of the fusion community on the RD and D timetable required for the development and commercialization of fusion--fission hybrids. The results presented are based on a review of related references as well as interviews with recognized experts in the field. Contributors from the academic and industrial communities are listed

Fission: An object lesson for fusion

International Nuclear Information System (INIS)

Weinberg, A.M.

1988-01-01

The development of a new, and possibly hazardous, long-range energy source is beset with two political problems (as well as the many technical ones): survival and public acceptance. By survival I mean continuing support, year after year, of a very expensive enterprise whose promise always seems greater than its achievement: can this support continue long enough to allow the promised goal to be achieved. By survival I mean continuing support, year after year, of a very expensive enterprise whose promise always seems greater than its achievement: can this support continue long enough to allow the promised goal to be achieved. By public acceptance, I mean the reaction the reaction of the public to the new energy source, assuming that it achieves its technological goals. Both of these problems have been faced by fission power : I propose to describe the experiences of fission in confronting these issues in the hope that they might be dealt with more deftly by fusion. My account will be anecdotal and personal

Control of a laser inertial confinement fusion-fission power plant

Science.gov (United States)

Moses, Edward I.; Latkowski, Jeffery F.; Kramer, Kevin J.

2015-10-27

A laser inertial-confinement fusion-fission energy power plant is described. The fusion-fission hybrid system uses inertial confinement fusion to produce neutrons from a fusion reaction of deuterium and tritium. The fusion neutrons drive a sub-critical blanket of fissile or fertile fuel. A coolant circulated through the fuel extracts heat from the fuel that is used to generate electricity. The inertial confinement fusion reaction can be implemented using central hot spot or fast ignition fusion, and direct or indirect drive. The fusion neutrons result in ultra-deep burn-up of the fuel in the fission blanket, thus enabling the burning of nuclear waste. Fuels include depleted uranium, natural uranium, enriched uranium, spent nuclear fuel, thorium, and weapons grade plutonium. LIFE engines can meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the highly undesirable stockpiles of depleted uranium, spent nuclear fuel and excess weapons materials.

Cold valleys in fusion and fission

International Nuclear Information System (INIS)

Misicu, S.

2003-01-01

The cold fission configuration after the preformation of the fragments resembles a short-lived dinuclear or quasi-molecular system. The most conceivable scission configuration is given by two fission fragments in touching with the symmetry axes aligned (pole-pole orientation). This conclusion was based on the simple argument that this configuration offers the optimal tunneling time, i.e. the difference between the Coulomb barrier and the decay energy Q is minimal. Other orientations are apparently precluded in cold spontaneous fission and should be regarded as quasi-fission doorways in the synthesis of superheavy elements by cold fusion. (orig.)

On the safety of conceptual fusion-fission hybrid reactors

International Nuclear Information System (INIS)

Kastenberg, W.E.; Okrent, D.; Badham, V.; Caspi, S.; Chan, C.K.; Ferrell, W.J.; Frederking, T.H.K.; Grzesik, J.; Lee, J.Y.; McKone, T.E.; Pomraning, G.C.; Ullman, A.Z.; Ting, T.D.; Kim, Y.I.

1979-01-01

A preliminary examination of some potential safety questions for conceptual fusion-fission hybrid reactors is presented in this paper. The study and subsequent analysis was largely based upon one design, a conceptual mirror fusion-fission reactor, operating on the deuterium-tritium plasma fusion fuel cycle and the uranium-plutonium fission fuel cycle. The major potential hazards were found to be: (a) fission products, (b) actinide elements, (c) induced radioactivity, and (d) tritium. As a result of these studies, it appears that highly reliable and even redundent decay heat removal must be provided. Loss of the ability to remove decay heat results in melting of fuel, with ultimate release of fission products and actinides to the containment. In addition, the studies indicate that blankets can be designed which will remain subcritical under extensive changes in both composition and geometry. Magnet safety and the effects of magnetic fields on thermal parameters were also considered. (Auth.)

Fusion-fission dynamics and synthesis of the superheavy elements

International Nuclear Information System (INIS)

Abe, Yasuhisa

2003-01-01

Experiments of fusion-fission reactions clarify that the life time of nuclear fission is much longer than that expected from Bohr-Wheeler formula from the measurements of multiplicities of neutrons, gamma rays etc. emitted prior scission, and thereby appear to require a dynamical treatment of the process. Following the pioneering work by Kramers with the dissipation- fluctuation dynamics, the fissioning degree of freedom is described with the viewpoint of Brownian motion under incessant interactions with the heat bath particles, i.e., with nucleons in thermal equilibrium, in the present case. In the dynamical description the fission width is no more constant in time, but has a transient feature, as well as the reduction factor, the so-called Kramers factor. Both result in a longer life time, consistent with anomalous multiplicities measured. In the fusion process, Coulomb barriers play a crucial role in lighter heavy ion systems, but in very heavy systems it is known that there exists a hindrance in fusion. That is, the Coulomb barrier is not enough for determination of fusion probability, but an extra-energy above the barrier height is required for the system to fuse. This is understood by the properties of the Liquid Drop Model. After overcoming the Coulomb barrier, the ions touch with each other. But the united system, i.e., the pear-shaped configuration is located outside of the conditional saddle point or of the ridgeline. Therefore, in order to form the spherical compound nucleus, the system has to overcome one more barrier. Naturally, in such a situation, the kinetic energy carried in by the incident projectile has been more or less dissipated, i.e., the composite system is heated up. Thus, the shape evolution toward the spherical shape or toward the re-separation can be considered as a Brownian motion with the heat bath inside. The present author et al. have proposed the two-step model for fusion of massive heavy-ion systems where the fusion probability is

Safety issues relating to the design of fusion power facilities

International Nuclear Information System (INIS)

Stasko, R.R.; Wong, K.Y.; Russell, S.B.

1986-06-01

In order to make fusion power a viable future source of energy, it will be necessary to ensure that the cost of power for fusion electric generation is competitive with advanced fission concepts. In addition, fusion power will have to live up to its original promise of being a more radiologically benign technology than fission, and be able to demonstrate excellent operational safety performance. These two requirements are interrelated, since the selection of an appropriate safety philosophy early in the design phase could greatly reduce or eliminate the capital costs of elaborate safety related and protective sytems. This paper will briefly overview a few of the key safety issues presently recognized as critical to the ultimate achievement of licensable, environmentally safe and socially acceptable fusion power facilities. 12 refs

Power-balance analysis of muon-catalyzed fusion-fission hybrid reactor systems

International Nuclear Information System (INIS)

Miller, R.L.; Krakowski, R.A.

1985-01-01

A power-balance model of a muon-catalyzed fusion system in the context of a fission-fuel factory is developed and exercised to predict the required physics performance of systems competitive with either pure muon-catalyzed fusion systems or thermonuclear fusion-fission fuel factory hybrid systems

Fusion-fission hybrid studies in the United States

International Nuclear Information System (INIS)

Moir, R.W.; Lee, J.D.; Berwald, D.H.; Cheng, E.T.; Delene, J.G.; Jassby, D.L.

1986-01-01

Systems and conceptual design studies have been carried out on the following three hybrid types: (1) The fission-suppressed hybrid, which maximizes fissile material produced (Pu or 233 U) per unit of total nuclear power by suppressing the fission process and multiplying neutrons by (n,2n) reactions in materials like beryllium. (2) The fast-fission hybrid, which maximizes fissile material produced per unit of fusion power by maximizing fission of 238 U (Pu is produced) in which twice the fissile atoms per unit of fusion power (but only a third per unit of nuclear power) are made. (3) The power hybrid, which amplifies power in the blanket for power production but does not produce fuel to sell. All three types must sell electrical power to be economical

Synergies in the design and development of fusion and generation IV fission reactors

International Nuclear Information System (INIS)

Bogusch, E.; Carre, F.; Knebel, J.; Aoto, K.

2007-01-01

Future fusion reactors or systems and Generation IV fission reactors are designed and developed in worldwide programmes mostly involving the same partners to investigate and assess their potential for realisation and contribution to meet the future energy needs beyond 2030. Huge scientific and financial effort is necessary to meet these objectives. First programmes have been launched in Generation IV International Forum (GIF) for fission and in the Broader Approach for fusion reactor system development. Except the physics basis for the energy source, future fusion and fission reactors, in particular those with fast neutron core face similar design issues and development needs. Therefore the call for the identification of synergies became evident. Beyond ITER cooled by water, future fusion reactors or systems will be designed for helium and liquid metal cooling and higher temperatures similar to those proposed for some of the six fission reactor concepts in GIF with their diverse coolants. Beside materials developments which are not discussed in this paper, design and performance of components and systems related to the diverse coolants including lifetime and maintenance aspects might offer significant potentials for synergies. Furthermore, the use of process heat for applications in addition to electricity production as well as their safety approaches might create synergistic design and development programmes. Therefore an early identification of possible synergies in the relevant programmes should be endorsed to minimise the effort for future power plants in terms of investments and resources. In addition to a general overview of a possible synergistic work programme which promotes the interaction between fusion and fission programmes towards an integrated organisation of their design and R and D programmes, some specific remarks will be given for joint design tools, numerical code systems and joint experiments in support of common technologies. (orig.)

Synergies in the design and development of fusion and generation IV fission reactors

International Nuclear Information System (INIS)

Bogusch, E.; Carre, F.; Knebel, J.U.; Aoto, K.

2008-01-01

Future fusion reactor and Generation IV fission reactor systems are designed and developed in worldwide programmes to investigate and assess their potential for realisation and contribution to the future energy needs beyond 2030 mostly involving the same partners. Huge scientific and financial effort is necessary to meet these objectives. First programmes have been launched in Generation IV International Forum (GIF) for fission and in the Broader Approach for fusion reactor system development. Except for the physics basis for the energy source, future fusion and fission reactors, in particular those with fast neutron core, face similar design issues and development needs. Therefore, the call for the identification of synergies became evident. Beyond ITER cooled by water, future fusion reactor systems will be designed for high-temperature helium and liquid metal cooling but also water including supercritical water and molten salt similar to those proposed for some of the six fission reactor concepts in GIF with their diverse coolants. Beside materials developments which are not discussed in this paper, design and performance of components and systems related to the diverse coolants including lifetime and maintenance aspects might offer significant potentials for synergies. Furthermore, the use of process heat for applications in addition to electricity production as well as their safety approaches can create synergistic design and development programmes. Therefore, an early identification of possible synergies in the relevant programmes should be endorsed to minimise the effort for future power plants in terms of investments and resources. In addition to a general overview of a possible synergistic work programme which promotes the interaction between fusion and fission programmes towards an integrated organisation of their design and R and D programmes, some specific remarks will be given for joint design tools, numerical code systems and joint experiments in

Advanced nuclear fuel production by using fission-fusion hybrid reactor

International Nuclear Information System (INIS)

Al-Kusayer, T.A.; Sahin, S.; Abdulraoof, M.

1993-01-01

Efforts are made at the College of Engineering, King Saud University, Riyadh to lay out the main structure of a prototype experimental fusion and fusion-fission (hybrid) reactor blanket in cylindrical geometry. The geometry is consistent with most of the current fusion and hybrid reactor design concepts in respect of the neutronic considerations. Characteristics of the fusion chamber, fusion neutrons and the blanket are provided. The studies have further shown that 1 GWe fission-fusion reactor can produce up to 957 kg/year which is enough to fuel five light water reactors of comparable power. Fuel production can be increased further. 29 refs

Advanced fission and fossil plant economics-implications for fusion

International Nuclear Information System (INIS)

Delene, J.G.

1994-01-01

In order for fusion energy to be a viable option for electric power generation, it must either directly compete with future alternatives or serve as a reasonable backup if the alternatives become unacceptable. This paper discusses projected costs for the most likely competitors with fusion power for baseload electric capacity and what these costs imply for fusion economics. The competitors examined include advanced nuclear fission and advanced fossil-fired plants. The projected costs and their basis are discussed. The estimates for these technologies are compared with cost estimates for magnetic and inertial confinement fusion plants. The conclusion of the analysis is that fusion faces formidable economic competition. Although the cost level for fusion appears greater than that for fission or fossil, the costs are not so high as to preclude fusion's potential competitiveness

Estimates of fission barrier heights for neutron-deficient Po to Ra nuclei produced in fusion reactions

Directory of Open Access Journals (Sweden)

Sagaidak Roman

2017-01-01

Full Text Available The cross section data for fission and evaporation residue production in fusion reactions leading to nuclei from Po to Ra have been considered in a systematic way in the framework of the conventional barrier-passing (fusion model coupled with the statistical model. The cross section data obtained in very asymmetric projectile-target combinations can be described within these models rather well with the adjusted model parameters. In particular, one can scale and fix the macroscopic (liquid-drop fission barrier heights (FBHs for nuclei involved in the de-excitation of compound nuclei produced in the reactions. The macroscopic FBHs for nuclei from Po to Ra have been derived in the framework of such analysis and compared with the predictions of various theoretical models.

Review of fission-fusion pellet designs and inertial confinement system studies at EIR

Energy Technology Data Exchange (ETDEWEB)

Seifriz, W [Eidgenoessisches Inst. fuer Reaktorforschung, Wuerenlingen (Switzerland)

1978-01-01

The article summarizes the work done so far at the Swiss Federal Institute for Reactor Research (EIR) in the field of the inertial confinement fusion technique. The following subjects are reviewed: a) fission fusion pellet designs using fissionable triggers, b) uranium tampered pellets, c) tampered pellets recycling unwanted actinide wastes from fission reactors in beam-driven micro-explosion reactors, and d) symbiotic fusion/fission reactor studies.

Cluster fusion-fission dynamics in the Singapore stock exchange

Science.gov (United States)

Teh, Boon Kin; Cheong, Siew Ann

2015-10-01

In this paper, we investigate how the cross-correlations between stocks in the Singapore stock exchange (SGX) evolve over 2008 and 2009 within overlapping one-month time windows. In particular, we examine how these cross-correlations change before, during, and after the Sep-Oct 2008 Lehman Brothers Crisis. To do this, we extend the complete-linkage hierarchical clustering algorithm, to obtain robust clusters of stocks with stronger intracluster correlations, and weaker intercluster correlations. After we identify the robust clusters in all time windows, we visualize how these change in the form of a fusion-fission diagram. Such a diagram depicts graphically how the cluster sizes evolve, the exchange of stocks between clusters, as well as how strongly the clusters mix. From the fusion-fission diagram, we see a giant cluster growing and disintegrating in the SGX, up till the Lehman Brothers Crisis in September 2008 and the market crashes of October 2008. After the Lehman Brothers Crisis, clusters in the SGX remain small for few months before giant clusters emerge once again. In the aftermath of the crisis, we also find strong mixing of component stocks between clusters. As a result, the correlation between initially strongly-correlated pairs of stocks decay exponentially with average life time of about a month. These observations impact strongly how portfolios and trading strategies should be formulated.

Comparative energetics of three fusion-fission symbiotic nuclear reactor systems

International Nuclear Information System (INIS)

Gordon, C.W.; Harms, A.A.

1975-01-01

The energetics of three symbiotic fusion-fission nuclear reactor concepts are investigated. The fuel and power balances are considered for various values of systems parameters. The results from this analysis suggest that symbiotic fusion-fission systems are advantageous from the standpoint of economy and resource utilization. (Auth.)

Near-barrier Fusion Evaporation and Fission of 28Si+174Yb and 32S+170Er

Science.gov (United States)

Wang, Dongxi; Lin, Chengjian; Jia, Huiming; Ma, Nanru; Sun, Lijie; Xu, Xinxing; Yang, Lei; Yang, Feng; Zhang, Huanqiao; Bao, Pengfei

2017-11-01

Fusion evaporation residues and fission fragments have been measured, respectively, at energies around the Coulomb barrier for the 28Si+174Yb and 32S+170Er systems forming the same compound nucleus 202Po. The excitation function of fusion evaporation, fission as well as capture reactions were deduced. Coupled-channels analyses reveal that couplings to the deformations of targets and the two-phonon states of projectiles contribute much to the enhancement of capture cross sections at sub-barrier energies. The mass and total kinetic energy of fission fragments were deduced by the time-difference method assuming full momentum transfer in a two-body kinematics. The mass-energy and mass-angle distributions were obtained and no obvious quasi-fission components were observed in this bombarding energy range. Further, mass distributions of fission fragments were fitted to extract their widths. Results show that the mass widths decrease monotonically with decreasing energy, but might start to increase when Ec.m./VB < 0.95 for both systems.

Some safety studies for conceptual fusion--fission hybrid reactors. Final report

International Nuclear Information System (INIS)

Kastenberg, W.E.; Okrent, D.

1978-07-01

The objective of this study was to make a preliminary examination of some potential safety questions for conceptual fusion-fission hybrid reactors. The study and subsequent analysis was largely based upon reference to one design, a conceptual mirror fusion-fission reactor, operating on the deuterium-tritium plasma fusion fuel cycle and the uranium-plutonium fission fuel cycle. The blanket is a fast-spectrum, uranium carbide, helium cooled, subcritical reactor, optimized for the production of fissile fuel. An attempt was made to generalize the results wherever possible

Dynamic treatment of fission and fusion in two dimensions

International Nuclear Information System (INIS)

Nazareth, R.A.M.S.

1977-01-01

The barrier penetrability in two dimensions for nuclear fusion and fission phenomena is studied. The equations of fission static trajectories (minimum potential) in Hofmann formalism are derived and the influence of inertia parameters on the penetrability is verified. For fusion case, a realistic potential for exactly penetrability calculation is proposed. The transverse momentum to the fusion and the unidimensional calculation in classical approximation by choose the trajectory which turn into maximum the penetrability are considered. The exact penetrability is compared with calculation in the classical approximation which takes in account the possibility of appearing discontinuity in the barrier along of fusion pathway. (M.C.K.) [pt

The role of the dinuclear system in the processes of nuclear fusion, quasi-fission, fission and cluster formation

International Nuclear Information System (INIS)

Volkov, V.V.

1999-01-01

The nuclear fusion, quasi-fission, fission and cluster formation in an excited nucleus are considered as the processes of the formation and evolution of the dinuclear system. This approach allows one to reveal new aspects of nuclear fusion, to show that quasi-fission plays an important role in nuclear reactions used to synthesise superheavy elements. A qualitative picture is given of the fission process of an excited nucleus and an important role of cluster formation in this process is shown

Preliminary neutronics calculation of fusion-fission hybrid reactor breeding spent fuel assembly

International Nuclear Information System (INIS)

Ma Xubo; Chen Yixue; Gao Bin

2013-01-01

The possibility of using the fusion-fission hybrid reactor breeding spent fuel in PWR was preliminarily studied in this paper. According to the fusion-fission hybrid reactor breeding spent fuel characteristics, PWR assembly including fusion-fission hybrid reactor breeding spent fuel was designed. The parameters such as fuel temperature coefficient, moderator temperature coefficient and their variation were investigated. Results show that the neutron properties of uranium-based assembly and hybrid reactor breeding spent fuel assembly are similar. The design of this paper has a smaller uniformity coefficient of power at the same fissile isotope mass percentage. The results will provide technical support for the future fusion-fission hybrid reactor and PWR combined with cycle system. (authors)

Simulation of fusion first-wall environment in a fission reactor

International Nuclear Information System (INIS)

Hassanein, A.M.; Kulcinski, G.L.; Longhurst, G.R.

1982-01-01

A novel concept to produce a realistic simulation of a fusion first-wall test environment has been proposed recently. This concept takes advantage of the (/eta/, α) reaction in 59 Ni to produce a high internal helium content in the metal while using the 3 He (/eta/, /rho/)T reaction in the gas surrounding the specimen to produce an external heat and particle flux. Models to calculate heat flux, erosion rate, implantation, and damage rate to the walls of the test module are presented. Preliminary results show that a number of important fusion technology issues could be tested experimentally in a fission reactor such as the Engineering Test Reactor

Overview of Fusion-Fission Hybrid Reactor Design Study in China

International Nuclear Information System (INIS)

Huang Jinhua; Feng Kaiming; Deng Baiquan; Deng, P.Zh.; Zhang Guoshu; Hu Gang; He Kaihui; Wu Yican; Qiu Lijian; Huang Qunying; Xiao Bingjia; Liu Xiaoping; Chen Yixue; Kong, M.H.

2002-01-01

The motivation for developing fusion-fission hybrid reactors is discussed in the context of electricity power requirements by 2050 in China. A detailed conceptual design of the Fusion Experimental Breeder (FEB) was developed from 1986-1995. The FEB has a subignited tokamak fusion core with a major radius of 4.0 m, a fusion power of 145 MW, and a fusion energy gain Q of 3. Based on this, an engineering outline design study of the FEB, FEB-E, has been performed. This design study is a transition from conceptual to engineering design in this research. The main results beyond that given in the detailed conceptual design are included in this paper, namely, the design studies of the blanket, divertor, test blanket, and tritium and environment issues. In-depth analyses have been performed to support the design. Studies of related advanced concepts such as the waste transmutation blanket concept and the spherical tokamak core concept are also presented

Critical issues for the early introduction of commercial fusion reactor

International Nuclear Information System (INIS)

Okano, Kunihiko; Yoshida, Tomoaki

1996-01-01

Critical issues for the realization of commercial fusion reactor are discussed on the basis of a prediction of power source composition in the next century. The key issue is rather a relaxation in the construction site condition than a competitive cost in comparison with the nuclear fission power plant. It seems a logical conclusion that the competitor of the fusion plant in the cost will be a future CCT (Clean Coal Technology) and/or LNG plant loaded with a CO 2 recovery system. (author)

Research Needs for Fusion-Fission Hybrid Systems. Report of the Research Needs Workshop (ReNeW) Gaithersburg, Maryland, September 30 - October 2, 2009

Energy Technology Data Exchange (ETDEWEB)

None

2009-09-30

Largely in anticipation of a possible nuclear renaissance, there has been an enthusiastic renewal of interest in the fusion-fission hybrid concept, driven primarily by some members of the fusion community. A fusion-fission hybrid consists of a neutron-producing fusion core surrounded by a fission blanket. Hybrids are of interest because of their potential to address the main long-term sustainability issues related to nuclear power: fuel supply, energy production, and waste management. As a result of this renewed interest, the U.S. Department of Energy (DOE), with the participation of the Office of Fusion Energy Sciences (OFES), Office of Nuclear Energy (NE), and National Nuclear Security Administration (NNSA), organized a three-day workshop in Gaithersburg, Maryland, from September 30 through October 2, 2009. Participants identified several goals. At the highest level, it was recognized that DOE does not currently support any R&D in the area of fusion-fission hybrids. The question to be addressed was whether or not hybrids offer sufficient promise to motivate DOE to initiate an R&D program in this area. At the next level, the workshop participants were asked to define the research needs and resources required to move the fusion-fission concept forward. The answer to the high-level question was given in two ways. On the one hand, when viewed as a standalone concept, the fusion-fission hybrid does indeed offer the promise of being able to address the sustainability issues associated with conventional nuclear power. On the other hand, when participants were asked whether these hybrid solutions are potentially more attractive than contemplated pure fission solutions (that is, fast burners and fast breeders), there was general consensus that this question could not be quantitatively answered based on the known technical information. Pure fission solutions are based largely on existing both fusion and nuclear technology, thereby prohibiting a fair side-by-side comparison

The existence and characterization of self-sustaining multiplicative fusion and fission reaction chains

International Nuclear Information System (INIS)

Harms, A.A.; Heindler, M.

1980-01-01

The mathematical-physical similarities and differences between fusion and fission multiplication processes are investigated. It is shown that advanced fusion cycles can sustain excursion tendencies which are essentially analogous to conventional fission cycles. The result that fission excursions are unbounded and that fusion excursions eventually attain an asymptote represents a significant distinction between these fundamental self-sustaining nuclear multiplicative chains. (Auth.)

First wall material damage induced by fusion-fission neutron environment

Energy Technology Data Exchange (ETDEWEB)

Khripunov, Vladimir, E-mail: Khripunov_VI@nrcki.ru

2016-11-01

Highlights: • The highest damage and gas production rates are experienced within the first wall materials of a hybrid fusion-fission system. • About ∼2 times higher dpa and 4–5 higher He appm are expected compared to the values distinctive for a pure fusion system at the same DT-neutron wall loading. • The specific nuclear heating may be increased by a factor of ∼8–9 due to fusion and fission neutrons radiation capture in metal components of the first wall. - Abstract: Neutronic performance and inventory analyses were conducted to quantify the damage and gas production rates in candidate materials when used in a fusion-fission hybrid system first wall (FW). The structural materials considered are austenitic SS, Cu-alloy and V- alloys. Plasma facing materials included Be, and CFC composite and W. It is shown that the highest damage rates and gas particles production in materials are experienced within the FW region of a hybrid similar to a pure fusion system. They are greatly influenced by a combined neutron energy spectrum formed by the two-component fusion-fission neutron source in front of the FW and in a subcritical fission blanket behind. These characteristics are non-linear functions of the fission neutron source intensity. Atomic displacement damage production rate in the FW materials of a subcritical system (at the safe subcriticality limit of ∼0.95 and the neutron multiplication factor of ∼20) is almost ∼2 times higher compared to the values distinctive for a pure fusion system at the same 14 MeV neutron FW loading. Both hydrogen (H) and helium (He) gas production rates are practically on the same level except of about ∼4–5 times higher He-production in austenitic and reduced activation ferritic martensitic steels. A proper simulation of the damage environment in hybrid systems is required to evaluate the expected material performance and the structural component residence times.

Evaluations of fusion-fission (hybrid) concepts: market penetration analysis for fusion-fission hybrids. Part A

International Nuclear Information System (INIS)

Engel, R.L.; Deonigi, D.E.

1976-01-01

This report summarizes findings of the fusion-fission studies conducted for the Electric Power Research Institute by Battelle, Pacific Northwest Laboratories. This particular study focused on the evaluation of fissile material producing hybrids. Technical results of the evaluation of actinide burning are presented in a companion volume, Part B

Measurement of reaction cross sections of fission products induced by DT neutrons

Energy Technology Data Exchange (ETDEWEB)

Nakano, Daisuke; Murata, Isao; Takahashi, Akito [Osaka Univ., Suita (Japan)

1998-03-01

With the view of future application of fusion reactor to incineration of fission products, we have measured the {sup 129}I(n,2n){sup 128}I reaction cross section by DT neutrons with the activation method. The measured cross section was compared with the evaluated nuclear data of JENDL-3.2. From the result, it was confirmed that the evaluation overestimated the cross section by about 20-40%. (author)

Fission fragment simulation of fusion neutron radiation effects on bulk mechanical properties

International Nuclear Information System (INIS)

Van Konynenburg, R.A.; Mitchell, J.B.; Guinan, M.W.; Stuart, R.N.; Borg, R.J.

1976-01-01

This research demonstrates the feasibility of using homogeneously-generated fission fragments to simulate high-fluence fusion neutron damage in niobium tensile specimens. This technique makes it possible to measure radiation effects on bulk mechanical properties at high damage states, using conveniently short irradiation times. The primary knock-on spectrum for a fusion reactor is very similar to that produced by fission fragments, and nearly the same ratio of gas atoms to displaced atoms is produced in niobium. The damage from fission fragments is compared to that from fusion neutrons and fission reactor neutrons in terms of experimentally measured yield strength increase, transmission electron microscopy (TEM) observations, and calculated damage energies

Fusion-fission hybrid reactors

International Nuclear Information System (INIS)

Greenspan, E.

1984-01-01

This chapter discusses the range of characteristics attainable from hybrid reactor blankets; blanket design considerations; hybrid reactor designs; alternative fuel hybrid reactors; multi-purpose hybrid reactors; and hybrid reactors and the energy economy. Hybrid reactors are driven by a fusion neutron source and include fertile and/or fissile material. The fusion component provides a copious source of fusion neutrons which interact with a subcritical fission component located adjacent to the plasma or pellet chamber. Fissile fuel and/or energy are the main products of hybrid reactors. Topics include high F/M blankets, the fissile (and tritium) breeding ratio, effects of composition on blanket properties, geometrical considerations, power density and first wall loading, variations of blanket properties with irradiation, thermal-hydraulic and mechanical design considerations, safety considerations, tokamak hybrid reactors, tandem-mirror hybrid reactors, inertial confinement hybrid reactors, fusion neutron sources, fissile-fuel and energy production ability, simultaneous production of combustible and fissile fuels, fusion reactors for waste transmutation and fissile breeding, nuclear pumped laser hybrid reactors, Hybrid Fuel Factories (HFFs), and scenarios for hybrid contribution. The appendix offers hybrid reactor fundamentals. Numerous references are provided

Opimization of fusion-driven fissioning systems

International Nuclear Information System (INIS)

Chapin, D.L.; Mills, R.G.

1976-01-01

Potential advantages of hybrid or fusion/fission systems can be exploited in different ways. With selection of the 238 U-- 239 Pu fuel cycle, we show that the system has greatest value as a power producer. Numerical examples of relative revenue from power production vs. 239 Pu production are discussed, and possible plant characteristics described. The analysis tends to show that the hybrid may be more economically attractive than pure fusion systems

From cutting-edge pointwise cross-section to groupwise reaction rate: A primer

Science.gov (United States)

Sublet, Jean-Christophe; Fleming, Michael; Gilbert, Mark R.

2017-09-01

The nuclear research and development community has a history of using both integral and differential experiments to support accurate lattice-reactor, nuclear reactor criticality and shielding simulations, as well as verification and validation efforts of cross sections and emitted particle spectra. An important aspect to this type of analysis is the proper consideration of the contribution of the neutron spectrum in its entirety, with correct propagation of uncertainties and standard deviations derived from Monte Carlo simulations, to the local and total uncertainty in the simulated reactions rates (RRs), which usually only apply to one application at a time. This paper identifies deficiencies in the traditional treatment, and discusses correct handling of the RR uncertainty quantification and propagation, including details of the cross section components in the RR uncertainty estimates, which are verified for relevant applications. The methodology that rigorously captures the spectral shift and cross section contributions to the uncertainty in the RR are discussed with quantified examples that demonstrate the importance of the proper treatment of the spectrum profile and cross section contributions to the uncertainty in the RR and subsequent response functions. The recently developed inventory code FISPACT-II, when connected to the processed nuclear data libraries TENDL-2015, ENDF/B-VII.1, JENDL-4.0u or JEFF-3.2, forms an enhanced multi-physics platform providing a wide variety of advanced simulation methods for modelling activation, transmutation, burnup protocols and simulating radiation damage sources terms. The system has extended cutting-edge nuclear data forms, uncertainty quantification and propagation methods, which have been the subject of recent integral and differential, fission, fusion and accelerators validation efforts. The simulation system is used to accurately and predictively probe, understand and underpin a modern and sustainable understanding

From cutting-edge pointwise cross-section to groupwise reaction rate: A primer

Directory of Open Access Journals (Sweden)

Sublet Jean-Christophe

2017-01-01

Full Text Available The nuclear research and development community has a history of using both integral and differential experiments to support accurate lattice-reactor, nuclear reactor criticality and shielding simulations, as well as verification and validation efforts of cross sections and emitted particle spectra. An important aspect to this type of analysis is the proper consideration of the contribution of the neutron spectrum in its entirety, with correct propagation of uncertainties and standard deviations derived from Monte Carlo simulations, to the local and total uncertainty in the simulated reactions rates (RRs, which usually only apply to one application at a time. This paper identifies deficiencies in the traditional treatment, and discusses correct handling of the RR uncertainty quantification and propagation, including details of the cross section components in the RR uncertainty estimates, which are verified for relevant applications. The methodology that rigorously captures the spectral shift and cross section contributions to the uncertainty in the RR are discussed with quantified examples that demonstrate the importance of the proper treatment of the spectrum profile and cross section contributions to the uncertainty in the RR and subsequent response functions. The recently developed inventory code FISPACT-II, when connected to the processed nuclear data libraries TENDL-2015, ENDF/B-VII.1, JENDL-4.0u or JEFF-3.2, forms an enhanced multi-physics platform providing a wide variety of advanced simulation methods for modelling activation, transmutation, burnup protocols and simulating radiation damage sources terms. The system has extended cutting-edge nuclear data forms, uncertainty quantification and propagation methods, which have been the subject of recent integral and differential, fission, fusion and accelerators validation efforts. The simulation system is used to accurately and predictively probe, understand and underpin a modern and

Role of fission-reactor-testing capabilities in the development of fusion technology

International Nuclear Information System (INIS)

Hsu, P.Y.; Deis, G.A.; Longhurst, G.R.; Miller, L.G.; Schmunk, R.E.; Takata, M.L.; Watts, K.D.

1981-01-01

Testing of fusion materials and components in fission reactors will be increasingly important in the future due to the near-term lack of fusion engineering test devices, and the long-term high demand for testing when fusion reactors become available. Fission testing is capable of filling many gaps in fusion reactor design information, and thus should be aggressively pursued. EG and G Idaho has investigated the application of fission testing in three areas, which are discussed in this paper. First, we investigated radiation damage to magnet insulators. This work is now continuing with the use of an improved test capsule. Second, a study was performed which indicated that a fission-suppressed hybrid blanket module could be effectively tested in a reactor such as the Engineering Test Reactor (ETR), closely reproducing the predicted performance in a fusion environment. Finally, we explored a conceptual design for a fission-based Integrated Test Facility (ITF), which can accommodate entire First Wall/Blanket (FW/B) modules for testing in a nuclear environment, simultaneously satisfying many of the FW/B test requirements. This ITF can provide a cyclic neutron/gamma flux, as well as the necessary module support functions

Nuclear structure in cold rearrangement processes in fission and fusion

Energy Technology Data Exchange (ETDEWEB)

Armbruster, P.

1998-11-01

In fission and fusion of heavy nuclei large numbers of nucleons are rearranged at a scale of excitation energy very small compared to the binding energy of the nuclei. The energies involved are less than 40 MeV at nuclear temperatures below 1.5 MeV. The shapes of the configurations in the rearrangement of a binary system into a monosystem in fusion, or vice versa in fission, change their elongations by as much as 8 fm, the radius of the monosystem. The dynamics of the reactions macroscopically described by a potential energy surface, inertia parameters, dissipation, and a collision energy is strongly modified by the nuclear structure of the participating nuclei. Experiments showing nuclear structure effects in fusion and fission of the heaviest nuclei are reviewed. The reaction kinematics and the multitude of isotopes involved are investigated by detector techniques and by recoil spectrometers. The advancement of the latter allows to find very small reaction branches in the range of 10{sup -5} to 10{sup -10}. The experiments reveal nuclear structure effects in all stages of the rearrangement processes. These are discussed pointing to analogies in fusion and fission on the microscopic scale, notwithstanding that both processes macroscopically are irreversible. Heavy clusters, as 132Sn, 208Pb, nuclei with closed shell configurations N=82,126, Z=50,82 survive in large parts of the nuclear rearrangement. They determine the asymmetry in the mass distribution of low energy fission, and they allow to synthesise superheavy elements, until now up to element 112. Experiments on the cold rearrangement in fission and fusion are presented. Here, in the range of excitation energies below 12 MeV the phenomena are observed most convincingly. (orig.)

Cluster expression in fission and fusion in high-dimensional macroscopic-microscopic calculations

International Nuclear Information System (INIS)

Iwamoto, Akira; Ichikawa, Takatoshi; Moller, Peter; Sierk, Arnold J.

2004-01-01

We discuss the relation between the fission-fusion potential-energy surfaces of very heavy nuclei and the formation process of these nuclei in cold-fusion reactions. In the potential-energy surfaces, we find a pronounced valley structure, with one valley corresponding to the cold-fusion reaction, the other to fission. As the touching point is approached in the cold-fusion entrance channel, an instability towards dynamical deformation of the projectile occurs, which enhances the fusion cross section. These two 'cluster effects' enhance the production of superheavy nuclei in cold-fusion reactions, in addition to the effect of the low compound-system excitation energy in these reactions. Heavy-ion fusion reactions have been used extensively to synthesize heavy elements beyond actinide nuclei. In order to proceed further in this direction, we need to understand the formation process more precisely, not just the decay process. The dynamics of the formation process are considerably more complex than the dynamics necessary to interpret the spontaneous-fission decay of heavy elements. However, before implementing a full dynamical description it is useful to understand the basic properties of the potential-energy landscape encountered in the initial stages of the collision. The collision process and entrance-channel landscape can conveniently be separated into two parts, namely the early-stage separated system before touching and the late-stage composite system after touching. The transition between these two stages is particularly important, but not very well understood until now. To understand better the transition between the two stages we analyze here in detail the potential energy landscape or 'collision surface' of the system both outside and inside the touching configuration of the target and projectile. In Sec. 2, we discuss calculated five-dimensional potential-energy landscapes inside touching and identify major features. In Sec. 3, we present calculated

Actinide cross section data and inertial confinement fusion for long term waste disposal

International Nuclear Information System (INIS)

Meldner, H.

1979-01-01

Actinide cross section data at thermonuclear neutron energies are needed for the calculation of ICF pellet center burnup of fission reactor waste, viz. 14 MeV neutron fission of the very long-lived actinides that pose storage problems. A major advantage of pellet center burnup is safety: only milligrams of highly toxic and active material need to be present in the fusion chamber, whereas blanket burnup requires the continued presence of tons of actinides in a small volume. The actinide data tables required for Monte Carlo calculations of the burnup of 241 Am and 243 Am are discussed in connection with typical burnup reactor fusion and fission spectra. 2 figures

Bidirectional motility of the fission yeast kinesin-5, Cut7

Energy Technology Data Exchange (ETDEWEB)

Edamatsu, Masaki, E-mail: cedam@mail.ecc.u-tokyo.ac.jp

2014-03-28

Highlights: • Motile properties of Cut7 (fission yeast kinesin-5) were studied for the first time. • Half-length Cut7 moved toward plus-end direction of microtubule. • Full-length Cut7 moved toward minus-end direction of microtubule. • N- and C-terminal microtubule binding sites did not switch the motile direction. - Abstract: Kinesin-5 is a homotetrameric motor with its motor domain at the N-terminus. Kinesin-5 crosslinks microtubules and functions in separating spindle poles during mitosis. In this study, the motile properties of Cut7, fission yeast kinesin-5, were examined for the first time. In in vitro motility assays, full-length Cut7 moved toward minus-end of microtubules, but the N-terminal half of Cut7 moved toward the opposite direction. Furthermore, additional truncated constructs lacking the N-terminal or C-terminal regions, but still contained the motor domain, did not switch the motile direction. These indicated that Cut7 was a bidirectional motor, and microtubule binding regions at the N-terminus and C-terminus were not involved in its directionality.

Fission fragment angular distributions and fission cross section validation

International Nuclear Information System (INIS)

Leong, Lou Sai

2013-01-01

The present knowledge of angular distributions of neutron-induced fission is limited to a maximal energy of 15 MeV, with large discrepancies around 14 MeV. Only 238 U and 232 Th have been investigated up to 100 MeV in a single experiment. The n-TOF Collaboration performed the fission cross section measurement of several actinides ( 232 Th, 235 U, 238 U, 234 U, 237 Np) at the n-TOF facility using an experimental set-up made of Parallel Plate Avalanche Counters (PPAC), extending the energy domain of the incident neutron above hundreds of MeV. The method based on the detection of the 2 fragments in coincidence allowed to clearly disentangle the fission reactions among other types of reactions occurring in the spallation domain. I will show the methods we used to reconstruct the full angular resolution by the tracking of fission fragments. Below 10 MeV our results are consistent with existing data. For example in the case of 232 Th, below 10 MeV the results show clearly the variation occurring at the first (1 MeV) and second (7 MeV) chance fission, corresponding to transition states of given J and K (total spin and its projection on the fission axis), and a much more accurate energy dependence at the 3. chance threshold (14 MeV) has been obtained. In the spallation domain, above 30 MeV we confirm the high anisotropy revealed in 232 Th by the single existing data set. I'll discuss the implications of this finding, related to the low anisotropy exhibited in proton-induced fission. I also explore the critical experiments which is valuable checks of nuclear data. The 237 Np neutron-induced fission cross section has recently been measured in a large energy range (from eV to GeV) at the n-TOF facility at CERN. When compared to previous measurements, the n-TOF fission cross section appears to be higher by 5-7 % beyond the fission threshold. To check the relevance of n-TOF data, we simulate a criticality experiment performed at Los Alamos with a 6 kg sphere of 237 Np. This

Tritium chemistry in fission and fusion reactors

International Nuclear Information System (INIS)

Roth, E.; Masson, M.; Briec, M.

1986-09-01

We are interested in the behaviour of tritium inside the solids where it is generated both in the case of fission nuclear reactor fuel elements, and in that of blankets of future fusion reactor. In the first case it is desirable to be able to predict whether tritium will be found in the hulls or in the uranium oxide, and under what chemical form, in order to take appropriate steps for it's removal in reprocessing plants. In fusion reactors breeding large amounts of tritium and burning it in the plasma should be accomplished in as short a cycle as possible in order to limit inventories that are associated with huge activities. Mastering the chemistry of every step is therefore essential. Amounts generated are not of the same order of magnitude in the two cases studied. Ternary fissions produce about 66 10 13 Bq (18 000 Ci) per year of tritium in a 1000 MWe fission generator, i.e., about 1.8 10 10 Bq (0.5 Ci) per day per ton of fuel

Energy for the long run: fission or fusion

International Nuclear Information System (INIS)

Kulcinski, G.L.; Kessler, G.; Holdren, J.; Haefele, W.

1979-01-01

The alternatives of the most likely and controversial long-range energy sources, fusion and fast-breeder fission, are compared in several areas: potential biological and social hazards, costs of research and development, capital costs, technical complexity, and time factors. It is concluded that from biological and social hazards standpoint, fusion is preferable to fast-breeder fission reactors; however, the LMFBR has already passed on the threshold of scientific and engineering feasibility. It is pointed out that LMFBR should not be compared with short-term energy sources, e.g. coal or oil, but should be compared only with other long-term energy sources, e.g. other types of breeder reactors

Fusion-fission energy systems evaluation

Energy Technology Data Exchange (ETDEWEB)

Teofilo, V.L.; Aase, D.T.; Bickford, W.E.

1980-01-01

This report serves as the basis for comparing the fusion-fission (hybrid) energy system concept with other advanced technology fissile fuel breeding concepts evaluated in the Nonproliferation Alternative Systems Assessment Program (NASAP). As such, much of the information and data provided herein is in a form that meets the NASAP data requirements. Since the hybrid concept has not been studied as extensively as many of the other fission concepts being examined in NASAP, the provided data and information are sparse relative to these more developed concepts. Nevertheless, this report is intended to provide a perspective on hybrids and to summarize the findings of the rather limited analyses made to date on this concept.

Fusion-fission energy systems evaluation

International Nuclear Information System (INIS)

Teofilo, V.L.; Aase, D.T.; Bickford, W.E.

1980-01-01

This report serves as the basis for comparing the fusion-fission (hybrid) energy system concept with other advanced technology fissile fuel breeding concepts evaluated in the Nonproliferation Alternative Systems Assessment Program (NASAP). As such, much of the information and data provided herein is in a form that meets the NASAP data requirements. Since the hybrid concept has not been studied as extensively as many of the other fission concepts being examined in NASAP, the provided data and information are sparse relative to these more developed concepts. Nevertheless, this report is intended to provide a perspective on hybrids and to summarize the findings of the rather limited analyses made to date on this concept

Analytic description of the fusion and fission processes through compact quasi-molecular shapes

International Nuclear Information System (INIS)

Royer, G.; Normand, C.; Druet, E.

1997-01-01

Recent studies have shown that the characteristics of the entrance and exit channels through compact quasi-molecular shapes are compatible with the experimental data on fusion, fission and cluster radioactivity when the deformation energy is determined within a generalized liquid drop model. Analytic expressions allowing to calculate rapidly the main characteristics of this deformation path through necked shapes with quasi-spherical ends are presented now; namely formulas for the fusion and fission barrier heights, the fusion barrier radius, the symmetric fission barriers and the proximity energy. (author)

Some applications of fission-based testing capabilities in the development of fusion technology

International Nuclear Information System (INIS)

Hsu, P.Y.; Deis, G.A.; Longhurst, G.R.; Masson, L.S.; Miller, L.G.; Schmunk, R.E.; Takata, M.L.; Watts, K.D.

1981-10-01

The testing of fusion materials and components in fission reactors will be increasingly important in the future due to the near-term lack of fusion engineering test devices, and the long-term high demand for fusion testing when they do become available. Fission testing is capable of filling many gaps in fusion reactor design information, and should be aggressively pursued. EG and G Idaho has investigated the application of fission testing in three areas, which are discussed in this paper. First, work was performed on the irradiation of magnet insulators. This work is continuing with an improved test environment. Second, a study was performed which indicated that a fission-suppressed hybrid blanket module could be effectively tested in a reactor such as the Engineering Test Reactor (ETR), closely reproducing the predicted performance in a fusion environment. Finally, a conceptual design is presented for a fission-based Integrated Test Facility (ITF), which can accommodate entire wall/blanket (FW/B) modules for testing in a nuclear environment, simultaneously satisfying many of the FW/B test requirements. This ITF can provide a cyclic neutron/gamma flux, as well as the necessary module support functions

An economic parametric analysis of the synthetic fuel produced by a fusion-fission complex

International Nuclear Information System (INIS)

Tai, A.S.; Krakowski, R.A.

1980-01-01

A simple analytic model is used to examine economic constraints of a fusion-fission complex in which a portion of a thermal energy is used for producing synthetic fuel (synfuel). Since the values of many quantities are not well-known, a parametric analysis has been carried out for testing the sensitivity of the synfuel production cost in relation to crucial economic and technological quantities (investment costs of hybrid and synfuel plants, energy multiplication of the fission blanket, recirculating power fraction of the fusion driver, etc.). In addition, a minimum synfuel selling price has been evaluated, from which the fission-fusion-synfuel complex brings about a higher economic benefit than does the fusion-fission hybrid entirely devoted to fissile-fuel and electricity generation. This paper describes the energy flow diagram of fusion-fission synfuel concept, express the revenue-to-cost formulation and the breakeven synfuel selling price. The synfuel production cost given by the model is evaluated within a range of values of crucial parameters. Assuming an electric cost of 2.7 cents/kWh, an annual investment cost per energy unit of 4.2 to 6 $/FJ for the fusion-fission complex and 1.5 to 3 $/GJ for the synfuel plant, the synfuel production cost lies between 6.5 and 8.5 $/GJ. These production costs can compete with those evaluated for other processes. The study points out a potential use of the fusion-fission hybrid reactor for other than fissile-fuel and electricity generation. (orig.) [de

A comparison of radioactive waste from first generation fusion reactors and fast fission reactors with actinide recycling

International Nuclear Information System (INIS)

Koch, M.; Kazimi, M.S.

1991-04-01

Limitations of the fission fuel resources will presumably mandate the replacement of thermal fission reactors by fast fission reactors that operate on a self-sufficient closed fuel cycle. This replacement might take place within the next one hundred years, so the direct competitors of fusion reactors will be fission reactors of the latter rather than the former type. Also, fast fission reactors, in contrast to thermal fission reactors, have the potential for transmuting long-lived actinides into short-lived fission products. The associated reduction of the long-term activation of radioactive waste due to actinides makes the comparison of radioactive waste from fast fission reactors to that from fusion reactors more rewarding than the comparison of radioactive waste from thermal fission reactors to that from fusion reactors. Radioactive waste from an experimental and a commercial fast fission reactor and an experimental and a commercial fusion reactor has been characterized. The fast fission reactors chosen for this study were the Experimental Breeder Reactor 2 and the Integral Fast Reactor. The fusion reactors chosen for this study were the International Thermonuclear Experimental Reactor and a Reduced Activation Ferrite Helium Tokamak. The comparison of radioactive waste parameters shows that radioactive waste from the experimental fast fission reactor may be less hazardous than that from the experimental fusion reactor. Inclusion of the actinides would reverse this conclusion only in the long-term. Radioactive waste from the commercial fusion reactor may always be less hazardous than that from the commercial fast fission reactor, irrespective of the inclusion or exclusion of the actinides. The fusion waste would even be far less hazardous, if advanced structural materials, like silicon carbide or vanadium alloy, were employed

A comparison of radioactive waste from first generation fusion reactors and fast fission reactors with actinide recycling

Energy Technology Data Exchange (ETDEWEB)

Koch, M.; Kazimi, M.S.

1991-04-01

Limitations of the fission fuel resources will presumably mandate the replacement of thermal fission reactors by fast fission reactors that operate on a self-sufficient closed fuel cycle. This replacement might take place within the next one hundred years, so the direct competitors of fusion reactors will be fission reactors of the latter rather than the former type. Also, fast fission reactors, in contrast to thermal fission reactors, have the potential for transmuting long-lived actinides into short-lived fission products. The associated reduction of the long-term activation of radioactive waste due to actinides makes the comparison of radioactive waste from fast fission reactors to that from fusion reactors more rewarding than the comparison of radioactive waste from thermal fission reactors to that from fusion reactors. Radioactive waste from an experimental and a commercial fast fission reactor and an experimental and a commercial fusion reactor has been characterized. The fast fission reactors chosen for this study were the Experimental Breeder Reactor 2 and the Integral Fast Reactor. The fusion reactors chosen for this study were the International Thermonuclear Experimental Reactor and a Reduced Activation Ferrite Helium Tokamak. The comparison of radioactive waste parameters shows that radioactive waste from the experimental fast fission reactor may be less hazardous than that from the experimental fusion reactor. Inclusion of the actinides would reverse this conclusion only in the long-term. Radioactive waste from the commercial fusion reactor may always be less hazardous than that from the commercial fast fission reactor, irrespective of the inclusion or exclusion of the actinides. The fusion waste would even be far less hazardous, if advanced structural materials, like silicon carbide or vanadium alloy, were employed.

Critical masses of miniexplosion in fission-fusion hybrid systems

Energy Technology Data Exchange (ETDEWEB)

Kaliski, S [Polska Akademia Nauk, Warsaw. Inst. Podstawowych Problemow Techniki

1976-01-01

The critical mass of the fissionable material subjected to the explosive compression and the action of the neutron stream originating from the process of D-T fusion in the spherical cavity was estimated. High energy recovery from the fissionable material was obtained and the energy of the laser pulse was minimized.

Genetically controlled fusion, exocytosis and fission of artificial vesicles-a roadmap

DEFF Research Database (Denmark)

Bönzli, Eva; Hadorn, Maik; de Lucrezia, Davide

2011-01-01

were shown to fuse if a special class of viral proteins, termed fusogenic peptides, were added to the external medium (Nomura et al. 2004). In the present work, we intend to develop genetically controlled fusion, fission and exocytosis of vesicles by the synthesis of peptides within vesicles. First, we...... enclosed synthesized peptides in vesicles to induce in a next step fusion of adjacent vesicles, fission and exocytosis of nested vesicles. Second, we will replace the peptides by an enclosed cell-free expression system to internally synthesize fusion peptides. To control the gene expression, different...

Neutron-induced fission cross sections

International Nuclear Information System (INIS)

Weigmann, H.

1991-01-01

In the history of fission research, neutron-induced fission has always played the most important role. The practical importance of neutron-induced fission rests upon the fact that additional neutrons are produced in the fission process, and thus a chain reaction becomes possible. The practical applications of neutron-induced fission will not be discussed in this chapter, but only the physical properties of one of its characteristics, namely (n,f) cross sections. The most important early summaries on the subject are the monograph edited by Michaudon which also deals with the practical applications, the earlier review article on fission by Michaudon, and the review by Bjornholm and Lynn, in which neutron-induced fission receives major attention. This chapter will attempt to go an intermediate way between the very detailed theoretical treatment in the latter review and the cited monograph which emphasizes the applied aspects and the techniques of fission cross-section measurements. The more recent investigations in the field will be included. Section II will survey the properties of cross sections for neutron-induced fission and also address some special aspects of the experimental methods applied in their measurement. Section Ill will deal with the formal theory of neutron-induced nuclear reactions for the resolved resonance region and the region of statistical nuclear reactions. In Section IV, the fission width, or fission transmission coefficient, will be discussed in detail. Section V will deal with the broader structures due to incompletely damped vibrational resonances, and in particular will address the special case of thorium and neighboring isotopes. Finally, Section VI will briefly discuss parity violation effects in neutron-induced fission. 74 refs., 14 figs., 3 tabs

Fusion--fission hybrid reactors: a capsule introduction

International Nuclear Information System (INIS)

Holdren, J.P.

1977-01-01

A short introduction to fusion-fission hybrid systems is provided touching on (a) basic technological characteristics; (b) potential applications; (c) relevance of environmental considerations in the development rationale for hybrids. References to the more technical literature are supplied

Fission--fusion systems: classification and critique

International Nuclear Information System (INIS)

Lidsky, L.M.

1974-01-01

A useful classification scheme for hybrid systems is described and some common features that the scheme makes apparent are pointed out. The early history of fusion-fission systems is reviewed. Some designs are described along with advantages and disadvantages of each. The extension to low and moderate Q devices is noted. (U.S.)

Study of α-particle multiplicity in 16O+196Pt fusion-fission reaction

International Nuclear Information System (INIS)

Kapoor, K.; Kumar, A.; Bansal, N.

2016-01-01

Study of dynamics of fusion-fission reaction is one of the interesting parts of heavy-ion-induced nuclear reaction. Extraction of fission time scales using different probes is of central importance for understanding the dynamics of fusion-fission process. In the past, extensive theoretical and experimental efforts have been made to understand the various aspects of the heavy ion induced fusion-fission reactions. Compelling evidences have been obtained from the earlier studies that the fission decay of hot nuclei is protracted process i.e. slowed down relative to the expectations of the standard statistical model, and large dynamical delays are required due to this hindrance. Nuclear dissipation is assumed to be responsible for this delay and more light particles are expected to be emitted during the fission process. One of neutron multiplicity measurements have been performed for the 16,18 O+ 194,198 Pt populating the CN 210,212,214,216 Rn and observed fission delay due to nuclear viscosity. In order to have complete understanding for the dynamics of 212 Rn nucleus, we measured the charged particle multiplicity for 16 O+ 196 Pt system. Study of charged particles will give us more information about the emitter in comparison to neutrons as charged particles faces Coulomb barrier and are more sensitive probe for understanding the dynamics of fusion-fission reactions. In the present work, we are reporting some of the preliminary results of charged particle multiplicity

Measurements of fission cross-sections. Chapter 4

International Nuclear Information System (INIS)

James, G.D.

1981-01-01

The steps involved in the measurement of fission cross sections are summarized and the range of techniques available are considered. Methods of fission detection are described with particular emphasis on the neutron energy dependent properties of the fission process and the details of fragment energy loss which can lead to energy-dependent changes in detector efficiency. Selected examples of fission cross-section measurements are presented and methods of data reduction, storage, analysis and evaluation, are examined. Finally requested accuracies for fission cross section data are compared to estimated available accuracies. (U.K.)

Heavy cluster in cold nuclear rearrangements in fusion and fission

International Nuclear Information System (INIS)

Armbruster, P.

1997-01-01

The experimental evidence for the appearance of cluster aspects in the dynamics of large rearrangements processes, as fusion and fission, is presented. Clusters in the sense as used in the following are strongly bound, doubly magic neutron rich nuclei as 48 Ca 28 , 78 Ni 50 , 132 Sn 82 , and 208 Pb 126 , the spherical nuclei Z=114 - 126 and N=184, and nuclei with closed shells N=28, 50, 82, and 126, and Z=28, 50, and 82. As with increasing nucleon numbers, the absolute shell corrections to the binding energies increase, the strongest effects are to be observed for the higher shells. The 132 cluster manifests itself in low energy fission (Faissner, H. and Wildermuth, K. Nucl. Phys., 58 (1964) 177). The 208 Pb cluster gave the new radioactivity (Rose, M.J. and Jones G.A., Nature, 307 (1984) 245) and the first superheavy elements (SHE) (Armbruster P., Ann. Rev. Nucl. Part. Sci., 35 (1985) 135-94; Munzenberg, G. Rep. Progr. Phys., 51 (1988) 57). The paper discuss experiments concerning the stability of clusters to intrinsic excitation energy in fusion and fission (Armbruster, P. Lect. Notes Phys., 158 (1982) 1). and the manifestation of clusters in the fusion entrance channel (Armbruster, P., J. Phys. Soc. Jpn., 58 (1989) 232). The importance of compactness of the clustering system seems to be equally decisive in fission and fusion. Finally, it s covered the importance of clusters for the production of SHEs)

Fission cross section calculations for 209Bi target nucleus based on fission reaction models in high energy regions

Directory of Open Access Journals (Sweden)

Kaplan Abdullah

2015-01-01

Full Text Available Implementation of projects of new generation nuclear power plants requires the solving of material science and technological issues in developing of reactor materials. Melts of heavy metals (Pb, Bi and Pb-Bi due to their nuclear and thermophysical properties, are the candidate coolants for fast reactors and accelerator-driven systems (ADS. In this study, α, γ, p, n and 3He induced fission cross section calculations for 209Bi target nucleus at high-energy regions for (α,f, (γ,f, (p,f, (n,f and (3He,f reactions have been investigated using different fission reaction models. Mamdouh Table, Sierk, Rotating Liquid Drop and Fission Path models of theoretical fission barriers of TALYS 1.6 code have been used for the fission cross section calculations. The calculated results have been compared with the experimental data taken from the EXFOR database. TALYS 1.6 Sierk model calculations exhibit generally good agreement with the experimental measurements for all reactions used in this study.

Static aspects of the fission and fusion of liquid 3He drops

International Nuclear Information System (INIS)

Guilleumas, M.; Barranco, M.; Pi, M.

1992-01-01

Using an effective 3 He- 3 He interaction, the fission and fusion of 3 He drops have been investigated from a static point of view. The calculations show that a fission barrier develops for these neutral systems, and that their saddle configurations are rather elongate. The transition from oblate to prolate shapes as a function of the angular momentum L, as well as critical values for fission and fusion are discussed for some selected cases. A kind of proximity potential can be extracted from the drop-drop interaction potentials. (author) 33 refs.; 9 figs

An optimized symbiotic fusion and molten-salt fission reactor system

International Nuclear Information System (INIS)

Blinkin, V.L.; Novikov, V.M.

A symbiotic fusion-fission reactor system which breeds nuclear fuel is discussed. In the blanket of the controlled thermonuclear reactor (CTR) uranium-233 is generated from thorium, which circulates in the form of ThF 4 mixed with molten sodium and beryllium fluorides. The molten-salt fission reactor (MSR) burns up the uranium-233 and generates tritium for the fusion reactor from lithium, which circulates in the form of LiF mixed with BeF 2 and 233 UF 4 through the MSR core. With a CTR-MSR thermal power ratio of 1:11 the system can produce electrical energy and breed fuel with a doubling time of 4-5 years. The system has the following special features: (1) Fuel reprocessing is much simpler and cheaper than for contemporary fission reactors; reprocessing consists simply in continuous removal of 233 U from the salt circulating in the CTR blanket by the fluorination method and removal of xenon from the MSR fuel salt by gas scavenging; the MSR fuel salt is periodically exchanged for fresh salt and the 233 U is then removed from it; (2) Tritium is produced in the fission reactor, which is a much simpler system than the fusion reactor; (3) The CTR blanket is almost ''clean''; no tritium is produced in it and fission fragment activity does not exceed the activity induced in the structural materials; (4) Almost all the thorium introduced into the CTR blanket can be used for producing 233 U

Fusion17 summary talk: windsurfing on a cross section profile

Directory of Open Access Journals (Sweden)

Ackermann Dieter

2017-01-01

Full Text Available The spectrum of physics, discussed in the 7th edition of the “Fusion” conference series, included a number of topics, ranging from reaction dynamics to structure studies, from the lightest to the heaviest nuclei, from inelastic reactions to fusion and fission, with applications of astrophysical interest and the newest developments and findings in theory and experiment. With this paper we try to summarize the most relevant issues discussed during the five days of Fusion17.

Major features of a mirror fusion--fast fission hybrid reactor

International Nuclear Information System (INIS)

Moir, R.W.; Lee, J.D.; Burleigh, R.J.

1974-01-01

A conceptual design was made of a fusion-fission reactor. The fusion component is a D-T plasma confined by a pair of magnetic mirror coils in a Yin-Yang configuration and sustained by hot neutral beam injection. The neutrons from the fusion plasma drive the fission assembly which is composed of natural uranium carbide fuel rods clad with stainless steel and is cooled by helium. It was shown how the reactor can be built using essentially present day construction technology and how the uranium bearing blanket modules can be routinely changed to allow separation of the bred fissile fuel of which approximately 1200 kg of plutonium are produced each year along with the approximately 750 MW of electricity. (U.S.)

Optimization of the fission--fusion hybrid concept

International Nuclear Information System (INIS)

Saltmarsh, M.J.; Grimes, W.R.; Santoro, R.T.

1979-04-01

One of the potentially attractive applications of controlled thermonuclear fusion is the fission--fusion hybrid concept. In this report we examine the possible role of the hybrid as a fissile fuel producer. We parameterize the advantages of the concept in terms of the performance of the fusion device and the breeding blanket and discuss some of the more troublesome features of existing design studies. The analysis suggests that hybrids based on deuterium--tritium (D--T) fusion devices are unlikely to be economically attractive and that they present formidable blanket technology problems. We suggest an alternative approach based on a semicatalyzed deuterium--deuterium (D--D) fusion reactor and a molten salt blanket. This concept is shown to emphasize the desirable features of the hybrid, to have considerably greater economic potential, and to mitigate many of the disadvantages of D--T-based systems

Review of the safety concept for fusion reactor concepts and transferability of the nuclear fission regulation to potential fusion power plants

Energy Technology Data Exchange (ETDEWEB)

Raeder, Juergen; Weller, Arthur; Wolf, Robert [Max-Planck-Institut fuer Plasmaphysik (IPP), Garching (Germany); Jin, Xue Zhou; Boccaccini, Lorenzo V.; Stieglitz, Robert; Carloni, Dario [Karlsruher Institute fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany); Pistner, Christoph [Oeko-Institut e.V., Darmstadt (Germany); Herb, Joachim [Gesellschaft fuer Anlagen- und Reaktorsicherheit, Koeln (Germany)

2016-01-15

This paper summarizes the current state of the art in science and technology of the safety concept for future fusion power plants (FPPs) and examines the transferability of the current nuclear fission regulation to the concepts of future fusion power plants. At the moment there exist only conceptual designs of future fusion power plants. The most detailed concepts with regards to safety aspects were found in the European Power Plant Conceptual Study (PPCS). The plant concepts discussed in the PPCS are based on magnetic confinement of the plasma. The safety concept of fusion power plants, which has been developed during the last decades, is based on the safety concepts of installations with radioactive inventories, especially nuclear fission power plants. It applies the concept of defence in depth. However, there are specific differences between the implementations of the safety concepts due to the physical and technological characteristics of fusion and fission. It is analysed whether for fusion a safety concept is required comparable to the one of fission. For this the consequences of a purely hypothetical release of large amounts of the radioactive inventory of a fusion power plant and a fission power plant are compared. In such an event the evacuation criterion outside the plant is exceeded by several orders of magnitude for a fission power plant. For a fusion power plant the expected radiological consequences are of the order of the evacuation criterion. Therefore, a safety concept is also necessary for fusion to guarantee the confinement of the radioactive inventory. The comparison between the safety concepts for fusion and fission shows that the fundamental safety function ''confinement of the radioactive materials'' can be transferred directly in a methodical way. For a fusion power plant this fundamental safety function is based on both, physical barriers as well as on active retention functions. After the termination of the fusion

Laser solenoid fusion--fission design

International Nuclear Information System (INIS)

Steinhauer, L.C.; Taussig, R.T.

1976-01-01

The dependence of breeding performance on system engineering parameters is examined for laser solenoid fusion-fission reactors. Reactor performance is found to be relatively insensitive to most of the engineering parameters, and compact designs can be built based on reasonable technologies. Point designs are described for the prototype series of reactors (mid-term technologies) and for second generation systems (advanced technologies). It is concluded that the laser solenoid has a good probability of timely application to fuel breeding needs

Systems study of tokamak fusion--fission reactors

International Nuclear Information System (INIS)

Tenney, F.H.; Bathke, C.G.; Price, W.G. Jr.; Bohlke, W.H.; Mills, R.G.; Johnson, E.F.; Todd, A.M.M.; Buchanan, C.H.; Gralnick, S.L.

1978-11-01

This publication reports the results of a two to three year effort at a systematic analysis of a wide variety of tokamak-driven fissioning blanket reactors, i.e., fusion--fission hybrids. It addresses the quantitative problems of determining the economically most desirable mix of the two products: electric power and fissionable fuel and shows how the price of electric power can be minimized when subject to a variety of constraints. An attempt has been made to avoid restricting assumptions, and the result is an optimizing algorithm that operates in a six-dimensional parameter space. Comparisons are made on sets of as many as 100,000 distinct machine models, and the principal results of the study have been derived from the examination of several hundred thousand possible reactor configurations

A fission-fusion hybrid reactor in steady-state L-mode tokamak configuration with natural uranium

International Nuclear Information System (INIS)

Reed, Mark; Parker, Ronald R.; Forget, Benoit

2012-01-01

This work develops a conceptual design for a fusion-fission hybrid reactor operating in steady-state L-mode tokamak configuration with a subcritical natural or depleted uranium pebble bed blanket. A liquid lithium-lead alloy breeds enough tritium to replenish that consumed by the D-T fusion reaction. The fission blanket augments the fusion power such that the fusion core itself need not have a high power gain, thus allowing for fully non-inductive (steady-state) low confinement mode (L-mode) operation at relatively small physical dimensions. A neutron transport Monte Carlo code models the natural uranium fission blanket. Maximizing the fission power gain while breeding sufficient tritium allows for the selection of an optimal set of blanket parameters, which yields a maximum prudent fission power gain of approximately 7. A 0-D tokamak model suffices to analyze approximate tokamak operating conditions. This fission blanket would allow the fusion component of a hybrid reactor with the same dimensions as ITER to operate in steady-state L-mode very comfortably with a fusion power gain of 6.7 and a thermal fusion power of 2.1 GW. Taking this further can determine the approximate minimum scale for a steady-state L-mode tokamak hybrid reactor, which is a major radius of 5.2 m and an aspect ratio of 2.8. This minimum scale device operates barely within the steady-state L-mode realm with a thermal fusion power of 1.7 GW. Basic thermal hydraulic analysis demonstrates that pressurized helium could cool the pebble bed fission blanket with a flow rate below 10 m/s. The Brayton cycle thermal efficiency is 41%. This reactor, dubbed the Steady-state L-mode non-Enriched Uranium Tokamak Hybrid (SLEUTH), with its very fast neutron spectrum, could be superior to pure fission reactors in terms of breeding fissile fuel and transmuting deleterious fission products. It would likely function best as a prolific plutonium breeder, and the plutonium it produces could actually be more

Advanced Computational Materials Science: Application to Fusion and Generation IV Fission Reactors (Workshop Report)

Energy Technology Data Exchange (ETDEWEB)

Stoller, RE

2004-07-15

The ''Workshop on Advanced Computational Materials Science: Application to Fusion and Generation IV Fission Reactors'' was convened to determine the degree to which an increased effort in modeling and simulation could help bridge the gap between the data that is needed to support the implementation of these advanced nuclear technologies and the data that can be obtained in available experimental facilities. The need to develop materials capable of performing in the severe operating environments expected in fusion and fission (Generation IV) reactors represents a significant challenge in materials science. There is a range of potential Gen-IV fission reactor design concepts and each concept has its own unique demands. Improved economic performance is a major goal of the Gen-IV designs. As a result, most designs call for significantly higher operating temperatures than the current generation of LWRs to obtain higher thermal efficiency. In many cases, the desired operating temperatures rule out the use of the structural alloys employed today. The very high operating temperature (up to 1000 C) associated with the NGNP is a prime example of an attractive new system that will require the development of new structural materials. Fusion power plants represent an even greater challenge to structural materials development and application. The operating temperatures, neutron exposure levels and thermo-mechanical stresses are comparable to or greater than those for proposed Gen-IV fission reactors. In addition, the transmutation products created in the structural materials by the high energy neutrons produced in the DT plasma can profoundly influence the microstructural evolution and mechanical behavior of these materials. Although the workshop addressed issues relevant to both Gen-IV and fusion reactor materials, much of the discussion focused on fusion; the same focus is reflected in this report. Most of the physical models and computational methods

A compact multi-plate fission chamber for the simultaneous measurement of 233U capture and fission cross-sections

Directory of Open Access Journals (Sweden)

Bacak M.

2017-01-01

Full Text Available 233U plays the essential role of fissile nucleus in the Th-U fuel cycle. A particularity of 233U is its small neutron capture cross-section which is about one order of magnitude lower than the fission cross-section on average. Therefore, the accuracy in the measurement of the 233U capture cross-section essentially relies on efficient capture-fission discrimination thus a combined setup of fission and γ-detectors is needed. At CERN n_TOF the Total Absorption Calorimeter (TAC coupled with compact fission detectors is used. Previously used MicroMegas (MGAS detectors showed significant γ-background issues above 100 eV coming from the copper mesh. A new measurement campaign of the 233U capture cross-section and alpha ratio is planned at the CERN n_TOF facility. For this measurement, a novel cylindrical multi ionization cell chamber was developed in order to provide a compact solution for 14 active targets read out by 8 anodes. Due to the high specific activity of 233U fast timing properties are required and achieved with the use of customized electronics and the very fast ionizing gas CF4 together with a high electric field strength. This paper describes the new fission chamber and the results of the first tests with neutrons at GELINA proving that it is suitable for the 233U measurement.

Fusion-Fission Hybrid for Fissile Fuel Production without Processing

Energy Technology Data Exchange (ETDEWEB)

Fratoni, M; Moir, R W; Kramer, K J; Latkowski, J F; Meier, W R; Powers, J J

2012-01-02

Two scenarios are typically envisioned for thorium fuel cycles: 'open' cycles based on irradiation of {sup 232}Th and fission of {sup 233}U in situ without reprocessing or 'closed' cycles based on irradiation of {sup 232}Th followed by reprocessing, and recycling of {sup 233}U either in situ or in critical fission reactors. This study evaluates a third option based on the possibility of breeding fissile material in a fusion-fission hybrid reactor and burning the same fuel in a critical reactor without any reprocessing or reconditioning. This fuel cycle requires the hybrid and the critical reactor to use the same fuel form. TRISO particles embedded in carbon pebbles were selected as the preferred form of fuel and an inertial laser fusion system featuring a subcritical blanket was combined with critical pebble bed reactors, either gas-cooled or liquid-salt-cooled. The hybrid reactor was modeled based on the earlier, hybrid version of the LLNL Laser Inertial Fusion Energy (LIFE1) system, whereas the critical reactors were modeled according to the Pebble Bed Modular Reactor (PBMR) and the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) design. An extensive neutronic analysis was carried out for both the hybrid and the fission reactors in order to track the fuel composition at each stage of the fuel cycle and ultimately determine the plant support ratio, which has been defined as the ratio between the thermal power generated in fission reactors and the fusion power required to breed the fissile fuel burnt in these fission reactors. It was found that the maximum attainable plant support ratio for a thorium fuel cycle that employs neither enrichment nor reprocessing is about 2. This requires tuning the neutron energy towards high energy for breeding and towards thermal energy for burning. A high fuel loading in the pebbles allows a faster spectrum in the hybrid blanket; mixing dummy carbon pebbles with fuel pebbles enables a softer spectrum in

Economic regimes for fission--fusion energy systems

International Nuclear Information System (INIS)

Deonigi, D.E.

1974-01-01

The objectives of this hybrid fusion-fission economic regimes study are to: (1) define the target costs to be met, (2) define the optimum fissile/electrical production ratio for hybrid blankets, (3) discover synergistic configurations, and (4) define the windows of economic hybrid design having desirable cost/benefit ratios. (U.S.)

Fusability and fissionability in 86Kr induced reactions near and below the fusion barrier

International Nuclear Information System (INIS)

Reisdorf, W.; Hessberger, F.P.; Hildenbrand, K.D.; Hofmann, S.; Muenzenberg, G.; Schmidt, K.H.; Schneider, W.F.W.; Suemmerer, K.; Wirth, G.; Kratz, J.V.; Schlitt, K.; Sahm, C.C.

1985-04-01

Evaporation-residue excitation functions for the reactions 86 Kr + sup(70,76)Ge, sup(92,100)Mo, sup(99,102,104)Ru have been measured using activation methods and the velocity filter SHIP. The data span the region from well below the fusion barrier up to and beyond the energy where limitation by fission competition takes place. The data are shown to be compatible with the concept of complete fusion followed by the statistical decay of the equilibrated compound nucleus. Information on both the fusion probability at and below the fusion threshold and the fissionability of the compound nuclei formed is extracted. The model dependence of the extracted fission barriers is discussed in detail. In analogy to studies involving lighter projectiles, strong correlations between the low-energy nuclear-structure properties of the nuclei and the subbarrier fusion probability are found. A relative shift of the fusion barrier to higher energies, that increases with the number of valence neutrons in the target nuclei, is observed. (orig.)

Modelisation of the fission cross section

International Nuclear Information System (INIS)

Morariu, Claudia

2013-03-01

The neutron cross sections of four nuclear systems (n+ 235 U, n+ 233 U, n+ 241 Am and n+ 237 Np) are studied in the present document. The target nuclei of the first case, like 235 U and 239 Pu, have a large fission cross section after the absorption of thermal neutrons. These nuclei are called 'fissile' nuclei. The other type of nuclei, like 237 Np and 241 Am, fission mostly with fast neutrons, which exceed the fission threshold energy. These types of nuclei are called 'fertile'. The compound nuclei of the fertile nuclei have a binding energy higher than the fission barrier, while for the fissile nuclei the binding energy is lower than the fission barrier. In this work, the neutron induced cross sections for both types of nuclei are evaluated in the fast energy range. The total, reaction and shape-elastic cross sections are calculated by the coupled channel method of the optical model code ECIS, while the compound nucleus mechanism are treated by the statistical models implemented in the codes STATIS, GNASH and TALYS. The STATIS code includes a refined model of the fission process. Results from the theoretical calculations are compared with data retrieved from the experimental data base EXFOR. (author) [fr

Fission cross section measurements at intermediate energies

International Nuclear Information System (INIS)

Laptev, Alexander

2005-01-01

The activity in intermediate energy particle induced fission cross-section measurements of Pu, U isotopes, minor actinides and sub-actinides in PNPI of Russia is reviewed. The neutron-induced fission cross-section measurements are under way in the wide energy range of incident neutrons from 0.5 MeV to 200 MeV at the GNEIS facility. In number of experiments at the GNEIS facility, the neutron-induced fission cross sections were obtained for many nuclei. In another group of experiments the proton-induced fission cross-section have been measured for proton energies ranging from 200 to 1000 MeV at 100 MeV intervals using the proton beam of PNPI synchrocyclotron. (author)

Neutron rich clusters and the dynamics of fission and fusion

International Nuclear Information System (INIS)

Armbruster, P.

1988-07-01

In this lecture I want to discuss experimental evidence for the appearance of cluster aspects in the dynamics of large rearrangement processes, as fusion and fission. Clusters in the sense as used in my lecture are the strongly bound doubly magic nuclei as 20 Ca 28 48 , 28 Ni 50 78 , 132 50 Sn 82 , and 208 82 Pb 126 and the superheavy nucleus 298 114 184 . Two of these nuclei, 78 Ni and 298 114 have not yet been identified. I discuss first the experimental findings from heavy element production. Then I cover the stability of cluster aspects to intrinsic excitation energy in fusion and fission. (orig./HSI)

Fission cross-section calculations and the multi-modal fission model

International Nuclear Information System (INIS)

Hambsch, F.J.

2004-01-01

New, self consistent, neutron-induced reaction cross section calculations for 235,238 U, 237 Np have been performed. The statistical model code STATIS was improved to take into account the multimodality of the fission process. The three most dominant fission modes, the two asymmetric standards I (S1) and standard II (S2) modes and the symmetric superlong (SL) mode have been taken into account. De-convoluted fission cross sections for those modes for 235,238 U(n,f) and 237 Np(n,f) based on experimental branching ratios, were calculated for the first time up to the second chance fission threshold. For 235 U(n,f), the calculations being made up to 28 MeV incident neutron energy, higher fission chances have been considered. This implied the need for additional calculations for the neighbouring isotopes. As a side product also mass yield distributions could be calculated at energies hitherto not accessible by experiment. Experimental validation of the predictions is being envisaged

Nuclear irradiation parameters of beryllium under fusion, fission and IFMIF irradiation conditions

International Nuclear Information System (INIS)

Fischer, U.; Chen, Y.; Leichtle, D.; Simakov, S.; Moeslang, A.; Vladimirov, P.

2004-01-01

A computational analysis is presented of the nuclear irradiation parameters for Beryllium under irradiation in typical neutron environments of fission and fusion reactors, and of the presently designed intense fusion neutron source IFMIF. The analysis shows that dpa and Tritium production rates at fusion relevant levels can be achieved with existing high flux fission reactors while the achievable Helium production is too low. The resulting He-Tritium and He/dpa ratios do not meet typical fusion irradiation conditions. Irradiation simulations in the medium flux test modules of the IFMIF neutron source facility were shown to be more suitable to match fusion typical irradiation conditions. To achieve sufficiently high production rates it is suggested to remove the creep-fatigue testing machine together with the W spectra shifter plate and move the tritium release module upstream towards the high flux test module. (author)

Laser driven fusion fission hybrids

International Nuclear Information System (INIS)

Hansen, L.F.; Maniscalco, J.A.

1977-11-01

The role of the fusion-fission hybrid reactor (FFHR) as a fissile fuel and/or power producer is discussed. As long range options to supply the world energy needs, hybrid-fueled thermal-burner reactors are compared to liquid metal fast breeder reactors (LMFBR). A discussion of different fuel cycles (thorium, depleted uranium, and spent fuel) is presented in order to compare the energy multiplication, the production of fissile fuel, the laser efficiency and pellet gain requirements of the hybrid reactor. Lawrence Livermore Laboratory (LLL) has collaborated with Bechtel Corporation and with Westinghouse in two engineering design studies of laser fusion driven hybrid power plants. The hybrid designs which have resulted from these two studies are briefly described and analyzed by considering operational parameters, such as energy multiplication, power density, burn-up and plutonium production as a function time

Fusion-Fission hybrid reactors and nonproliferation

International Nuclear Information System (INIS)

Greenspan, E.

1984-09-01

New options for the development of the nuclear energy economy which might become available by a successful development of fusion-breeders or fusion-fission hybrid power reactors, identified and their nonproliferative attributes are discussed. The more promising proliferation-resistance ettributes identified include: (1) Justification for a significant delay in the initiation of fuel processing, (2) Denaturing the plutonium with 238 Pu before its use in power reactors of any kind, and (3) Making practical the development of denatured uranium fuel cycles and, in particular, denaturing the uranium with 232 U. Fuel resource utilization, time-table and economic considerations associated with the use of fusion-breeders are also discussed. It is concluded that hybrid reactors may enable developing a nuclear energy economy which is more proliferation resistant than possible otherwise, whileat the same time, assuring high utilization of t he uranium and thorium resources in an economically acceptable way. (author)

Laser Intertial Fusion Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

Energy Technology Data Exchange (ETDEWEB)

Kramer, Kevin James [Univ. of California, Berkeley, CA (United States)

2010-04-08

This study investigates the neutronics design aspects of a hybrid fusion-fission energy system called the Laser Fusion-Fission Hybrid (LFFH). A LFFH combines current Laser Inertial Confinement fusion technology with that of advanced fission reactor technology to produce a system that eliminates many of the negative aspects of pure fusion or pure fission systems. When examining the LFFH energy mission, a significant portion of the United States and world energy production could be supplied by LFFH plants. The LFFH engine described utilizes a central fusion chamber surrounded by multiple layers of multiplying and moderating media. These layers, or blankets, include coolant plenums, a beryllium (Be) multiplier layer, a fertile fission blanket and a graphite-pebble reflector. Each layer is separated by perforated oxide dispersion strengthened (ODS) ferritic steel walls. The central fusion chamber is surrounded by an ODS ferritic steel first wall. The first wall is coated with 250-500 μm of tungsten to mitigate x-ray damage. The first wall is cooled by Li₁₇Pb₈₃ eutectic, chosen for its neutron multiplication and good heat transfer properties. The Li₁₇Pb₈₃ flows in a jacket around the first wall to an extraction plenum. The main coolant injection plenum is immediately behind the Li₁₇Pb₈₃, separated from the Li₁₇Pb₈₃ by a solid ODS wall. This main system coolant is the molten salt flibe (2LiF-BeF₂), chosen for beneficial neutronics and heat transfer properties. The use of flibe enables both fusion fuel production (tritium) and neutron moderation and multiplication for the fission blanket. A Be pebble (1 cm diameter) multiplier layer surrounds the coolant injection plenum and the coolant flows radially through perforated walls across the bed. Outside the Be layer, a fission fuel layer comprised of depleted uranium contained in Tristructural-isotropic (TRISO) fuel particles

Progress on the conceptual design of a mirror hybrid fusion--fission reactor

International Nuclear Information System (INIS)

Moir, R.W.; Lee, J.D.; Burleigh, R.J.

1975-01-01

A conceptual design study was made of a fusion-fission reactor for the purpose of producing fissile material and electricity. The fusion component is a D-T plasma confined by a pair of magnetic mirror coils in a Yin-Yang configuration and is sustained by neutral beam injection. The neutrons from the fusion plasma drive the fission assembly which is composed of natural uranium carbide fuel rods clad with stainless steel and helium cooled. It was shown conceptually how the reactor might be built using essentially present-day technology and how the uranium-bearing blanket modules can be routinely changed to allow separation of the bred fissile fuel

Roles of plasma neutron source reactor in development of fusion reactor engineering: Comparison with fission reactor engineering

International Nuclear Information System (INIS)

Hirayama, Shoichi; Kawabe, Takaya

1995-01-01

The history of development of fusion power reactor has come to a turning point, where the main research target is now shifting from the plasma heating and confinement physics toward the burning plasma physics and reactor engineering. Although the development of fusion reactor system is the first time for human beings, engineers have experience of development of fission power reactor. The common feature between them is that both are plants used for the generation of nuclear reactions for the production of energy, nucleon, and radiation on an industrial scale. By studying the history of the development of the fission reactor, one can find the existence of experimental neutron reactors including irradiation facilities for fission reactor materials. These research neutron reactors played very important roles in the development of fission power reactors. When one considers the strategy of development of fusion power reactors from the points of fusion reactor engineering, one finds that the fusion neutron source corresponds to the neutron reactor in fission reactor development. In this paper, the authors discuss the roles of the plasma-based neutron source reactors in the development of fusion reactor engineering, by comparing it with the neutron reactors in the history of fission power development, and make proposals for the strategy of the fusion reactor development. 21 refs., 6 figs

Fusion and fission of atomic clusters: recent advances

DEFF Research Database (Denmark)

Obolensky, Oleg I.; Solov'yov, Ilia; Solov'yov, Andrey V.

2005-01-01

We review recent advances made by our group in finding optimized geometries of atomic clusters as well as in description of fission of charged small metal clusters. We base our approach to these problems on analysis of multidimensional potential energy surface. For the fusion process we have...... developed an effective scheme of adding new atoms to stable cluster geometries of larger clusters in an efficient way. We apply this algorithm to finding geometries of metal and noble gas clusters. For the fission process the analysis of the potential energy landscape calculated on the ab initio level...... of theory allowed us to obtain very detailed information on energetics and pathways of the different fission channels for the Na^2+_10 clusters....

Nuclear dynamics in heavy ion induced fusion-fission reactions

International Nuclear Information System (INIS)

Kapoor, S.S.

1992-01-01

Heavy ion induced fission and fission-like reactions evolve through a complex nuclear dynamics encountered in the medium energy nucleus-nucleus collisions. In the recent years, measurements of the fragment-neutron and fragment-charged particle angular correlations in heavy ion induced fusion-fission reactions, have provided new information on the dynamical times of nuclear deformations of the initial dinuclear complex to the fission saddle point and the scission point. From the studies of fragment angular distributions in heavy ion induced fission it has been possible to infer the relaxation times of the dinuclear complex in the K-degree of freedom and our recent measurements on the entrance channel dependence of fragment anisotropies have provided an experimental signature of the presence of fissions before K-equilibration. This paper reviews recent experimental and theoretical status of the above studies with particular regard to the questions relating to dynamical times, nuclear dissipation and the effect of nuclear dissipation on the K-distributions at the fission saddle in completely equilibrated compound nucleus. (author). 19 refs., 9 figs

Maintenance of fission and fusion reactors. 10. workshop on fusion reactor engineering

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-02-01

This report contains copies of OHP presented at the title meeting. The presented topics are as follows, maintenance of nuclear power plants and ITER, exchange of shroud in BWR type reactors, deterioration of fission and fusion reactor materials, standards of pressure vessels, malfunction diagnosis method with neural network. (J.P.N.)

Mirror hybrid (fusion--fission) reactor

International Nuclear Information System (INIS)

Bender, D.J.; Lee, J.D.; Neef, W.S.; Devoto, R.S.; Galloway, T.R.; Fink, J.H.; Schultz, K.R.; Culver, D.; Rao, S.

1977-10-01

The reference mirror hybrid reactor design performed by LLL and General Atomic is summarized. The reactor parameters have been chosen to minimize the cost of producing fissile fuel for consumption in fission power reactors. As in the past, we have emphasized the use of existing technology where possible and a minimum extrapolation of technology otherwise. The resulting reactor may thus be viewed as a comparatively near-term goal of the fusion program, and we project improved performance for the hybrid in the future as more advanced technology becomes available

Remarks on the fission barriers of super-heavy nuclei

Energy Technology Data Exchange (ETDEWEB)

Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Goethe-Universitaet Frankfurt, Institut fuer Physik, Frankfurt (Germany); Heinz, S.; Mann, R.; Maurer, J.; Muenzenberg, G.; Barth, W.; Dahl, L.; Kindler, B.; Kojouharov, I.; Lang, R.; Lommel, B.; Runke, J.; Scheidenberger, C.; Tinschert, K. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Antalic, S. [Comenius University, Department of Nuclear Physics and Biophysics, Bratislava (Slovakia); Eberhardt, K.; Thoerle-Pospiech, P.; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz (Germany); Grzywacz, R. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States); Hamilton, J.H. [Vanderbilt University, Department of Physics and Astronomy, Nashville, TN (United States); Henderson, R.A.; Kenneally, J.M.; Moody, K.J.; Shaughnessy, D.A.; Stoyer, M.A. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Miernik, K. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); University of Warsaw, Warsaw (Poland); Miller, D. [University of Tennessee, Knoxville, TN (United States); Morita, K. [RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama (Japan); Nishio, K. [Japan Atomic Energy Agency, Tokai, Ibaraki (Japan); Popeko, A.G.; Yeremin, A.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Roberto, J.B.; Rykaczewski, K.P. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Uusitalo, J. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland)

2016-04-15

Shell-correction energies of super-heavy nuclei are approximated by using Q{sub α} values of measured decay chains. Five decay chains were analyzed, which start at the isotopes {sup 285}Fl, {sup 294}118, {sup 291}Lv, {sup 292}Lv and {sup 293}Lv. The data are compared with predictions of macroscopic-microscopic models. Fission barriers are estimated that can be used to eliminate uncertainties in partial fission half-lives and in calculations of evaporation-residue cross-sections. In that calculations, fission probability of the compound nucleus is a major factor contributing to the total cross-section. The data also provide constraints on the cross-sections of capture and quasi-fission in the entrance channel of the fusion reaction. Arguments are presented that fusion reactions for synthesis of isotopes of elements 118 and 120 may have higher cross-sections than assumed so far. (orig.)

Environmental life cycle assessment of high temperature nuclear fission and fusion biomass gasification plants

International Nuclear Information System (INIS)

Takeda, Shutaro; Sakurai, Shigeki; Kasada, Ryuta; Konishi, Satoshi

2017-01-01

The authors propose nuclear biomass gasification plant as an advancement of conventional gasification plants. Environmental impacts of both fission and fusion plants were assessed through life cycle assessment. The result suggested the reduction of green-house gas emissions would be as large as 85.9% from conventional plants, showing a potential for the sustainable future for both fission and fusion plants. (author)

Brief review of the fusion-fission hybrid reactor

International Nuclear Information System (INIS)

Tenney, F.H.

1977-01-01

Much of the conceptual framework of present day fusion-fission hybrid reactors is found in the original work of the early 1950's. Present day motivations for development are quite different. The role of the hybrid reactor is discussed as well as the current activities in the development program

Fission, fusion and the energy crisis

Energy Technology Data Exchange (ETDEWEB)

Hunt, S E [Aston Univ., Birmingham (UK)

1980-01-01

The subject is covered in chapters, entitled: living on capital (energy reserves and consumption forecasts); the atom and its nucleus, mass and energy; fission and the bomb; the natural uranium reactor; enriched reactors; control and safety; long-term economics (the breeder reactions and nuclear fuel reserves); short-term economics (cost per kilowatt hour); national nuclear power programmes; nuclear power and the environment (including reprocessing, radioactive waste management, public relations); renewable energy sources; the fusion programme; summary and comment.

Conceptual design of a fusion-fission hybrid reactor for transmutation of high level nuclear waste

International Nuclear Information System (INIS)

Qiu, L.J.; Wu, Y.C.; Yang, Y.W.; Wu, Y.; Luan, G.S.; Xu, Q.; Guo, Z.J.; Xiao, B.J.

1994-01-01

To assess the feasibility of the transmutation of long-lived radioactive waste using fusion-fission hybrid reactors, we are studying all the possible types of blanket, including a comparison of the thermal and fast neutron spectrum blankets. Conceptual designs of a small tokamak hybrid blanket with small inventory of actinides and fission products are presented. The small inventory of wastes makes the system safer. The small hybrid reactor system based on a fusion core with experimental parameters to be realized in the near future can effectively transmute actinides and fission products at a neutron wall loading of 1MWm -2 . An innovative energy system is also presented, including a fusion driver, fuel breeder, high level waste transmuter, fission reactor and so on. An optimal combination of all types of reactor is proposed in the system. ((orig.))

HYPERFUSE: a hypervelocity inertial confinement system for fusion energy production and fission waste transmutation

International Nuclear Information System (INIS)

Makowitz, H.; Powell, J.R.; Wiswall, R.

1980-01-01

Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from a LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs, 90 Sr, 129 I, 99 Tc, etc. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n,2n), (n,α), (n,γ), etc.) that convert the long-lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product. The transmutation parametric studies conclude that the design of the hypervelocity projectiles should emphasize the achievement of high densities in the transmutation regions (greater than the DT fusion fuel density), as well as the DT ignition and burn criterion (rho R = 1.0 to 3.0) requirements. These studies also indicate that masses on the order of 1.0 g at densities of rho greater than or equal to 500.0 g/cm 3 are required for a practical fusion-based fission product transmutation system

Tunneling process in heavy-ion fusion and fission

Energy Technology Data Exchange (ETDEWEB)

Iwamoto, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kondratyev, V.; Bonasera, A.

1998-10-01

We present a model towards the many-body description of sub-barrier fusion and spontaneous fission based on the semiclassical Vlasov equation and the Feynman path integral method. We define suitable collective variables from the Vlasov solution and use the imaginary time technique for the dynamics below the Coulomb barrier. (author)

Utility market penetration assessment of fusion-fission hybrids

International Nuclear Information System (INIS)

Jensen, B.K.; Nour, N.E.; Piascik, T.M.

1981-01-01

The objective of this paper is to describe the utility generation expansion evaluation procedure and to present the results of a fusion-fission hybrid market penetration assessment in a model of a typical utility system. The analysis addresses the key factors and tradeoffs affecting the utility's evaluation of generation alternatives

Consultancy on the potential of fusion/fission sub-critical neutron systems for energy production and transmutation. Working material

International Nuclear Information System (INIS)

2005-01-01

The Workshop on Sub-critical Neutron Production held at the University of Maryland and the Eisenhower Institute on 11-13 October 2004 brought together members of fusion, fission and accelerator technical communities to discuss issues of spent fuel, nonproliferation, reactor safety and the use of neutrons for sub-critical operation of nuclear reactors. The Workshop strongly recommended that the fusion community work closely with other technical communities to ensure that a wider range of technical solutions is available to solve the spent fuel problem and to utilize the current actinide inventories. Participants of the Workshop recommended that a follow-on Workshop, possibly under the aegis of the IAEA, should be held in the first half of the year 2005. The Consultancy Meeting is the response to this recommendation. The objectives of the Consultancy meeting were to hold discussions on the role of fusion/fission systems in sub-critical operations of nuclear reactors. The participants agreed that development of innovative (fourth generation) fission reactors, advanced fuel cycle options, and disposition of existing spent nuclear fuel inventories in various Member Sates can significantly benefit from including sub-critical systems, which are driven by external neutron sources. Spallation neutrons produced by accelerators have been accepted in the past as the means of driving sub-critical reactors. The accelerator community deserves credit in pioneering this novel approach to reactor design. Progress in the design and operation of fusion devices now offers additional innovative means, broadening the range of sub-critical operations of fission reactors. Participants felt that fusion should participate with accelerators in providing a range of technical options in reactor design. Participants discussed concrete steps to set up a small fusion/fission system to demonstrate actinide burning in the laboratory and what advice should be given to the Agency on its role in

Neutron cross sections for fusion

International Nuclear Information System (INIS)

Haight, R.C.

1979-10-01

First generation fusion reactors will most likely be based on the 3 H(d,n) 4 He reaction, which produces 14-MeV neutrons. In these reactors, both the number of neutrons and the average neutron energy will be significantly higher than for fission reactors of the same power. Accurate neutron cross section data are therefore of great importance. They are needed in present conceptual designs to calculate neutron transport, energy deposition, nuclear transmutation including tritium breeding and activation, and radiation damage. They are also needed for the interpretation of radiation damage experiments, some of which use neutrons up to 40 MeV. In addition, certain diagnostic measurements of plasma experiments require nuclear cross sections. The quality of currently available data for these applications will be reviewed and current experimental programs will be outlined. The utility of nuclear models to provide these data also will be discussed. 65 references

Fission cross sections in the intermediate energy region

International Nuclear Information System (INIS)

Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J.; Carlson, A.D.; Wasson, O.A.; Hill, N.W.

1991-01-01

Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for 235 U and 238 U compared to intranuclear cascade and statistical model predictions

Fission cross sections in the intermediate energy region

Energy Technology Data Exchange (ETDEWEB)

Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J. (Los Alamos National Lab., NM (USA)); Carlson, A.D.; Wasson, O.A. (National Inst. of Standards and Technology, Gaithersburg, MD (USA)); Hill, N.W. (Oak Ridge National Lab., TN (USA))

1991-01-01

Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for {sup 235}U and {sup 238}U compared to intranuclear cascade and statistical model predictions.

A comparison of microstructures in copper irradiated with fission, fusion, and spallation neutrons

International Nuclear Information System (INIS)

Muroga, T.; Heinisch, H.L.; Sommer, W.F.; Ferguson, P.D.

1992-01-01

The objective of this work is to investigate the effects of the neutron energy spectrum in low dose irradiations on the microstructure and mechanical properties of metals. The microstructures of pure copper irradiated to low doses at 36-90 C with spallation neutrons, fusion neutrons and fission neutrons are compared. The defect cluster densities for the spallation and fusion neutrons are very similar when compared on the basis of displacements per atom (dpa). In both cases, the density increases in proportion to the square root of the dpa. The difference in defect density between fusion neutrons and fission neutrons corresponds with differences observed in data on yield stress changes

The Radiological and Thermal Characteristics of Fission Waste from a Deep-Burn Fusion-Fission Hybrid (LIFE) and Implications for Repository Performance

International Nuclear Information System (INIS)

Shaw, H.F.; Blink, J.; Farmer, J.; Latkowski, J.; Kramer, K.

2009-01-01

We are studying the use of a Laser Inertial-confinement Fusion Engine (LIFE) to drive a hybrid fusion-fission system that can generate electrical power and/or burn nuclear waste. The system uses the neutrons from laser driven ICF to produce tritium and to drive nuclear reactions in a subcritical fission blanket. The fusion neutron source obviates the need for a self-sustaining chain reaction in the fission blanket. Either fissile or fertile could be used as fission fuel, thus eliminating the need for isotopic enrichment. The 'driven' system potentially allows very high levels of burnup to be reached, extracting a large fraction of the available energy in the fission fuel without the need for reprocessing. In this note, we discuss the radionuclide inventory of a depleted uranium (DU) fuel burned to greater than 95% FIMA (Fissions per Initial heavy Metal Atom), the implications for thermal management of the resulting waste, and the implications of this waste for meeting the dose standards for releases from a geological repository for high-level waste. The fission waste discussed here would be that produced by a LIFE hybrid with a 500-MW fusion source. The fusion neutrons are multiplied and moderated by a sequence of concentric shells of materials before encountering the fission fuel, and fission in this region is largely due to thermal neutrons. The fission blanket consists of 40 metric tons (MT) of DU, assumed to be in the form of TRISO-like UOC fuel particles embedded in 2-cm-diameter graphite pebbles. (It is recognized that TRISO-based fuel may not reach the high burnup of the fertile fuel considered here, and other fuel options are being investigated. We postulate the existence of a fuel that can reach >95% FIMA so that the waste disposal implications of high burnup can be assessed.) The engine and plant design considered here would receive one load of fission fuel and produce ∼2 GWt of power (fusion + fission) over its 50- to 70-year lifetime. Neutron and

Scoping studies of 233U breeding fusion fission hybrid

International Nuclear Information System (INIS)

Maniscalco, J.A.; Hansen, L.F.; Allen, W.O.

1978-05-01

Neutronic calculations have been carried out in order to design a laser fusion driven hybrid blanket which maximizes 233 U production per unit of thermal energy (greater than or equal to 1 kg/MW/sub T/-year) with acceptable fusion energy multiplication (M/sub F/ approximately 4). Two hybrid blankets, a thorium and a uranium-thorium blanket, are discussed in detail and their performance is evaluated by incorporating them into an existing hybrid design (the LLL/Bechtel design). The overall performance of the two laser fusion driven 233 U producers is discussed and estimates are given of (1) the number of equivalent thermal power fission reactors (LWR, HWR, SSCR and HTGR) that these fusion breeders can fuel, (2) their capital cost, and (3) the cost of electricity in the combined fusion breder-converter reactor scenario

Scoping studies of 233U breeding fusion fission hybrid

International Nuclear Information System (INIS)

Maniscalco, J.A.; Hansen, L.F.; Allen, W.O.

1978-01-01

Neutronic calculations have been carried out in order to design a laser fusion driven hybrid blanket which maximizes 233 U production per unit of thermal energy (greater than or equal to 1 kg/MW/sub T/-year) with acceptable fusion energy multiplication (M/sub F/ approx. 4). Two hybrid blankets, a thorium and a uranium--thorium blanket, are discussed in detail and their performance is evaluated by incorporating them into an existing hybrid design (the LLL/Bechtel design). The overall performance of the two laser fusion driven 233 U producers is discussed and estimates are given of (1) the number of equivalent thermal power fission reactors (LWR, HWR, SSCR and HTGR) that these fusion breeders can fuel, (2) their capital cost, and (3) the cost of electricity in the combined fusion breeder-converter reactor scenario

Neutron irradiation facilities for fission and fusion reactor materials studies

International Nuclear Information System (INIS)

Rowcliffe, A.F.

1985-01-01

The successful development of energy-conversion machines based upon nuclear fission or fusion reactors is critically dependent upon the behavior of the engineering materials used to construct the full containment and primary heat extraction systems. The development of radiation damage-resistant materials requires irradiation testing facilities which reproduce, as closely as possible, the thermal and neutronic environment expected in a power-producing reactor. The Oak Ridge National Laboratory (ORNL) reference core design for the Center for Neutron Research (CNR) reactor provides for instrumented facilities in regions of both hard and mixed neutron spectra, with substantially higher fluxes than are currently available. The benefits of these new facilities to the development of radiation damage resistant materials are discussed in terms of the major US fission and fusion reactor programs

Materials compatibility considerations for a fusion-fission hybrid reactor design

International Nuclear Information System (INIS)

DeVan, J.H.; Tortorelli, P.F.

1983-01-01

The Tandem Mirror Hybrid Reactor is a fusion reactor concept that incorporates a fission-suppressed breeding blanket for the production of 233 U to be used in conventional fission power reactors. The present paper reports on compatibility considerations related to the blanket design. These considerations include solid-solid interactions and liquid metal corrosion. Potential problems are discussed relative to the reference blanket operating temperature (490 0 C) and the recycling time of breeding materials (<1 year)

Determination of procedures for transmutation of fission product wastes by fusion neutrons. Volume 2. Final report

International Nuclear Information System (INIS)

Lang, G.P.

1980-12-01

This study is concerned with the engineering aspects of the transmutation of fission products utilizing neutrons generated in fusion reactors. It is assumed that fusion reactors, although not yet developed, will be available around the turn of the century. Therefore, early studies of this type are appropriate as a guide to the large amount of further investigations that will be needed to fully evaluate this concept. Not all of the radioactive products from light water reactors can be economically transmuted, but it appears that the most hazardous can. This requires that fission-product wastes must first be separated into a number of fractions, and in some instances this must be accomplished with extremely high separation factors. A review of current commercial separation processes and of promising methods that are now in the laboratory stage indicate that the necessary processes can most likely be developed but will require an active and sustained development program. Current fusion reactor concepts were examined as to their suitability for transmuting the separated fission wastes. It was concluded that the long-lived fission products were most amenable to transmutation. The medium-lived fission products, Cs-137 and Sr-90, require higher neutron fluxes than are available in the most developed fusion reactor concepts. Concepts which are less developed may eventually be adaptable as transmuters of these fission products

Neutron transport-burnup code MCORGS and its application in fusion fission hybrid blanket conceptual research

Science.gov (United States)

Shi, Xue-Ming; Peng, Xian-Jue

2016-09-01

Fusion science and technology has made progress in the last decades. However, commercialization of fusion reactors still faces challenges relating to higher fusion energy gain, irradiation-resistant material, and tritium self-sufficiency. Fusion Fission Hybrid Reactors (FFHR) can be introduced to accelerate the early application of fusion energy. Traditionally, FFHRs have been classified as either breeders or transmuters. Both need partition of plutonium from spent fuel, which will pose nuclear proliferation risks. A conceptual design of a Fusion Fission Hybrid Reactor for Energy (FFHR-E), which can make full use of natural uranium with lower nuclear proliferation risk, is presented. The fusion core parameters are similar to those of the International Thermonuclear Experimental Reactor. An alloy of natural uranium and zirconium is adopted in the fission blanket, which is cooled by light water. In order to model blanket burnup problems, a linkage code MCORGS, which couples MCNP4B and ORIGEN-S, is developed and validated through several typical benchmarks. The average blanket energy Multiplication and Tritium Breeding Ratio can be maintained at 10 and 1.15 respectively over tens of years of continuous irradiation. If simple reprocessing without separation of plutonium from uranium is adopted every few years, FFHR-E can achieve better neutronic performance. MCORGS has also been used to analyze the ultra-deep burnup model of Laser Inertial Confinement Fusion Fission Energy (LIFE) from LLNL, and a new blanket design that uses Pb instead of Be as the neutron multiplier is proposed. In addition, MCORGS has been used to simulate the fluid transmuter model of the In-Zinerater from Sandia. A brief comparison of LIFE, In-Zinerater, and FFHR-E will be given.

Multispecies exclusion process with fusion and fission of rods: A model inspired by intraflagellar transport

Science.gov (United States)

Patra, Swayamshree; Chowdhury, Debashish

2018-01-01

We introduce a multispecies exclusion model where length-conserving probabilistic fusion and fission of the hard rods are allowed. Although all rods enter the system with the same initial length ℓ =1 , their length can keep changing, because of fusion and fission, as they move in a step-by-step manner towards the exit. Two neighboring hard rods of lengths ℓ1 and ℓ2 can fuse into a single rod of longer length ℓ =ℓ1+ℓ2 provided ℓ ≤N . Similarly, length-conserving fission of a rod of length ℓ'≤N results in two shorter daughter rods. Based on the extremum current hypothesis, we plot the phase diagram of the model under open boundary conditions utilizing the results derived for the same model under periodic boundary condition using mean-field approximation. The density profile and the flux profile of rods are in excellent agreement with computer simulations. Although the fusion and fission of the rods are motivated by similar phenomena observed in intraflagellar transport (IFT) in eukaryotic flagella, this exclusion model is too simple to account for the quantitative experimental data for any specific organism. Nevertheless, the concepts of "flux profile" and "transition zone" that emerge from the interplay of fusion and fission in this model are likely to have important implications for IFT and for other similar transport phenomena in long cell protrusions.

FORIG: a computer code for calculating radionuclide generation and depletion in fusion and fission reactors. User's manual

International Nuclear Information System (INIS)

Blink, J.A.

1985-03-01

In this manual we describe the use of the FORIG computer code to solve isotope-generation and depletion problems in fusion and fission reactors. FORIG runs on a Cray-1 computer and accepts more extensive activation cross sections than ORIGEN2 from which it was adapted. This report is an updated and a combined version of the previous ORIGEN2 and FORIG manuals. 7 refs., 15 figs., 13 tabs

Hefei experimental hybrid fusion-fission reactor conceptual design

International Nuclear Information System (INIS)

Qiu Lijian; Luan Guishi; Xu Qiang

1992-03-01

A new concept of hybrid reactor is introduced. It uses JET-like(Joint European Tokamak) device worked at sub-breakeven conditions, as a source of high energy neutrons to induce a blanket fission of depleted uranium. The solid breeding material and helium cooling technique are also used. It can produce 100 kg of 239 Pu per year by partial fission suppressed. The energy self-sustained of the fusion core is not necessary. Plasma temperature is maintained by external 20 MW ICRF (ion cyclotron resonance frequency) and 10 MW ECRF (electron cyclotron resonance frequency) heating. A steady state plasma current at 1.5 Ma is driven by 10 MW LHCD (lower hybrid current driven). Plasma density will be kept by pellet injection. ICRF can produce a high energy tail in ion distribution function and lead to significant enhancement of D-T reaction rate by 2 ∼ 5 times so that the neutron source strength reaches to the level of 1 x 10 19 n/s. This system is a passive system. It's power density is 10 W/cm 3 and the wall loading is 0.6 W/cm 2 that is the lower limitation of fusion and fission technology. From the calculation of neutrons it could always be in sub-critical and has intrinsic safety. The radiation damage and neutron flux distribution on the first wall are also analyzed. According to the conceptual design the application of this type hybrid reactor earlier is feasible

Simultaneous fitting of statistical-model parameters to symmetric and asymmetric fission cross sections

International Nuclear Information System (INIS)

Mancusi, D; Charity, R J; Cugnon, J

2013-01-01

The de-excitation of compound nuclei has been successfully described for several decades by means of statistical models. However, accurate predictions require some fine-tuning of the model parameters. This task can be simplified by studying several entrance channels, which populate different regions of the parameter space of the compound nucleus. Fusion reactions play an important role in this strategy because they minimise the uncertainty on the entrance channel by fixing mass, charge and excitation energy of the compound nucleus. If incomplete fusion is negligible, the only uncertainty on the compound nucleus comes from the spin distribution. However, some de-excitation channels, such as fission, are quite sensitive to spin. Other entrance channels can then be used to discriminate between equivalent parameter sets. The focus of this work is on fission and intermediate-mass-fragment emission cross sections of compound nuclei with 70 70 ≲ A ≲ 240. 240. The statistical de-excitation model is GEMINI++. The choice of the observables is natural in the framework of GEMINI++, which describes fragment emission using a fissionlike formalism. Equivalent parameter sets for fusion reactions can be resolved using the spallation entrance channel. This promising strategy can lead to the identification of a minimal set of physical ingredients necessary for a unified quantitative description of nuclear de-excitation.

Evaluation of DD and DT fusion fuel cycles for different fusion-fission energy systems

International Nuclear Information System (INIS)

Gohar, Y.

1980-01-01

A study has been carried out in order to investigate the characteristics of an energy system to produce a new source of fissile fuel for existing fission reactors. The denatured fuel cycles were used because it gives additional proliferation resistance compared to other fuel cycles. DT and DD fusion drivers were examined in this study with a thorium or uranium blanket for each fusion driver. Various fuel cycles were studied for light-water and heavy-water reactors. The cost of electricity for each energy system was calculated

Physical Investigation for Neutron Consumption and Multiplication in Blanket Module of Fusion-Fission Hybrid Reactor

International Nuclear Information System (INIS)

Tariq Siddique, M.; Kim, Myung Hyun

2014-01-01

Fusion-fission hybrid reactor can be the first milestone of fusion technology and achievable in near future. It can provide operational experience for tritium recycling for pure fusion reactor and be used for incineration of high-level long-lived waste isotopes from existing fission power reactors. Hybrid reactor for waste transmutation (Hyb-WT) was designed and optimized to assess its otential for waste transmutation. ITER will be the first large scaled experimental tokamak facility for the testing of test blanket modules (TBM) which will layout the foundation for DEMO fusion power plants. Similarly hybrid test blanket module (HTBM) will be the foundation for rationality of fusion fission hybrid reactors. Designing and testing of hybrid blankets will lead to another prospect of nuclear technology. This study is initiated with a preliminary design concept of a hybrid test blanket module (HTBM) which would be tested in ITER. The neutrons generated in D-T fusion plasma are of high energy, 14.1 MeV which could be multiplied significantly through inelastic scattering along with fission in HTBM. In current study the detailed neutronic analysis is performed for the blanket module which involves the neutron growth and loss distribution within blanket module with the choice of different fuel and coolant materials. TRU transmutation and tritium breeding performance of HTBM is analyzed under ITER irradiation environment for five different fuel types and with Li and LiPb coolants. Simple box geometry with plate type TRU fuel is adopted so that it can be modelled with heterogeneous material geometry in MCNPX. Waste transmutation ratio (WTR) of TRUs and tritium breeding ration (TBR) is computed to quantify the HTBM performance. Neutron balance is computed in detail to analyze the performance parameters of HTBM. Neutron spectrum and fission to capture ratio in TRU fuel types is also calculated for detailed analysis of HTBM

Physical Investigation for Neutron Consumption and Multiplication in Blanket Module of Fusion-Fission Hybrid Reactor

Energy Technology Data Exchange (ETDEWEB)

Tariq Siddique, M.; Kim, Myung Hyun [Kyung Hee Univ., Yongin (Korea, Republic of)

2014-05-15

Fusion-fission hybrid reactor can be the first milestone of fusion technology and achievable in near future. It can provide operational experience for tritium recycling for pure fusion reactor and be used for incineration of high-level long-lived waste isotopes from existing fission power reactors. Hybrid reactor for waste transmutation (Hyb-WT) was designed and optimized to assess its otential for waste transmutation. ITER will be the first large scaled experimental tokamak facility for the testing of test blanket modules (TBM) which will layout the foundation for DEMO fusion power plants. Similarly hybrid test blanket module (HTBM) will be the foundation for rationality of fusion fission hybrid reactors. Designing and testing of hybrid blankets will lead to another prospect of nuclear technology. This study is initiated with a preliminary design concept of a hybrid test blanket module (HTBM) which would be tested in ITER. The neutrons generated in D-T fusion plasma are of high energy, 14.1 MeV which could be multiplied significantly through inelastic scattering along with fission in HTBM. In current study the detailed neutronic analysis is performed for the blanket module which involves the neutron growth and loss distribution within blanket module with the choice of different fuel and coolant materials. TRU transmutation and tritium breeding performance of HTBM is analyzed under ITER irradiation environment for five different fuel types and with Li and LiPb coolants. Simple box geometry with plate type TRU fuel is adopted so that it can be modelled with heterogeneous material geometry in MCNPX. Waste transmutation ratio (WTR) of TRUs and tritium breeding ration (TBR) is computed to quantify the HTBM performance. Neutron balance is computed in detail to analyze the performance parameters of HTBM. Neutron spectrum and fission to capture ratio in TRU fuel types is also calculated for detailed analysis of HTBM.

Nuclear fission and neutron-induced fission cross-sections

CERN Document Server

James, G D; Michaudon, A; Michaudon, A; Cierjacks, S W; Chrien, R E

2013-01-01

Nuclear Fission and Neutron-Induced Fission Cross-Sections is the first volume in a series on Neutron Physics and Nuclear Data in Science and Technology. This volume serves the purpose of providing a thorough description of the many facets of neutron physics in different fields of nuclear applications. This book also attempts to bridge the communication gap between experts involved in the experimental and theoretical studies of nuclear properties and those involved in the technological applications of nuclear data. This publication will be invaluable to those interested in studying nuclear fis

Nuclear data for structural materials of fission and fusion reactors

International Nuclear Information System (INIS)

Goulo, V.

1989-06-01

The document presents the status of nuclear reaction theory concerning optical model development, level density models and pre-equilibrium and direct processes used in calculation of neutron nuclear data for structural materials of fission and fusion reactors. 6 refs

Review of Battelle-Northwest technical studies on fusion--fission (hybrid) energy systems

International Nuclear Information System (INIS)

Liikala, R.C.; Leonard, B.R. Jr.; Wolkenhauer, W.C.; Aase, D.T.

1974-01-01

A variety of studies conducted over the past few years and the principal results of these studies are summarized. Studies of power producing hybrids, the use of fusion neutrons for transmutation of radioactive wastes, and the evaluation of the most likely combinations of fusion and fission technologies are discussed. (U.S.)

Fission cross section measurements of actinides at LANSCE

Energy Technology Data Exchange (ETDEWEB)

Tovesson, Fredrik [Los Alamos National Laboratory; Laptev, Alexander B [Los Alamos National Laboratory; Hill, Tony S [INL

2010-01-01

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

HYPERFUSE: a hypervelocity inertial confinement system for fusion energy production and fission waste transmutation

International Nuclear Information System (INIS)

Makowitz, H.; Powell, J.R.; Wiswall, R.

1980-01-01

Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs, 90 Sr, 129 I, 99 Tc, etc. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n,2n), (n,α), (n,γ), etc.) that convert the long-lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product. The transmutation parametric studies conclude that the design of the hypervelocity projectiles should emphasize the achievement of high densities in the transmutation regions (greater than the DT fusion fuel density), as well as the DT ignition and burn criterion (rho R=1.0 to 3.0) requirements

Review of ENDF/B-VI Fission-Product Cross Section

Energy Technology Data Exchange (ETDEWEB)

Wright, R.Q.

1999-01-01

In response to concerns raised in the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 93-2, the U.S. Department of Energy (DOE) developed a comprehensive program to help assure that the DOE maintain and enhance its capability to predict the criticality of systems throughout the complex. Tasks developed to implement the response to DNFSB recommendation 93-2 included Critical Experiments, Criticality Benchmarks, Training, Analytical Methods, and Nuclear Data. The Nuclear Data Task consists of a program of differential measurements at the Oak Ridge Electron Linear Accelerator (ORELA), precise fitting of the differential data with the generalized least-squares fitting code SAMMY to represent the data with resonance parameters using the Reich-Moore formalism along with covariance (uncertainty) information, and the development of complete evaluations for selected nuclides for inclusion in the Evaluated Nuclear Data File (ENDFB). The current ENDF/B library was developed for fast and thermal fission reactors and fusion reactors. Criticality safety practitioners recognize that many situations around the DOE complex are characterized by neutron spectra in the intermediate-energy region, as opposed to the high-energy region for fast reactors and fusion systems and the low-energy region for thermal reactors. Consequently, the Nuclear Data Task focuses primarily on the intermediate-energy region so that upgrades to existing evaluated data will remove deficiencies in the current ENDF/B evaluations. The ORELA allows high-resolution measurements in the intermediate-energy region and the SAMMY fitting code provides high quality resonance parameters in the resolved and unresolved energy range using the sophisticated Reich-Moore (RM) formalism for superior representation of the data in the intermediate energy region. In addition, the SAMMY fitting procedure provides covariance information for the resonance parameters that can be used in subsequent analyses to assess

AUS, Neutron Transport and Gamma Transport System for Fission Reactors and Fusion Reactors

International Nuclear Information System (INIS)

1990-01-01

1 - Description of program or function: AUS is a neutronics code system which may be used for calculations of a wide range of fission reactors, fusion blankets and other neutron applications. The present version, AUS98, has a nuclear cross section library based on ENDF/B-VI and includes modules which provide for reactor lattice calculations, one-dimensional transport calculations, multi-dimensional diffusion calculations, cell and whole reactor burnup calculations, and flexible editing of results. Calculations of multi-region resonance shielding, coupled neutron and photon transport, energy deposition, fission product inventory and neutron diffusion are combined within the one code system. The major changes from the previous release, AUS87, are the inclusion of a cross-section library based on ENDF/B-VI, the addition of the POW3D multi-dimensional diffusion module, the addition of the MICBURN module for controlling whole reactor burnup calculations, and changes to the system as a consequence of moving from IBM mainframe computers to UNIX workstations. 2 - Method of solution: AUS98 is a modular system in which the modules are complete programs linked by a path given in the input stream. A simple path is simply a sequence of modules, but the path is actually pre-processed and compiled using the Fortran 77 compiler. This provides for complex module linking if required. Some of the modules included in AUS98 are: MIRANDA Cross-section generation in a multi-region resonance subgroup calculation and preliminary group condensation. ANAUSN One-dimensional discrete ordinates calculation. ICPP Isotropic collision probability calculation in one dimension and for rod clusters. POW3D Multi-dimensional neutron diffusion calculation including feedback-free kinetics. AUSIDD One-dimensional diffusion calculation. EDITAR Reaction-rate editing and group collapsing following a transport calculation. CHAR Lattice and global burnup calculation. MICBURN Control of global burnup

Advantages of Production of New Fissionable Nuclides for the Nuclear Power Industry in Hybrid Fusion-Fission Reactors

Science.gov (United States)

Tsibulskiy, V. F.; Andrianova, E. A.; Davidenko, V. D.; Rodionova, E. V.; Tsibulskiy, S. V.

2017-12-01

A concept of a large-scale nuclear power engineering system equipped with fusion and fission reactors is presented. The reactors have a joint fuel cycle, which imposes the lowest risk of the radiation impact on the environment. The formation of such a system is considered within the framework of the evolution of the current nuclear power industry with the dominance of thermal reactors, gradual transition to the thorium fuel cycle, and integration into the system of the hybrid fusion-fission reactors for breeding nuclear fuel for fission reactors. Such evolution of the nuclear power engineering system will allow preservation of the existing structure with the dominance of thermal reactors, enable the reprocessing of the spent nuclear fuel (SNF) with low burnup, and prevent the dangerous accumulation of minor actinides. The proposed structure of the nuclear power engineering system minimizes the risk of radioactive contamination of the environment and the SNF reprocessing facilities, decreasing it by more than one order of magnitude in comparison with the proposed scheme of closing the uranium-plutonium fuel cycle based on the reprocessing of SNF with high burnup from fast reactors.

Conceptual design of a fission-based integrated test facility for fusion reactor components

International Nuclear Information System (INIS)

Watts, K.D.; Deis, G.A.; Hsu, P.Y.S.; Longhurst, G.R.; Masson, L.S.; Miller, L.G.

1982-01-01

The testing of fusion materials and components in fission reactors will become increasingly important because of lack of fusion engineering test devices in the immediate future and the increasing long-term demand for fusion testing when a fusion reactor test station becomes available. This paper presents the conceptual design of a fission-based Integrated Test Facility (ITF) developed by EG and G Idaho. This facility can accommodate entire first wall/blanket (FW/B) test modules such as those proposed for INTOR and can also accommodate smaller cylindrical modules similar to those designed by Oak Ridge National laboratory (ORNL) and Westinghouse. In addition, the facility can be used to test bulk breeder blanket materials, materials for tritium permeation, and components for performance in a nuclear environment. The ITF provides a cyclic neutron/gamma flux as well as the numerous module and experiment support functions required for truly integrated tests

238U subthreshold neutron induced fission cross section

International Nuclear Information System (INIS)

Difilippo, F.C.; Perez, R.B.; De Saussure, G.; Olsen, D.K.; Ingle, R.W.

1976-01-01

High resolution measurements of the 238 U neutron induced fission cross section are reported for neutron energies between 600 eV and 2 MeV. The average subthreshold fission cross section between 10 and 100 keV was found to be 44 +- 6 μb

Thermal safety analysis for pebble bed blanket fusion-fission hybrid reactor

International Nuclear Information System (INIS)

Wei Renjie

1998-01-01

Pebble bed blanket hybrid reactor may have more advantages than slab element blanket hybrid reactor in nuclear fuel production and nuclear safety. The thermo-hydraulic calculations of the blanket in the Tokamak helium cooling pebble bed blanket fusion-fission hybrid reactor developed in China are carried out using the Code THERMIX and auxiliary code. In the calculations different fuel pebble material and steady state, depressurization and total loss of flow accident conditions are included. The results demonstrate that the conceptual design of the Tokamak helium cooling pebble bed blanket fusion-fission hybrid reactor with dump tank is feasible and safe enough only if the suitable fuel pebble material is selected and the suitable control system and protection system are established. Some recommendations for due conceptual design are also presented

Systems Modeling For The Laser Fusion-Fission Energy (LIFE) Power Plant

International Nuclear Information System (INIS)

Meier, W.R.; Abbott, R.; Beach, R.; Blink, J.; Caird, J.; Erlandson, A.; Farmer, J.; Halsey, W.; Ladran, T.; Latkowski, J.; MacIntyre, A.; Miles, R.; Storm, E.

2008-01-01

A systems model has been developed for the Laser Inertial Fusion-Fission Energy (LIFE) power plant. It combines cost-performance scaling models for the major subsystems of the plant including the laser, inertial fusion target factory, engine (i.e., the chamber including the fission and tritium breeding blankets), energy conversion systems and balance of plant. The LIFE plant model is being used to evaluate design trade-offs and to identify high-leverage R and D. At this point, we are focused more on doing self consistent design trades and optimization as opposed to trying to predict a cost of electricity with a high degree of certainty. Key results show the advantage of large scale (>1000 MWe) plants and the importance of minimizing the cost of diodes and balance of plant cost

Measurement of MA fission cross sections at YAYOI

Energy Technology Data Exchange (ETDEWEB)

Ohkawachi, Yasushi; Ohki, Shigeo; Wakabayashi, Toshio [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

1998-03-01

Fission cross section ratios of minor actinide nuclides (Am-241, Am-243) relative to U-235 in the fast neutron energy region have been measured using a back-to-back (BTB) fission chamber at YAYOI fast neutron source reactor. A small BTB fission chamber was developed to measure the fission cross section ratios in the center of the core at YAYOI reactor. Dependence of the fission cross section ratios on neutron spectra was investigated by changing the position of the detector in the reactor core. The measurement results were compared with the fission cross sections in the JENDL-3.2, ENDF/B-VI and JEF-2.2 libraries. It was found that calculated values of Am-241 using the JENDL-3.2, ENDF/B-VI and JEF-2.2 data are lower by about 15% than the measured value in the center of the core (the neutron average energy is 1.44E+6(eV)). And, good agreement can be seen the measured value and calculated value of Am-243 using the JENDL-3.2 data in the center of the core (the neutron average energy is 1.44E+6)(eV), but calculated values of Am-243 using the ENDF/B-VI and JEF-2.2 data are lower by 11% and 13% than the measured value. (author)

Technical issues for beryllium use in fusion blanket applications

International Nuclear Information System (INIS)

McCarville, T.J.; Berwald, D.H.; Wolfer, W.; Fulton, F.J.; Lee, J.D.; Maninger, R.C.; Moir, R.W.; Beeston, J.M.; Miller, L.G.

1985-01-01

Beryllium is an excellent non-fissioning neutron multiplier for fusion breeder and fusion electric blanket applications. This report is a compilation of information related to the use of beryllium with primary emphasis on the fusion breeder application. Beryllium resources, production, fabrication, properties, radiation damage and activation are discussed. A new theoretical model for beryllium swelling is presented

Storage and Containment of Nuclear Targets for Pulsed Fission-Fusion Testing

Data.gov (United States)

National Aeronautics and Space Administration — The combined fission-fusion fuel target is the heart of an engine concept that can open the solar system to fast and efficient human exploration. This is a unique...

Consultancy to review and finalize the IAEA publication 'Compendium on the use of fusion/fission hybrids for the utilization and transmutation of actinides and long-lived fission products'. Working material

International Nuclear Information System (INIS)

2004-01-01

In addition to the traditional fission reactor research, fusion R and D activities are becoming of interest also to nuclear fission power development. There is renewed interest in utilizing fusion neutrons, Heavy Liquid Metals, and molten salts for innovative systems (energy production and transmutation). Indeed, for nuclear power development to become sustainable as a long-term energy option, innovative fuel cycle and reactor technologies will have to be developed to solve the problems of resource utilization and long-lived radioactive waste management. In this context Member States clearly expressed the need for comparative assessments of various transmutation reactors. Both the fusion and fission communities are currently investigating the potential of innovative reactor and fuel cycle strategies that include a fusion/fission system. The attention is mainly focused on substantiating the potential advantages of such systems: utilization and transmutation of actinides and long-lived fission products, intrinsic safety features, enhanced proliferation resistance, and fuel breeding capabilities. An important aspect of the ongoing activities is the comparison with the accelerator driven subcritical system (spallation neutron source), which is the other main option for producing excess neutrons. Apart from comparative assessments, knowledge preservation is another subject of interest to the Member States: the goal, applied to fusion/fission systems, is to review the status of, and to produce a 'compendium' of past and present achievements in this area

Measurements of Fission Cross Sections of Actinides

CERN Multimedia

Wiescher, M; Cox, J; Dahlfors, M

2002-01-01

A measurement of the neutron induced fission cross sections of $^{237}$Np, $^{241},{243}$Am and of $^{245}$Cm is proposed for the n_TOF neutron beam. Two sets of fission detectors will be used: one based on PPAC counters and another based on a fast ionization chamber (FIC). A total of 5x10$^{18}$ protons are requested for the entire fission measurement campaign.

Neutron analysis of a hybrid system fusion-fission

International Nuclear Information System (INIS)

Dorantes C, J. J.; Francois L, J. L.

2011-11-01

The use of energy at world level implies the decrease of natural resources, reduction of fossil fuels, in particular, and a high environmental impact. In view of this problem, an alternative is the energy production for nuclear means, because up to now is one of the less polluting energy; however, the nuclear fuel wastes continue being even a problem without being solved. For the above mentioned this work intends the creation of a device that incorporates the combined technologies of fission and nuclear fusion, called Nuclear Hybrid Reactor Fusion-Fission (HRFF). The HRFF has been designed theoretically with base in experimental fusion reactors in different parts of the world like: United States, Russia, Japan, China and United Kingdom, mainly. The hybrid reactor model here studied corresponds at the Compact Nuclear Facility Source (CNFS). The importance of the CNFS resides in its feasibility, simple design, minor size and low cost; uses deuterium-tritium like main source of neutrons, and as fuel can use the spent fuel of conventional nuclear reactors, such as the current light water reactors. Due to the high costs of experimental research, this work consists on simulating in computer a proposed model of CNFS under normal conditions of operation, to modify the arrangement of the used fuel: MOX and IMF, to analyze the obtained results and to give final conclusions. In conclusion, the HRFF can be a versatile system for the management of spent fuel of light water reactors, so much for the possibility of actinides destruction, like for the breeding of fissile material. (Author)

Prediction of fission mass-yield distributions based on cross section calculations

International Nuclear Information System (INIS)

Hambsch, F.-J.; G.Vladuca; Tudora, Anabella; Oberstedt, S.; Ruskov, I.

2005-01-01

For the first time, fission mass-yield distributions have been predicted based on an extended statistical model for fission cross section calculations. In this model, the concept of the multi-modality of the fission process has been incorporated. The three most dominant fission modes, the two asymmetric standard I (S1) and standard II (S2) modes and the symmetric superlong (SL) mode are taken into account. De-convoluted fission cross sections for S1, S2 and SL modes for 235,238 U(n, f) and 237 Np(n, f), based on experimental branching ratios, were calculated for the first time in the incident neutron energy range from 0.01 to 5.5 MeV providing good agreement with the experimental fission cross section data. The branching ratios obtained from the modal fission cross section calculations have been used to deduce the corresponding fission yield distributions, including mean values also for incident neutron energies hitherto not accessible to experiment

Activation and Radiation Damage Behaviour of Russian Structural Materials for Fusion Reactors in the Fission and Fusion Reactors

International Nuclear Information System (INIS)

Blokhin, A.; Demin, N.; Chernov, V.; Leonteva-Smirnova, M.; Potapenko, M.

2006-01-01

Various structural low (reduced) activated materials have been proposed as a candidate for the first walls-blankets of fusion reactors. One of the main problems connected with using these materials - to minimise the production of long-lived radionuclides from nuclear transmutations and to provide with good technological and functional properties. The selection of materials and their metallurgical and fabrication technologies for fusion reactor components is influenced by this factor. Accurate prediction of induced radioactivity is necessary for the development of the fusion reactor materials. Low activated V-Ti-Cr alloys and reduced activated ferritic-martensitic steels are a leading candidate material for fusion first wall and blanket applications. At the present time a range of compositions and an impurity level are still being investigated to better understand the sensitive of various functional and activation properties to small compositional variations and impurity level. For the two types of materials mentioned above (V-Ti-Cr alloys and 9-12 % Cr f/m steels) and manufactured in Russia (Russia technologies) the analysis of induced activity, hydrogen and helium-production as well as the accumulation of such elements as C, N, O, P, S, Zn and Sn as a function of irradiation time was performed. Materials '' were irradiated '' by fission (BN-600, BOR-60) and fusion (Russian DEMO-C Reactor Project) typical neutron spectra with neutron fluency up to 10 22 n/cm 2 and the cooling time up to 1000 years. The calculations of the transmutation of elements and the induced radioactivity were carried out using the FISPACT inventory code, and the different activation cross-section libraries like the ACDAM, FENDL-2/A and the decay data library FENDL-2/D. It was shown that the level of impurities controls a long-term behaviour of induced activity and contact dose rate for materials. From this analysis the concentration limits of impurities were obtained. The generation of gas

The Sustainable Nuclear Future: Fission and Fusion E.M. Campbell Logos Technologies

Science.gov (United States)

Campbell, E. Michael

2010-02-01

Global industrialization, the concern over rising CO2 levels in the atmosphere and other negative environmental effects due to the burning of hydrocarbon fuels and the need to insulate the cost of energy from fuel price volatility have led to a renewed interest in nuclear power. Many of the plants under construction are similar to the existing light water reactors but incorporate modern engineering and enhanced safety features. These reactors, while mature, safe and reliable sources of electrical power have limited efficiency in converting fission power to useful work, require significant amounts of water, and must deal with the issues of nuclear waste (spent fuel), safety, and weapons proliferation. If nuclear power is to sustain its present share of the world's growing energy needs let alone displace carbon based fuels, more than 1000 reactors will be needed by mid century. For this to occur new reactors that are more efficient, versatile in their energy markets, require minimal or no water, produce less waste and more robust waste forms, are inherently safe and minimize proliferation concerns will be necessary. Graphite moderated, ceramic coated fuel, and He cooled designs are reactors that can satisfy these requirements. Along with other generation IV fast reactors that can further reduce the amounts of spent fuel and extend fuel resources, such a nuclear expansion is possible. Furthermore, facilities either in early operations or under construction should demonstrate the next step in fusion energy development in which energy gain is produced. This demonstration will catalyze fusion energy development and lead to the ultimate development of the next generation of nuclear reactors. In this presentation the role of advanced fission reactors and future fusion reactors in the expansion of nuclear power will be discussed including synergies with the existing worldwide nuclear fleet. )

Issues for the electric utilities posed by DT tokamak fusion powerplants

International Nuclear Information System (INIS)

Roth, J.R.

1990-01-01

The DT tokamak is the mainline approach to magnetic fusion energy in all industrialized countries with a major commitment to fusion research. It achieved this status largely through historical accident and not as the result of considered choice among alternatives. After twenty-five years of intensive tokamak research, it is appropriate to ask whether the path down which the tokamak concept is leading the fusion community is the way to an acceptable powerplant for the electric utilities, or an aberration which should be replaced with an approach more promising in the long term. Issues surrounding the DT tokamak can be grouped in three broad areas: physics; safety/environmental; and engineering/economic. In addition to these problems, detailed engineering design studies of DT tokamak fusion powerplants over a twenty year period have revealed a number of additional problems. Most of thee are related to the presence of tritium and energetic neutron fluxes, which tend to make the cost of electricity of DT tokamaks higher than that of fossil or fission powerplants. These safety and economic issues of the DT tokamak powerplant also appear to be intractable, and have not been made to go away by twenty years of progressively more detailed and extensive engineering design studies

HYPERFUSE: a novel inertial confinement system utilizing hypervelocity projectiles for fusion energy production and fission waste transmutation

International Nuclear Information System (INIS)

Makowitz, H.; Powell, J.R.; Wiswall, R.

1980-01-01

Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs or 90 Sr. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n, 2n), (n, α), etc.) that convert the long lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product

Fission-fusion correlations for swelling and microstructure in stainless steels: effect of the helium-to-displacement-per-atom ratio

International Nuclear Information System (INIS)

Odette, G.R.; Maziaz, P.J.; Spitznagel, J.A.

1981-01-01

The initial irradiated structural materials data base for fusion applications will be developed in fission reactors. Hence, this data may need to be adjusted using physically-based procedures to represent behavior in fusion environments, viz. - fission-fusion correlations. Such correlation should reflect a sound mechanistic understanding, and be verified in facilities which most closely simulate fusion conditions. In this paper we review the effects of only one of a number of potentially significant damage variables, the helium to displacement per atom ratio, on microstructural evolution in austenitic stainless steels. Dual-ion and helium preinjection data are analyzed to provide mechanistic guidance; these results appear to be qualitatively consistent with a more detailed comparison made between fast (EBR-II) and mixed (HFIR) spectrum neutron data for a single heat of 20% cold-worked 316 stainless steel. These two fission environments bound fusion (He/dpa ratios. A model calibrated to the fission reactor data is used to extrapolate to fusion conditions. Both the theory and broad empirical observation suggest that helium to dpa ratios have both a qualitative and quantitative influence on microstructural evolution; and that the very high and low ratios found in HFIR and EBR-II may not result in behavior which brackets intermediate fusion conditions

Comparison of environmental impact of waste disposal from fusion, fission and coal-fired power plants

Energy Technology Data Exchange (ETDEWEB)

Frey, Bruno [Fichtner GmbH und Co. KG, Stuttgart (Germany)

2011-08-15

The radiotoxic hazard of waste from fusion power plants has been compared with that of fission power and radioactive trace elements in coal ash within some research programs such as SEAFP and SEIF. Within another program, in 2005 a Power Plant Conceptual Study (PPCS) has been finalized investigating 4 fusion power plant models A to D. In this paper, the radiotoxicity of model B is compared with a fission power plant, concentrating on the production of wastes. The hazard of the respective masses of enriched uranium before use in a fission power plant and coal ash of a power plant generating the same amount of electricity are used as benchmarks. It is evident that the development of ingestion and inhalation hazard of the PPCS model B is different from the results of earlier studies because of different assumptions on material impurities and other constraints. An important aspect is the presence of actinides in fusion power plant waste. (orig.)

Observation of fission residues in the 16O + 181Ta system at Elab ≈ 6 MeV/A

Directory of Open Access Journals (Sweden)

Singh B. P.

2011-10-01

Full Text Available Present paper reports on the production cross-section of 24 fission like events (30 ≤ Z ≤ 60 formed via complete fusion-fission and/or incomplete fusion-fission processes in 16O+181Ta system at energies ≈ 6 MeV/A. Experiments have been performed using the recoil-catcher technique followed by off-line γ-spectroscopy. The measured cross-section of fission-like events is satisfactorily described by a statistical model code. Further, an attempt has been made to study the mass and isotopic yield distributions of fission fragments. The variance of the presently measured isotopic yield distributions has been found to be in agreement with the literature values for some other fissioning systems.

Reprocessing free nuclear fuel production via fusion fission hybrids

Energy Technology Data Exchange (ETDEWEB)

Kotschenreuther, Mike, E-mail: mtk@mail.utexas.edu [Intitute for Fusion Studies, University of Texas at Austin (United States); Valanju, Prashant; Mahajan, Swadesh [Intitute for Fusion Studies, University of Texas at Austin (United States)

2012-05-15

Fusion fission hybrids, driven by a copious source of fusion neutrons can open qualitatively 'new' cycles for transmuting nuclear fertile material into fissile fuel. A totally reprocessing-free (ReFree) Th{sup 232}-U{sup 233} conversion fuel cycle is presented. Virgin fertile fuel rods are exposed to neutrons in the hybrid, and burned in a traditional light water reactor, without ever violating the integrity of the fuel rods. Throughout this cycle (during breeding in the hybrid, transport, as well as burning of the fissile fuel in a water reactor) the fissile fuel remains a part of a bulky, countable, ThO{sub 2} matrix in cladding, protected by the radiation field of all fission products. This highly proliferation-resistant mode of fuel production, as distinct from a reprocessing dominated path via fast breeder reactors (FBR), can bring great acceptability to the enterprise of nuclear fuel production, and insure that scarcity of naturally available U{sup 235} fuel does not throttle expansion of nuclear energy. It also provides a reprocessing free path to energy security for many countries. Ideas and innovations responsible for the creation of a high intensity neutron source are also presented.

Reprocessing free nuclear fuel production via fusion fission hybrids

International Nuclear Information System (INIS)

Kotschenreuther, Mike; Valanju, Prashant; Mahajan, Swadesh

2012-01-01

Fusion fission hybrids, driven by a copious source of fusion neutrons can open qualitatively “new” cycles for transmuting nuclear fertile material into fissile fuel. A totally reprocessing-free (ReFree) Th 232 –U 233 conversion fuel cycle is presented. Virgin fertile fuel rods are exposed to neutrons in the hybrid, and burned in a traditional light water reactor, without ever violating the integrity of the fuel rods. Throughout this cycle (during breeding in the hybrid, transport, as well as burning of the fissile fuel in a water reactor) the fissile fuel remains a part of a bulky, countable, ThO 2 matrix in cladding, protected by the radiation field of all fission products. This highly proliferation-resistant mode of fuel production, as distinct from a reprocessing dominated path via fast breeder reactors (FBR), can bring great acceptability to the enterprise of nuclear fuel production, and insure that scarcity of naturally available U 235 fuel does not throttle expansion of nuclear energy. It also provides a reprocessing free path to energy security for many countries. Ideas and innovations responsible for the creation of a high intensity neutron source are also presented.

Fusion probability and survivability in estimates of heaviest nuclei production

International Nuclear Information System (INIS)

Sagaidak, Roman

2012-01-01

A number of theoretical models have been recently developed to predict production cross sections for the heaviest nuclei in fusion-evaporation reactions. All the models reproduce cross sections obtained in experiments quite well. At the same time they give fusion probability values P fus ≡ P CN differed within several orders of the value. This difference implies a corresponding distinction in the calculated values of survivability. The production of the heaviest nuclei (from Cm to the region of superheavy elements (SHE) close to Z = 114 and N = 184) in fusion-evaporation reactions induced by heavy ions has been considered in a systematic way within the framework of the barrier-passing (fusion) model coupled with the standard statistical model (SSM) of the compound nucleus (CN) decay. Both models are incorporated into the HIVAP code. Available data on the excitation functions for fission and evaporation residues (ER) produced in very asymmetric combinations can be described rather well within the framework of HIVAP. Cross-section data obtained in these reactions allow one to choose model parameters quite definitely. Thus one can scale and fix macroscopic (liquid-drop) fission barriers for nuclei involved in the evaporation-fission cascade. In less asymmetric combinations (with 22 Ne and heavier projectiles) effects of fusion suppression caused by quasi-fission are starting to appear in the entrance channel of reactions. The P fus values derived from the capture-fission and fusion-fission cross-sections obtained at energies above the Bass barrier were plotted as a function of the Coulomb parameter. For more symmetric combinations one can deduce the P fus values semi-empirically, using the ER and fission excitation functions measured in experiments, and applying SSM model with parameters obtained in the analysis of a very asymmetric combination leading to the production of (nearly) the same CN, as was done for reactions leading to the pre-actinide nuclei formation

Measurements of fission cross-sections and of neutron production rates

International Nuclear Information System (INIS)

Billaud, P.; Clair, C.; Gaudin, M.; Genin, R.; Joly, R.; Leroy, J.L.; Michaudon, A.; Ouvry, J.; Signarbieux, C.; Vendryes, G.

1958-01-01

a) Measurements of neutron induced fission cross-sections in the low energy region. The variation of the fission cross sections of several fissile isotopes has been measured and analysed, for neutron energies below 0,025 eV. The monochromator was a crystal spectrometer used in conjunction with a mechanical velocity selector removing higher order Bragg reflections. The fissile material was laid down on the plates of a fission chamber by painting technic. An ionization chamber, having its plates coated with thin 10 B layers, was used as the neutron flux monitor. b) Measurement of the fission cross section of 235 U. We intend to measure the variation of the neutron induced fission cross section of 235 U over the neutron energy range from 1 keV by the time of flight method. The neutron source is the uranium target of a pulsed 28 MeV electron linear accelerator. The detector is a large fission chamber, with parallel plates, containing about 10 g of 235 U (20 deposits of 25 cm diameter). The relative fission data were corrected for the neutron spectrum measured with a set of BF 3 proportional counters. c) Mean number ν of neutrons emitted in neutron induced fission. We measured the value of ν for several fissile isotopes in the case of fission induced by 14 MeV neutrons. The 14 MeV neutrons were produced by D (t, n) α reaction by means of a 300 kV Cockcroft Walton generator. (author) [fr

Evaluation of Cross-Section Sensitivities in Computing Burnup Credit Fission Product Concentrations

International Nuclear Information System (INIS)

Gauld, I.C.

2005-01-01

U.S. Nuclear Regulatory Commission Interim Staff Guidance 8 (ISG-8) for burnup credit covers actinides only, a position based primarily on the lack of definitive critical experiments and adequate radiochemical assay data that can be used to quantify the uncertainty associated with fission product credit. The accuracy of fission product neutron cross sections is paramount to the accuracy of criticality analyses that credit fission products in two respects: (1) the microscopic cross sections determine the reactivity worth of the fission products in spent fuel and (2) the cross sections determine the reaction rates during irradiation and thus influence the accuracy of predicted final concentrations of the fission products in the spent fuel. This report evaluates and quantifies the importance of the fission product cross sections in predicting concentrations of fission products proposed for use in burnup credit. The study includes an assessment of the major fission products in burnup credit and their production precursors. Finally, the cross-section importances, or sensitivities, are combined with the importance of each major fission product to the system eigenvalue (k eff ) to determine the net importance of cross sections to k eff . The importances established the following fission products, listed in descending order of priority, that are most likely to benefit burnup credit when their cross-section uncertainties are reduced: 151 Sm, 103 Rh, 155 Eu, 150 Sm, 152 Sm, 153 Eu, 154 Eu, and 143 Nd

Fusion-Fission Transmutation Scheme-Efficient destruction of nuclear waste

International Nuclear Information System (INIS)

Kotschenreuther, M.; Valanju, P.M.; Mahajan, S.M.; Schneider, E.A.

2009-01-01

A fusion-assisted transmutation system for the destruction of transuranic nuclear waste is developed by combining a subcritical fusion-fission hybrid assembly uniquely equipped to burn the worst thermal nonfissile transuranic isotopes with a new fuel cycle that uses cheaper light water reactors for most of the transmutation. The center piece of this fuel cycle, the high power density compact fusion neutron source (100 MW, outer radius <3 m), is made possible by a new divertor with a heat-handling capacity five times that of the standard alternative. The number of hybrids needed to destroy a given amount of waste is an order of magnitude below the corresponding number of critical fast-spectrum reactors (FRs) as the latter cannot fully exploit the new fuel cycle. Also, the time needed for 99% transuranic waste destruction reduces from centuries (with FR) to decades

Fusion Canada issue 10

International Nuclear Information System (INIS)

1990-02-01

A short bulletin from the National Fusion Program. Included in this issue is a report on Fusion Materials Research, ITER physics research, fusion performance record at JET, and design options for reactor building. 4 figs

Fusion Canada issue 28

International Nuclear Information System (INIS)

1995-06-01

A short bulletin from the National Fusion Program highlighting in this issue the Canada - US fusion meeting in Montreal, fusion breeder work in Chile, new management at CFFTP, fast electrons in tokamaks: new data from TdeV, a program review of CCFM and Velikhov to address Montreal fusion meeting. 1 fig

Hyper fuse: a novel inertial confinement system utilizing hypervelocity projectiles for fusion energy production and fission waste transmutation

International Nuclear Information System (INIS)

Makowitz, H.; Powell, J.R.; Wiswall, R.

1979-01-01

Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with a target in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs or 90 Sr. The 14 MeV fusion neutrons released during the pellet burn cause transmutation reactions [e.g., (n, 2n), (n, α), etc.] that convert the long lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product

Actinide neutron-induced fission cross section measurements at LANSCE

Energy Technology Data Exchange (ETDEWEB)

Tovesson, Fredrik K [Los Alamos National Laboratory; Laptev, Alexander B [Los Alamos National Laboratory; Hill, Tony S [INL

2010-01-01

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

Fission cross section measurements for minor actinides

Energy Technology Data Exchange (ETDEWEB)

Fursov, B. [IPPE, Obninsk (Russian Federation)

1997-03-01

The main task of this work is the measurement of fast neutron induced fission cross section for minor actinides of {sup 238}Pu, {sup 242m}Am, {sup 243,244,245,246,247,248}Cm. The task of the work is to increase the accuracy of data in MeV energy region. Basic experimental method, fissile samples, fission detectors and electronics, track detectors, alpha counting, neutron generation, fission rate measurement, corrections to the data and error analysis are presented in this paper. (author)

Fusion--fission hybrid reactors based on the laser solenoid

International Nuclear Information System (INIS)

Steinhauer, L.C.; Taussig, R.T.; Quimby, D.C.

1976-01-01

Fusion-fission reactors, based on the laser solenoid concept, can be much smaller in scale than their pure fusion counterparts, with moderate first-wall loading and rapid breeding capabilities (1 to 3 tonnes/yr), and can be designed successfully on the basis of classical plasma transport properties and free-streaming end-loss. Preliminary design information is presented for such systems, including the first wall, pulse coil, blanket, superconductors, laser optics, and power supplies, accounting for the desired reactor performance and other physics and engineering constraints. Self-consistent point designs for first and second generation reactors are discussed which illustrate the reactor size, performance, component parameters, and the level of technological development required

Diamond Wire Cutting of the Tokamak Fusion Test Reactor

International Nuclear Information System (INIS)

Keith Rule; Erik Perry; Robert Parsells

2003-01-01

The Tokamak Fusion Test Reactor (TFTR) is a one-of-a-kind, tritium-fueled fusion research reactor that ceased operation in April 1997. As a result, decommissioning commenced in October 1999. The 100 cubic meter volume of the donut-shaped reactor makes it the second largest fusion reactor in the world. The deuterium-tritium experiments resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 MeV neutrons. The total tritium content within the vessel is in excess of 7,000 Curies, while dose rates approach 50 mRem/hr. These radiological hazards along with the size of the tokamak present a unique and challenging task for dismantling. Engineers at the Princeton Plasma Physics Laboratory (PPPL) decided to investigate an alternate, innovative approach for dismantlement of the TFTR vacuum vessel: diamond wire cutting technology. In August 1999, this technology was successfully demonstrated and evaluated on vacuum vessel surrogates. Subsequently, the technology was improved and redesigned for the actual cutting of the vacuum vessel. Ten complete cuts were performed in a 6-month period to complete the removal of this unprecedented type of DandD (Decontamination and Decommissioning) activity

Study of transfer induced fission and fusion-fission reactions for 28 Si + 232 Th system at 340 MeV

International Nuclear Information System (INIS)

Prete, G.; Rizzi, V.; Fioretto, E.; Cinausero, M.; Shetty, D.V.; Pesente, S.; Brondi, A.; La Rana, G.; Moro, R.; Vardaci, E.; Boiano, A.; Ordine, A.; Gelli, N.; Lucarelli, F.; Bortignon, P.F.; Saxena, A.; Nayak, B.K.; Biswas, D.C.; Choudhury, R.K.; Kapoor, R.S.

2001-01-01

and fusion-fission reactions. We have extracted the ratio of yield of transfer induced fission events to the singles yield of transfer products observed at grazing angle for different Z of ejectiles (PLF). It is seen that transfer induced fission yield increases with increasing Z transfer up to DZ = 4 and then becomes flat and starts to decrease for higher Z-transfers. This may indicate the onset of other processes which inhibit the fission; projectile break-up may be responsible for lowering the transfer of excitation energy and angular momentum to the fissioning system or the evaporation of charged particles may promptly reduce the excitation energy of the compound system which survive fission. This has been investigated looking at PLF in coincidence with protons, a particles, fission and target-like fragments. We have also analyzed the neutron energy spectra for the fusion-fission reaction obtained after correcting for the neutron detector efficiency. Fourteen laboratory neutron energy spectra for various fission-neutron correlation angles were simultaneously fitted with three moving sources. The results show a post- and pre-scission temperature of about 1.0 MeV and 2.24 MeV respectively, comparable to that observed in others low energy measurements and consistent with the compound nuclear excitation energy of 218 MeV, assuming a level density parameter a =A/8 MeV-1. (Author)

Mass distribution of fission-like fragments formed in 20Ne + 165Ho system at Elab≈ 8.2 MeV/A

International Nuclear Information System (INIS)

Singh, D.; Linda, Sneha Bharti; Giri, Pankaj K.

2017-01-01

In the present work, an attempt has been made to study CFF and IFF in 20 Ne + 165 Ho system at projectile energy ≈ 8.2 MeV/A. Twelve fission like fragments (FLF) produced through complete fusion-fission (CFF) and/or incomplete fusion-fission (IFF) in the present system have been identified. The production cross-sections of identified fission like fragments have been measured and the mass distribution of fission like fragments studied

Measurement of fast neutron induced fission cross section of minor-actinide

International Nuclear Information System (INIS)

Hirakawa, Naohiro

2000-06-01

In fuel cycles with recycled actinide, core characteristics are largely influenced by minor actinide (MA: Np, Am, Cm). Accurate nuclear data of MA such as fission cross section are required to estimate the effect of MA with high accuracy. In this study, fast neutron induced fission cross section of MA is measured using Dynamitron accelerator in Tohoku University. The followings were performed in this fiscal year; (1) Research of nuclear data of MA, (2) Sample preparation and sample mass assay, (3) Investigation of neutron sources with the energy of several 10 keV, (4) Preliminary measurement of fission cross section using Dynamitron accelerator. As the result, four 237 Np samples were prepared and the sample mass were measured using alpha-spectrometry with the accuracy of 1.2%. Then, it was confirmed that a neutron source via 7 Li(p,n) 7 Be reaction using a Li-thick target is suitable for measuring fission cross section of MA in the energy region of several 10 keV. Furthermore, it was verified by the preliminary measurement that the measurement of fission cross section of MA is available using a fission chamber and electronics developed in this study. (author)

Fusion Canada issue 25

International Nuclear Information System (INIS)

1994-08-01

A short bulletin from the National Fusion Program highlighting in this issue an economic impact study of the Canadian site for ITER, Harvey Skarsgard: fusion pioneer retires, NFP: Phillips and Holtslander exchange roles, Europe's fusion funding proposals and an update of CCFM/TdeV. 1 fig

Nuclear fusion and fission, and related technologies department: 2007 progress report

International Nuclear Information System (INIS)

2007-12-01

ENEA continues to contribute to broadening plasma physics knowledge as well as to developing the relevant technologies in the framework of the EURATOM-ENEA Association for fusion. This report describes the 2007 research activities carried out by the ENEA Fusion Research Group of the Nuclear Fusion and Fission, and Related Technologies Department (FPN). Other ENEA research groups also contributed to the activities. The following fields were addressed: magnetically confined nuclear fusion (physics and technology), superconductivity and inertial fusion. Planning of the 2007 fusion activities took into account the different scenarios determined by the new organisation of the European programme based on the start of ITER construction. The establishment of the ITER International Organisation and the European Domestic Agency (Fusion for Energy) required a new organisational scheme. This has implied not only the implementation of a more project oriented structure but also the need to launch the constitution of a consortium agreement between the Associations in order to cope with the needs for the design and construction of the components of ITER that require specific know-how, e.g., diagnostics and test blanket module

Fusion or Fission: The Destiny of Mitochondria In Traumatic Brain Injury of Different Severities.

Science.gov (United States)

Di Pietro, Valentina; Lazzarino, Giacomo; Amorini, Angela Maria; Signoretti, Stefano; Hill, Lisa J; Porto, Edoardo; Tavazzi, Barbara; Lazzarino, Giuseppe; Belli, Antonio

2017-08-23

Mitochondrial dynamics are regulated by a complex system of proteins representing the mitochondrial quality control (MQC). MQC balances antagonistic forces of fusion and fission determining mitochondrial and cell fates. In several neurological disorders, dysfunctional mitochondria show significant changes in gene and protein expression of the MQC and contribute to the pathophysiological mechanisms of cell damage. In this study, we evaluated the main gene and protein expression involved in the MQC in rats receiving traumatic brain injury (TBI) of different severities. At 6, 24, 48 and 120 hours after mild TBI (mTBI) or severe TBI (sTBI), gene and protein expressions of fusion and fission were measured in brain tissue homogenates. Compared to intact brain controls, results showed that genes and proteins inducing fusion or fission were upregulated and downregulated, respectively, in mTBI, but downregulated and upregulated, respectively, in sTBI. In particular, OPA1, regulating inner membrane dynamics, cristae remodelling, oxidative phosphorylation, was post-translationally cleaved generating differential amounts of long and short OPA1 in mTBI and sTBI. Corroborated by data referring to citrate synthase, these results confirm the transitory (mTBI) or permanent (sTBI) mitochondrial dysfunction, enhancing MQC importance to maintain cell functions and indicating in OPA1 an attractive potential therapeutic target for TBI.

Influence of fusion dynamics on fission observables: A multidimensional analysis

Science.gov (United States)

Schmitt, C.; Mazurek, K.; Nadtochy, P. N.

2018-01-01

An attempt to unfold the respective influence of the fusion and fission stages on typical fission observables, and namely the neutron prescission multiplicity, is proposed. A four-dimensional dynamical stochastic Langevin model is used to calculate the decay by fission of excited compound nuclei produced in a wide set of heavy-ion collisions. The comparison of the results from such a calculation and experimental data is discussed, guided by predictions of the dynamical deterministic HICOL code for the compound-nucleus formation time. While the dependence of the latter on the entrance-channel properties can straigthforwardly explain some observations, a complex interplay between the various parameters of the reaction is found to occur in other cases. A multidimensional analysis of the respective role of these parameters, including entrance-channel asymmetry, bombarding energy, compound-nucleus fissility, angular momentum, and excitation energy, is proposed. It is shown that, depending on the size of the system, apparent inconsistencies may be deduced when projecting onto specific ordering parameters. The work suggests the possibility of delicate compensation effects in governing the measured fission observables, thereby highlighting the necessity of a multidimensional discussion.

Fusion as an energy option

International Nuclear Information System (INIS)

Steiner, D.

1976-01-01

The environmental issues, alternative fusion fuels, the economic potential, and the time scale of fusion power are assessed. It is common for the advocate of a long-term energy source to claim his source (fission, fusion, solar, etc.) as the ultimate solution to man's energy needs. The author does not believe that such a stance will lead to a rational energy policy. Dr. Steiner encourages a long-term energy policy that has as its goal the development of fission breeders, fusion, and solar energy--not be totally reliant on a single source. He does advocate vigorous funding for fusion, not because it is a guarantee for ''clean, limitless, and cheap power,'' but because it may provide an important energy option for the next century

The impact of intermediate structure on the average fission cross sections

International Nuclear Information System (INIS)

Bouland, O.; Lynn, J.E.; Talou, P.

2014-01-01

This paper discusses two common approximations used to calculate average fission cross sections over the compound energy range: the disregard of the W II factor and the Porter-Thomas hypothesis made on the double barrier fission width distribution. By reference to a Monte Carlo-type calculation of formal R-matrix fission widths, this work estimates an overall error ranging from 12% to 20% on the fission cross section in the case of the 239 Pu fissile isotope in the energy domain from 1 to 100 keV with very significant impact on the competing capture cross section. This work is part of a recent and very comprehensive formal R-matrix study over the Pu isotope series and is able to give some hints for significant accuracy improvements in the treatment of the fission channel. (authors)

Conceptual design of a hybrid fusion-fission reactor with intrinsic safety and optimized energy productivity

International Nuclear Information System (INIS)

Talebi, Hosein; Sadat Kiai, S.M.

2017-01-01

Highlights: • Designing a high yield and feasible Dense Plasma Focus for driving the reactor. • Presenting a structural method to design the dual layer cylindrical blankets. • Finding, the blanket production energy, in terms of its geometrical and material parameters. • Designing a subcritical blanket with optimization of energy amplification in detail. - Abstract: A hybrid fission-fusion reactor with a Dense Plasma Focus (DPF) as a fusion core and the dual layer fissionable blanket as the energy multiplier were conceptually designed. A cylindrical DPF, energized by a 200 kJ bank energy, is considered to produce fusion neutron, and these neutrons drive the subcritical fission in the surrounding blankets. The emphasis has been placed on the safety and energy production with considering technical and economical limitations. Therefore, the k eff-t of the dual cylindrical blanket was defined and mathematically, specified. By applying the safety criterion (k eff-t ≤ 0.95), the geometrical and material parameters of the blanket optimizing the energy amplification were obtained. Finally, MCNPX code has been used to determine the detailed dimensions of the blankets and fuel rods.

The Complete Burning of Weapons Grade Plutonium and Highly Enriched Uranium with (Laser Inertial Fusion-Fission Energy) LIFE Engine

Energy Technology Data Exchange (ETDEWEB)

Farmer, J C; Diaz de la Rubia, T; Moses, E

2008-12-23

millions of fuel pebbles, which can be tagged as individual accountable items, and thus made difficult to divert in large quantities. This report discusses the application of the LIFE concept to nonproliferation issues, initially looking at the LIFE (Laser Inertial Fusion-Fission Energy) engine as a means of completely burning WG Pu and HEU. By combining a neutron-rich inertial fusion point source with energy-rich fission, the once-through closed fuel-cycle LIFE concept has the following characteristics: it is capable of efficiently burning excess weapons or separated civilian plutonium and highly enriched uranium; the fission blanket is sub-critical at all times (keff < 0.95); because LIFE can operate well beyond the point at which light water reactors (LWRs) need to be refueled due to burn-up of fissile material and the resulting drop in system reactivity, fuel burn-up of 99% or more appears feasible. The objective of this work is to develop LIFE technology for burning of WG-Pu and HEU.

Measurement of fast neutron induced fission cross section of minor-actinide

International Nuclear Information System (INIS)

Hirakawa, Naohiro

1997-03-01

In fuel cycles with recycled actinide, core characteristics are largely influenced by minor actinide (MA: Np, Am, Cm). Accurate nuclear data of MA such as fission cross section are required to estimate the effect of MA with high accuracy. In this study, fast neutron induced fission cross section of MA is measured using Dynamitron Accelerator in Tohoku University. The experimental method and the samples, which were developed or introduced during the last year, were improved in this fiscal year: (1) Development of a sealed fission chamber, (2) Intensification of Li neutron target, (3) Improvement of time-resolution of Time-of-Flight (TOF) electronic circuit, (4) Introduction of Np237 samples with large sample mass and (5) Introduction of a U235 sample with high purity. Using these improved tools and samples, the fission cross section ratio of Np237 relative to U235 was measured between 5 to 100 keV, and the fission cross section of Np237 was deduced. On the other hand, samples of Am241 and Am243 were obtained from Japan Atomic Energy Research Institute (JAERI) after investigating fission cross section of two americium isotopes (Am241 and Am 243) which are important for core physics calculation of fast reactors. (author)

Sub-Coulomb fusion with halo nuclei

International Nuclear Information System (INIS)

Fekou-Youmbi, V.; Sida, J.L.; Alamanos, N.; Auger, F.; Bazin, D.; Borcea, C.; Cabot, C.; Cunsolo, A.; Foti, A.; Gillibert, A.; Lepine, A.; Lewitowicz, M.; Liguori-Neto, R.; Mittig, W.; Pollacco, E.; Roussel-Chomaz, P.; Volant, C.; Yong Feng, Y.

1995-01-01

The nuclear structure of halo nuclei may have strong influence on the fusion cross section at sub-barrier energies. The actual theoretical debate is briefly reviewed and sub-barrier fusion calculations for the system 11 Be+ 238 U are presented. An experimental program on sub-barrier fusion for the systems 7,9,10,11 Be+ 238 U is underway at GANIL. First results with 9 Be and 11 Be beams were obtained using the F.U.S.ION detector. Relative fission cross sections are presented. ((orig.))

To follow or not? How animals in fusion-fission societies handle conflicting information during group decision-making.

Science.gov (United States)

Merkle, Jerod A; Sigaud, Marie; Fortin, Daniel

2015-08-01

When group members possess differing information about the environment, they may disagree on the best movement decision. Such conflicts result in group break-ups, and are therefore a fundamental driver of fusion-fission group dynamics. Yet, a paucity of empirical work hampers our understanding of how adaptive evolution has shaped plasticity in collective behaviours that promote and maintain fusion-fission dynamics. Using movement data from GPS-collared bison, we found that individuals constantly associated with other animals possessing different spatial knowledge, and both personal and conspecific information influenced an individual's patch choice decisions. During conflict situations, bison used group familiarity coupled with their knowledge of local foraging options and recently sampled resource quality when deciding to follow or leave a group - a tactic that led to energy-rewarding movements. Natural selection has shaped collective behaviours for coping with social conflicts and resource heterogeneity, which maintain fusion-fission dynamics and play an essential role in animal distribution. © 2015 John Wiley & Sons Ltd/CNRS.

Fusion Canada issue 9

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-11-01

A short bulletin from the National Fusion Program. Included in this issue is a report on availability of Canadian Tritium, an ITER update, a CCFM update on Tokamak and the new team organization, an international report on Fusion in Canada and a Laser Fusion Project at the University of Toronto. 3 figs.

Fusion Canada issue 17

International Nuclear Information System (INIS)

1992-05-01

A short bulletin from the National Fusion Program. Included in this issue is a report on increased funding for the Canadian Fusion Program, news of the compact Toroid fuelling gun, an update on Tokamak de Varennes, the Canada - U.S. fusion meeting, measurements of plasma flow velocity, and replaceable Tokamak divertors. 4 figs

Fusion Canada issue 17

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-05-01

A short bulletin from the National Fusion Program. Included in this issue is a report on increased funding for the Canadian Fusion Program, news of the compact Toroid fuelling gun, an update on Tokamak de Varennes, the Canada - U.S. fusion meeting, measurements of plasma flow velocity, and replaceable Tokamak divertors. 4 figs.

Fusion Canada issue 9

International Nuclear Information System (INIS)

1989-11-01

A short bulletin from the National Fusion Program. Included in this issue is a report on availability of Canadian Tritium, an ITER update, a CCFM update on Tokamak and the new team organization, an international report on Fusion in Canada and a Laser Fusion Project at the University of Toronto. 3 figs

Overview of materials R and D for fusion and Gen-4

Energy Technology Data Exchange (ETDEWEB)

Kohyama, A. [Kyoto Univ., lnstitute of Advanced Energy (Japan); Tavassoli, F.; Carre, F.; Billot, P. [CEA Saclay, 91 - Gif sur Yvette (France); Zinide, S. [Oak Ridge National Laboratory, Materials Science and Technology Div., AK TN (United States)

2007-07-01

Full text of publication follows: In view of the growing need for energy, the risk of exhaustion of fossil fuel and the problem of global warming, the nuclear energy is receiving added attention as a realistic and viable advanced solution. International collaborations on Generation IV (Gen-IV) fission reactors and on ITER and DEMO fusion reactors are developing. This is particularly the case in the sector of materials, where they hold the key to success of these systems. The international community has recognized and planned its materials R and D work for Fusion and Gen-IV reactors with the following considerations: 1- The time allotted to materials R and D is short and may not allow development of totally new materials. 2- Activities required, to cover existing materials variations and service conditions necessary for reactor design, are very time consuming. 3- The work to be done must build upon the existing knowledge of materials and avoid duplications. Although ITER for fusion and Generation four International Forum (GIF) for Gen-IV are important international collaborative programs, they are insufficient to meet all the national energy policies of the participating countries. This paper provides an overview of the materials R and D carried out for fusion and Gen-IV reactors at international and national levels. Materials programs discussed include both cross-cutting and reactor specific actions, where major tasks can be defined as: + Cross-cutting materials tasks: - materials for high temperature service; - materials with neutron damage tolerance; - materials behavior analysis and modeling; - high temperature design methodology. + Reactor specific materials tasks: - very high temperature alloys; - carbon, high temperature ceramics and their composites; - materials compatibilities. Starting with a brief introduction of materials R and D strategies, ITER and Broader Approach (BA), overall activities for fusion and GIF for Gen-IV will be reviewed. Domestic

Fusion Canada issue 23

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-01-01

A short bulletin from the National Fusion Program highlighting in this issue TdeV tokamak updates, fusion research in Korea, CCFM program review, TdeV divertor plasma, and CFFTP program review. 4 figs.

Fusion Canada issue 23

International Nuclear Information System (INIS)

1994-01-01

A short bulletin from the National Fusion Program highlighting in this issue TdeV tokamak updates, fusion research in Korea, CCFM program review, TdeV divertor plasma, and CFFTP program review. 4 figs

Present status of the EPFL (Swiss) fusion-fission experiment 'LOTUS'

International Nuclear Information System (INIS)

Haldy, P.A.; Frueh, R.; Ligou, J.; Schneeberger, J.P.; Kumar, A.

1984-01-01

The present status of the LOTUS project - a fusion-fission hybrid research facility under construction at the Ecole Polytechnique Federale de Lausanne (EPFL) Switzerland - is presented. Emphasis is places on the description of the facility and on the design studies of an initial blanket of the ''fission-suppressed'' type. The LOTUS facility consists of a parallelepiped-shaped blanket, occupying roughly a volume of 1 m 3 , driven by a sealed 14 MeV (D,T) neutron generator with a rated source strength of 5x10 12 n/s. The experiment is housed in a massive concrete shielding of 220 cm thick walls, which leaves an experimental test chamber of 360 cm by 240 cm lateral dimensions and a height of 300 cm. (orig.) [de

Fusion Canada issue 27

International Nuclear Information System (INIS)

1995-03-01

A short bulletin from the National Fusion Program highlighting in this issue ITER reactor siting, a major upgrade for TdeV tokamak, Ceramic Breeders: new tritium mapping technique and Joint Fusion Symposium. 2 figs

Fusion Power Deployment

International Nuclear Information System (INIS)

Schmidt, J.A.; Ogden, J.M.

2002-01-01

Fusion power plants could be part of a future portfolio of non-carbon dioxide producing energy supplies such as wind, solar, biomass, advanced fission power, and fossil energy with carbon dioxide sequestration. In this paper, we discuss key issues that could impact fusion energy deployment during the last half of this century. These include geographic issues such as resource availability, scale issues, energy storage requirements, and waste issues. The resource needs and waste production associated with fusion deployment in the U.S. should not pose serious problems. One important feature of fusion power is the fact that a fusion power plant should be locatable within most local or regional electrical distribution systems. For this reason, fusion power plants should not increase the burden of long distance power transmission to our distribution system. In contrast to fusion power, regional factors could play an important role in the deployment of renewable resources such as wind, solar and biomass or fossil energy with CO2 sequestration. We examine the role of these regional factors and their implications for fusion power deployment

Workshop summaries for the third US/USSR symposium on fusion-fission reactors

International Nuclear Information System (INIS)

Jassby, D.L.

1979-07-01

Workshop summaries on topics related to the near-term development requirements for fusion-fission (hybrid) reactors are presented. The summary topics are as follows: (1) external factors, (2) plasma engineering, (3) ICF hybrid reactors, (4) blanket design, (5) materials and tritium, and (6) blanket engineering development requirements

The controlled thermonuclear fusion

International Nuclear Information System (INIS)

Barre, Bertrand

2014-01-01

After some generalities on particle physics, and on fusion and fission reactions, the author outlines that the fission reaction is easier to obtain than the fusion reaction, evokes the fusion which takes place in stars, and outlines the difficulty to manage and control this reaction: one of its application is the H bomb. The challenge is therefore to find a way to control this reaction and make it a steady and continuous source of energy. The author then presents the most promising way: the magnetic confinement fusion. He evokes its main issues, the already performed experiments (tokamak), and gives a larger presentation of the ITER project. Then, he evokes another way, the inertial confinement fusion, and the two main experimental installations (National Ignition Facility in Livermore, and the Laser Megajoule in Bordeaux). Finally, he gives a list of benefits and drawbacks of an industrial nuclear fusion

Fusion Canada issue 18

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-08-01

A short bulletin from the National Fusion Program. Included in this issue is a report on the ITER agreement signed with the EDA, the robotic maintenance for NET, the CFFTP Fusion Pilot Study, the new IEA joint programs on environment, safety and economic aspects of fusion power, and a review by the CCFM advisory committee. 3 figs.

Fusion Canada issue 18

International Nuclear Information System (INIS)

1992-08-01

A short bulletin from the National Fusion Program. Included in this issue is a report on the ITER agreement signed with the EDA, the robotic maintenance for NET, the CFFTP Fusion Pilot Study, the new IEA joint programs on environment, safety and economic aspects of fusion power, and a review by the CCFM advisory committee. 3 figs

Remote welding and cutting techniques for fusion experimental reactors

International Nuclear Information System (INIS)

Onozuka, M.; Ishide, T.; Oda, Y.; Nagaoka, E.; Ue, K.; Kamei, H.

1995-01-01

Experimental investigation of the YAG laser cutting/welding and plasma gouging techniques has been conducted to examine their suitability for remote maintenance systems in future fusion experimental reactors. Using a hybrid beam coupling system, two laser beams of 500W and 740W powers were successfully combined to provide a 1,240W beam power. The combined laser was transmitted through the optical fiber for cutting and welding. The transmission loss for the beams is in the range of 13% to 14%, which is low. As for plasma gouging, the shallow gouging made a groove measuring 10 mm in width and 4 mm in depth on the stainless steel plates at a traversing speed of 75 cm/min, while the deep gouging made a groove of 12 mm in width and 7.5 mm in depth at a traversing speed of 50 cm/min. In addition, it was found that the shallow gouging did not leave byproducts from the material, providing a clean surface. Based on the findings, it is shown that the YAG laser cutting/welding and plasma gouging techniques can be us3ed for remote welding and cutting in future fusion experimental reactors

Remote welding and cutting techniques for fusion experimental reactors

Energy Technology Data Exchange (ETDEWEB)

Onozuka, M.; Ishide, T.; Oda, Y.; Nagaoka, E.; Ue, K.; Kamei, H. [Mitsubishi Heavy Industries, Ltd., Yokohama (Japan)

1995-12-31

Experimental investigation of the YAG laser cutting/welding and plasma gouging techniques has been conducted to examine their suitability for remote maintenance systems in future fusion experimental reactors. Using a hybrid beam coupling system, two laser beams of 500W and 740W powers were successfully combined to provide a 1,240W beam power. The combined laser was transmitted through the optical fiber for cutting and welding. The transmission loss for the beams is in the range of 13% to 14%, which is low. As for plasma gouging, the shallow gouging made a groove measuring 10 mm in width and 4 mm in depth on the stainless steel plates at a traversing speed of 75 cm/min, while the deep gouging made a groove of 12 mm in width and 7.5 mm in depth at a traversing speed of 50 cm/min. In addition, it was found that the shallow gouging did not leave byproducts from the material, providing a clean surface. Based on the findings, it is shown that the YAG laser cutting/welding and plasma gouging techniques can be us3ed for remote welding and cutting in future fusion experimental reactors.

Fusion Canada issue 20

International Nuclear Information System (INIS)

1993-03-01

Fusion Canada's publication of the National Fusion Program. Included in this issue is the CFFTP Industrial Impact Study, CCFM/TdeV Update:helium pumping, research funds, and deuterium in beryllium - high temperature behaviour. 3 figs

Calculation of high-dimensional fission-fusion potential-energy surfaces in the SHE region

International Nuclear Information System (INIS)

Moeller, Peter; Sierk, Arnold J.; Ichikawa, Takatoshi; Iwamoto, Akira

2004-01-01

We calculate in a macroscopic-microscopic model fission-fusion potential-energy surfaces relevant to the analysis of heavy-ion reactions employed to form heavy-element evaporation residues. We study these multidimensional potential-energy surfaces both inside and outside the touching point.Inside the point of contact we define the potential on a multi-million-point grid in 5D deformation space where elongation, merging projectile and target spheroidal shapes, neck radius and projectile/target mass asymmetry are independent shape variables. The same deformation space and the corresponding potential-energy surface also describe the shape evolution from the nuclear ground-state to separating fragments in fission, and the fast-fission trajectories in incomplete fusion.For separated nuclei we study the macroscopic-microscopic potential energy, that is the ''collision surface'' between a spheroidally deformed target and a spheroidally deformed projectile as a function of three coordinates which are: the relative location of the projectile center-of-mass with respect to the target center-of-mass and the spheroidal deformations of the target and the projectile. We limit our study to the most favorable relative positions of target and projectile, namely that the symmetry axes of the target and projectile are collinear

Interference analysis of fission cross section

International Nuclear Information System (INIS)

Toshkov, S.A.; Yaneva, N.B.

1976-01-01

The formula for the reaction cross-section based on the R-matrix formalism considering the interference between the two neighbouring resonances, referred to the same value of total momentum was used for the analysis of the cross-section of resonance neutron induced fission of 230Pu. The experimental resolution and thermal motion of the target nuclei were accounted for numerical integration

MCNP6 Fission Cross Section Calculations at Intermediate and High Energies

OpenAIRE

Mashnik, Stepan G.; Sierk, Arnold J.; Prael, Richard E.

2013-01-01

MCNP6 has been Validated and Verified (V&V) against intermediate- and high-energy fission cross-section experimental data. An error in the calculation of fission cross sections of 181Ta and a few nearby target nuclei by the CEM03.03 event generator in MCNP6 and a "bug: in the calculation of fission cross sections with the GENXS option of MCNP6 while using the LAQGSM03.03 event generator were detected during our V&V work. After fixing both problems, we find that MCNP6 using CEM03.03 and LAQGSM...

Fusion Canada issue 6

International Nuclear Information System (INIS)

1989-02-01

A short bulletin from the National Fusion Program. Included in this issue is a funding report for CFFTP, a technical update for Tokamak de Varennes and a network for university research by the National Fusion Program. 4 figs

Fission-fusion and lineal effect: aspects of the population structure of the Semai Senoi of Malaysia.

Science.gov (United States)

Fix, A G

1975-09-01

Analysis of histories and genealogies from seven relatively unacculturated, swidden-farming Semai settlements shows that the composition of local groups fluctuates through time. This instability is similar to a pattern which Neel and his colleagues have suggested is typical of primitive society, the fission-fusion model. In addition, the individuals comprising Semai fission groups are kinsmen which implies that the number of independent genomes represented is markedly less than the number of individual migrants (the lineal effect). Fission groups may form new villages or fuse with an established settlement. In either case, the genetic effects of such migration are more pronounced than would be expected on the basis of founder effect or random migration. Despite several conspicuous differences in social organization between the Semai and the South American Indians (e.g., bilateral vs. unilineal descent) whose population structure provided the empirical basis for the fission-fusion, lineal effect model, the basic similarities are striking. The Semai case thus lends support to the proposition that this pattern may be of some generality in technologically primitive populations.

Progress in fission product nuclear data

International Nuclear Information System (INIS)

Lammer, M.

1981-06-01

This is the seventh issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The present issue contains also a section with some recent references relative to fission product nuclear data, which were not covered by the contributions submitted. The types of activities being included in this report are measurements, compilations and evaluations of: fission product yields (neutron induced and spontaneous fission); neutron reaction cross sections of fission products; data related to the radioactive decay of fission products; delayed neutron data of fission products; and lumped fission product data (decay heat, absorption etc.). The sixth issue of this series has been published in June 1980 as INDC(NDS)-113/G+P. The present issue includes contributions which were received by NDS between 1 August 1980 and 25 May 1981

Fusion Canada issue 12

International Nuclear Information System (INIS)

1990-10-01

A short bulletin from the National Fusion Program. Included in this issue is a report on Darlington's Tritium Removal Facility, work at universities on Deuterium Diffusivity in Beryllium, Fusion Studies, confinement research and the operation of divertors at Tokamak de Varennes. 5 figs

Systematics of fission cross sections at the intermediate energy region

Energy Technology Data Exchange (ETDEWEB)

Fukahori, Tokio; Chiba, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-03-01

The systematics was obtained with fitting experimental data for proton induced fission cross sections of Ag, {sup 181}Ta, {sup 197}Au, {sup 206,207,208}Pb, {sup 209}Bi, {sup 232}Th, {sup 233,235,238}U, {sup 237}Np and {sup 239}Pu above 20 MeV. The low energy cross section of actinoid nuclei is omitted from systematics study, since the cross section has a complicated shape and strongly depends on characteristic of nucleus. The fission cross sections calculated by the systematics are in good agreement with experimental data. (author)

Progress in fission product nuclear data

International Nuclear Information System (INIS)

Lammer, M.

1984-09-01

This is the tenth issue of a report series on Fission Product Data, which informs us about all the activities in this field, which are planned, ongoing, or have recently been completed. The types of activities included are measurements, compilations and evaluations of: fission product yields (neutron induced and spontaneous fission), neutron reaction cross sections of fission products, data related to the radioactive decay of fission products, delayed neutron data of fission products, lumped fission product data (decay heat, absorption, etc.). There is also a section with recent references relative to fission product nuclear data

Safety analysis on tokamak helium cooling slab fuel fusion-fission hybrid reactor

International Nuclear Information System (INIS)

Wei Renjie; Jian Hongbing

1992-01-01

The thermal analyses for steady state, depressurization and total loss of flow in the tokamak helium cooling slab fuel element fusion-fission hybrid reactor are presented. The design parameters, computed results of HYBRID program and safety evaluation for conception design are given. After all, it gives some recommendations for developing the design

Fusion Canada issue 12

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-10-01

A short bulletin from the National Fusion Program. Included in this issue is a report on Darlington`s Tritium Removal Facility, work at universities on Deuterium Diffusivity in Beryllium, Fusion Studies, confinement research and the operation of divertors at Tokamak de Varennes. 5 figs.

Dynamical limitations to heavy-ion fusion

International Nuclear Information System (INIS)

Back, B.B.

1983-01-01

In spite of the many attempts to synthesize superheavy elements in recent years, these efforts have not yet been successful. Recent improved theoretical models of heavy-ion fusion reactions suggest that the formation of super-heavy elements is hindered by the dynamics of the process. Several recent experiments lend support to these theories. The necessity of an excess radial velocity (extra push) over the Coulomb barrier in order to induce fusion is observed experimentally as predicted by the theory. So is a new reaction mechanism, called quasi-fission which tend to exhaust the part of the reaction cross section, which would otherwise lead to fusion. The present study shows that the angular distribution of fragments from quasi-fission processes are very sensitive to the occurrence of this reaction mechanism. A slight modification of one parameter in the theory demanded by the observation of quasi-fission for lighter projectiles via the angular distributions, has the consequence of posing even more-stringent limitations on heavy-ion-fusion reactions. This reduces even further the possibility for synthesizing and identifying superheavy elements in heavy-ion-fusion reactions

Is there hope for fusion?

International Nuclear Information System (INIS)

Fowler, T.K.

1990-01-01

From the outset in the 1950's, fusion research has been motivated by environmental concerns as well as long-term fuel supply issues. Compared to fossil fuels both fusion and fission would produce essentially zero emissions to the atmosphere. Compared to fission, fusion reactors should offer high demonstrability of public protection from accidents and a substantial amelioration of the radioactive waste problem. Fusion still requires lengthy development, the earliest commercial deployment being likely to occur around 2025--2050. However, steady scientific progress is being made and there is a wide consensus that it is time to plan large-scale engineering development. A major international effort, called the International Thermonuclear Experimental Reactor (ITER), is being carried out under IAEA auspices to design the world's first fusion engineering test reactor, which could be constructed in the 1990's. 4 figs., 3 tabs

Assessment of fusion reactor development. Proceedings

International Nuclear Information System (INIS)

Inoue, N.; Tazima, T.

1994-04-01

Symposium on assessment of fusion reactor development was held to make clear critical issues, which should be resolved for the commercial fusion reactor as a major energy source in the next century. Discussing items were as follows. (1) The motive force of fusion power development from viewpoints of future energy demand, energy resources and earth environment for 'Sustainable Development'. (2) Comparison of characteristics with other alternative energy sources, i.e. fission power and solar cell power. (3) Future planning of fusion research and advanced fuel fusion (D 3 He). (4) Critical issues of fusion reactor development such as Li extraction from the sea water, structural material and safety. (author)

Cross sections of the lumped fission products for the AMZ library

International Nuclear Information System (INIS)

Ono, S.; Corcueca, R.P.; Nascimento, J.A.

1985-01-01

The preparation of the lumped fission product cross section for the AMZ library is described. For this purpose 100 nuclides were selected. The cross sections for each nuclide were generated by the NJOY code with evaluated nuclear data from ENDF/B-V, complemented with ENDF/B-IV data. A comparison is performed between the data obtained and the lumped fission product cross section of JFS-II [pt

Fusion Canada issue 8

International Nuclear Information System (INIS)

1989-08-01

A short bulletin from the National Fusion Program. Included in this issue are Canada-ITER contributions, NET Fuel Processing Loop, Bilateral Meeting for Canada-Europe, report from Tokamak de Varennes and a report from the University of Toronto on materials research for Fusion Reactors. 3 figs

Fusion Canada issue 8

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-08-01

A short bulletin from the National Fusion Program. Included in this issue are Canada-ITER contributions, NET Fuel Processing Loop, Bilateral Meeting for Canada-Europe, report from Tokamak de Varennes and a report from the University of Toronto on materials research for Fusion Reactors. 3 figs.

Materials degradation in fission reactors: Lessons learned of relevance to fusion reactor systems

International Nuclear Information System (INIS)

Was, Gary S.

2007-01-01

The management of materials in power reactor systems has become a critically important activity in assuring the safe, reliable and economical operation of these facilities. Over the years, the commercial nuclear power reactor industry has faced numerous 'surprises' and unexpected occurrences in materials. Mitigation strategies have sometimes solved one problem at the expense of creating another. Other problems have been solved successfully and have motivated the development of techniques to foresee problems before they occur. This paper focuses on three aspects of fission reactor experience that may benefit future fusion systems. The first is identification of parameters and processes that have had a large impact on the behavior of materials in fission systems such as temperature, dose rate, surface condition, gradients, metallurgical variability and effects of the environment. The second is the development of materials performance and failure models to provide a basis for assuring component integrity. Last is the development of proactive materials management programs that identify and pre-empt degradation processes before they can become problems. These aspects of LWR experience along with the growing experience with materials in the more demanding advanced fission reactor systems form the basis for a set of 'lessons learned' to aid in the successful management of materials in fusion reactor systems

Curves and tables of neutron cross sections of fission product nuclei in JENDL-3

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Tsuneo [ed.

1992-06-15

Neutron cross sections of 172 nuclei in the fission product region stored in JENDL-3 are shown in graphs and tables. The evaluation work of these nuclei was made by the Fission Product Nuclear Data Working Group of the Japanese Nuclear Data Committee, in the neutron energy region from 10{sup {minus}5} eV to 20 MeV. Almost of the cross section data reproduced in graphs in this report. The cross section averaged over 38 energy intervals are listed in a table. Shown in order tables are thermal cross sections, resonance integrals, Maxwellian neutron flux average cross sections, fission spectrum average cross sections, 14-MeV cross sections, one group average cross sections in neutron flux of typical types of fission reactors and average cross sections in the 30-keV Maxwellian spectrum.

Curves and tables of neutron cross sections of fission product nuclei in JENDL-3

International Nuclear Information System (INIS)

Nakagawa, Tsuneo

1992-06-01

Neutron cross sections of 172 nuclei in the fission product region stored in JENDL-3 are shown in graphs and tables. The evaluation work of these nuclei was made by the Fission Product Nuclear Data Working Group of the Japanese Nuclear Data Committee, in the neutron energy region from 10 -5 eV to 20 MeV. Almost all the cross section data are reproduced in graphs in this report. The cross section averaged over 38 energy intervals are listed in a table. Shown in other tables are thermal cross sections, resonance integrals, Maxwellian neutron flux average cross sections, fission spectrum average cross sections, 14-MeV cross sections, one group average cross sections in neutron flux of typical types of fission reactors and average cross sections in the 30-keV Maxwellian spectrum. (author)

Measurement of tritium production rate distribution for a fusion-fission hybrid conceptual reactor

International Nuclear Information System (INIS)

Wang Xinhua; Guo Haiping; Mou Yunfeng; Zheng Pu; Liu Rong; Yang Xiaofei; Yang Jian

2013-01-01

A fusion-fission hybrid conceptual reactor is established. It consists of a DT neutron source and a spherical shell of depleted uranium and hydrogen lithium. The tritium production rate (TPR) distribution in the conceptual reactor was measured by DT neutrons using two sets of lithium glass detectors with different thicknesses in the hole in the vertical direction with respect to the D + beam of the Cockcroft-Walton neutron generator in direct current mode. The measured TPR distribution is compared with the calculated results obtained by the three-dimensional Monte Carlo code MCNP5 and the ENDF/B-Ⅵ data file. The discrepancy between the measured and calculated values can be attributed to the neutron data library of the hydrogen lithium lack S(α, β) thermal scattering model, so we show that a special database of low-energy and thermal neutrons should be established in the physics design of fusion-fission hybrid reactors. (authors)

Status update on the NIFFTE high precision fission cross section measurement program

International Nuclear Information System (INIS)

Laptev, Alexander B.; Tovesson, Fredrik; Burgett, Eric; Greife, Uwe; Grimes, Steven; Heffner, Michael D.; Hertel, Nolan E.; Hill, Tony; Isenhower, Donald; Klay, Jennifer L.; Kornilov, Nickolay; Kudo, Ryuho; Loveland, Walter; Massey, Thomas; McGrath, Chris; Pickle, Nathan; Qu, Hai; Sharma, Sarvagya; Snyder, Lucas; Thornton, Tyler; Towell, Rusty S.; Watson, Shon

2010-01-01

The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) program has been underway for nearly two years. The program's mission is to measure fission cross sections of the primary fissionable and fissile materials ( 235 U, 239 Pu, 238 U) as well as the minor actinides across energies from approximately 50 keV up to 20 MeV with an absolute uncertainty of less than one percent while investigating energy ranges from below an eV to 600 MeV. This basic nuclear physics data is being reinvestigated to support the next generation power plants and a fast burner reactor program. Uncertainties in the fast, resolved and unresolved resonance regions in plutonium and other transuranics are extremely large, dominating safety margins in the next generation nuclear power plants and power plants of today. This basic nuclear data can be used to support all aspects of the nuciear renaissance. The measurement campaign is utilizing a Time Projection Chamber or TPC as the tool to measure these cross sections to these unprecedented levels. Unlike traditional fission cross section measurements using time-of-flight and a multiple fission foil configurations in which fission cross sections in relation to that of 235 U are performed, the TPC project uses time-of-flight and hydrogen as the benchmark cross section. Using the switch to hydrogen, a simple, smooth cross section that can be used which removes the uncertainties associated with the resolved and unresolved resonances in 235 U.

System model for analysis of the mirror fusion-fission reactor

International Nuclear Information System (INIS)

Bender, D.J.; Carlson, G.A.

1977-01-01

This report describes a system model for the mirror fusion-fission reactor. In this model we include a reactor description as well as analyses of capital cost and blanket fuel management. In addition, we provide an economic analysis evaluating the cost of producing the two hybrid products, fissile fuel and electricity. We also furnish the results of a limited parametric analysis of the modeled reactor, illustrating the technological and economic implications of varying some important reactor design parameters

Progress in fission product nuclear data

International Nuclear Information System (INIS)

Lammer, M.

1983-08-01

This is the ninth issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The main part of this report consists of unaltered original contributions which the authors have sent to IAEA/NDS. The present issue contains also a section with some recent references relative to fission product nuclear data, which were not covered by the contributions submitted. The types of activities being included in this report are measurements, compilations and evaluations of: Fission product yields (neutron induced and spontaneous fission); Neutron reaction cross sections of fission products; Data related to the radioactive decay of fission products; Delayed neutron data of fission products; and lumped fission product data (decay heat, absorption etc.). The eighth issue of this series has been published in July 1982 as INDC(NDS)-130. The present issue includes contributions which were received by NDS between 1 August 1982 and 25 June 1983

Progress in fission product nuclear data

International Nuclear Information System (INIS)

Lammer, G.

1975-01-01

This is the first issue of a report series on Fission Product Nuclear Data (FPND), published every six months by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). Its purpose is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The types of activities being included in this report are measurements, compilations and evaluations of: fission product yields; neutron cross-section data of fission products; data related to β-, γ-decay of fission products; delayed neutron data; and fission product decay-heat. The present issue includes contributions which were received by NDS before 1 November 1975

Complexity versus availability for fusion: The potential advantages of inertial fusion energy

International Nuclear Information System (INIS)

Perkins, L.J.

1996-01-01

Probably the single largest advantage of the inertial route to fusion energy (IFE) is the perception that its power plant embodiments could achieve acceptable capacity factors. This is a result of its relative simplicity, the decoupling of the driver and reactor chamber, and the potential to employ thick liquid walls. We examine these issues in terms of the complexity, reliability, maintainability and, therefore, availability of both magnetic and inertial fusion power plants and compare these factors with corresponding scheduled and unscheduled outage data from present day fission experience. We stress that, given the simple nature of a fission core, the vast majority of unplanned outages in fission plants are due to failures outside the reactor vessel itself Given we must be prepared for similar outages in the analogous plant external to a fusion power core, this puts severe demands on the reliability required of the fusion core itself. We indicate that such requirements can probably be met for IFE plants. We recommend that this advantage be promoted by performing a quantitative reliability and availability study for a representative IFE power plant and suggest that databases are probably adequate for this task

Technical issues in fusion reactors

International Nuclear Information System (INIS)

Rohatgi, V.K.; Vijayan, T.

1989-01-01

In this paper the issues in fusion reactor technology are examined. Rapid progress in fusion technology research in recent years can be attributed to the advances in various technologies. The commercial generation of fusion power greatly depends on the evolution and improvements in these technologies. With better understanding of plasma physics, fusion reactor designs are becoming more and more realistic and comprehensive. It is now possible to compare various concepts within the framework of established technologies. The technological issues needing better understanding and solutions to problem areas are identified. Various instabilities and energy losses are major problem areas. Extensive developments in reactor-relevant advanced materials, compact and powerful superconducting magnets, high-power systems, and plasma heating drivers need to be undertaken and emphasized

Fusion Canada issue 15

International Nuclear Information System (INIS)

1991-10-01

A short bulletin from the National Fusion Program. Included in this issue is a report on the 1996 IAEA Fusion Conference site, operations at the Tokamak de Varennes including divertor pumping of impurities and pumping of carbon monoxide and methane, a discussion of the CFFTP and it's role. 1 fig

Fusion Canada issue 22

International Nuclear Information System (INIS)

1993-10-01

A short bulletin from the National Fusion Program highlighting in this issue a bi-lateral meeting between Canada and Japan, water and hydrogen detritiation, in-situ tokamak surface analysis, an update of CCFM/TdeV and tritium accounting Industry guidance in Fusion, fast probe for plasma-surface interaction. 4 figs

Fusion Canada issue 15

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-10-01

A short bulletin from the National Fusion Program. Included in this issue is a report on the 1996 IAEA Fusion Conference site, operations at the Tokamak de Varennes including divertor pumping of impurities and pumping of carbon monoxide and methane, a discussion of the CFFTP and it`s role. 1 fig.

Fusion Canada issue 22

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-10-01

A short bulletin from the National Fusion Program highlighting in this issue a bi-lateral meeting between Canada and Japan, water and hydrogen detritiation, in-situ tokamak surface analysis, an update of CCFM/TdeV and tritium accounting Industry guidance in Fusion, fast probe for plasma-surface interaction. 4 figs.

Feasibility study of a fission-suppressed tandem-mirror hybrid reactor

International Nuclear Information System (INIS)

Lee, J.D.; Moir, R.W.; Barr, W.L.

1982-04-01

Results of a conceptual design study of a U-233 producing fusion breeder consisting of a tandem mirror fusion device and two types of fission-suppressed blankets are presented. The majority of the study was devoted to the conceptual design and evaluation of the two blankets. However, studies in the areas of fusion engineering, reactor safety, fuel reprocessing, other fuel cycle issues, economics, and deployment were also performed

High-energy Neutron-induced Fission Cross Sections of Natural Lead and Bismuth-209

CERN Document Server

Tarrio, D; Carrapico, C; Eleftheriadis, C; Leeb, H; Calvino, F; Herrera-Martinez, A; Savvidis, I; Vlachoudis, V; Haas, B; Koehler, P; Vannini, G; Oshima, M; Le Naour, C; Gramegna, F; Wiescher, M; Pigni, M T; Audouin, L; Mengoni, A; Quesada, J; Becvar, F; Plag, R; Cennini, P; Mosconi, M; Rauscher, T; Couture, A; Capote, R; Sarchiapone, L; Vlastou, R; Domingo-Pardo, C; Dillmann, I; Pavlopoulos, P; Karamanis, D; Krticka, M; Jericha, E; Ferrari, A; Martinez, T; Trubert, D; Oberhummer, H; Karadimos, D; Plompen, A; Isaev, S; Terlizzi, R; Cortes, G; Cox, J; Cano-Ott, D; Pretel, C; Colonna, N; Berthoumieux, E; Vaz, P; Heil, M; Lopes, I; Lampoudis, C; Walter, S; Calviani, M; Gonzalez-Romero, E; Embid-Segura, M; Stephan, C; Igashira, M; Papachristodoulou, C; Aerts, G; Tavora, L; Berthier, B; Rudolf, G; Andrzejewski, J; Villamarin, D; Ferreira-Marques, R; Tain, J L; O'Brien, S; Reifarth, R; Kadi, Y; Neves, F; Poch, A; Kerveno, M; Rubbia, C; Lazano, M; Dahlfors, M; Wisshak, K; Salgado, J; Dridi, W; Ventura, A; Andriamonje, S; Assimakopoulos, P; Santos, C; Voss, F; Ferrant, L; Patronis, N; Chiaveri, E; Guerrero, C; Perrot, L; Vicente, M C; Lindote, A; Praena, J; Baumann, P; Kappeler, F; Rullhusen, P; Furman, W; David, S; Marrone, S; Tassan-Got, L; Gunsig, F; Alvarez-Velarde, F; Massimi, C; Mastinu, P; Pancin, J; Papadopoulos, C; Tagliente, G; Haight, R; Chepel, V; Kossionides, E; Badurek, G; Marganiec, J; Lukic, S; Pavlik, A; Goncalves, I; Duran, I; Alvarez, H; Abbondanno, U; Fujii, K; Milazzo, P M; Moreau, C

2011-01-01

The CERN Neutron Time-Of-Flight (n\\_TOF) facility is well suited to measure small neutron-induced fission cross sections, as those of subactinides. The cross section ratios of (nat)Pb and (209)Bi relative to (235)U and (238)U were measured using PPAC detectors. The fragment coincidence method allows to unambiguously identify the fission events. The present experiment provides the first results for neutron-induced fission up to 1 GeV for (nat)Pb and (209)Bi. A good agreement with previous experimental data below 200 MeV is shown. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross section is close to 1 GeV.

Physics of Fission and Fusion for the Diagnostics and Monitoring of the Deadliest Illness of Mankind

Science.gov (United States)

Saxena, Arjun

2015-03-01

The physics of fission and fusion has been well known for the past several decades. It has been used primarily for destructive purposes (e. g., nuclear armaments) with both processes. However for peaceful purposes, e. g., generation of energy, only fission has been used, but not yet fusion. It is also well known that the deadliest illness of mankind is the group of illnesses called mental illnesses. A large segment of the world population is afflicted by them causing more loss of human lives, destruction of families, businesses and overall economy than all the other illnesses combined. Despite outstanding advancements in medical research and huge investments, unfortunately no diagnostic techniques have yet been found which can characterize the patient's mental illness. Consequently, no quantitative monitoring techniques are available to evaluate the efficacy of the various medicines used to treat the patients, and to develop them in the pharmaceutical labs. The purpose of this paper is to apply the constructive aspects of fission and fusion to identify the missing links in the diagnosis and treatment of mental illnesses. Each patient is a unique human being, not a disease or a group of symptoms. This makes it even more difficult to treat the patients suffering from mental illnes

Tensile property changes of metals and irradiated to low doses with fission, fusion and spallation neutrons

International Nuclear Information System (INIS)

Heinisch, H.L.; Hamilton, M.L.; Sommer, W.F.; Ferguson, P.D.

1992-01-01

The objective of this work is to investigate the effects of the neutron energy spectrum in low dose irradiations on the microstructures and mechanical properties of metals. Radiation effects due to low doses of spallation neutrons are compared directly to those produced by fission and fusion neutrons. Yield stress changes of pure Cu, alumina-dispersion-strengthened Cu and AISI 316 stainless steel irradiated at 36-55 C in the Los Alamos Spallation Radiation Effects Facility (LASREF) are compared with earlier results of irradiations at 90 C using 14 MeV D-T fusion neutrons at the Rotating Target Neutron Source and fission reactor neutrons in the Omega West Reactor. At doses up to 0.04 displacements per atom (dpa), the yield stress changes due to the three quite different neutron spectra correlate well on the basis of dpa in the stainless steel and the Cu alloy. However, in pure Cu, the measured yield stress changes due to spallation neutrons were anomalously small and should be verified by additional irradiations. With the exception of pure Cu, the low dose, low temperature experiments reveal no fundamental differences in radiation hardening by fission, fusion or spallation neutrons when compared on the basis of dpa

The Fukushima nuclear disaster and its effects on media framing of fission and fusion energy technologies

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Luisa; Horta, Ana; Pereira, Sergio; Delicado, Ana [Institute of Social Sciences of the University of Lisbon, Av. Prof. Anibal de Bettencourt, 9 1600-189 Lisbon (Portugal)

2015-07-01

This paper presents results of a comparison of media coverage of fusion and fission energy technologies in three countries (Germany, Spain and Portugal) and in the English language international print media addressing transnational elite, from 2008 to 2012. The analysis showed that the accident in Fukushima in March 2010 did not have significant impact on media framing of nuclear fusion in the major part of print media under investigation. In fact, fusion is clearly dissociated from traditional nuclear (fission) energy and from nuclear accidents. It tends to be portrayed as a safe, clean and unlimited source of energy, although less credited when confronted with research costs, technological feasibility and the possibility to be achieved in a reasonable period of time. On the contrary, fission is portrayed as a hazardous source of energy, expensive when compared to research costs of renewables, hardly a long-term energy option, susceptible to contribute to the proliferation of nuclear weapons or rogue military use. Fukushima accident was consistently discussed in the context of safety problems of nuclear power plants and in many cases appeared not as an isolated event but rather as a reminder of previous nuclear disasters such as Three Miles Island and Chernobyl. (authors)

The Fukushima nuclear disaster and its effects on media framing of fission and fusion energy technologies

International Nuclear Information System (INIS)

Schmidt, Luisa; Horta, Ana; Pereira, Sergio; Delicado, Ana

2015-01-01

This paper presents results of a comparison of media coverage of fusion and fission energy technologies in three countries (Germany, Spain and Portugal) and in the English language international print media addressing transnational elite, from 2008 to 2012. The analysis showed that the accident in Fukushima in March 2010 did not have significant impact on media framing of nuclear fusion in the major part of print media under investigation. In fact, fusion is clearly dissociated from traditional nuclear (fission) energy and from nuclear accidents. It tends to be portrayed as a safe, clean and unlimited source of energy, although less credited when confronted with research costs, technological feasibility and the possibility to be achieved in a reasonable period of time. On the contrary, fission is portrayed as a hazardous source of energy, expensive when compared to research costs of renewables, hardly a long-term energy option, susceptible to contribute to the proliferation of nuclear weapons or rogue military use. Fukushima accident was consistently discussed in the context of safety problems of nuclear power plants and in many cases appeared not as an isolated event but rather as a reminder of previous nuclear disasters such as Three Miles Island and Chernobyl. (authors)

Measurement of the neutron-induced fission cross-section of 240,242Pu

International Nuclear Information System (INIS)

Salvador-Castineira, P.; Hambsch, F.J.; Brys, T.; Oberstedt, S.; Vidali, M.; Pretel, C.

2014-01-01

Fast spectrum neutron-induced fission cross-section data for transuranic isotopes are in high demand in the nuclear data community. In particular, highly accurate data are needed for the new Generation-IV nuclear applications. The aim is to obtain precise neutron-induced fission cross-sections for 240 Pu and 242 Pu. In this context accurate data on spontaneous fission half-lives have also been measured. To minimise the total uncertainty on the fission cross-sections the detector efficiency has been studied in detail. Both isotopes have been measured using a twin Frisch-grid ionisation chamber (TFGIC) due to its superiority compared to other detector systems in view of radiation hardness, 2 x 2π solid angle coverage and very good energy resolution. (authors)

Study of the effect of {sup 11}Be halo on the sub-coulombian fusion; Etude de l`effet du halo du {sup 11}Be sur la fusion sous-coulombienne

Energy Technology Data Exchange (ETDEWEB)

Felou Youmbi, V

1996-12-11

Fission cross sections of {sup 9,11}Be + {sup 238}U systems are measured in the energy range of the coulomb barrier. These measures allow the study of neutron halo effect on sub coulombian fusion. {sup 9,11}Be beams are obtained by fragmentation at the GANIL facilities. The fusion between incident particle and the target nucleus leads to a compound nucleus which disappears by fission. The FUSION detector is used to detect the fission fragments by coincidence. We present some calculations of potential barriers by using Wong formula. The nucleus-nucleus interaction is simulated by a double convolution between the nucleus density and the effective M3Y interaction. In a more realistic framework ECIS94 code calculates the fusion cross section by using a coupling formalism. Theoretical values and experimental results are compared. We get a good agreement for {sup 9}Be + {sup 238}U system and an unusual behaviour appears for {sup 11}Be + {sup 238}U system 116 refs.

Positron annihilation lifetime measurements of vanadium alloy and F82H irradiated with fission and fusion neutrons

International Nuclear Information System (INIS)

Sato, K.; Inoue, K.; Yoshiie, T.; Xu, Q.; Wakai, E.; Kutsukake, C.; Ochiai, K.

2009-01-01

V-4Cr-4Ti, F82H, Ni and Cu were irradiated with fission and fusion neutrons at room temperature and 473 K. Defect structures were analyzed and compared using positron annihilation lifetime measurement, and microstructural evolution was discussed. The mean lifetime of positrons (the total amount of residual defects) increased with the irradiation dose. The effect of cascade impact was detected in Ni at room temperature. The size and the number of vacancy clusters were not affected by the displacement rate in the fission neutron irradiation at 473 K for the metals studied. The vacancy clusters were not formed in V-4Cr-4Ti irradiated at 473 K in the range of 10 -6 -10 -3 dpa. In F82H irradiated at 473 K, the defect evolution was prevented by pre-existing defects. The mean lifetime of positrons in fission neutron irradiation was longer than that in fusion neutron irradiation in V-4Cr-4Ti at 473 K. It was interpreted that more closely situated subcascades were formed in the fusion neutron irradiation and subcascades interacted with each other, and consequently the vacancy clusters did not grow larger.

Dynamical fission life-times deduced from gamma-ray emission observed in the fusion-fission reaction : Ne-20 on Bi-209.

NARCIS (Netherlands)

vanderPloeg, H; Bacelar, JCS; Buda, A; Dioszegi, [No Value; vantHof, G; vanderWoude, A

1996-01-01

The gamma-ray emission spectra between 4 and 20 MeV have been measured for the fusion-fission reactions Ne-20 on Bi-209 --> Np-229* at beam energies 150, 186 and 220 MeV. In addition for the latter experiment the angular dependence of the gamma-ray emission with respect to the spin axis has been

Fusion Canada issue 4

International Nuclear Information System (INIS)

1988-05-01

A short bulletin from the National Fusion Program. Included in this issue is a technical update on Tokamak de Varennes, a report on the Beatrix II Breeding Materials Test Program, the Tritium glovebox system for UPM, Saudi Arabia, a broad update of the Canadian Fusion Fuels Technology Project is also included. 1 fig

Fusion Canada issue 4

Energy Technology Data Exchange (ETDEWEB)

NONE

1988-05-01

A short bulletin from the National Fusion Program. Included in this issue is a technical update on Tokamak de Varennes, a report on the Beatrix II Breeding Materials Test Program, the Tritium glovebox system for UPM, Saudi Arabia, a broad update of the Canadian Fusion Fuels Technology Project is also included. 1 fig.

Fusion barrier distributions - What have we learned?

International Nuclear Information System (INIS)

Hinde, D. J.; Dasgupta, M.

1998-01-01

The study of nuclear fusion received a strong impetus from the realisation that an experimental fusion barrier distribution could be determined from precisely measured fusion cross-sections. Experimental data for different reactions have shown in the fusion barrier distributions clear signatures of a range of nuclear excitations, for example the effects of static quadrupole and hexadecapole deformations, single- and double-phonon states, transfer of nucleons, and high-lying excited states. The improved understanding of fusion barrier distributions allows more reliable prediction of fusion angular momentum distributions, which aids interpretation of fission probabilities and fission anisotropies, and understanding of the population of super-deformed bands for nuclear structure studies. Studies of the relationship between the fusion barrier distribution and the extra-push energy should improve our understanding of the mechanism of the extra-push effect, and may help to predict new ways of forming very heavy or super-heavy nuclei

Atomic physics issues in fusion

International Nuclear Information System (INIS)

Post, D.E.

1982-01-01

Atomic physics issues have played a large role in controlled fusion research. A general introduction to the present role of atomic processes in both inertial and magnetic controlled fusion work is presented. (Auth.)

First inverse-kinematics fission measurements in a gaseous active target

Energy Technology Data Exchange (ETDEWEB)

Rodríguez-Tajes, C., E-mail: rodriguez@ganil.fr [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Bd. Henri Becquerel, 14076 Caen (France); Universidade de Santiago de Compostela, E-15706 Santiago de Compostela (Spain); Farget, F. [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Bd. Henri Becquerel, 14076 Caen (France); Acosta, L. [Departamento de Ciencias Integradas, Universidad de Huelva, E-21071 Huelva (Spain); Alvarez-Pol, H. [Universidade de Santiago de Compostela, E-15706 Santiago de Compostela (Spain); Babo, M.; Boulay, F. [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Bd. Henri Becquerel, 14076 Caen (France); Caamaño, M. [Universidade de Santiago de Compostela, E-15706 Santiago de Compostela (Spain); Damoy, S. [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Bd. Henri Becquerel, 14076 Caen (France); Fernández-Domínguez, B. [Universidade de Santiago de Compostela, E-15706 Santiago de Compostela (Spain); Galaviz, D. [Centro de Física Nuclear da Universidade de Lisboa, CFNUL, 1649-003 Lisboa (Portugal); Grinyer, G.F.; Grinyer, J. [Grand Accélérateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Bd. Henri Becquerel, 14076 Caen (France); Harakeh, M.N. [KVI-CART, University of Groningen, Zernikelaan 25, NL-9747 AA Groningen (Netherlands); Konczykowski, P. [Universidade de Santiago de Compostela, E-15706 Santiago de Compostela (Spain); and others

2017-02-15

The fission of a variety of actinides was induced by fusion and transfer reactions between a {sup 238}U beam and {sup 12}C nuclei, in the active target MAYA. The performance of MAYA was studied, as well as its capability to reconstruct the fission-fragment trajectories. Furthermore, a full characterization of the different transfer reactions was achieved, and the populated excitation-energy distributions were investigated as a function of the kinetic energy in the entrance channel. The ratio between transfer- and fusion-induced fission cross-sections was also determined, in order to investigate the competition between both reaction types and its evolution with the incident energy. The experimental results will be discussed with a view to forthcoming radioactive-ion beam facilities, and next-generation active-target setups.

Comparison of material irradiation conditions for fusion, spallation, stripping and fission neutron sources

International Nuclear Information System (INIS)

Vladimirov, P.; Moeslang, A.

2004-01-01

Selection and development of materials capable of sustaining irradiation conditions expected for a future fusion power reactor remain a big challenge for material scientists. Design of other nuclear facilities either in support of the fusion materials testing program or for other scientific purposes presents a similar problem of irradiation resistant material development. The present study is devoted to an evaluation of the irradiation conditions for IFMIF, ESS, XADS, DEMO and typical fission reactors to provide a basis for comparison of the data obtained for different material investigation programs. The results obtained confirm that no facility, except IFMIF, could fit all user requirements imposed for a facility for simulation of the fusion irradiation conditions

Preparation of multigroup lumped fission product cross-sections from ENDF/B-VI for FBRs

International Nuclear Information System (INIS)

Devan, K.; Gopalakrishnan, V.; Mohanakrishnan, P.; Sridharan, M.S.

1997-01-01

Multigroup pseudo fission product cross-sections were computed from the American evaluated nuclear data library ENDF/B-VI, corresponding to various burnups of the proposed 500 MWe prototype fast breeder reactor (PFBR), in India. The data were derived from the cross-sections of 111 selected fission products that account for almost complete capture of fission products in an FBR. The dependence of burnup on the pseudo fission product cross-sections, and comparison with other data sets, viz. JNDC, ENDF/B-IV and ABBN, are discussed. (author)

Fusion Canada issue 14

International Nuclear Information System (INIS)

1991-05-01

A short bulletin from the National Fusion Program. Included in this issue is a report on a fusion cooperation agreement between Japan and Canada, an update at Tokamak de Varennes on plasma biasing experiments and boronization tests and a collaboration between Canada and the U.S. on a compact toroid fuelling gun. 4 figs

Nuclear fusion: The issues

International Nuclear Information System (INIS)

Griffin, R.D.

1993-01-01

The taming of fusion energy, has proved one of the most elusive quests of modern science. For four decades, the United States has doggedly pursued energy's holy grail, pumping more than $9 billion into research and reactor prototypes. This year, the federal government is slated to spend $339 million on fusion, more than the combined amount the government will spend for research on oil, natural gas, solar power, wind power, geothermal energy, biofuels and conservation. This article summarizes the technical, political in terms of international cooperation, economic, planning, etc. issues surrounding the continued development of fusion as a possible power source for the next century. Brief descriptions of how fusion works and of the design of a tokamak fusion machine are included

Prospects for improved fusion reactors

International Nuclear Information System (INIS)

Krakowski, R.A.; Miller, R.L.; Hagenson, R.L.

1986-01-01

Ideally, a new energy source must be capable of displacing old energy sources while providing both economic opportunities and enhanced environmental benefits. The attraction of an essentially unlimited fuel supply has generated a strong impetus to develop advanced fission breeders and, even more strongly, the exploitation of nuclear fusion. Both fission and fusion systems trade a reduced fuel charge for a more capital-intensive plant needed to utilize a cheaper and more abundant fuel. Results from early conceptual designs of fusion power plants, however, indicated a capital intensiveness that could override cost savings promised by an inexpensive fuel cycle. Early warnings of these problems appeared, and generalized routes to more economically attractive systems have been suggested; specific examples have also recently been given. Although a direct reduction in the cost (and mass) of the fusion power core (FPC, i.e., plasma chamber, first wall, blanket, shield, coils, and primary structure) most directly reduces the overall cost of fusion power, with the mass power density (MPD, ratio of net electric power to FPC mass, kWe/tonne) being suggested as a figure-of-merit in this respect, other technical, safety/environmental, and institutional issues also enter into the definition of and direction for improved fusion concepts. These latter issues and related tradeoffs are discussed

Fusion Canada issue 19

International Nuclear Information System (INIS)

1992-12-01

A short bulletin from the National Fusion Program. Included in this issue is a report on the IAEA Plasma Biasing Meeting, the new IEA program -Nuclear Technology of Fusion reactors, TFTR tritium purification system, an update by CCFM on machine additions and modifications, and news of a new compact Toroid injector at the University of Saskatchewan. 1 fig

Disentangling association patterns in fission-fusion societies using African buffalo as an example

Science.gov (United States)

Cross, P.C.; Lloyd-Smith, James O.; Getz, W.M.

2005-01-01

A description of the social network of a population aids us in understanding dispersal, the spread of disease, and genetic structure in that population. Many animal populations can be classified as fission–fusion societies, whereby groups form and separate over time. Examples discussed in the literature include ungulates, primates and cetaceans (Lott and Minta, 1983, Whitehead et al., 1991, Henzi et al., 1997, Christal et al., 1998 and Chilvers and Corkeron, 2002). In this study, we use a heuristic simulation model to illustrate potential problems in applying traditional techniques of association analysis to fission–fusion societies and propose a new index of association: the fission decision index (FDI). We compare the conclusions resulting from traditional methods with those of the FDI using data from African buffalo, Syncerus caffer, in the Kruger National Park. The traditional approach suggested that the buffalo population was spatially and temporally structured into four different ‘herds’ with adult males only peripherally associated with mixed herds. Our FDI method indicated that association decisions of adult males appeared random, but those of other sex and age categories were nonrandom, particularly when we included the fission events associated with adult males. Furthermore, the amount of time that individuals spent together was only weakly correlated with their propensity to remain together during fission events. We conclude with a discussion of the applicability of the FDI to other studies.

Study of the effect of 11Be halo on the sub-coulombian fusion

International Nuclear Information System (INIS)

Felou Youmbi, V.

1996-01-01

Fission cross sections of 9,11 Be + 238 U systems are measured in the energy range of the coulomb barrier. These measures allow the study of neutron halo effect on sub coulombian fusion. 9,11 Be beams are obtained by fragmentation at the GANIL facilities. The fusion between incident particle and the target nucleus leads to a compound nucleus which disappears by fission. The FUSION detector is used to detect the fission fragments by coincidence. We present some calculations of potential barriers by using Wong formula. The nucleus-nucleus interaction is simulated by a double convolution between the nucleus density and the effective M3Y interaction. In a more realistic framework ECIS94 code calculates the fusion cross section by using a coupling formalism. Theoretical values and experimental results are compared. We get a good agreement for 9 Be + 238 U system and an unusual behaviour appears for 11 Be + 238 U system

Comparison of 235U fission cross sections in JENDL-3.3 and ENDF/B-VI

International Nuclear Information System (INIS)

Kawano, Toshihiko; Carlson, Allan D.; Matsunobu, Hiroyuki; Nakagawa, Tsuneo; Shibata, Keiichi

2002-01-01

Comparisons of evaluated fission cross sections for 235 U in JENDL-3.3 and ENDF/B-VI are carried out. The comparisons are made for both the differential and integral data. The fission cross sections as well as the fission ratios are compared with the experimental data in detail. Spectrum averaged cross sections are calculated and compared with the measurements. The employed spectra are the 235 U prompt fission neutron spectrum, the 252 Cf spontaneous fission neutron spectrum, and the neutron spectrum produced by a 9 Be(d, xn) reaction. For 235 U prompt fission neutron spectrum, the ENDF/B-VI evaluation reproduces experimental averaged cross sections. For 252 Cf and 9 Be(d, xn) neutron spectra, the JENDL-3.3 evaluation gives better results than ENDF/B-VI. (author)

The ties that bind: genetic relatedness predicts the fission and fusion of social groups in wild African elephants.

Science.gov (United States)

Archie, Elizabeth A; Moss, Cynthia J; Alberts, Susan C

2006-03-07

Many social animals live in stable groups. In contrast, African savannah elephants (Loxodonta africana) live in unusually fluid, fission-fusion societies. That is, 'core' social groups are composed of predictable sets of individuals; however, over the course of hours or days, these groups may temporarily divide and reunite, or they may fuse with other social groups to form much larger social units. Here, we test the hypothesis that genetic relatedness predicts patterns of group fission and fusion among wild, female African elephants. Our study of a single Kenyan population spans 236 individuals in 45 core social groups, genotyped at 11 microsatellite and one mitochondrial DNA (mtDNA) locus. We found that genetic relatedness predicted group fission; adult females remained with their first order maternal relatives when core groups fissioned temporarily. Relatedness also predicted temporary fusion between social groups; core groups were more likely to fuse with each other when the oldest females in each group were genetic relatives. Groups that shared mtDNA haplotypes were also significantly more likely to fuse than groups that did not share mtDNA. Our results suggest that associations between core social groups persist for decades after the original maternal kin have died. We discuss these results in the context of kin selection and its possible role in the evolution of elephant sociality.

State of the art of fusion material recycling and remaining issues

International Nuclear Information System (INIS)

Massaut, V.; Broden, K.; Pace, L. Di; Ooms, L.; Pampin, R.

2006-01-01

Fusion as a power production system presents several advantages in terms of safety and environmental impact, one of these being the limited amount of radioactive waste production which is burden for future generations. Nevertheless, even if fusion does not produce long term radioactive waste, e.g. by adequate material selection for plasma facing components, there are two important aspects deserving consideration: the presence of tritium in relatively large quantity, and the very hard neutron spectrum leading to large amounts of active materials. In order to keep radioactive waste levels to a minimum it has been proposed to recycle the materials removed from the reactor, after adequate decay period and proper handling and treatment. Treatment may include detritiation, separation of different material types and sorting of the non reusable materials, among others. Moreover if recycle or reuse (within the nuclear industry in general or, for some particular materials, within the fusion industry) are foreseen, the material has to be melted or reduced to reusable raw material, machined or the pieces fabricated again, assembled and checked (for geometrical correctness, or leak tightness for instance). And all this has to be made on industrial scale, as fusion will produce large amounts of material presenting various degrees of radioactivity and tritium content. Even if some experience of recycling exists in the nuclear fission industry, which can be used for fusion materials, the different steps mentioned above are challenging operations when dealing with tritiated materials or highly radioactive components. The paper presents a review of the current situation and state-of-the-art recycling methods for typical fusion materials (e.g. Beryllium, Tungsten, Copper and Copper alloys, steel, Carbon) and components of future fusion plants based on current conceptual design studies. It also focuses attention on R-and-D issues to be addressed in order to be able to recycle as much

Above-threshold structure in {sup 244}Cm neutron-induced fission cross section

Energy Technology Data Exchange (ETDEWEB)

Maslov, V.M. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

1997-03-01

The quasi-resonance structure appearing above the fission threshold in neutron-induced fission cross section of {sup 244}Cm(n,f) is interpreted. It is shown to be due to excitation of few-quasiparticle states in fissioning {sup 245}Cm and residual {sup 244}Cm nuclides. The estimate of quasiparticle excitation thresholds in fissioning nuclide {sup 245}Cm is consistent with pairing gap and fission barrier parameters. (author)

JEFF 3.1.2 - Joint evaluated nuclear data library for fission and fusion applications - February 2012 (DVD)

International Nuclear Information System (INIS)

2012-02-01

The Joint Evaluated Fission and Fusion File (JEFF) project is a collaboration between NEA Data Bank member countries. The JEFF library combines the efforts of the JEFF and EFF/EAF Working Groups to produce a common sets of evaluated nuclear data, mainly for fission and fusion applications. The JEFF-3.1.2 version, released in February 2012, contains a number of different data types, including neutron and proton interaction data, radioactive decay data, fission yields, and thermal scattering law data. Currently, JEFF-3.1.2 data are available in ENDF-6 format (neutron library) from the Web. This new release is an update from JEFF-3.1.1 which concerns 115 material files from the general purpose incident neutron library which have been modified since JEFF-3.1.1. Modifications include: Hf isotopes: 6 new Hf evaluations have replaced previous ones; Gamma production data from neutron capture (MF=6 MT=102) has been added to 89 fission products (FP) evaluations; 47 of these FP have been replaced by ENDF-B/VII.0 evaluations, with gamma data added in this release. Corrections from JEFF-Beta feedback have been incorporated for 15 materials. Corrections that solve NJOY covariance processing problems and JANIS warnings have been made to 6 files. This DVD contains: - General purpose incident neutron data in ENDF-6 and ACE formats; - Activation data; - Thermal scattering data; - Incident proton data; - Radioactive decay data; - Neutron-induced fission yields data; - Spontaneous fission yields data

Measurement of the 235U/238U fission cross section ratio in the 235U fission neutron spectrum

International Nuclear Information System (INIS)

Azimi-Garakani, D.; Bagheri-Darbandi, M.

1983-06-01

Fission cross section ratio of 235 U to 238 U has been measured in the fast neutron field generated by the 235 U fission plate installed on the thermal column of the Tehran Research Reactor (TRR) with a Makrofol solid state nuclear track detector. The experiments were carried out with a set of total six enriched 235 U and depleted 238 U deposits with different masses and Makrofol films of 0.025mm and 0.060mm thicknesses. The chemically etched tracks were counted by an optical microscope. No significant differences were observed with the thin and the thick films. The results showed that the average fission cross section ratio is 3.83+-0.25. (author)

Inner-membrane proteins PMI/TMEM11 regulate mitochondrial morphogenesis independently of the DRP1/MFN fission/fusion pathways.

Science.gov (United States)

Rival, Thomas; Macchi, Marc; Arnauné-Pelloquin, Laetitia; Poidevin, Mickael; Maillet, Frédéric; Richard, Fabrice; Fatmi, Ahmed; Belenguer, Pascale; Royet, Julien

2011-03-01

Mitochondria are highly dynamic organelles that can change in number and morphology during cell cycle, development or in response to extracellular stimuli. These morphological dynamics are controlled by a tight balance between two antagonistic pathways that promote fusion and fission. Genetic approaches have identified a cohort of conserved proteins that form the core of mitochondrial remodelling machineries. Mitofusins (MFNs) and OPA1 proteins are dynamin-related GTPases that are required for outer- and inner-mitochondrial membrane fusion respectively whereas dynamin-related protein 1 (DRP1) is the master regulator of mitochondrial fission. We demonstrate here that the Drosophila PMI gene and its human orthologue TMEM11 encode mitochondrial inner-membrane proteins that regulate mitochondrial morphogenesis. PMI-mutant cells contain a highly condensed mitochondrial network, suggesting that PMI has either a pro-fission or an anti-fusion function. Surprisingly, however, epistatic experiments indicate that PMI shapes the mitochondria through a mechanism that is independent of drp1 and mfn. This shows that mitochondrial networks can be shaped in higher eukaryotes by at least two separate pathways: one PMI-dependent and one DRP1/MFN-dependent.

Measurements of fission cross-sections and of neutron production rates; Mesures de sections efficaces de fission et du nombre de neutrons prompts emis par fission

Energy Technology Data Exchange (ETDEWEB)

Billaud, P; Clair, C; Gaudin, M; Genin, R; Joly, R; Leroy, J L; Michaudon, A; Ouvry, J; Signarbieux, C; Vendryes, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

a) Measurements of neutron induced fission cross-sections in the low energy region. The variation of the fission cross sections of several fissile isotopes has been measured and analysed, for neutron energies below 0,025 eV. The monochromator was a crystal spectrometer used in conjunction with a mechanical velocity selector removing higher order Bragg reflections. The fissile material was laid down on the plates of a fission chamber by painting technic. An ionization chamber, having its plates coated with thin {sup 10}B layers, was used as the neutron flux monitor. b) Measurement of the fission cross section of {sup 235}U. We intend to measure the variation of the neutron induced fission cross section of {sup 235}U over the neutron energy range from 1 keV by the time of flight method. The neutron source is the uranium target of a pulsed 28 MeV electron linear accelerator. The detector is a large fission chamber, with parallel plates, containing about 10 g of {sup 235}U (20 deposits of 25 cm diameter). The relative fission data were corrected for the neutron spectrum measured with a set of BF{sub 3} proportional counters. c) Mean number {nu} of neutrons emitted in neutron induced fission. We measured the value of {nu} for several fissile isotopes in the case of fission induced by 14 MeV neutrons. The 14 MeV neutrons were produced by D (t, n) {alpha} reaction by means of a 300 kV Cockcroft Walton generator. (author)Fren. [French] a) Mesures de sectionficaces de fission a basse energie. Nous avons mesure et analyse la variation de la section efficace de fission de divers isotopes fissiles pour des neutrons d'energie inferieure a 0,025 eV. Le monochromateur est constitue par un spectrometre a cristal auquel est associe un selecteur mecanique destine a eliminer les diffractions de Bragg d'ordre superieur au premier. Le materiau fissile est contenu dans une chambre a fission sous forme de depots realises par peinture; une chambre d'ionisation a depots minces de B{sub 10

Fission cross section and fission fragment angular distribution for oriented nucleus fission by intermediate energy neutrons (epsilon < or approximately 1 Mev)

International Nuclear Information System (INIS)

Barabanov, A.L.; Grechukhin, D.P.

1985-01-01

General analysis is conducted, and formulae for fission cross section and angular distribution of fission fragments of oriented nuclei by fast neutrons are presented. Geometrical coefficients making up the formulae permitting to carry out calculations for target nuclei with spins I=3/2, 5/2, 7/2 at interaction energies epsilon < or approximately 1 MeV are tabulated. Results of demonstrative calculation of fission fragment angular distribution of oriented sup(235)U nuclei by 0.1 <= epsilon <= 1.0 MeV neutrons reveal that angular distribution weakly depends on the set of permeability factors of neutron waves applied in the calculations

Mitigation: cross-sectoral and other issues

Energy Technology Data Exchange (ETDEWEB)

Leemans, R. [National Inst. of Public Health and Environmental Protection, Bilthoven (Netherlands). Coordination Center for Effects

1996-12-31

Measures, methodologies and technologies to reduce emissions and enhance sinks of greenhouse gases (GHG) are assessed in this paper, together with other options for limiting anthropogenic climatic change and consequences. This chapter of the Intergovernmental Panel on Climate Change Working Group II`s 1996 report discusses the cross-sectorial potential for reducing emissions between areas discussed specifically in other chapters namely energy supply, industry, transportation, human settlements, agriculture and forestry, aiming to provide an integrated analysis of mitigation options with cross-cutting themes. Energy supply and demand issues within a low GHG emissions scenario are discussed as are issues relating to land use and land cover. Broadly-based concepts for counterbalancing climatic change are described and their mitigation potential assessed. (UK)

Search of fission products in 20Ne-ion beam interaction with 165Ho at 8 MeV/nucleon

International Nuclear Information System (INIS)

Singh, D.; Ali, R.; Afzal Ansari, M.; Rashid, M.H.

2006-01-01

In the present work, during the study complete fusion (CF) and incomplete fusion (ICF) in 20 Ne-induced reactions, the production cross-sections for several fission products in 20 Ne + 165 Ho system have been measured

Measuring Cross-Section and Estimating Uncertainties with the fissionTPC

Energy Technology Data Exchange (ETDEWEB)

Bowden, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Manning, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sangiorgio, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Seilhan, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-01-30

The purpose of this document is to outline the prescription for measuring fission cross-sections with the NIFFTE fissionTPC and estimating the associated uncertainties. As such it will serve as a work planning guide for NIFFTE collaboration members and facilitate clear communication of the procedures used to the broader community.

Demonstrating diamond wire cutting of the TFTR

International Nuclear Information System (INIS)

Rule, K.; Perry, E.; Larson, S.; Viola, M.

2000-01-01

The Tokamak Fusion Test Reactor (TFTR) ceased operation in April 1997 and decommissioning commenced in October 1999. The deuterium-tritium fusion experiments resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 50 mRem/hr. These radiological hazards along with the size of the Tokamak (100 cubic meters) present a unique and challenging task for dismantling. Plasma arc cutting is the current baseline technology for the dismantlement of fission reactors. This technology is typically used because of its faster cutting times. Alternatively, an innovative approach for dismantlement of the TFTR is the use of diamond wire cutting technology. Recent improvements in diamond wire technology have allowed the cutting of carbon steel components such as pipe, plate, and tube bundles in heat exchangers. Some expected benefits of this technology include: significantly reduction in airborne contaminates, reduced personnel exposure, a reduced risk of spread of tritium contamination, and reduced overall costs as compared to using plasma arc cutting. This paper will provide detailed results of the diamond wire cutting demonstration that was completed in September of 1999, on a mock-up of this complex reactor. The results will identify cost, safety, industrial and engineering parameters, and the related performance of each situation

Demonstrating diamond wire cutting of the TFTR

Energy Technology Data Exchange (ETDEWEB)

Rule, K.; Perry, E.; Larson, S.; Viola, M. [and others

2000-02-24

The Tokamak Fusion Test Reactor (TFTR) ceased operation in April 1997 and decommissioning commenced in October 1999. The deuterium-tritium fusion experiments resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 50 mRem/hr. These radiological hazards along with the size of the Tokamak (100 cubic meters) present a unique and challenging task for dismantling. Plasma arc cutting is the current baseline technology for the dismantlement of fission reactors. This technology is typically used because of its faster cutting times. Alternatively, an innovative approach for dismantlement of the TFTR is the use of diamond wire cutting technology. Recent improvements in diamond wire technology have allowed the cutting of carbon steel components such as pipe, plate, and tube bundles in heat exchangers. Some expected benefits of this technology include: significantly reduction in airborne contaminates, reduced personnel exposure, a reduced risk of spread of tritium contamination, and reduced overall costs as compared to using plasma arc cutting. This paper will provide detailed results of the diamond wire cutting demonstration that was completed in September of 1999, on a mock-up of this complex reactor. The results will identify cost, safety, industrial and engineering parameters, and the related performance of each situation.

US-DOE Fusion-Breeder Program: blanket design and system performance

International Nuclear Information System (INIS)

Lee, J.D.

1983-01-01

Conceptual design studies are being used to assess the technical and economic feasibility of fusion's potential to produce fissile fuel. A reference design of a fission-suppressed blanket using conventional materials is under development. Theoretically, a fusion breeder that incorporates this fusion-suppressed blanket surrounding a 3000-MW tandem mirror fusion core produces its own tritium plus 5600 kg of 233 U per year. The 233 U could then provide fissile makeup for 21 GWe of light-water reactor (LWR) power using a denatured thorium fuel cycle with full recycle. This is 16 times the net electric power produced by the fusion breeder (1.3 GWe). The cost of electricity from this fusion-fission system is estimated to be only 23% higher than the cost from LWRs that have makeup from U 3 O 8 at present costs (55 $/kg). Nuclear performance, magnetohydrodynamics (MHD), radiation effects, and other issues concerning the fission-suppressed blanket are summarized, as are some of the present and future objectives of the fusion breeder program

EDITORIAL: Special issue: overview reports from the Fusion Energy Conference (FEC) (Daejeon, South Korea, 2010) Special issue: overview reports from the Fusion Energy Conference (FEC) (Daejeon, South Korea, 2010)

Science.gov (United States)

Thomas, Paul

2011-09-01

-U tokamak in China. Other MCF Overview of results from the Large Helical Device; Overview of TJ-II experiments; Overview of the RFX fusion science program. ICF Progress toward ignition on the National Ignition Facility; Studying ignition schemes on European laser facilities; Cross device or cross programme topical overviews Effects of 3D magnetic perturbations on toroidal plasmas; Toroidal momentum transport. We trust that, as usual, this issue will be a useful resource for the community and we thank all of the authors and referees for their hard work in preparing the papers for publication. Whilst the number of overview reports is the same as for the Geneva FEC special issue (2009 Nucl. Fusion 49 100201), we are pleased to note that we have a complete set of summaries in this issue.

Short-Term Forecasting of Taiwanese Earthquakes Using a Universal Model of Fusion-Fission Processes

NARCIS (Netherlands)

Cheong, S.A.; Tan, T.L.; Chen, C.-C.; Chang, W.-L.; Liu, Z.; Chew, L.Y.; Sloot, P.M.A.; Johnson, N.F.

2014-01-01

Predicting how large an earthquake can be, where and when it will strike remains an elusive goal in spite of the ever-increasing volume of data collected by earth scientists. In this paper, we introduce a universal model of fusion-fission processes that can be used to predict earthquakes starting

Progress in fission product nuclear data

International Nuclear Information System (INIS)

Lammer, M.

1982-07-01

This is the eighth issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The main part of this report consists of unaltered original contributions which the authors have sent to IAEA/NDS. Therefore, the IAEA cannot be held responsible for the information contained nor for any consequences resulting from the use of this information. The present issue contains also a section with some recent references relative to fission product nuclear data, which were not covered by the contributions submitted. The types of activities being included in this report are measurements, compilations and evaluations of: Fission product yields (neutron induced and spontaneous fission); Neutron reaction cross sections of fission products; Data related to the radioactive decay of fission products; Delayed neutron data of fission products; and lumped fission product data (decay heat, absorption etc.). The seventh issue of this series has been published in July 1981 as INDC(NDS)-116. The present issue includes contributions which were received by NDS between 1 August 1981 and 15 June 1982

Tables of RCN-2 fission-product cross section evaluation

International Nuclear Information System (INIS)

Gruppelaar, H.

1979-05-01

This report (continuation of ECN-13 and ECN-33) describes the third part of the RCN-2 evaluation of neutron cross sections for fission product nuclides in KEDAK format. It contains evaluated data for nine nuclides, i.e. 142 Nd, 143 Nd, 144 Nd, 145 Nd, 146 Nd, 147 Nd, 148 Nd, 150 Nd and 147 Pm. Most emphasis has been given to the evaluation of the radiative capture cross section, in order to provide a data base for adjustment calculations using results of integral measurements. Short evaluation reports are given for this cross section. The evaluated capture cross sections are compared with recent experimental differential and integral data. Graphs are given of the capture cross sections at neutron energies above 1 keV, in which also adjusted point cross sections, based upon integral STEK and CFRMF data have been plotted. Moreover, the results are compared with those of the well-known ENDF/B-IV evaluation for fission product nucleides. Finally, evaluation summaries are given, which include tables of other important neutron cross sections, such as the total, elastic scattering and inelastic scattering cross sections

What can be learnt from the channel analysis of the 232Th neutron fission cross section

International Nuclear Information System (INIS)

Abou Yehia, H.; Jary, J.; Trochon, J.; Boldeman, J.W.; Musgrove, A.R. de L.

1979-10-01

Channel analyses of the neutron fission cross section of 232 Th have been made in two laboratories. The calculated fission cross sections and fission fragment anisotropies are compared with the experimental data. Despite some differences in the methods used, the conclusions on the physical aspects of the fission process are very similar

Simultaneous measurement of neutron-induced fission and capture cross sections for {sup 241}Am at neutron energies below fission threshold

Energy Technology Data Exchange (ETDEWEB)

Hirose, K., E-mail: hirose.kentaro@jaea.go.jp [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Nishio, K.; Makii, H.; Nishinaka, I.; Ota, S. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Nagayama, T. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Graduate School of Science and Engineering, Ibaraki University, Mito 310-0056 (Japan); Tamura, N. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Goto, S. [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Andreyev, A.N. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Vermeulen, M.J. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Gillespie, S.; Barton, C. [Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Kimura, A.; Harada, H. [Nuclear Science and Engineering Center, JAEA, Tokai, Ibaraki 319-1195 (Japan); Meigo, S. [J-PARC Center, JAEA, Tokai, Ibaraki 319-1195 (Japan); Chiba, S. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Ohtsuki, T. [Research Reactor Institute, Kyoto University, Kumatori-cho S' ennangun,Osaka 590-0494 (Japan)

2017-06-01

Fission and capture reactions were simultaneously measured in the neutron-induced reactions of {sup 241}Am at the spallation neutron facility of the Japan Proton Accelerator Research Complex (J-PARC). Data for the neutron energy range of E{sub n}=0.1–20 eV were taken with the TOF method. The fission events were observed by detecting prompt neutrons accompanied by fission using liquid organic scintillators. The capture reaction was measured by detecting γ rays emitted in the deexcitation of the compound nuclei using the same detectors, where the prompt fission neutrons and capture γ rays were separated by a pulse shape analysis. The cross sections were obtained by normalizing the relative yields at the first resonance to evaluations or other experimental data. The ratio of the fission to capture cross sections at each resonance is compared with those from an evaluated nuclear data library and other experimental data. Some differences were found between the present values and the library/literature values at several resonances.

Determination of the neutron-induced fission cross section of 242Pu

International Nuclear Information System (INIS)

Koegler, Toni Joerg

2016-01-01

Neutron induced fission cross sections of actinides like the Pu-isotopes are of relevance for the development of nuclear transmutation technologies. For 242 Pu, current uncertainties are of around 21%. Sensitivity studies show that the total uncertainty has to be reduced to below 5% to allow for reliable neutron physics simulations. This challenging task was performed at the neutron time-of-flight facility of the new German National Center for High Power Radiation Sources at HZDR, Dresden. Within the TRAKULA project, thin, large and homogeneous deposits of 235 U and 242 Pu have been produced successfully. Using two consecutively placed fission chambers allowed the determination of the neutron induced fission cross section of 242 Pu relative to 235 U. The areal density of the Plutonium targets was calculated using the measured spontaneous fission rate. Experimental results of the fast neutron induced fission of 242 Pu acquired at nELBE will be presented and compared to recent experiments and evaluated data. Corrections addressing the neutron scattering are discussed by using results of different neutron transport simulations (Geant 4, MCNP 6 and FLUKA).

The fusion-fission process in the reaction {sup 34}S+{sup 186}W near the interaction barrier

Energy Technology Data Exchange (ETDEWEB)

Harca, I. M. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, (FLNR JINR) Dubna, Russia and Faculty of Physics, University of Bucharest - P.O. Box MG 11, RO 77125, Bucharest-Magurele (Romania); Dmitriev, S.; Itkis, J.; Kozulin, E. M.; Knyazheva, G.; Loktev, T.; Novikov, K. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, (FLNR JINR) Dubna (Russian Federation); Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D. [IPN, CNRS/IN2P3, Univ. Paris-Sud, 91405 Orsay (France); Chubarian, G. [Cyclotron Institute, Texas A and M University, College Station, TX 77843-3366 (United States); Hanappe, F. [Universite Libre de Bruxelles (ULB), Bruxelles (Belgium); Piot, J.; Schmitt, C. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Trzaska, W. H. [Accelerator Laboratory of University of Jyväskylä (JYFL), Jyväskylä (Finland); Vardaci, E. [Dipartamento di Scienze Fisiche and INFN (INFN-Na), Napoli (Italy)

2015-02-24

The reaction {sup 34}S+{sup 186}W at E{sub lab}=160 MeV was investigated with the aim of diving into the features of the fusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiency gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer for fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The coupling of the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fission process and gives information regarding production of neutron-rich heavy nuclei. The FF–γ coincidence method is of better use then the γ – γ coincidence method when dealing with low statistic measurements and also offers the opportunity to precisely correct the Dopler shift for in-flight emitted gamma rays. Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to shell effects in the fragments. Coincident measurements allow for discrimination between the gamma rays by accepting a specific range within the mass distribution of the reaction products. Details regarding the experimental setup, methods of processing the acquisitioned data and preliminary results are presented.

Fusion-fission of heavy systems

International Nuclear Information System (INIS)

Rivet, M.F.; Alami, R.; Borderie, B.; Fuchs, H.; Gardes, D.; Gauvin, H.

1988-01-01

The influence of the entrance channel on fission processes was studied by forming the same composite system by two different target-projectile combinations ( 40 Ar + 209 Bi and 56 Fe + 187 Re, respectively). Compound nucleus fission and quasi fission were observed and the analysis was performed in the framework of the extra-extra-push model, which provides a qualitative interpretation of the results; limits for the extra-extra-push threshold are given, but problems with quantitative predictions for the extra-push are noted. (orig.)

Study of DD versus DT fusion fuel cycles for different fusion-fission hybrid energy systems

International Nuclear Information System (INIS)

Gohar, Y.; Baker, C.C.

1981-01-01

A study was performed to investigate the characteristics of an energy system to produce fissile fuel for fission reactors. DD and DT fusion reactors were examined in this study with either a thorium or uranium blanket for each fusion reactor. Various fuel cycles were examined for light-water reactors including the denatured fuel cycles (which may offer proliferation resistance compared to other fuel cycles); these fuel cycles include a uranium fuel cycle with 239 Pu makeup, a thorium fuel cycle with 239 Pu makeup, a denatured uranium fuel cycle with 233 U makeup, and a denatured thorium fuel cycle with 233 U makeup. Four different blankets were considered for this study. The first two blankets have a tritium breeding capability for DT reactors. Lithium oxide (Li 2 O) was used for tritium breeding due to its high lithium density and high temperature capability; however, the use of Li 2 O may result in higher tritium inventories compared to other solid breeders

Fusion breeder: its potential role and prospects

International Nuclear Information System (INIS)

Lee, J.D.

1981-01-01

The fusion breeder is a concept that utilizes 14 MeV neutrons from D + T → n(14.1 MeV) + α(3.5 MeV) fusion reactions to produce more fuel than the tritium (T) needed to sustain the fusion process. This excess fuel production capacity is used to produce fissile material (Pu-239 or U-233) for subsequent use in fission reactors. We are concentrating on a class of blankets we call fission suppressed. The blanket is the region surrounding the fusion plasma in which fusion neutrons interact to produce fuel and heat. The fission-suppressed blanket uses non-fission reactions (mainly (n,2n) or (n,n't)) to generate excess neutrons for the production of net fuel. This is in contrast to the fast fission class of blankets which use (n,fiss) reactions to generate excess neutrons. Fusion reactors with fast fission blankets are commony known as fusion-fission hybrids because they combine fusion and fission in the same device

Muon catalyzed fusion - fission reactor driven by a recirculating beam

International Nuclear Information System (INIS)

Eliezer, S.; Tajima, T.; Rosenbluth, M.N.

1986-01-01

The recent experimentally inferred value of multiplicity of fusion of deuterium and tritium catalyzed by muons has rekindled interest in its application to reactors. Since the main energy expended is in pion (and consequent muon) productions, we try to minimize the pion loss by magnetically confining pions where they are created. Although it appears at this moment not possible to achieve energy gain by pure fusion, it is possible to gain energy by combining catalyzed fusion with fission blankets. We present two new ideas that improve the muon fusion reactor concept. The first idea is to combine the target, the converter of pions into muons, and the synthesizer into one (the synergetic concept). This is accomplished by injecting a tritium or deuterium beam of 1 GeV/nucleon into DT fuel contained in a magnetic mirror. The confined pions slow down and decay into muons, which are confined in the fuel causing little muon loss. The necessary quantity of tritium to keep the reactor viable has been derived. The second idea is that the beam passing through the target is collected for reuse and recirculated, while the strongly interacted portion of the beam is directed to electronuclear blankets. The present concepts are based on known technologies and on known physical processes and data. 29 refs., 6 figs., 4 tabs

Comparison of {sup 235}U fission cross sections in JENDL-3.3 and ENDF/B-VI

Energy Technology Data Exchange (ETDEWEB)

Kawano, Toshihiko [Kyushu Univ., Fukuoka (Japan); Carlson, Allan D. [National Institute of Standards and Technology (United States); Matsunobu, Hiroyuki [Data Engineering, Inc., Fujisawa, Kanagawa (Japan); Nakagawa, Tsuneo; Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Talou, Patrick; Young, Philip G.; Chadwick, Mark B. [Los Alamos National Laboratory, Los Alamos, NM (United States)

2002-01-01

Comparisons of evaluated fission cross sections for {sup 235}U in JENDL-3.3 and ENDF/B-VI are carried out. The comparisons are made for both the differential and integral data. The fission cross sections as well as the fission ratios are compared with the experimental data in detail. Spectrum averaged cross sections are calculated and compared with the measurements. The employed spectra are the {sup 235}U prompt fission neutron spectrum, the {sup 252}Cf spontaneous fission neutron spectrum, and the neutron spectrum produced by a {sup 9}Be(d, xn) reaction. For {sup 235}U prompt fission neutron spectrum, the ENDF/B-VI evaluation reproduces experimental averaged cross sections. For {sup 252}Cf and {sup 9}Be(d, xn) neutron spectra, the JENDL-3.3 evaluation gives better results than ENDF/B-VI. (author)

Fusion-fission hybrid design with analysis of direct enrichment and non-proliferation features (the SOLASE-H study)

International Nuclear Information System (INIS)

Conn, R.W.; Abdel-Khalik, S.I.; Moses, G.A.; Kulcinski, G.L.; Larsen, E.; Maynard, C.W.; Magheb, M.M.H.; Sviatolslavsky, I.N.; Vogelsang, W.F.; Wolfer, W.G.

1981-01-01

The role of a fusion-fission hybrid in the context of a nuclear economy with and without reprocessing is examined. An inertial confinement fusion driver is assumed and a consistent set of reactor parameters are developed. The form of the driver is not critical, however, to the general concepts. The use of the hybrid as a fuel factory within a secured fuel production and reprocessing center is considered. Either the hybrid or a low power fission reactor can be used to mildly irradiate fuel prior to shipment to offsite reactors thereby rendering the fuel resistant to diversion. A simplified economic analysis indicates a hybrid providing fuel to 10 fission reactors of equal thermal power is insensitive to the recirculating power fraction provided reprocessing is permitted. If reprocessing is not allowed, the hybrid can be used to directly enrich light water reactor fuel bundles fabricated initially from fertile fuel (either ThO 2 or 238 UO 2 ). A detailed neutronic analysis indicates such direct enrichments is feasible but the support ratio for 233 U or 239 Pu production is only 2, making such an approach highly sensitive to the hybrid cost. The hybrid would have to produce considerable net power for economic feasibility in this case. Inertial confinement fusion performance requirements for hybrid application are also examined and an integrated design, SOLASE-H, is described based upon the direct enrichment concept. (orig.)

Predation risk shapes social networks in fission-fusion populations.

Directory of Open Access Journals (Sweden)

Jennifer L Kelley

Full Text Available Predation risk is often associated with group formation in prey, but recent advances in methods for analysing the social structure of animal societies make it possible to quantify the effects of risk on the complex dynamics of spatial and temporal organisation. In this paper we use social network analysis to investigate the impact of variation in predation risk on the social structure of guppy shoals and the frequency and duration of shoal splitting (fission and merging (fusion events. Our analyses revealed that variation in the level of predation risk was associated with divergent social dynamics, with fish in high-risk populations displaying a greater number of associations with overall greater strength and connectedness than those from low-risk sites. Temporal patterns of organisation also differed according to predation risk, with fission events more likely to occur over two short time periods (5 minutes and 20 minutes in low-predation fish and over longer time scales (>1.5 hours in high-predation fish. Our findings suggest that predation risk influences the fine-scale social structure of prey populations and that the temporal aspects of organisation play a key role in defining social systems.

Predation Risk Shapes Social Networks in Fission-Fusion Populations

Science.gov (United States)

Kelley, Jennifer L.; Morrell, Lesley J.; Inskip, Chloe; Krause, Jens; Croft, Darren P.

2011-01-01

Predation risk is often associated with group formation in prey, but recent advances in methods for analysing the social structure of animal societies make it possible to quantify the effects of risk on the complex dynamics of spatial and temporal organisation. In this paper we use social network analysis to investigate the impact of variation in predation risk on the social structure of guppy shoals and the frequency and duration of shoal splitting (fission) and merging (fusion) events. Our analyses revealed that variation in the level of predation risk was associated with divergent social dynamics, with fish in high-risk populations displaying a greater number of associations with overall greater strength and connectedness than those from low-risk sites. Temporal patterns of organisation also differed according to predation risk, with fission events more likely to occur over two short time periods (5 minutes and 20 minutes) in low-predation fish and over longer time scales (>1.5 hours) in high-predation fish. Our findings suggest that predation risk influences the fine-scale social structure of prey populations and that the temporal aspects of organisation play a key role in defining social systems. PMID:21912627

Formation of heavy compound nuclei, their survival and correlation with longtime-scale fission

International Nuclear Information System (INIS)

Karamyan, S.A.; Yakushev, A.B.

2006-01-01

Fusion of two massive nuclei with formation of super-heavy compound nucleus (CN) is driven by the potential energy gradient, as follows from the analysis of nuclear reaction cross-sections. The conservative energy of the system is deduced in simple approximation using regularized nuclear mass and interaction barrier values. Different reactions for the synthesis of Z c 110-118 nuclei are compared and the favourable conditions are found for fusion of the stable (W-Pt) isotopes with radioactive fission fragment projectiles, like 94 Kr or 100 Sr. Thus, the cold fusion method can be extended for a synthesis of elements with Z > 113. Survival of the evaporation residue is defined by the neutron-to-fission probability ratio and by the successful emission of gammas at the final step of the reaction. Numerical estimates are presented. Fixation of evaporation residue products must correlate with longtime-scale fission and available experimental results are discussed

Neutronics analysis of water-cooled energy production blanket for a fusion-fission hybrid reactor

International Nuclear Information System (INIS)

Jiang Jieqiong; Wang Minghuang; Chen Zhong; Qiu Yuefeng; Liu Jinchao; Bai Yunqing; Chen Hongli; Hu Yanglin

2010-01-01

Neutronics calculations were performed to analyse the parameters of blanket energy multiplication factor (M) and tritium breeding ratio (TBR) in a fusion-fission hybrid reactor for energy production named FDS (Fusion-Driven hybrid System)-EM (Energy Multiplier) blanket. The most significant and main goal of the FDS-EM blanket is to achieve the energy gain of about 1 GWe with self-sustaining tritium, i.e. the M factor is expected to be ∼90. Four different fission materials were taken into account to evaluate M in subcritical blanket: (i) depleted uranium, (ii) natural uranium, (iii) enriched uranium, and (iv) Nuclear Waste (transuranic from 33 000 MWD/MTU PWR (Pressurized Water Reactor) and depleted uranium) oxide. These calculations and analyses were performed using nuclear data library HENDL (Hybrid Evaluated Nuclear Data Library) and a home-developed code VisualBUS. The results showed that the performance of the blanket loaded with Nuclear Waste was most attractive and it could be promising to effectively obtain tritium self-sufficiency and a high-energy multiplication.

Complexity and availability for fusion power plants: The potential advantages of inertial fusion energy

International Nuclear Information System (INIS)

Perkins, L.J.

1997-01-01

Probably the single largest advantage of the inertial route to fusion energy (IFE) is the perception that its power plant embodiments could achieve acceptable capacity factors. This is a result of its relative simplicity, the decoupling of the driver and reactor chamber, and the potential to employ thick liquid walls. The author examines these issues in terms of the complexity, reliability, maintainability and, therefore, availability of both magnetic and inertial fusion power plants and compares these factors with corresponding scheduled and unscheduled outage data from present day fission experience. The author stresses that, given the simple nature of a fission core, the vast majority of unplanned outages in fission plants are due to failures outside the reactor vessel itself. Given one must be prepared for similar outages in the analogous plant external to a fusion power core, this puts severe demands on the reliability required of the fusion core itself. The author indicates that such requirements can probably be met for IFE plants. He recommends that this advantage be promoted by performing a quantitative reliability and availability study for a representative IFE power plant and suggests that databases are probably adequate for this task. 40 refs., 4 figs., 3 tabs

Fission cross section measurements at the LLL 100-MeV linac

International Nuclear Information System (INIS)

Browne, J.C.

1975-01-01

The fission cross section for 235 U was measured from thermal energy to 20 MeV in several steps. First, the cross section was measured from 8 MeV to 20 MeV relative to the n,p scattering cross section and then from thermal to one MeV relative to 6 Li(n,α). In addition, a measurement of the ratio of the fission cross sections of 235 U and 238 U relative to 235 U has been completed in the range 1 keV to 30 MeV for 233 U and 100 keV to 30 MeV for 238 U. Statistical uncertainties are less than 4 percent. (U.S.)

Fusion Canada issue 13

International Nuclear Information System (INIS)

1991-01-01

A short bulletin from the National Fusion Program. Included in this issue is a report on Canada's plans to participate in the Engineering Design Activities (EDA), bilateral meetings with Canada and the U.S., committee meeting with Canada-Europe, an update at Tokamak de Varennes on Plasma Biasing experiments and boronized graphite tests, fusion materials research at the University of Toronto using a dual beam accelerator and a review of the CFFTP and the CCFM. 2 figs

Fission theory and actinide fission data

Energy Technology Data Exchange (ETDEWEB)

Michaudon, A.

1975-06-01

The understanding of the fission process has made great progress recently, as a result of the calculation of fission barriers, using the Strutinsky prescription. Double-humped shapes were obtained for nuclei in the actinide region. Such shapes could explain, in a coherent manner, many different phenomena: fission isomers, structure in near-threshold fission cross sections, intermediate structure in subthreshold fission cross sections and anisotropy in the emission of the fission fragments. A brief review of fission barrier calculations and relevant experimental data is presented. Calculations of fission cross sections, using double-humped barrier shapes and fission channel properties, as obtained from the data discussed previously, are given for some U and Pu isotopes. The fission channel theory of A. Bohr has greatly influenced the study of low-energy fission. However, recent investigation of the yields of prompt neutrons and γ rays emitted in the resonances of {sup 235}U and {sup 239}Pu, together with the spin determination for many resonances of these two nuclei cannot be explained purely in terms of the Bohr theory. Variation in the prompt neutron and γ-ray yields from resonance to resonance does not seem to be due to such fission channels, as was thought previously, but to the effect of the (n,γf) reaction. The number of prompt fission neutrons and the kinetic energy of the fission fragments are affected by the energy balance and damping or viscosity effects in the last stage of the fission process, from saddle point to scission. These effects are discussed for some nuclei, especially for {sup 240}Pu.

Comparison of nuclear irradiation parameters of fusion breeder materials in high flux fission test reactors and a fusion power demonstration reactor

International Nuclear Information System (INIS)

Fischer, U.; Herring, S.; Hogenbirk, A.; Leichtle, D.; Nagao, Y.; Pijlgroms, B.J.; Ying, A.

2000-01-01

Nuclear irradiation parameters relevant to displacement damage and burn-up of the breeder materials Li 2 O, Li 4 SiO 4 and Li 2 TiO 3 have been evaluated and compared for a fusion power demonstration reactor and the high flux fission test reactor (HFR), Petten, the advanced test reactor (ATR, INEL) and the Japanese material test reactor (JMTR, JAERI). Based on detailed nuclear reactor calculations with the MCNP Monte Carlo code and binary collision approximation (BCA) computer simulations of the displacement damage in the polyatomic lattices with MARLOWE, it has been investigated how well the considered HFRs can meet the requirements for a fusion power reactor relevant irradiation. It is shown that a breeder material irradiation in these fission test reactors is well suited in this regard when the neutron spectrum is well tailored and the 6 Li-enrichment is properly chosen. Requirements for the relevant nuclear irradiation parameters such as the displacement damage accumulation, the lithium burn-up and the damage production function W(T) can be met when taking into account these prerequisites. Irradiation times in the order of 2-3 full power years are necessary for the HFR to achieve the peak values of the considered fusion power Demo reactor blanket with regard to the burn-up and, at the same time, the dpa accumulation

Preparation of lumped fission product (FP) cross sections for a multigroup library

International Nuclear Information System (INIS)

Ono, S.; Corcuera, R.P.

1984-01-01

A method for the calculation of lumped Fission Product (FP) cross sections has been developed. The group constants fo each nuclide are generated by NJOY code, based on ENDF/B-V data. In this first version, cross section of 28 nuclides are lumped for typical characteristics of Binary Breeder Reactor (BBR). One energy group calculations are made for a 1000 MWe fast reactor to verify the influence of burnup, number of FP and fuel composition on the lumped fission product cross sections. (Author) [pt

Non-electrical uses of thermal energy generated in the production of fissile fuel in fusion--fission reactors: a comparative economic parametric analysis for a hybrid with or without synthetic fuel production

International Nuclear Information System (INIS)

Tai, A.S.; Krakowski, R.A.

1979-01-01

A parametric analysis has been carried out for testing the sensitivity of the synfuel production cost in relation to crucial economic and technologic quantities (investment costs of hybrid and synfuel plant, energy multiplication of the fission blanket, recirculating power fraction of the fusion driver, etc.). In addition, a minimum synfuel selling price has been evaluated, from which the fission--fusion--synfuel complex brings about a higher economic benefit than does the fusion--fission hybrid entirely devoted to fissile-fuel and electricity generation. Assuming an electricity cost of 2.7 cents/kWh, an annual investment cost per power unit of 4.2 to 6 $/GJ (132 to 189 k$/MWty) for the fission--fusion complex and 1.5 to 3 $/GJ (47 to 95 k$/MWty) for the synfuel plant, the synfuel production net cost (i.e., revenue = cost) varies between 6.5 and 8.6 $/GJ. These costs can compete with those obtained by other processes (natural gas reforming, resid partial oxidation, coal gasification, nuclear fission, solar electrolysis, etc.). This study points out a potential use of the fusion--fission hybrid other than fissile-fuel and electricity generation

Investigation of tritium and 233U breeding in a fission-fusion hybrid reactor fuelling with ThO2

International Nuclear Information System (INIS)

Yildiz, K.; Sahin, S.; Sahin, H. M.; Acir, A.; Yalcin, S.; Altinok, T.; Bayrak, M.; Alkan, M.; Durukan, O.

2007-01-01

In the world, thorium reserves are three times more than natural Uranium reserves. It is planned in the near future that nuclear reactors will use thorium as a fuel. Thorium is not a fissile isotope because it doesn't make fission with thermal neutrons so it could be converted to 2 33U isotope which has very high quality fission cross-section with thermal neutrons. 2 33U isotope can be used in present LWRs as an enrichment fuel. In the fusion reactors, tritium is the most important fossil fuel. Because tritium is not natural isotope, it has to be produced in the reactor. The purpose of this work is to investigate the tritium and 2 33U breeding in a fission-fusion hybrid reactor fuelling with ThO 2 for Δt=10 days during a reactor operation period in five years. The neutronic analysis is performed on an experimental hybrid blanket geometry. In the center of the hybrid blanket, there is a line neutron source in a cylindrical cavity, which simulates the fusion plasma chamber where high energy neutrons (14.1 MeV) are produced. The conventional fusion reaction delivers the external neutron source for blankets following, 2 D + 3 T →? 4 He (3.5 MeV) + n (14.1 MeV). (1) The fuel zone made up of natural-ThO 2 fuel and it is cooled with different coolants. In this work, five different moderator materials, which are Li 2 BeF 4 , LiF-NaF-BeF 2 , Li 2 0Sn 8 0, natural Lithium and Li 1 7Pb 8 3, are used as coolants. The radial reflector, called tritium breeding zones, is made of different Lithium compounds and graphite in sandwich structure. In the work, eight different Lithium compounds were used as tritium breeders in the tritium breeding zones, which are Li 3 N, Li 2 O, Li 2 O 2 , Li 2 TiO 3 , Li 4 SiO 3 , Li 2 ZrO 3 , LiBr and LiH. Neutron transport calculations are conducted in spherical geometry with the help of SCALE4.4A SYSTEM by solving the Boltzmann transport equation with code CSAS and XSDRNPM, under consideration of unresolved and resolved resonances, in S 8 -P 3

Canadian contributions to the safety and environmental aspects of fusion

International Nuclear Information System (INIS)

Stasko, R.; Wong, K.

1987-05-01

Since next-step fusion devices will be fuelled with mixtures of tritium and deuterium, the knowledge base and tritium handling experience associated with the operation of CANDU reactors is viewed as relevant to the development of safe fusion technology. Fusion safety issues will be compared with fission safety experience, after which specific Canadian activities in support of fusion safety will be overviewed. In addition, recommendations for appropriate fusion safety criteria will be summarized. 18 refs

Challenging fission cross section simulation with long standing macro-microscopic model of nucleus potential energy surface

International Nuclear Information System (INIS)

Tamagno, Pierre

2015-01-01

The work presented here aims to improve models used in the fission cross section evaluation. The results give insights for a significant breakthrough in this field and yielded large extensions of the evaluation code CONRAD. Partial cross sections are inherently strongly correlated together as of the competition of the related reactions must yield the total cross section. Therefore improving fission cross section benefits to all partial cross sections. A sound framework for the simulation of competitive reactions had to be settled in order to further investigate on the fission reaction; this was implemented using the TALYS reference code as guideline. After ensuring consistency and consistency of the framework, focus was made on fission. Perspective resulting from the use of macroscopic-microscopic models such as the FRDM and FRLDM were analyzed; these models have been implemented and validated on experimental data and benchmarks. To comply with evaluation requirements in terms of computation time, several specific numerical methods have been used and parts of the program were written to run on GPU. These macroscopic-microscopic models yield potential energy surfaces that can be used to extract a one-dimensional fission barrier. This latter can then be used to obtained fission transmission coefficients that can be used in a Hauser-Feshbach model. This method has been finally tested for the calculation of the average fission cross section for 239 Pu(n,f). (author) [fr

Issues in the commercialization of magnetic fusion power

International Nuclear Information System (INIS)

Rockwood, A.D.; Willke, T.L.

1979-12-01

This study identifies and outlines the issues that must be considered if fusion is to be put into commercial practice. The issues are put into perspective around a consistent framework and a program of study and research is recommended to anticipate and handle the issues for a successful fusion commercialization program

Fusion Canada issue 11

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-06-01

A short bulletin from the National Fusion Program. Included in this issue is a report on operation at Tokamak de Varennes, CRITIC irradiations at AECL, Tritium systems at TFTR, physics contribution at ITER. 4 figs.

Evaluations of fission product capture cross sections for ENDF/B-V

International Nuclear Information System (INIS)

Schenter, R.E.; Johnson, D.L.; Mann, F.M.; Schmittroth, F.

1979-01-01

Capture cross section evaluations were made for the 36 most important fission product absorbers in a fast reactor system. These evaluations were obtained by use of a generalized least-squares approach with calculations being performed with the computer code FERRET. These results will provide the major revisions to the ENDF/B-IV Fission Product Cross Section File which will be released as part of ENDF/B-V. Input for the cross section adjustment calculations included both integral and differential experimental data results. The differential cross sections and their uncertainties were obtained from the CSIRS library. Integral measurement results came from CFRMF and STEK Assemblies 500, 1000, 2000, 3000, and 4000. Comparisons of these evaluations with recent capture measurements are presented. 14 figures

Fusion probability and survivability in estimates of heaviest nuclei production

Directory of Open Access Journals (Sweden)

Sagaidak Roman N.

2012-02-01

Full Text Available Production of the heavy and heaviest nuclei (from Po to the region of superheavy elements close to Z=114 and N=184 in fusion-evaporation reactions induced by heavy ions has been considered in a systematic way within the framework of the barrier-passing model coupled with the statistical model (SM of de-excitation of a compound nucleus (CN. Excitation functions for fission and evaporation residues (ER measured in very asymmetric combinations can be described rather well. One can scale and fix macroscopic (liquid-drop fission barriers for nuclei involved in the calculation of survivability with SM. In less asymmetric combinations, effects of fusion suppression caused by quasi-fission (QF are starting to appear in the entrance channel of reactions. QF effects could be semi-empirically taken into account using fusion probabilities deduced as the ratio of measured ER cross sections to the ones obtained in the assumption of absence of the fusion suppression in corresponding reactions. SM parameters (fission barriers obtained at the analysis of a very asymmetric combination leading to the production of (nearly the same CN should be used for this evaluation.

Issues in the commercialization of magnetic fusion power

Energy Technology Data Exchange (ETDEWEB)

Rockwood, A.D.; Willke, T.L.

1979-12-01

This study identifies and outlines the issues that must be considered if fusion is to be put into commercial practice. The issues are put into perspective around a consistent framework and a program of study and research is recommended to anticipate and handle the issues for a successful fusion commercialization program. (MOW)

Comparison of different Skyrme forces: Fusion barriers and fusion cross sections

International Nuclear Information System (INIS)

Puri, R.K.; Gupta, R.K.

1995-01-01

Fusion barriers and fusion cross sections are calculated using the Skyrme energy-density formalism. To study the role of different parametrizations of the Skyrme interaction, we use two typical forces, i.e., the original Skyrme force S and the widely used Skyrme force SIII. Our calculations show that, in the reactions considered here, the Skyrme force S gives higher fusion cross sections compared to that of the Skyrme force SIII. The main part of this difference can be associated with the presence of the spin-density contribution in the Skyrme force SIII

Mitochondrial fusion and fission proteins as novel therapeutic targets for treating cardiovascular disease

OpenAIRE

Ong, Sang-Bing; Kalkhoran, Siavash Beikoghli; Cabrera-Fuentes, Hector A.; Hausenloy, Derek?J.

2015-01-01

The past decade has witnessed a number of exciting developments in the field of mitochondrial dynamics - a phenomenon in which changes in mitochondrial shape and movement impact on cellular physiology and pathology. By undergoing fusion and fission, mitochondria are able to change their morphology between elongated interconnected networks and discrete fragmented structures, respectively. The cardiac mitochondria, in particular, have garnered much interest due to their unique spatial arrangeme...

Dynamic of fission and quasi-fission revealed by pre-scission neutron evaporation

International Nuclear Information System (INIS)

Hinde, D.J.

1991-06-01

The dependence of pre-scission neutron multiplicities (ν-pre) on the mass-split and total kinetic energy (TKE) in fusion-fission and quasi-fission has been measured for a wide range of projectile-target combinations. the data indicate that the fusion-fission time scale is shorter for asymmetric splits than for symmetric splits, whilst there is no dependence on TKE. For quasi-fission reactions induced using 64 Ni projectiles, ν-pre falls rapidly with increasing TKE, indicating that these neutrons are emitted near to or after scission. A new interpretation of both neutron multiplicities and mean energies (the neutron clock-thermometer) allows the extraction of time scales with much less uncertainty than previously, and also gives information about the deformation from which the neutrons are emitted. 15 refs., 13 figs

Consultants’ Meeting on Recommended Input Parameters for Fission Cross-Section Calculations. Summary Report

International Nuclear Information System (INIS)

Capote Noy, Roberto; Simakov, Stanislav; Goriely, Stephane; Hilaire, Stephane; Iwamoto, Osamu; Kawano, Toshihiko; Koning, Arjan

2014-12-01

A Consultants’ Meeting on “Recommended Input Parameters for Fission Cross-Section Calculations” was held at IAEA Headquarters, Vienna, Austria to define the scope, deliverables and appropriate work programme of a possible Coordinated Research Project (CRP) on the subject. Presentations are available online at https://www-nds.iaea.org/indexmeeting-crp/CM-RIPL-fission/. A new CRP was endorsed to recommend a comprehensive set of fission input parameters needed for the modelling of fission cross sections. Special attention will be given to the modelling of photon and nucleon induced reactions on actinides with emphasis on incident energies below 30 MeV. The goals and detailed deliverables of the planned CRP were proposed. A Hauser-Feshbach code intercomparison was recommended. (author)

Study of fission cross sections induced by nucleons and pions using the cascade-exciton model CEM95

International Nuclear Information System (INIS)

Yasin, Z.; Shahzad, M. I.

2007-01-01

Nucleon and pion-induced fission cross sections at intermediate and at higher energies are important in current nuclear applications, such as accelerator driven-systems (ADS), in medicine, for effects on electronics etc. In the present work, microscopic fission cross sections induced by nucleons and pions are calculated using the cascade-exciton model code CEM95 for different projectile-target combinations; at various energies and the computed cross sections are compared with the experimental data found in literature. A new approach is used to compute the fission cross sections in which a change of the ratio of the level density parameter in fission to neutron emission channels was taken into account with the change in the incident energy of the projectile. We are unable to describe well the fission cross sections without using this new approach. Proton induced fission cross sections are calculated for targets 1 97Au, 2 08Pb, 2 09Bi, 2 38U and 2 39Pu in the energy range from 20 MeV to 2000 MeV. Neutron induced fission cross sections are computed for 2 38U and 2 39Pu in the energy range from 20 MeV to 200 MeV. Negative pion induced cross sections for fission are calculated for targets 1 97Au and 2 08Pb from 50 MeV to 2500 MeV energy range. The calculated cross sections are essential to build a data library file for accelerator driven systems just like was built for conventional nuclear reactors. The computed values exhibited reasonable agreement with the experimental values found in the literature across a wide range of beam energies

Fission neutron spectrum averaged cross sections for threshold reactions on arsenic

International Nuclear Information System (INIS)

Dorval, E.L.; Arribere, M.A.; Kestelman, A.J.; Comision Nacional de Energia Atomica, Cuyo Nacional Univ., Bariloche; Ribeiro Guevara, S.; Cohen, I.M.; Ohaco, R.A.; Segovia, M.S.; Yunes, A.N.; Arrondo, M.; Comision Nacional de Energia Atomica, Buenos Aires

2006-01-01

We have measured the cross sections, averaged over a 235 U fission neutron spectrum, for the two high threshold reactions: 75 As(n,p) 75 mGe and 75 As(n,2n) 74 As. The measured averaged cross sections are 0.292±0.022 mb, referred to the 3.95±0.20 mb standard for the 27 Al(n,p) 27 Mg averaged cross section, and 0.371±0.032 mb referred to the 111±3 mb standard for the 58 Ni(n,p) 58m+g Co averaged cross section, respectively. The measured averaged cross sections were also evaluated semi-empirically by numerically integrating experimental differential cross section data extracted for both reactions from the current literature. The calculations were performed for four different representations of the thermal-neutron-induced 235 U fission neutron spectrum. The calculated cross sections, though depending on analytical representation of the flux, agree with the measured values within the estimated uncertainties. (author)

Analysis of laser remote fusion cutting based on a mathematical model

Energy Technology Data Exchange (ETDEWEB)

Matti, R. S. [Department of Engineering Sciences and Mathematics, Luleå University of Technology, S-971 87 Luleå (Sweden); Department of Mechanical Engineering, College of Engineering, University of Mosul, Mosul (Iraq); Ilar, T.; Kaplan, A. F. H. [Department of Engineering Sciences and Mathematics, Luleå University of Technology, S-971 87 Luleå (Sweden)

2013-12-21

Laser remote fusion cutting is analyzed by the aid of a semi-analytical mathematical model of the processing front. By local calculation of the energy balance between the absorbed laser beam and the heat losses, the three-dimensional vaporization front can be calculated. Based on an empirical model for the melt flow field, from a mass balance, the melt film and the melting front can be derived, however only in a simplified manner and for quasi-steady state conditions. Front waviness and multiple reflections are not modelled. The model enables to compare the similarities, differences, and limits between laser remote fusion cutting, laser remote ablation cutting, and even laser keyhole welding. In contrast to the upper part of the vaporization front, the major part only slightly varies with respect to heat flux, laser power density, absorptivity, and angle of front inclination. Statistical analysis shows that for high cutting speed, the domains of high laser power density contribute much more to the formation of the front than for low speed. The semi-analytical modelling approach offers flexibility to simplify part of the process physics while, for example, sophisticated modelling of the complex focused fibre-guided laser beam is taken into account to enable deeper analysis of the beam interaction. Mechanisms like recast layer generation, absorptivity at a wavy processing front, and melt film formation are studied too.

Analysis of laser remote fusion cutting based on a mathematical model

International Nuclear Information System (INIS)

Matti, R. S.; Ilar, T.; Kaplan, A. F. H.

2013-01-01

Laser remote fusion cutting is analyzed by the aid of a semi-analytical mathematical model of the processing front. By local calculation of the energy balance between the absorbed laser beam and the heat losses, the three-dimensional vaporization front can be calculated. Based on an empirical model for the melt flow field, from a mass balance, the melt film and the melting front can be derived, however only in a simplified manner and for quasi-steady state conditions. Front waviness and multiple reflections are not modelled. The model enables to compare the similarities, differences, and limits between laser remote fusion cutting, laser remote ablation cutting, and even laser keyhole welding. In contrast to the upper part of the vaporization front, the major part only slightly varies with respect to heat flux, laser power density, absorptivity, and angle of front inclination. Statistical analysis shows that for high cutting speed, the domains of high laser power density contribute much more to the formation of the front than for low speed. The semi-analytical modelling approach offers flexibility to simplify part of the process physics while, for example, sophisticated modelling of the complex focused fibre-guided laser beam is taken into account to enable deeper analysis of the beam interaction. Mechanisms like recast layer generation, absorptivity at a wavy processing front, and melt film formation are studied too

Mathematical modelling and linear stability analysis of laser fusion cutting

International Nuclear Information System (INIS)

Hermanns, Torsten; Schulz, Wolfgang; Vossen, Georg; Thombansen, Ulrich

2016-01-01

A model for laser fusion cutting is presented and investigated by linear stability analysis in order to study the tendency for dynamic behavior and subsequent ripple formation. The result is a so called stability function that describes the correlation of the setting values of the process and the process’ amount of dynamic behavior.

Mathematical modelling and linear stability analysis of laser fusion cutting

Energy Technology Data Exchange (ETDEWEB)

Hermanns, Torsten; Schulz, Wolfgang [RWTH Aachen University, Chair for Nonlinear Dynamics, Steinbachstr. 15, 52047 Aachen (Germany); Vossen, Georg [Niederrhein University of Applied Sciences, Chair for Applied Mathematics and Numerical Simulations, Reinarzstr.. 49, 47805 Krefeld (Germany); Thombansen, Ulrich [RWTH Aachen University, Chair for Laser Technology, Steinbachstr. 15, 52047 Aachen (Germany)

2016-06-08

A model for laser fusion cutting is presented and investigated by linear stability analysis in order to study the tendency for dynamic behavior and subsequent ripple formation. The result is a so called stability function that describes the correlation of the setting values of the process and the process’ amount of dynamic behavior.

Neutron-induced Fission Cross Sections of Am and Cm isotopes (Final Report of Research Contract 14485). Resonance and Fast Neutron Induced Fission Cross Sections of Americium and Curium Nuclides (Third-year Progress Report of Research Contract 14485)

International Nuclear Information System (INIS)

Alekseev, A.A.; Bergman, A.A.; Berlev, A.I.; Koptelov, E.A.; Egorov, A.S.; Samylin, B.F.; Trufanov, A.M.; Fursov, B.I.; Shorin, V.S.

2012-01-01

The neutron induced fission cross sections of Am and Cm isotopes were measured relative to 239 Pu in the neutron energy range from 1 eV to 20 keV at the INR RAS lead slowing down spectrometer LSDS-100. The fission resonance integrals were also estimated using the measured cross section data. The results have been compared with the available experimental and evaluated data. This analysis has shown the present status of the measured fission cross sections and the necessity to revise the evaluated cross sections libraries for the minor actinides. (author)

Comparison of the recently proposed super-Marx generator approach to thermonuclear ignition with the deuterium-tritium laser fusion-fission hybrid concept by the Lawrence Livermore National Laboratory

International Nuclear Information System (INIS)

Winterberg, F.

2009-01-01

The recently proposed super-Marx generator pure deuterium microdetonation ignition concept is compared to the Lawrence Livermore National Ignition Facility (NIF) Laser deuterium-tritium fusion-fission hybrid concept (LIFE). In a super-Marx generator, a large number of ordinary Marx generators charge up a much larger second stage ultrahigh voltage Marx generator from which for the ignition of a pure deuterium microexplosion an intense GeV ion beam can be extracted. Typical examples of the LIFE concept are a fusion gain of 30 and a fission gain of 10, making up a total gain of 300, with about ten times more energy released into fission as compared to fusion. This means the substantial release of fission products, as in fissionless pure fission reactors. In the super-Marx approach for the ignition of pure deuterium microdetonation, a gain of the same magnitude can, in theory, be reached. If feasible, the super-Marx generator deuterium ignition approach would make lasers obsolete as a means for the ignition of thermonuclear microexplosions

Overview of nonelectrical applications of fusion

International Nuclear Information System (INIS)

Miley, G.H.

1979-01-01

The potential for, and importance of, nonelectrical applications of fusion energy is discussed. Three possibilities are reviewed in some detail: fusion-fission hybrids for fissile fuel production; high-temperature electrolysis and thermochemical processes for hydrogen production; and high-temperature steam for coal gasification. The hybrid could be an early application of fusion if this route is identified as a desirable goal. Hydrogen production and coal gasification processes appear feasible and could be developed as a part of the conventional fusion blanket research and development. The question of economics, particularly in view of the high capital cost of fusion plants, remains an open issue requiring more study

Block-free optical quantum Banyan network based on quantum state fusion and fission

International Nuclear Information System (INIS)

Zhu Chang-Hua; Meng Yan-Hong; Quan Dong-Xiao; Zhao Nan; Pei Chang-Xing

2014-01-01

Optical switch fabric plays an important role in building multiple-user optical quantum communication networks. Owing to its self-routing property and low complexity, a banyan network is widely used for building switch fabric. While, there is no efficient way to remove internal blocking in a banyan network in a classical way, quantum state fusion, by which the two-dimensional internal quantum states of two photons could be combined into a four-dimensional internal state of a single photon, makes it possible to solve this problem. In this paper, we convert the output mode of quantum state fusion from spatial-polarization mode into time-polarization mode. By combining modified quantum state fusion and quantum state fission with quantum Fredkin gate, we propose a practical scheme to build an optical quantum switch unit which is block free. The scheme can be extended to building more complex units, four of which are shown in this paper. (general)

Fission-neutron displacement cross sections in metals

International Nuclear Information System (INIS)

Takamura, Saburo; Aruga, Takeo; Nakata, Kiyotomo

1985-01-01

The sensitivity damage rates for 22 metals were measured after fission-spectrum neutron irradiation at low temperature and the experimental damage rates were compared with the theoretical calculation. The relation between the theoretical displacement cross section and the atomic weight of metals can be written by two curves; one is for fcc and hcp metals, and another is for bcc metals. On the other hand, the experimental displacement cross section versus atomic weight is shown approximately by a curve for both fcc and bcc metals, and the cross section for hcp metals deviates from the curve. The defect production efficiency is 0.3-0.4 for fcc metals and 0.6-0.8 for bcc metals. (orig.)

Liquid metal coolants for fusion-fission hybrid system: A neutronic analysis

Energy Technology Data Exchange (ETDEWEB)

Marques, Renato V.A.; Velasquez, Carlos E.; Pereira, Claubia; Veloso, Maria Auxiliadora F.; Costa, Antonella L., E-mail: claubia@nuclear.ufmg.br [Universidade de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Barros, Graiciany P. [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

2017-07-01

Based on a work already published by the UFMG Nuclear Engineering Department, it was suggested to use different coolant materials in a fusion-fission system after a fuel burnup simulation, including that one used in reference work. The goal is to compare the neutron parameters, such as the effect multiplication factor and actinide amounts in transmutation layer, for each used coolant and find the best(s) coolant material(s) to be applied in the considered system. Results indicate that the lead and lead-bismuth coolant are the most suitable choices to be applied to cool the system. (author)

Unified description of neutron-, proton- and photon-induced fission cross sections in intermediate energy region

International Nuclear Information System (INIS)

Fukahori, Tokio; Iwamoto, Osamu; Chiba, Satoshi

2003-01-01

For an accelerator-driven nuclear waste transmutation system, it is very important to estimate sub-criticality of core system for feasibility and design study of the system. The fission cross section in the intermediate energy range has an important role. A program FISCAL has been developed to calculate neutron-, proton- and photon-induced fission cross sections in the energy region from several tens of MeV to 3 GeV. FISCAL adopts the systematics considering experimental data for Ag- 243 Am. It is found that unified description of neutron-, proton- and photon-induced fission cross sections is available. (author)

Measurements of neutron-induced capture and fission reactions on $^{235}$ U: cross sections and ${\\alpha}$ ratios, photon strength functions and prompt ${\\gamma}$-ray from fission

CERN Multimedia

We propose to measure the neutron-induced capture cross section of the fissile isotope $^{235}$U using a fission tagging set-up. This new set-up has been tested successfully in 2010 and combines the n_TOF 4${\\pi}$ Total Absorption Calorimeter (TAC) with MicroMegas (MGAS) fission detectors. It has been proven that such a combination of detectors allows distinguishing with very good reliability the electromagnetic cascades from the capture reactions from dominant ${\\gamma}$-ray background coming from the fission reactions. The accurate discrimination of the fission background is the main challenge in the neutron capture cross section measurements of fissile isotopes. The main results from the measurement will be the associated capture cross section and ${\\alpha}$ ratio in the resolved (0.3-2250 eV) and unresolved (2.25-30 keV) resonance regions. According to the international benchmarks and as it is mentioned in the NEA High Priority Request List (HPRL), the 235U(n,${\\gamma}$) cross section is of utmost impo...

Fusion dynamics in 40Ca induced reactions

International Nuclear Information System (INIS)

Prasad, E.; Hinde, D.J.; Williams, E.

2017-01-01

Synthesis of superheavy elements (SHEs) and investigation of their properties are among the most challenging research topics in modern science. A non-compound nuclear process called quasi fission is partly responsible for the very low production cross sections of SHEs. The formation and survival probabilities of the compound nucleus (CN) strongly depend on the competition between fusion and quasi fission. A clear understanding of these processes and their dynamics is required to make reliable predictions of the best reactions to synthesise new SHEs. All elements beyond Nh are produced using hot fusion reactions and beams of 48 Ca were used in most of these experiments. In this context a series of fission measurements have been carried out at the Australian National University (ANU) using 40;48 Ca beams on various targets ranging from 142 Nd to 249 Cf. Some of the 40 Ca reactions will be discussed in this symposium

Fusion Canada issue 7

International Nuclear Information System (INIS)

1989-05-01

A short bulletin from the National Fusion Program. Included in this issue are CFFTP highlights on the Karlsruhe Isotope Separation System, a report on ITER tritium process systems, an experimental update on Tokamak de Varennes and Canada-U.S. bilateral technical collaboration topics. 2 figs

Fusion Canada issue 7

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-05-01

A short bulletin from the National Fusion Program. Included in this issue are CFFTP highlights on the Karlsruhe Isotope Separation System, a report on ITER tritium process systems, an experimental update on Tokamak de Varennes and Canada-U.S. bilateral technical collaboration topics. 2 figs.

Fission and fusion interaction phenomena of mixed lump kink solutions for a generalized (3+1)-dimensional B-type Kadomtsev-Petviashvili equation

Science.gov (United States)

Liu, Yaqing; Wen, Xiaoyong

2018-05-01

In this paper, a generalized (3+1)-dimensional B-type Kadomtsev-Petviashvili (gBKP) equation is investigated by using the Hirota’s bilinear method. With the aid of symbolic computation, some new lump, mixed lump kink and periodic lump solutions are derived. Based on the derived solutions, some novel interaction phenomena like the fission and fusion interactions between one lump soliton and one kink soliton, the fission and fusion interactions between one lump soliton and a pair of kink solitons and the interactions between two periodic lump solitons are discussed graphically. Results might be helpful for understanding the propagation of the shallow water wave.

Setup for fission and evaporation cross-section measurements in reactions induced by secondary beams

International Nuclear Information System (INIS)

Hassan, A.A.; Luk'yanov, S.M.; Kalpakchieva, R.; Skobelev, N.K.; Penionzhkevich, Yu.Eh.; Dlouhy, Z.; Radnev, S.; Poroshin, N.V.

2002-01-01

A setup for studying reactions induced by secondary radioactive beams has been constructed. It allows simultaneous measurement of α-particle and fission fragment energy spectra. By measuring the α-particles, identification of evaporation residues is achieved. A set of three targets can be used so as to ensure sufficient statistics. Two silicon detectors, located at 90 degrees to the secondary beam direction, face each target, thus covering 30% of the solid angle. This experimental setup is to be used to obtain excitation functions of fusion-fission reactions and of reactions leading to evaporation residue production

Status of recent fast capture cross section evaluations for important fission product nuclides

International Nuclear Information System (INIS)

Gruppelaar, H.

1982-01-01

A comparison is made between recent evaluations of fission-product cross sections as given in the CNEN/CEA, ENDF/B-IV, ENDF/V-V, JENDL-1, RCN-2 and RCN-3 data libraries. The intercomparison is restricted to 24 important fission products in a fast power reactor. The evaluation methods used to obtain the various data files are reviewed and possible shortcomings are indicated. A survey is given of the experimental data based used in the various evaluations. Some graphs are included showing the new ENDF/B-V and RCN-3 fastcapture cross-section evaluations. Further intercomparisons are made by means of multi-group and one-group cross sections. It is shown that lumped fission-product cross sections calculated from the most recent versions of the data files are in quite good agreement with each other. This review concludes with a discussion on observed discrepancies and requests for new measurements. 78 references

Competition between fusion and quasi-fission in heavy ion induced reactions

International Nuclear Information System (INIS)

Back, B.B.

1986-09-01

Quantitative analyses of angular distributions and angle-mass correlations have been applied to the U + Ca reaction to obtain upper limit estimates for the cross sections for complete fusion near or below the interaction barrier. Extrapolating to the systems Ca + Cm and Ca + Es using the well established scaling properties of the extra push model, an estimate of the cross sections relevant to the efforts of synthesizing super-heavy elements in the region Z = 116 and N = 184 via heavy-ion fusion reactions are obtained. A simple evaporation calculation using properties of the super heavy elements shows that the failure to observe super-heavy elements with the Ca + Cm reaction is consistent with estimates of the complete fusion process. 33 refs., 9 figs., 1 tab

Cross-cutting european thermal-hydraulics research for innovative nuclear systems

International Nuclear Information System (INIS)

Roelofs, F.; Class, A.; Cheng, X.; Meloni, P.; Van Tichelen, K.; Boudier, P.; Prasser, M.

2010-01-01

Thermal-hydraulics is recognized as a key scientific subject in the development of different innovative nuclear reactor systems. From the thermal-hydraulic point of view, different innovative reactors are mainly characterized by their coolants (gas, water, liquid metals and molten salt). This results in different micro- and macroscopic behavior of flow and heat transfer and requires specific models and advanced analysis tools. However, many common thermal-hydraulic issues are identified among various innovative nuclear systems. In Europe, such cross-cutting thermal-hydraulic issues are the subject of the 7. framework programme THINS (Thermal-Hydraulics of Innovative Nuclear Systems) project which runs from 2010 until 2014. This paper will describe the activities in this project which address the main identified thermal hydraulics issues for innovative nuclear systems. (authors)

Survey on the fusion/fission-hybrid-reactors, a literature review

International Nuclear Information System (INIS)

A survey, based on existing literature, of the work being pursued worldwide on fusion - fission (hybrid) reactor systems is presented. Six areas are reviewed: Plasma physics parameters; Blankets concepts; Fuel cycles; Reactor conceptual designs; Safety and environmental problems; System studies and economic perspectives. Attention has been restricted to systems using magnetically confined plasmas, mainly to mirror and Tokamak - type concepts. The aim is to provide sufficient information, even if not exhaustive, on hybrid reactor concepts in order to help understand what may be expected from their possible development and the ways in which hybrids could affect the future energy scenario. Some concluding remarks are made which represent the personal view of the authors only

Fusion Canada issue 29

International Nuclear Information System (INIS)

1995-10-01

A short bulletin from the National Fusion Program highlighting in this issue Canada-Europe Accords: 5 year R and D collaboration for the International Thermonuclear Experimental Reactor (ITER) AECL is designated to arrange and implement the Memorandum of Understanding (MOU) and the ITER Engineering Design Activities (EDA) while EUROTAM is responsible for operating Europe's Fusion R and D programs plus MOU and EDA. The MOU includes tokamaks, plasma physics, fusion technology, fusion fuels and other approaches to fusion energy (as alternatives to tokamaks). STOR-M Tokamak was restarted at the University of Saskatchewan following upgrades to the plasma chamber to accommodate the Compact Toroid (CT) injector. The CT injector has a flexible attachment thus allowing for injection angle adjustments. Real-time video images of a single plasma discharge on TdeV showing that as the plasma density increases, in a linear ramp divertor, the plasma contact with the horizontal plate decreases while contact increases with the oblique plate. Damage-resistant diffractive optical elements (DOE) have been developed for Inertial Confinement Fusion (ICF) research by Gentac Inc. and the National Optics Institute, laser beam homogeniser and laser harmonic separator DOE can also be made using the same technology. Studies using TdeV indicate that a divertor will be able to pump helium from the tokamak with a detached-plasma divertor but helium extraction performance must first be improved, presently the deuterium:helium retention radio-indicates that in order to pump enough helium through a fusion reactor, too much deuterium-tritium fuel would be pumped out. 2 fig

FINESSE: study of the issues, experiments and facilities for fusion nuclear technology research and development. Interim report. Volume IV

International Nuclear Information System (INIS)

Abdou, M.

1984-10-01

This volume contains the following chapters (1) neutronics tests, (2) fluence considerations, (3) instrumentation and test matrix, (4) non-neutron test stands, (5) accelerator-based point neutron sources, (6) utilization of fission reactors, (7) tandem mirror test facilities, (8) tokamak fusion test facilities, (9) reliability development testing impacts on fusion reactor availability, and (10) fusion development scenarios. In addition, the following appendices are included: (1) evaluation of experience from fast breeder reactors, (2) observations of experts from the fission field, (3) evaluation of experience from the aerospace industry, (4) characterization of fusion nuclear systems operating environment, (5) modelling of MFTF-α+T high gamma mode performance, and (6) small-scale, multiple effects testing at US/DOE breeder reactor in-pile facilities

Cross-cutting activities: Soil quality and soil metagenomics

OpenAIRE

Motavalli, Peter P.; Garrett, Karen A.

2008-01-01

This presentation reports on the work of the SANREM CRSP cross-cutting activities "Assessing and Managing Soil Quality for Sustainable Agricultural Systems" and "Soil Metagenomics to Construct Indicators of Soil Degradation." The introduction gives an overview of the extensiveness of soil degradation globally and defines soil quality. The objectives of the soil quality cross cutting activity are: CCRA-4 (Soil Metagenomics)

Evidence of pair correlations in actinide neutron-induced fission cross sections

International Nuclear Information System (INIS)

Maslov, V.M.

2000-01-01

It is shown that irregularities in fission cross sections in MeV incident neutron energy region could be attributed to the interplay of few-quasiparticle excitations in the level density of the fissioning and residual nuclei. It is suggested the intrinsic quasiparticle state density modelling approach both at stable and saddle-point deformations. The experimental manifestation of few-quasiparticle irregularities in the level density depends on the fission barrier structure and internal excitation energy at the saddle point, corresponding to the higher barrier hump. The explicit evidence is observed in case of fissile and non-fissile target nuclides [ru

Fusion power: Expected environmental characteristics and status of R and D

International Nuclear Information System (INIS)

Fowler, T.K.

1989-01-01

From the outset in the 1950's, fusion research has been motivated by environmental concerns as well as long-term fuel supply issues. Compared to fossil fuels both fusion and fission would produce essentially zero emissions to the atmosphere. Compared to fission, fusion reactors should offer high demonstrability of public protection from accidents and a substantial amelioration of the radioactive waste problem. Fusion still requires lengthy development, the earliest commercial deployment being likely to occur around 2025-2050. However, steady scientific progress is being made and there is a wide consensus that it is time to plan large-scale engineering development. A major international effort, called the International Thermonuclear Experimental Reactor (ITER), is being carried out under IAEA auspices to design the world's first fusion engineering test reactor, which could be constructed in the 1990's. 5 figs., 3 tabs

Nuclear data processing for cross-sections generation for fusion-fission, ADS, and IV generation reactors utilization

International Nuclear Information System (INIS)

Velasquez, Carlos E.; Fernandes, Lorena C.; Pereira, Claubia; Veloso, Maria Auxiliadora F.; Costa, Antonella L.

2017-01-01

One of the mains topics about nuclear reactors is the microscopic cross section for incident neutrons. Therefore, in this work, it is evaluated the microscopic and macroscopic cross section for a nuclide and a material. One of the nuclides microscopic cross-section studied is the 56 Fe which is the highest compound from the material macroscopic cross section studied SS316. On the other hand, it was studied the microscopic cross section of the 242 Pu which is one of the nuclides that composes the nuclear fuel. The nuclear fuel chosen is a spent fuel reprocessed by UREX+ technique and spiked with thorium with 20% of fissile material. Therefore it was studied the macroscopic cross section from this nuclear fuel. Both of them were compared by using three different ways to reprocess the nuclides, one for LWR, another for ADS and the last one for Fusion reactors. The library used was JEFF-3.2 recommend for the reactors studied. The comparison was made at 1200 K for the nuclear fuel and 700K for the SS316.The results present differences due to the energy discretization, the number of groups chosen for each reactor and some nuclear reactions taken into consideration according to the neutron spectrum for each reactor. The nuclides were processed by NJOY99.364 and plotted with MCNP-Vised. (author)

Nuclear data processing for cross-sections generation for fusion-fission, ADS, and IV generation reactors utilization

Energy Technology Data Exchange (ETDEWEB)

Velasquez, Carlos E.; Fernandes, Lorena C.; Pereira, Claubia; Veloso, Maria Auxiliadora F.; Costa, Antonella L. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

2017-11-01

One of the mains topics about nuclear reactors is the microscopic cross section for incident neutrons. Therefore, in this work, it is evaluated the microscopic and macroscopic cross section for a nuclide and a material. One of the nuclides microscopic cross-section studied is the {sup 56}Fe which is the highest compound from the material macroscopic cross section studied SS316. On the other hand, it was studied the microscopic cross section of the {sup 242}Pu which is one of the nuclides that composes the nuclear fuel. The nuclear fuel chosen is a spent fuel reprocessed by UREX+ technique and spiked with thorium with 20% of fissile material. Therefore it was studied the macroscopic cross section from this nuclear fuel. Both of them were compared by using three different ways to reprocess the nuclides, one for LWR, another for ADS and the last one for Fusion reactors. The library used was JEFF-3.2 recommend for the reactors studied. The comparison was made at 1200 K for the nuclear fuel and 700K for the SS316.The results present differences due to the energy discretization, the number of groups chosen for each reactor and some nuclear reactions taken into consideration according to the neutron spectrum for each reactor. The nuclides were processed by NJOY99.364 and plotted with MCNP-Vised. (author)

Progress in fission product nuclear data. No. 14

International Nuclear Information System (INIS)

Lammer, M.

1994-06-01

This is the 14th issue of a report series on Fission Product Nuclear Data published by the Nuclear Data Section of the IAEA. The types of activities included are measurements, compilations and evaluations of fission product yields, neutron reaction cross sections of fission products, data related to the radioactive decay of fission products, delayed neutron data from neutron induced and spontaneous fission, lumped fission product data. The first part of the report consists of unaltered original contributions which the authors have sent to IAEA/NDS. The second part contains some recent references relative to fission product nuclear data, which were not covered by the contributions submitted, and selected papers from conferences. The third part contains requirements for further measurements

Progress in fission product nuclear data. No. 13

International Nuclear Information System (INIS)

Lammer, M.

1990-11-01

This is the 13th issue of a report series published by the Nuclear Data Section of the IAEA. The types of activities included are measurements, compilations and evaluations of: Fission product yields (neutron induced and spontaneous fission), neutron reaction cross-sections of fission products, data related to the radioactive decay of fission products, delayed neutron data of fission products and bumped fission product data (decay heat, absorption, etc.). The first part of the report consists of unaltered original data which the authors have sent to IAEA/NDS. The second part contains some recent references relative to fission product nuclear data, which were not covered by the contributions submitted, and selected papers from conferences. Part 3 contains requirements for further measurements

Determination of minor actinides fission cross sections by means of transfer reactions

Energy Technology Data Exchange (ETDEWEB)

Jurado, B.; Aiche, M.; Barreau, G.; Boyer, S.; Czajkowski, S.; Dassie, D.; Grosjean, C.; Guiral, A.; Haas, B.; Osmanov, B.; Petit, M. [CENBG - UMR 5795 CNRS/IN2P3-Univ. Bordeaux 1- Le Haut Vigneau, 33175 Gradignan (France); Berthoumieux, E.; Gunsing, F.; Perrot, L.; Theisen, Ch. [CEN Saclay, DSM/DAPNIA/SPhN, 91191 Gif-sur-Yvette cedex (France); Bauge, E. [CEA, SPhN, BP12 91680 Bruyeres-le-Chatel (France); Michel-Sendis, F. [IPN, 15 rue G. Clemenceau, 91406 Orsay cedex (France); Billebaud, A. [LPSC, 53 Avenue des Martyrs, 38026 Grenoble cedex (France); Wilson, J. N. [IPN, 15 rue G. Clemenceau, 91406 Orsay cedex (France); LPSC, 53 Avenue des Martyrs, 38026 Grenoble cedex (France); Ahmad, I.; Greene, J.P.; Janssens, R. V. F. [ANL, 9700 S. Cass Avenue, Argonne, IL 60439 (United States)

2005-07-01

We present an original method that allows to determine neutron-induced cross sections of very short-lived minor actinides. This indirect method, based on the use of transfer reactions, has already been applied with success for the determination of the neutron-induced fission and capture cross section of {sup 233}Pa, a key nucleus in the {sup 232}Th - {sup 233}U fuel cycle. A recent experiment using this technique has been performed to determine the neutron-induced fission cross sections of {sup 242,243,244}Cm and {sup 241}Am which are present in the nuclear waste of the current U-Pu fuel cycle. These cross sections are highly relevant for the design of reactors capable to incinerate minor actinides. The first results will be illustrated. (authors)

Fusion-fission hybrid as an alternative to the fast breeder reactor

International Nuclear Information System (INIS)

Barrett, R.J.; Hardie, R.W.

1980-09-01

This report compares the fusion-fission hybrid on the plutonium cycle with the classical fast breeder reactor (FBR) cycle as a long-term nuclear energy source. For the purpose of comparison, the current light-water reactor once-through (LWR-OT) cycle was also analyzed. The methods and models used in this study were developed for use in a comparative analysis of conventional nuclear fuel cycles. Assessment areas considered in this study include economics, energy balance, proliferation resistance, technological status, public safety, and commercial viability. In every case the characteristics of all fuel cycle facilities were accounted for, rather than just those of the reactor

Recycling fusion materials

International Nuclear Information System (INIS)

Ooms, L.

2005-01-01

The inherent safety and environmental advantages of fusion power in comparison with other energy sources play an important role in the public acceptance. No waste burden for future generations is therefore one of the main arguments to decide for fusion power. The waste issue has thus been studied in several documents and the final conclusion of which it is stated that there is no permanent disposal waste needed if recycling is applied. But recycling of fusion reactor materials is far to be obvious regarding mostly the very high specific activity of the materials to be handled, the types of materials and the presence of tritium. The main objective of research performed by SCK-CEN is to study the possible ways of recycling fusion materials and analyse the challenges of the materials management from fusion reactors, based on current practices used in fission reactors and the requirements for the manufacture of fusion equipment

ENDF/B-5 fission product cross section evaluations

International Nuclear Information System (INIS)

Schenter, R.E.; England, T.R.

1979-12-01

Cross section evaluations were made for the 196 fission product nuclides on the ENDF/B-5 data files. Most of the evaluations involve updating the capture cross sections of the important absorbers for fast and thermal reactor systems. This included updating thermal values, resonance integrals, resonance parameter sets, and fast capture cross sections. For the fast capture results generalized least-squares calculations were made with the computer code FERRET. Input for these cross section adjustments included nuclear models calculations and both integral and differential experimental data results. The differential cross sections and their uncertainties were obtained from the CSIRS library. Integral measurement results came from CFRMF and STEK Assemblies 500, 1000, 2000, 3000, 4000. Comparisons of these evaluations with recent capture measurements are shown. 15 figures, 10 tables

Dynamics in heavy ion fusion and fission

International Nuclear Information System (INIS)

Bjoernholm, S.

1972-01-01

Dynamical aspects of heavy ion fussion and fission, mainly the aspect of damping which is meant as the dissipation of kinetic energy and the aspect of the effective mass of the fission motion, are discussed. Two categories of evidence of damping effects are given. One relates to the damping of the fission motion for the ground state shape and for the isomeric more elongated shape. The other relates to the damping of the fission motion from the last barrier to the scission point. The dependence of the effective mass associated with the fission motion on the deormation of nucleus is shown. As the elongation of the nucleus increases the effective mass of the fission motion varies strongly from being about forty times greater than the reduced mass in the beta-vibrational state of the ground state shape to being equal to the reduced mass in the moment of scission. Damping effects are expected to be propartional to the difference between the effective mass and the reduced mass. It is concluded that the damping in fussion reactions is relatively weak for lighter products and quite strong for superheavy products like 236 U or 252 Cf. (S.B.)

Measurement of 235U fission spectrum-averaged cross sections and neutron spectrum adjusted with the activation data

International Nuclear Information System (INIS)

Kobayashi, Katsuhei; Kobayashi, Tooru

1992-01-01

The 235 U fission spectrum-averaged cross sections for 13 threshold reactions were measured with the fission plate (27 cm in diameter and 1.1 cm thick) at the heavy water thermal neutron facility of the Kyoto University Reactor. The Monte Carlo code MCNP was applied to check the deviation from the 235 U fission neutron spectrum due to the room-scattered neutrons, and it was found that the resultant spectrum was close to that of 235 U fission neutrons. Supplementally, the relations to derive the absorbed dose rates with the fission plate were also given using the calculated neutron spectra and the neutron Kerma factors. Finally, the present values of the fission spectrum-averaged cross sections were employed to adjust the 235 U fission neutron spectrum with the NEUPAC code. The adjusted spectrum showed a good agreement with the Watt-type fission neutron spectrum. (author)

Fusion Canada issue 21

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-08-01

A short bulletin from the National Fusion Program highlighting in this issue Europe proposes Canada`s participation in ITER, tritium for JET, CCFM/TdeV-Tokamak helium pumping and TdeV update, ITER-related R and D at CFFTP, ITER Deputy Director visits Canada, NFP Director to Chair IFRC, Award for Akira Hirose. 3 figs.

Fusion Canada issue 21

International Nuclear Information System (INIS)

1993-08-01

A short bulletin from the National Fusion Program highlighting in this issue Europe proposes Canada's participation in ITER, tritium for JET, CCFM/TdeV-Tokamak helium pumping and TdeV update, ITER-related R and D at CFFTP, ITER Deputy Director visits Canada, NFP Director to Chair IFRC, Award for Akira Hirose. 3 figs

Mirror fusion reactors

International Nuclear Information System (INIS)

Carlson, G.A.; Moir, R.W.

1978-01-01

We have carried out conceptual design studies of fusion reactors based on the three current mirror confinement concepts: the standard mirror, the tandem mirror, and the field-reversed mirror. Recent studies of the standard mirror have emphasized its potential as a fusion-fission hybrid reactor, designed to produce fission fuel for fission reactors. We have designed a large commercial hybrid based on standard mirror confinement, and also a small pilot plant hybrid. Tandem mirror designs include a commercial 1000 MWe fusion power plant and a nearer term tandem mirror hybrid. Field-reversed mirror designs include a multicell commercial reactor producing 75 MWe and a single cell pilot plant

Proton-induced fission cross sections on "2"0"8Pb at high kinetic energies

International Nuclear Information System (INIS)

Rodriguez-Sanchez, J.L.; Benlliure, J.; Paradela, C.; Ayyad, Y.; Alvarez-Pol, H.; Cortina-Gil, D.; Pietras, B.; Ramos, D.; Vargas, J.; Taieb, J.; Chatillon, A.; Belier, G.; Boutoux, G.; Gorbinet, T.; Laurent, B.; Martin, J.F.; Pellereau, E.; Casarejos, E.; Rodriguez-Tajes, C.

2014-01-01

Total fission cross sections of "2"0"8Pb induced by protons have been determined at 370 A, 500 A, and 650 A MeV. The experiment was performed at GSI Darmstadt where the combined use of the inverse kinematics technique with an efficient detection setup allowed us to determine these cross sections with an uncertainty below 6%. This result was achieved by an accurate beam selection and registration of both fission fragments in coincidence which were also clearly distinguished from other reaction channels. These data solve existing discrepancies between previous measurements, providing new values for the Prokofiev systematics. The data also allow us to investigate the fission process at high excitation energies and small deformations. In particular, some fundamental questions about fission dynamics have been addressed, which are related to dissipative and transient time effects. (authors)

Fusion Canada issue 16

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-01-01

A short bulletin from the National Fusion Program. Included in this issue is a report on Ontario Hydro`s contract for tritium supply from Germany, a CCFM update on plasma biasing, divertor operation, radiofrequency plasma current drive and the plasma heating system for the Tokamak de Varennes, and an agreement for ITER engineering design activities. 5 figs.

Fusion Canada issue 26

International Nuclear Information System (INIS)

1994-11-01

A short bulletin from the National Fusion Program highlighting in this issue tritium supply for Japanese research, Canada to host the 1995 IAEA Conference on Tritium, studies on the tokamak divertor and edge plasma studies, a tritium field release study, erosion studies on plasma facing materials, G. Pacher returns to CCFM and an update on CCFM/TdeV

Fusion Canada issue 16

International Nuclear Information System (INIS)

1992-01-01

A short bulletin from the National Fusion Program. Included in this issue is a report on Ontario Hydro's contract for tritium supply from Germany, a CCFM update on plasma biasing, divertor operation, radiofrequency plasma current drive and the plasma heating system for the Tokamak de Varennes, and an agreement for ITER engineering design activities. 5 figs

Fusion Canada issue 24

International Nuclear Information System (INIS)

1994-04-01

A short bulletin from the National Fusion Program highlighting in this issue the opening of the Garching ITER site, a CCFM/TdeV update,a tritium release field test, measuring radial profile of plasma current density on TdeV, power supplies for TdeV, 5th International Tritium Technology conference, and 1994 basic tritium course. 4 figs

Fission-like decay of 20Ne: eccentric behavior in the B+B fusion processes

International Nuclear Information System (INIS)

Toledo, A.S. de; Coimbra, M.M.; Added, N.; Anjos, R.M.; Carlin Filho, N.; Fante Junior, L.; Figueira, M.C.S.; Guimaraes, V.; Szanto, E.M.

1988-08-01

Cross sections for the fusion of 10,11 B+ 10,11 B have been measured in the energy range from 1.5 MeV/A to 5 MeV/A. The 10 B+ 10 B system unexpectedly presents a hindered fusion cross section when compared to the 10 B+ 11 B and 11 B+ 11 B reactions and to standard model predictions. The missing fusion cross section was diverted the 10 B exit channel with a total kinetic energy characteristic of strongly damped collisions. Q-values and kinematical analysis together with angular distributions suggest a binary symmetric decay of the composite 20 Ne system. (author) [pt

Identification of fission-like events in the 16O + 181Ta system: Mass and isotopic yield distribution

International Nuclear Information System (INIS)

Sharma, Vijay R.; Yadav, Abhishek; Singh, Devendra P.; Unnati,; Singh, B. P.; Prasad, R.; Singh, Pushpendra P.; Sharma, Manoj K.; Kumar, R.; Golda, K. S.; Sinha, A. K.

2011-01-01

In this paper, nuclear reaction cross sections for 24 fission-like fragments (30≤Z≤60) have been measured for the 6.5 MeV/A 16 O + 181 Ta system. The recoil-catcher activation technique was employed followed by off-line γ spectroscopy. The isotopic yield distributions for yttrium and indium isotopes have been obtained from the experimental data. The variance of the presently measured isotopic yield distributions have been found to be in agreement with the literature values. However, the variance of the mass distribution of fission residues has found to be narrower as compared to other relatively heavier systems. A self-consistent approach to determining the isobaric charge dispersion parameters has been adopted. The measured fission cross sections at 97 and 100 MeV are satisfactorily described by a statistical model code. An attempt has been made to explain the production cross sections of intermediate mass residues in the fission of heavy residues populated via complete and/or incomplete fusion processes.

Determination of the fast-neutron-induced fission cross-section of 242Pu at nELBE

Science.gov (United States)

Kögler, Toni; Beyer, Roland; Junghans, Arnd R.; Schwengner, Ronald; Wagner, Andreas

2018-03-01

The fast-neutron-induced fission cross section of 242Pu was determined in the energy range of 0.5 MeV to 10MeV at the neutron time-of-flight facility nELBE. Using a parallel-plate fission ionization chamber this quantity was measured relative to 235U(n,f). The number of target nuclei was thereby calculated by means of measuring the spontaneous fission rate of 242Pu. An MCNP 6 neutron transport simulation was used to correct the relative cross section for neutron scattering. The determined results are in good agreement with current experimental and evaluated data sets.

Metabolic Syndrome and Antipsychotics: The Role of Mitochondrial Fission/Fusion Imbalance

Directory of Open Access Journals (Sweden)

Andrea del Campo

2018-04-01

Full Text Available Second-generation antipsychotics (SGAs are known to increase cardiovascular risk through several physiological mechanisms, including insulin resistance, hepatic steatosis, hyperphagia, and accelerated weight gain. There are limited prophylactic interventions to prevent these side effects of SGAs, in part because the molecular mechanisms underlying SGAs toxicity are not yet completely elucidated. In this perspective article, we introduce an innovative approach to study the metabolic side effects of antipsychotics through the alterations of the mitochondrial dynamics, which leads to an imbalance in mitochondrial fusion/fission ratio and to an inefficient mitochondrial phenotype of muscle cells. We believe that this approach may offer a valuable path to explain SGAs-induced alterations in metabolic homeostasis.

New signatures on dissipation from fission induced by relativistic heavy-ion collisions

Energy Technology Data Exchange (ETDEWEB)

Jurado, B.; Schmitt, C.; Schmidt, K.H.; Enqvist, T.; Kelic, A.; Rejmund, F.; Benlliure, J. [Universidad de Santiago de Compostela (Spain); Junghans, A.R. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany)

2004-03-01

Fissile nuclei with small shape distortion relative to the ground-state deformation and with low angular momentum were produced in peripheral heavy-ion collisions. Under the conditions of small shape distortions and low angular momentum, the theoretical description of the fission process can be considerably simplified, and the relevant information on dissipation can be better extracted than in conventional experiments based on fusion-fission reactions. In addition, this experimental approach induces very high excitation energies, a condition necessary to observe transient effects. The experimental data were taken at GSI using a set-up especially conceived for fission studies in inverse kinematics. This set-up allowed determining three observables whose sensitivity to dissipation was investigated for the first time: the total fission cross sections of {sup 238}U at 1 A GeV as a function of the target mass, and, for the reaction of {sup 238}U at 1 A GeV on a (CH{sub 2}){sub n} target, the partial fission cross sections and the partial charge distributions of the fission fragments. The comparison of the new experimental data with a reaction code adapted to the conditions of the reactions investigated leads to clear conclusions on the strength of dissipation at small deformation where the existing results are rather contradictory. (orig.)

New signatures on dissipation from fission induced by relativistic heavy-ion collisions

International Nuclear Information System (INIS)

Jurado, B.; Schmitt, C.; Schmidt, K.H.; Enqvist, T.; Kelic, A.; Rejmund, F.; Benlliure, J.; Junghans, A.R.

2004-03-01

Fissile nuclei with small shape distortion relative to the ground-state deformation and with low angular momentum were produced in peripheral heavy-ion collisions. Under the conditions of small shape distortions and low angular momentum, the theoretical description of the fission process can be considerably simplified, and the relevant information on dissipation can be better extracted than in conventional experiments based on fusion-fission reactions. In addition, this experimental approach induces very high excitation energies, a condition necessary to observe transient effects. The experimental data were taken at GSI using a set-up especially conceived for fission studies in inverse kinematics. This set-up allowed determining three observables whose sensitivity to dissipation was investigated for the first time: the total fission cross sections of 238 U at 1 A GeV as a function of the target mass, and, for the reaction of 238 U at 1 A GeV on a (CH 2 ) n target, the partial fission cross sections and the partial charge distributions of the fission fragments. The comparison of the new experimental data with a reaction code adapted to the conditions of the reactions investigated leads to clear conclusions on the strength of dissipation at small deformation where the existing results are rather contradictory. (orig.)

Progress in fission product nuclear data. Issue no. 6

International Nuclear Information System (INIS)

Lammer, G.; Lammer, M.

1980-06-01

This is the sixth issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed

Impact of fusion-fission hybrids on world nuclear future

International Nuclear Information System (INIS)

Abdel-Khalick, S.; Jansen, P.; Kessler, G.; Klumpp, P.

1980-08-01

An investigation has been conducted to examine the impact of fusion-fission hybrids on world nuclear future. The primary objectives of this investigation have been: (1) to determine whether hybrids can allow us to meet the projected nuclear component of the world energy demand within current estimates of uranium resources without fast breeders, and (2) to identify the preferred hybrid concept from a resource standpoint. The results indicate that hybrids have the potential to lower the world uranium demand to values well below the resource base. However, the time window for hybrid introduction is quite near and narrow (2000-2020). If historical market penetration rates are assumed, the demand will not be met within the resource base unless hybrids are coupled to the breeders. The results also indicate that from a resource standpoint hybrids which breed their own tritium and have a low blanket energy multiplication are preferable. (orig.) [de

Fission 2009 4. International Workshop on Nuclear Fission and Fission Product Spectroscopy - Compilation of slides

International Nuclear Information System (INIS)

2009-01-01

This conference is dedicated to the last achievements in experimental and theoretical aspects of the nuclear fission process. The topics include: mass, charge and energy distribution, dynamical aspect of the fission process, nuclear data evaluation, quasi-fission and fission lifetime in super heavy elements, fission fragment spectroscopy, cross-section and fission barrier, and neutron and gamma emission. This document gathers the program of the conference and the slides of the presentations

Elastocapillary Instability in Mitochondrial Fission

Science.gov (United States)

Gonzalez-Rodriguez, David; Sart, Sébastien; Babataheri, Avin; Tareste, David; Barakat, Abdul I.; Clanet, Christophe; Husson, Julien

2015-08-01

Mitochondria are dynamic cell organelles that constantly undergo fission and fusion events. These dynamical processes, which tightly regulate mitochondrial morphology, are essential for cell physiology. Here we propose an elastocapillary mechanical instability as a mechanism for mitochondrial fission. We experimentally induce mitochondrial fission by rupturing the cell's plasma membrane. We present a stability analysis that successfully explains the observed fission wavelength and the role of mitochondrial morphology in the occurrence of fission events. Our results show that the laws of fluid mechanics can describe mitochondrial morphology and dynamics.

The cross sections of fusion-evaporation reactions: the most promising route to superheavy elements beyond Z=118

Directory of Open Access Journals (Sweden)

Jadambaa Khuyagbaatar

2017-01-01

Full Text Available The synthesis of superheavy elements beyond oganesson (Og, which has atomic number Z = 118, is currently one of the main topics in nuclear physics. An absence of sufficient amounts of target material with atomic numbers heavier than californium (Z = 98 forces the use of projectiles heavier than 48Ca (Z = 20, which has been successfully used for the discoveries of elements with Z = 114 - 118 in complete fusion reactions. Experimental cross sections of 48Ca with actinide targets behave very differently to “cold” and “hot” fusion-evaporation reactions, where doubly-magic lead and deformed actinides are used as targets, respectively. The known cross sections of these reactions have been analysed compared to calculated fission barriers. It has been suggested that observed discrepancies between the cross sections of 48Ca-induced and other fusionevaporation reactions originate from the shell structure of the compound nucleus, which lies in the island of the stability. Besides scarcely known data on other reactions involving heavier projectiles, the most promising projectile for the synthesis of the elements beyond Og seems to be 50Ti. However, detailed studies of 50Ti, 54Cr, 58Fe and 64Ni-induced reactions are necessary to be performed in order to fully understand the complexities of superheavy element formation.

The cross sections of fusion-evaporation reactions: the most promising route to superheavy elements beyond Z=118

Science.gov (United States)

Jadambaa, Khuyagbaatar

2017-11-01

The synthesis of superheavy elements beyond oganesson (Og), which has atomic number Z = 118, is currently one of the main topics in nuclear physics. An absence of sufficient amounts of target material with atomic numbers heavier than californium (Z = 98) forces the use of projectiles heavier than 48Ca (Z = 20), which has been successfully used for the discoveries of elements with Z = 114 - 118 in complete fusion reactions. Experimental cross sections of 48Ca with actinide targets behave very differently to "cold" and "hot" fusion-evaporation reactions, where doubly-magic lead and deformed actinides are used as targets, respectively. The known cross sections of these reactions have been analysed compared to calculated fission barriers. It has been suggested that observed discrepancies between the cross sections of 48Ca-induced and other fusionevaporation reactions originate from the shell structure of the compound nucleus, which lies in the island of the stability. Besides scarcely known data on other reactions involving heavier projectiles, the most promising projectile for the synthesis of the elements beyond Og seems to be 50Ti. However, detailed studies of 50Ti, 54Cr, 58Fe and 64Ni-induced reactions are necessary to be performed in order to fully understand the complexities of superheavy element formation.

International conference on fifty years research in nuclear fission

International Nuclear Information System (INIS)

1989-02-01

These proceedings contain extended abstracts of the papers presented at the named conference. They deal with static properties of fission, instrumentation for fission studies, fission in compound-nucleus reactions, fission dynamics, fission-like heavy ion reactions, and fusion reactions. See hints under the relevant topics. (HSI)

Development of fine-group (315n/42γ) cross section library ENDL3.0/FG for fusion-fission hybrid systems

International Nuclear Information System (INIS)

Zeng Qin; Zou Jun; Xu Dezhen; Jiang Jieqiong; Wang Minghuang; Wu Yican; Qiu Yuefeng; Chen Zhong; Chen Yan

2011-01-01

To improve the accuracy of the neutron analyses for subcritical systems with thermal fission blanket, a coupled neutron and photon (315 n + 42γ) fine-group cross section library HENDL3.0/FG based on ENDF/B-Ⅶ. 0 has been produced by FDS team. In order to test the availability and reliability of the HENDL3.0/FG data library, shielding and critical safety benchmarks were performed with VisualBUS code. The testing results indicated that the discrepancy between calculation and experimental values of nuclear parameters fell in a reasonable range. (authors)

Determination of the fast-neutron-induced fission cross-section of 242Pu at nELBE

Directory of Open Access Journals (Sweden)

Kögler Toni

2018-01-01

Full Text Available The fast-neutron-induced fission cross section of 242Pu was determined in the energy range of 0.5 MeV to 10MeV at the neutron time-of-flight facility nELBE. Using a parallel-plate fission ionization chamber this quantity was measured relative to 235U(n,f. The number of target nuclei was thereby calculated by means of measuring the spontaneous fission rate of 242Pu. An MCNP 6 neutron transport simulation was used to correct the relative cross section for neutron scattering. The determined results are in good agreement with current experimental and evaluated data sets.

Magnetic fusion reactor economics

International Nuclear Information System (INIS)

Krakowski, R.A.

1995-01-01

An almost primordial trend in the conversion and use of energy is an increased complexity and cost of conversion systems designed to utilize cheaper and more-abundant fuels; this trend is exemplified by the progression fossil fission → fusion. The present projections of the latter indicate that capital costs of the fusion ''burner'' far exceed any commensurate savings associated with the cheapest and most-abundant of fuels. These projections suggest competitive fusion power only if internal costs associate with the use of fossil or fission fuels emerge to make them either uneconomic, unacceptable, or both with respect to expensive fusion systems. This ''implementation-by-default'' plan for fusion is re-examined by identifying in general terms fusion power-plant embodiments that might compete favorably under conditions where internal costs (both economic and environmental) of fossil and/or fission are not as great as is needed to justify the contemporary vision for fusion power. Competitive fusion power in this context will require a significant broadening of an overly focused program to explore the physics and simbiotic technologies leading to more compact, simplified, and efficient plasma-confinement configurations that reside at the heart of an attractive fusion power plant

Critical angular momentum dependence of the fission barriers and the stability of superheavy nuclei

International Nuclear Information System (INIS)

Magda, M.T.; Sandulescu, A.

1978-10-01

Measured complete fusion and evaporation cross section data are used to determine the critical angular momenta for which the fission barriers are vanishing in the region of nuclei with Z = 102 - 116. It is shown that, in order to fit these data, larger values of the critical angular momenta are obtained for superheavy nuclei (Z = 110 - 112) than for heavy ones (Z = 102 - 107), which indicates a relatively higher stability against fission for superheavy nuclei, in agreement with the theoretically predicted island of stability. (author)

Reexamination of fission fragment angular distributions and the fission process: Formalism

International Nuclear Information System (INIS)

Bond, P.D.

1985-01-01

The theory of fission fragment angular distributions is examined and the universally used expression is found to be valid only under restrictive assumptions. A more general angular distribution formula is derived and applied to recent data of high spin systems. At the same time it is shown that the strong anisotropies observed from such systems can be understood without changing the essential basis of standard fission theory. The effects of reaction mechanisms other than complete fusion on fission fragment angular distributions are discussed and possible angular distribution signatures of noncompound nucleus formation are mentioned

Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN – n_TOF

Directory of Open Access Journals (Sweden)

Diakaki M.

2016-01-01

Full Text Available The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at CERN – n_TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards.

Tritium control and capture in salt-cooled fission and fusion reactors: Status, challenges, and path forward

International Nuclear Information System (INIS)

Forsberg, Charles W.; Lam, Stephen; Carpenter, David M.; Whyte, Dennis G.; Scarlat, Raluca

2017-01-01

Three advanced nuclear power systems use liquid salt coolants that generate tritium and thus face the common challenges of containing and capturing tritium to prevent its release to the environment. The Fluoride-salt-cooled High-temperature Reactor (FHR) uses clean fluoride salt coolants and the same graphite-matrix coated-particle fuel as high-temperature gas-cooled reactors. Molten salt reactors (MSRs) dissolve the fuel in a fluoride or chloride salt with release of fission product tritium into the salt. In most FHR and MSR systems, the base-line salts contain lithium where isotopically separated "7Li is proposed to minimize tritium production from neutron interactions with the salt. The Chinese Academy of Science plans to start operation of a 2-MWt molten salt test reactor by 2020. For high-magnetic-field fusion machines, the use of lithium enriched in "6Li is proposed to maximize tritium generation the fuel for a fusion machine. Advances in superconductors that enable higher power densities may require the use of molten lithium salts for fusion blankets and as coolants. Recent technical advances in these three reactor classes have resulted in increased government and private interest and the beginning of a coordinated effort to address the tritium control challenges in 700 °C liquid salt systems. We describe characteristics of salt-cooled fission and fusion machines, the basis for growing interest in these technologies, tritium generation in molten salts, the environment for tritium capture, models for high-temperature tritium transport in salt systems, alternative strategies for tritium control, and ongoing experimental work. Several methods to control tritium appear viable. Finally, limited experimental data is the primary constraint for designing efficient cost-effective methods of tritium control.

Environmental sampling: Issues for the cut-off regime

International Nuclear Information System (INIS)

Fearey, B.L.

1995-01-01

The fissile material cut-off treaty (FMCT) initiative under the Conference on Disarmament mandate is envisioned to include certain aspects of environmental sampling and monitoring. One of the intents of this treaty is to bring certain non-NPT signatories (e.g., threshold states) under this treaty agreement along with the nuclear weapon states (NWSs). This paper provides a brief overview of some of the relevant issues that may be involved in the implementation and use of environmental monitoring for (1) verification of the cut-off regime declarations, (2) the detection of undeclared activities, and, (3) application in non-routine inspections. The intent is to provide backstopping information important for treaty negotiators. Specific issues addressed within this paper include signature sampling, differences in the proposed detection regime, potential signature integrators, specific examples and spoofing concerns. Many of these issues must be carefully considered and weighed in order to create a credibly verifiable inspection regime. Importantly, the cut-off treaty must enable nondiscriminatory implementation, while carefully assuring that nonproliferation treaty requirements are maintained (i.e., preventing unintentional release of critical weapons design information--potentially through environmental sampling and analysis)

Neutrons and fusion

International Nuclear Information System (INIS)

Maynard, C.W.

1976-01-01

The production of energy from fusion reactions does not require neutrons in the fundamental sense that they are required in a fission reactor. Nevertheless, the dominant fusion reaction, that between deuterium and tritium, yields a 14 MeV neutron. To contrast a fusion reactor based on this reaction with the fission case, 3 x 10 20 such neutrons produced per gigawatt of power. This is four times as many neutrons as in an equivalent fission reactor and they carry seven times the energy of the fission neutrons. Thus, they dominate the energy recovery problem and create technological problems comparable to the original plasma confinement problem as far as a practical power producing device is concerned. Further contrasts of the fusion and fission cases are presented to establish the general role of neutrons in fusion devices. Details of the energy deposition processes are discussed and those reactions necessary for producing additional tritium are outlined. The relatively high energy flux with its large intensity will activate almost any materials of which the reactor may be composed. This activation is examined from the point of view of decay heat, radiological safety, and long-term storage. In addition, a discussion of the deleterious effects of neutron interactions on materials is given in some detail; this includes the helium and hydrogen producing reactions and displacement rate of the lattice atoms. The various materials that have been proposed for structural purposes, for breeding, reflecting, and moderating neutrons, and for radiation shielding are reviewed from the nuclear standpoint. The specific reactions of interest are taken up for various materials and finally a report is given on the status and prospects of data for fusion studies

Progress in fission product nuclear data. Information about activities in the field of measurements and compilations/evaluations of fission product nuclear data (FPND)

International Nuclear Information System (INIS)

Lammer, G.

1978-07-01

This is the fourth issue of a report series on Fission Product Nuclear Data (FPND) which is published by the Nuclear Data Section (NDS) of the International Atomic Energy Agency (IAEA). The purpose of this series is to inform scientists working on FPND, or using such data, about all activities in this field which are planned, ongoing, or have recently been completed. The main part of this report consists of unaltered original contributions which the authors have sent to IAEA/NDS. The types of activities being included in this report are measurements, compilations and evaluations of: Fission product yields (neutron induced and spontaneous fission); neutron reaction cross sections of fission products; data related to the radioactive decay of fission products; delayed neutron data of fission products; and lumped fission product data (decay heat, absorption etc.)

Impact of fusion-fission hybrids on world nuclear future

International Nuclear Information System (INIS)

Abdel-Khalik, S.I.; Jansen, P.; Kessler, G.; Klumpp, P.

1981-01-01

An investigation has been conducted to examine the impact of fusion-fission hybrids on world nuclear future. The primary objectives of this investigation have been: (1) to determine whether hybrids can allow us to meet the projected nuclear component of the world energy demand within current estimates of uranium resources with or without fast breeders, and (2) to identify the preferred hybrid concept from a resource standpoint. The results indicate that hybrids have the potential to lower the world uranium demand to values well below the resource base. However, the time window for hybrid introduction is quite near and narrow (2000-2020). If historical market penetration rates are assumed, the demand will not be met within the resource base unless hybrids are coupled to the breeders. The results also indicate that from a resource standpoint hybrids which breed their own tritium and have a low blanket energy multiplication are preferable. (orig.) [de

Impact of fusion-fission hybrids on world nuclear future

International Nuclear Information System (INIS)

Abdel-Khalik, S.I.

1980-01-01

An investigation has been conducted to examine the impact of fusion-fission hybrids on world nuclear future. The primary objectives of this investigation have been (1) to determine whether hybrids can allow us to meet the projected nuclear component of the world energy demand within current estimates of uranium resources with or without fast breeders, and (2) to identify the preferred hybrid concept from a resource standpoint. The results indicate that hybrids have the potential to lower the world uranium demand to values well below the resource base. However, the time window for hybrid introduction is quite near and narrow (2000-2020). If historical market penetration rates are assumed, the demand will not be met within the resource base unless hybrides are coupled to the breeders. The results also indicate that from a resource standpaint hybrids which breed their own tritium and have a low blanket energy multiplication are preferable. (orig.) [de

The U.S. program for fusion nuclear technology development

International Nuclear Information System (INIS)

Clarke, J.F.; Haas, G.M.

1989-01-01

The Fusion Nuclear Technology (FNT) research and development program in the United States is shaped by a hierarchy of documents and by the environment for nuclear energy existing in the United States. The fission nuclear industry in the United States has suffered problems with public perception of safety, waste disposal issues, and economics as influenced by safety and environmental issues. For fusion to be a viable energy alternative, it must offer significant improvements in these areas. The hierarchy of documents defining objectives, plans, and strategy of the U.S. FNT program consists of the Magnetic Fusion Program Plan (MFPP) (February 1985), the Technical Planning Activity Final Report (January 1987), the Finesse Program Report (January 1987), and the Blanket Comparison and Selection Study Final Report (September 1984). In addition, two other documents are also significant in shaping FNT policy. These are the IEA report on Material for Fusion (December 1986) and the Summary of the Report of the Senior Committee on Environmental, Safety, and Economic Aspects of Magnetic Fusion Energy (September 1987). The U.S. Magnetic Fusion Program Plan defines four key technical issues (magnetic confinement systems, properties of burning plasmas, fusion nuclear technology, and fusion materials). (orig./KP)

Feasibility study of a fission-suppressed tokamak fusion breeder

International Nuclear Information System (INIS)

Moir, R.W.; Lee, J.D.; Neef, W.S.

1984-12-01

The preliminary conceptual design of a tokamak fissile fuel producer is described. The blanket technology is based on the fission suppressed breeding concept where neutron multiplication occurs in a bed of 2 cm diameter beryllium pebbles which are cooled by helium at 50 atmospheres pressure. Uranium-233 is bred in thorium metal fuel elements which are in the form of snap rings attached to each beryllium pebble. Tritium is bred in lithium bearing material contained in tubes immersed in the pebble bed and is recovered by a purge flow of helium. The neutron wall load is 3 MW/m 2 and the blanket material is ferritic steel. The net fissile breeding ratio is 0.54 +- 30% per fusion reaction. This results in the production of 4900 kg of 233 U per year from 3000 MW of fusion power. This quantity of fuel will provide makeup fuel for about 12 LWRs of equal thermal power or about 18 1 GW/sub e/ LWRs. The calculated cost of the produced uranium-233 is between $23/g and $53/g or equivalent to $10/kg to $90/kg of U 3 O 8 depending on government financing or utility financing assumptions. Additional topics discussed in the report include the tokamak operating mode (both steady state and long pulse considered), the design and breeding implications of using a poloidal divertor for impurity control, reactor safety, the choice of a tritium breeder, and fuel management

Nuclear dissipation effects on fission and evaporation in systems of intermediate fissility

Directory of Open Access Journals (Sweden)

Gelli N.

2010-03-01

Full Text Available The systems of intermediate fissility 132Ce and 158Er have been studied experimentally and theoretically in order to investigate the dissipation properties of nuclear matter. Cross sections of fusion-fission and evaporation residues channels together with charged particles multiplicities in both channels, their spectra, angular correlations and mass-energy distribution of fission fragments have been measured. Theoretical analysis has been performed using multi-dimensional stochastic approach with realistic treatment of particle evaporation. The results of analysis show that full one-body or unusually strong two-body dissipation allows to reproduce experimental data. No temperature dependent dissipation was needed.

Technology issues for decommissioning the Tokamak Fusion Test Reactor

International Nuclear Information System (INIS)

Spampinato, P.T.; Walton, G.R.

1994-01-01

The approach for decommissioning the Tokamak Fusion Test Reactor has evolved from a conservative plan based on cutting up and burying all of the systems, to one that considers the impact tritium contamination will have on waste disposal, how large size components may be used as their own shipping containers, and even the possibility of recycling the materials of components such as the toroidal field coils and the tokamak structure. In addition, the project is more carefully assessing the requirements for using remotely operated equipment. Finally, valuable cost database is being developed for future use by the fusion community

New neutron cross sections for fusion materials studies

International Nuclear Information System (INIS)

Greenwood, L.R.; Smither, R.K.

1985-01-01

Neutron cross sections are being developed for a variety of fusion-related applications including neutron dosimetry, fusion plasma diagnostics, the activation of very long-lived isotopes, and high-energy accelerator neutron sources

Neutron induced 238U subthreshold fission cross section for neutron energies between 5 eV and 3.5 MeV

International Nuclear Information System (INIS)

Perez, R.B.; Difilippo, F.C.; Saussure, G. de; Ingle, R.W.

1978-01-01

A measurement of the 238 U fission cross section between 5 eV and 3.5 MeV was performed. Included is the identification of 85 resonances or clusters of resonances below 200 keV. Also the fission widths for the 27 resolved class I levels were computed from their fission areas, and a neutron width of 0.005 MeV was estimated for the quasi-class II level in the 721 eV fission cluster. The fission level spacing and cross sections are discussed. 9 references

Case for the fusion hybrid

International Nuclear Information System (INIS)

Rose, R.P.

1981-01-01

The use of nuclear fusion to produce fuel for nuclear fission power stations is discussed in the context of a crucial need for future energy options. The fusion hybrid is first considered as an element in the future of nuclear fission power to provide long term assurance of adequate fuel supplies for both breeder and convertor reactors. Generic differences in neutronic characteristics lead to a fuel production potential of fusion-fission hybrid systems which is significantly greater than that obtainable with fission systems alone. Furthermore, cost benefit studies show a variety of scenarios in which the hybrid offers sufficient potential to justify development costs ranging in the tens of billions of dollars. The hybrid is then considered as an element in the ultimate development of fusion electric power. The hybrid offers a near term application of fusion where experience with the requisite technologies can be derived as a vital step in mapping a credible route to eventual commercial feasibility of pure fusion systems. Finally, the criteria for assessment of future energy options are discussed with prime emphasis on the need for rational comparision of alternatives