Funding schemes in OECD countries for future decommissioning of nuclear power

International Nuclear Information System (INIS)

Stevens, G.H.; Yasui, M.

1993-01-01

This paper provides a brief overview of the funding schemes for decommissioning implemented in selected OECD countries. The scope of this paper includes only the schemes for future decommissioning costs of private company's nuclear power plants. Countries such as Finland, Spain and Sweden have an official funding scheme, in which the government fixes the amount of money to be put aside, specifies a funding scheme and control the fund. In Belgium and Usa, the government do the same but leaves the management of the fund to the facility owners or external organization. In Canada, France, Germany, Italy, Japan, Netherlands and UK, there is no official funding scheme

Electromagnetically induced transparency and retrieval of light pulses in a Λ-type and a V-type level scheme in Pr3+:Y2SiO5

International Nuclear Information System (INIS)

Beil, Fabian; Klein, Jens; Halfmann, Thomas; Nikoghosyan, Gor

2008-01-01

We examine electromagnetically induced transparency (EIT), the optical preparation of persistent nuclear spin coherences and the retrieval of light pulses both in a Λ-type and a V-type coupling scheme in a Pr 3+ :Y 2 SiO 5 crystal, cooled to cryogenic temperatures. The medium is prepared by optical pumping and spectral hole burning, creating a spectrally isolated Λ-type and a V-type system within the inhomogeneous bandwidth of the 3 H 4 ↔ 1 D 2 transition of the Pr 3+ ions. By EIT, in the Λ-type scheme we drive a nuclear spin coherence between the ground-state hyperfine levels, while in the V-type scheme we drive a coherence between the excited-state hyperfine levels. We observe the cancellation of absorption due to EIT and the retrieval of light pulses in both level schemes. This also permits the determination of dephasing times of the nuclear spin coherence, either in the ground state or the optically excited state

Disposal of high level nuclear wastes: Thermodynamic equilibrium and environment ethics

Institute of Scientific and Technical Information of China (English)

RANA Mukhtar Ahmed

2009-01-01

Contamination of soil, water or air, due to a failure of containment or disposal of high level nuclear wastes, can potentially cause serious hazards to the environment or human health. Essential elements of the environment and radioactivity dangers to it are illustrated. Issues of high level nuclear waste disposal are discussed with a focus on thermodynamic equilibrium and environment ethics. Major aspects of the issues are analyzed and described briefly to build a perception of risks involved and ethical implications. Nuclear waste containment repository should be as close as possible to thermodynamic equilibrium. A clear demonstration about safety aspects of nuclear waste management is required in gaining public and political confidence in any possible scheme of permanent disposal. Disposal of high level nuclear waste offers a spectrum of environment connected challenges and a long term future of nuclear power depends on the environment friendly solution of the problem of nuclear wastes.

Disposal of high level nuclear wastes: thermodynamic equilibrium and environment ethics

International Nuclear Information System (INIS)

Rana, M.A.

2009-01-01

Contamination of soil, water or air, due to a failure of containment or disposal of high level nuclear wastes, can potentially cause serious hazards to the environment or human health. Essential elements of the environment and radioactivity dangers to it are illustrated. Issues of high level nuclear waste disposal are discussed with a focus on thermodynamic equilibrium and environment ethics. Major aspects of the issues are analyzed and described briefly to build a perception of risks involved and ethical implications. Nuclear waste containment repository should be as close as possible to thermodynamic equilibrium. A clear demonstration about safety aspects of nuclear waste management is required in gaining public and political confidence in any possible scheme of permanent disposal. Disposal of high level nuclear waste offers a spectrum of environment connected challenges and a long term future of nuclear power depends on the environment friendly solution of the problem of nuclear wastes. (authors)

The nuclear heating calculation scheme for material testing in the future Jules Horowitz Reactor

International Nuclear Information System (INIS)

Huot, N.; Aggery, A.; Blanchet, D.; Courcelle, A.; Czernecki, S.; Di-Salvo, J.; Doederlein, C.; Serviere, H.; Willermoz, G.

2004-01-01

An innovative nuclear heating calculation scheme for materials testing carried out in in the future Jules Horowitz reactor (JHR) is described. A heterogeneous gamma source calculation is first performed at assembly level using the deterministic code APOLLO2. This is followed by a Monte Carlo gamma transport calculation in the whole core using the TRIPOLI4 code. The calculated gamma sources at the assembly level are applied in the whole core simulation using a weighting based on power distribution obtained from the neutronic core calculation. (authors)

Combinatorial nuclear level density by a Monte Carlo method

International Nuclear Information System (INIS)

Cerf, N.

1994-01-01

We present a new combinatorial method for the calculation of the nuclear level density. It is based on a Monte Carlo technique, in order to avoid a direct counting procedure which is generally impracticable for high-A nuclei. The Monte Carlo simulation, making use of the Metropolis sampling scheme, allows a computationally fast estimate of the level density for many fermion systems in large shell model spaces. We emphasize the advantages of this Monte Carlo approach, particularly concerning the prediction of the spin and parity distributions of the excited states,and compare our results with those derived from a traditional combinatorial or a statistical method. Such a Monte Carlo technique seems very promising to determine accurate level densities in a large energy range for nuclear reaction calculations

Schemes of detecting nuclear spin correlations by dynamical decoupling based quantum sensing

Science.gov (United States)

Ma, Wen-Long Ma; Liu, Ren-Bao

Single-molecule sensitivity of nuclear magnetic resonance (NMR) and angstrom resolution of magnetic resonance imaging (MRI) are the highest challenges in magnetic microscopy. Recent development in dynamical decoupling (DD) enhanced diamond quantum sensing has enabled NMR of single nuclear spins and nanoscale NMR. Similar to conventional NMR and MRI, current DD-based quantum sensing utilizes the frequency fingerprints of target nuclear spins. Such schemes, however, cannot resolve different nuclear spins that have the same noise frequency or differentiate different types of correlations in nuclear spin clusters. Here we show that the first limitation can be overcome by using wavefunction fingerprints of target nuclear spins, which is much more sensitive than the ''frequency fingerprints'' to weak hyperfine interaction between the targets and a sensor, while the second one can be overcome by a new design of two-dimensional DD sequences composed of two sets of periodic DD sequences with different periods, which can be independently set to match two different transition frequencies. Our schemes not only offer an approach to breaking the resolution limit set by ''frequency gradients'' in conventional MRI, but also provide a standard approach to correlation spectroscopy for single-molecule NMR.

Discretisation Schemes for Level Sets of Planar Gaussian Fields

Science.gov (United States)

Beliaev, D.; Muirhead, S.

2018-01-01

Smooth random Gaussian functions play an important role in mathematical physics, a main example being the random plane wave model conjectured by Berry to give a universal description of high-energy eigenfunctions of the Laplacian on generic compact manifolds. Our work is motivated by questions about the geometry of such random functions, in particular relating to the structure of their nodal and level sets. We study four discretisation schemes that extract information about level sets of planar Gaussian fields. Each scheme recovers information up to a different level of precision, and each requires a maximum mesh-size in order to be valid with high probability. The first two schemes are generalisations and enhancements of similar schemes that have appeared in the literature (Beffara and Gayet in Publ Math IHES, 2017. https://doi.org/10.1007/s10240-017-0093-0; Mischaikow and Wanner in Ann Appl Probab 17:980-1018, 2007); these give complete topological information about the level sets on either a local or global scale. As an application, we improve the results in Beffara and Gayet (2017) on Russo-Seymour-Welsh estimates for the nodal set of positively-correlated planar Gaussian fields. The third and fourth schemes are, to the best of our knowledge, completely new. The third scheme is specific to the nodal set of the random plane wave, and provides global topological information about the nodal set up to `visible ambiguities'. The fourth scheme gives a way to approximate the mean number of excursion domains of planar Gaussian fields.

GRAP, Gamma-Ray Level-Scheme Assignment

International Nuclear Information System (INIS)

Franklyn, C.B.

2002-01-01

1 - Description of program or function: An interactive program for allocating gamma-rays to an energy level scheme. Procedure allows for searching for new candidate levels of the form: 1) L1 + G(A) + G(B) = L2; 2) G(A) + G(B) = G(C); 3) G(A) + G(B) = C (C is a user defined number); 4) L1 + G(A) + G(B) + G(C) = L2. Procedure indicates intensity balance of feed and decay of each energy level. Provides for optimization of a level energy (and associated error). Overall procedure allows for pre-defining of certain gamma-rays as belonging to particular regions of the level scheme, for example, high energy transition levels, or due to beta- decay. 2 - Method of solution: Search for cases in which the energy difference between two energy levels is equal to a gamma-ray energy within user-defined limits. 3 - Restrictions on the complexity of the problem: Maximum number of gamma-rays: 999; Maximum gamma ray energy: 32000 units; Minimum gamma ray energy: 10 units; Maximum gamma-ray intensity: 32000 units; Minimum gamma-ray intensity: 0.001 units; Maximum number of levels: 255; Maximum level energy: 32000 units; Minimum level energy: 10 units; Maximum error on energy, intensity: 32 units; Minimum error on energy, intensity: 0.001 units; Maximum number of combinations: 6400 (ca); Maximum number of gamma-ray types : 127

ESCL8R and LEVIT8R: interactive graphical analysis of {gamma}-{gamma} and {gamma}-{gamma}-{gamma} coincidence data for level schemes

Energy Technology Data Exchange (ETDEWEB)

Radford, D C [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

1992-08-01

The extraction of complete and consistent nuclear level schemes from high-fold coincidence data will require intelligent computer programs. These will need to present the relevant data in an easily assimilated manner, keep track of all {gamma}-ray assignments and expected coincidence intensities, and quickly find significant discrepancies between a proposed level scheme and the data. Some steps in this direction have been made at Chalk River. The programs ESCL8R and LEVIT8R, for analysis of two-fold and three-fold data sets respectively, allow fast and easy inspection of the data, and compare the results to expectations calculations on the basis of a proposed level scheme. Least-squares fits directly to the 2D and/or 3D data, with the intensities and energies of the level scheme transitions as parameters, allow fast and easy extraction of the optimum physics results. (author). 4 refs., 3 figs.

A new MV bus transfer scheme for nuclear power plants

International Nuclear Information System (INIS)

Chang, C.K.

2015-01-01

The auxiliary power system of many generating stations consists of offsite power supply system and onsite power supply system, including emergency diesel generators (EDG) to provide secure power to auxiliary loads. If a normal power supply fails to supply power, then the power source is transferred to a standby power supply. In the case of nuclear power plants (NPP), the unit auxiliary transformer (UAT) and standby auxiliary transformer (SAT) - or station service transformer - are installed and powered from 2 offsite power circuits to meet regulatory requirements. The transfer methods of a motor bus from a normal source to a standby source used in power generating stations are fast bus transfer, in-phase transfer, or residual transfer. Fast bus transfer method is the most popular and residual voltage transfer method that is used as a backup in medium voltage buses in general. The use of the advanced technology like open circuit voltage prediction and digital signal processing algorithms can improve the reliability of fast transfer scheme. However, according to the survey results of the recent operation records in nuclear power plants, there were many instances where the fast transfer scheme has failed. To assure bus transfer in any conditions and circumstances, un-interruptible bus transfer scheme utilizing the state of the art medium voltage UPS (Un-interruptible Power Supply) is discussed and elaborated

Possibility of combining nuclear level pumping in plasma with lasing in solid

International Nuclear Information System (INIS)

Karamyan, S.A.; Carroll, J.J.

2002-01-01

Nuclear isomers can be used for the storage and release of 'clean' nuclear energy, and the visible schemes are discussed. Resonance between the atomic and nuclear transitions may be manifested in a form of the hybridization of atomic-nuclear excitation at the appropriate case. The nuclear levels - candidates for triggering via atomic transitions are described. A variety of the ionization states and atomic-shell configurations arises in hot plasma generated by the short powerful pulse of laser light. The nonradiative conversion of the ionization energy within atom can be suppressed in the hot-plasma surroundings. Time-scales of different processes in nuclear, atomic and condensed-matter subsystems are compared. The processes of fast ionization in solid, X-ray radiance in plasma, sample melting and recrystallisation may precede nuclear fluorescence. Time-scale shorter 0.1 ns makes this sequence promising for the group excitation of short-lived modes in nuclear subsystem

Nuclear level density

International Nuclear Information System (INIS)

Cardoso Junior, J.L.

1982-10-01

Experimental data show that the number of nuclear states increases rapidly with increasing excitation energy. The properties of highly excited nuclei are important for many nuclear reactions, mainly those that go via processes of the compound nucleus type. In this case, it is sufficient to know the statistical properties of the nuclear levels. First of them is the function of nuclear levels density. Several theoretical models which describe the level density are presented. The statistical mechanics and a quantum mechanics formalisms as well as semi-empirical results are analysed and discussed. (Author) [pt

Schemes for Probabilistic Teleportation of an Unknown Three-Particle Three-Level Entangled State

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

In this paper, two schemes for teleporting an unknown three-particle three-level entangled state are proposed. In the first scheme, two partial three-particle three-level entangled states are used as the quantum channels, while in the second scheme, three two-particle three-level non-maximally entangled states are employed as quantum channels.It is shown that the teleportation can be successfully realized with certain probability, for both two schemes, if a receiver adopts some appropriate unitary transformations. It is shown also that the successful probabilities of these two schemes are different.

Experimental nuclear level densities and γ-ray strength functions in Sc and V isotopes

International Nuclear Information System (INIS)

Larsen, A. C.; Guttormsen, M.; Ingebretsen, F.; Messelt, S.; Rekstad, J.; Siem, S.; Syed, N. U. H.; Chankova, R.; Loennroth, T.; Schiller, A.; Voinov, A.

2008-01-01

The nuclear physics group at the Oslo Cyclotron Laboratory has developed a method to extract nuclear level density and γ-ray strength function from first-generation γ-ray spectra. This method is applied on the nuclei 44,45 Sc and 50,51 V in this work. The experimental level densities of 44,45 Sc are compared to calculated level densities using a microscopic model based on BCS quasiparticles within the Nilsson level scheme. The γ-ray strength functions are also compared to theoretical expectations, showing an unexpected enhancement of the γ-ray strength for low γ energies (E γ ≤3 MeV) in all the isotopes studied here. The physical origin of this enhancement is not yet understood

Four-level conservative finite-difference schemes for Boussinesq paradigm equation

Science.gov (United States)

Kolkovska, N.

2013-10-01

In this paper a two-parametric family of four level conservative finite difference schemes is constructed for the multidimensional Boussinesq paradigm equation. The schemes are explicit in the sense that no inner iterations are needed for evaluation of the numerical solution. The preservation of the discrete energy with this method is proved. The schemes have been numerically tested on one soliton propagation model and two solitons interaction model. The numerical experiments demonstrate that the proposed family of schemes has second order of convergence in space and time steps in the discrete maximal norm.

Adopting the EU sustainable performance scheme Level(s) in the Danish building sector

DEFF Research Database (Denmark)

Kanafani, Kai; Rasmussen, Freja Nygaard; Zimmermann, Regitze Kjær

2018-01-01

to life cycle assessment (LCA) requirements within the Level(s) scheme. As a measure for the Danish building sector’s LCA practice, the specifications for LCAbyg, the official Danish building LCA tool, is used. In 2017, the European commission’s Joint Research Centre has launched Level(s) as a vo...

Nuclear Level Densities

International Nuclear Information System (INIS)

Grimes, S.M.

2005-01-01

Recent research in the area of nuclear level densities is reviewed. The current interest in nuclear astrophysics and in structure of nuclei off of the line of stability has led to the development of radioactive beam facilities with larger machines currently being planned. Nuclear level densities for the systems used to produce the radioactive beams influence substantially the production rates of these beams. The modification of level-density parameters near the drip lines would also affect nucleosynthesis rates and abundances

Revisiting the level scheme of the proton emitter 151Lu

International Nuclear Information System (INIS)

Wang, F.; Sun, B.H.; Liu, Z.; Scholey, C.; Eeckhaudt, S.; Grahn, T.; Greenlees, P.T.; Jones, P.; Julin, R.; Juutinen, S.; Kettelhut, S.; Leino, M.; Nyman, M.; Rahkila, P.; Saren, J.; Sorri, J.; Uusitalo, J.; Ashley, S.F.; Cullen, I.J.; Garnsworthy, A.B.; Gelletly, W.; Jones, G.A.; Pietri, S.; Podolyak, Z.; Steer, S.; Thompson, N.J.; Walker, P.M.; Williams, S.; Bianco, L.; Darby, I.G.; Joss, D.T.; Page, R.D.; Pakarinen, J.; Rigby, S.; Cullen, D.M.; Khan, S.; Kishada, A.; Gomez-Hornillos, M.B.; Simpson, J.; Jenkins, D.G.; Niikura, M.; Seweryniak, D.; Shizuma, Toshiyuki

2015-01-01

An experiment aiming to search for new isomers in the region of proton emitter 151 Lu was performed at the Accelerator Laboratory of the University of Jyväskylä (JYFL), by combining the high resolution γ-ray array JUROGAM, gas-filled RITU separator and GREAT detectors with the triggerless total data readout acquisition (TDR) system. In this proceeding, we revisit the level scheme of 151 Lu by using the proton-tagging technique. A level scheme consistent with the latest experimental results is obtained, and 3 additional levels are identified at high excitation energies. (author)

A scheme for the evaluation of dominant time-eigenvalues of a nuclear reactor

International Nuclear Information System (INIS)

Modak, R.S.; Gupta, Anurag

2007-01-01

This paper presents a scheme to obtain the fundamental and few dominant solutions of the prompt time eigenvalue problem (referred to as α-eigenvalue problem) for a nuclear reactor using multi-group neutron diffusion theory. The scheme is based on the use of an algorithm called Orthomin(1). This algorithm was originally proposed by Suetomi and Sekimoto [Suetomi, E., Sekimoto, H., 1991. Conjugate gradient like methods and their application to eigenvalue problems for neutron diffusion equations. Ann. Nucl. Energy 18 (4), 205-227] to obtain the fundamental K-eigenvalue (K-effective) of nuclear reactors. Recently, it has been shown that the algorithm can be used to obtain the further dominant K-modes also. Since α-eigenvalue problem is usually more difficult to solve than the K-eigenvalue problem, an attempt has been made here to use Orthomin(1) for its solution. Numerical results are given for realistic 3-D test case

Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

Directory of Open Access Journals (Sweden)

Fapojuwo Abraham O

2007-01-01

Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

Directory of Open Access Journals (Sweden)

Abraham O. Fapojuwo

2007-11-01

Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

ZZ-CENPL, Chinese Evaluated Nuclear Parameter Library. ZZ CENPL-DLS, Discrete Level Schemes and Gamma Branching Ratios Library; ZZ CENPL-FBP, Fission Barrier Parameter Library; ZZ CENPL-GDRP, Giant Dipole Resonance Parameter Library; ZZ CENPL-NLD, Nuclear Level Density Parameter Library; ZZ CENPL-MCC, Nuclear Ground State Atomic Masses Library; ZZ CENPL-OMP, Optical Model Parameter Library

International Nuclear Information System (INIS)

Su Zongdi

1995-01-01

Description of program or function: CENPL - GDRP (Giant Dipole Resonance Parameters for Gamma-Ray): - Format: special format described in documentation; - Nuclides: V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er, Lu, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, Th, U, Np, Pu. - Origin: Experimental values offered by S.S. Dietrich and B.L. Berman. CENPL - FBP (Fission Barrier Parameter Sub-Library): - Format: special format described in documentation; - Nuclides: (1) 51 nuclei region from Th-230 to Cf-255, (2) 46 nuclei region from Th-229 to Cf-253, (3) 24 nuclei region from Pa-232 to Cf-253; - Origin: (1) Lynn, (2) Analysis of experimental data by Back et al., (3) Ohsawa. CENPL - DLS (Discrete level scheme and branch ratio of gamma decay: - Format: Special format described in documentation; - Origin: ENSDF - BNL. CENPL - NLD (Nuclear Level Density): - Format: Special format described in documentation; - Origin: Huang Zhongfu et al. CENPL - OMP (Optical model parameter sub-library): - Format: special format described in documentation ; - Origin: CENDL, ENDF/B-VI, JENDL-3. CENPL - MC (I) and (II) (Atomic masses and characteristic constants for nuclear ground states) : - Format: Brief table format; - Nuclides: 4760 nuclides ranging from Z=0 A=1 to Z=122 A=318. - Origin: Experimental data and systematic results evaluated by Wapstra, theoretical results calculated by Moller, ENSDF - BNL and Nuclear Wallet Cards. CENPL contains the following six sub-libraries: 1. Atomic Masses and Characteristic Constants for nuclear ground states (MCC). This data consists of calculated and in most cases also measured mass excesses, atomic masses, total binding energies, spins, parities, and half-lives of nuclear ground states, abundances, etc. for 4800 nuclides. 2. Discrete Level Schemes and branching ratios of gamma decay (DLS). The data on nuclear discrete levels are based on the Evaluated

Sensor data security level estimation scheme for wireless sensor networks.

Science.gov (United States)

Ramos, Alex; Filho, Raimir Holanda

2015-01-19

Due to their increasing dissemination, wireless sensor networks (WSNs) have become the target of more and more sophisticated attacks, even capable of circumventing both attack detection and prevention mechanisms. This may cause WSN users, who totally trust these security mechanisms, to think that a sensor reading is secure, even when an adversary has corrupted it. For that reason, a scheme capable of estimating the security level (SL) that these mechanisms provide to sensor data is needed, so that users can be aware of the actual security state of this data and can make better decisions on its use. However, existing security estimation schemes proposed for WSNs fully ignore detection mechanisms and analyze solely the security provided by prevention mechanisms. In this context, this work presents the sensor data security estimator (SDSE), a new comprehensive security estimation scheme for WSNs. SDSE is designed for estimating the sensor data security level based on security metrics that analyze both attack prevention and detection mechanisms. In order to validate our proposed scheme, we have carried out extensive simulations that show the high accuracy of SDSE estimates.

A novel scheme for making cheap electricity with nuclear energy

International Nuclear Information System (INIS)

Pettibone, J.S.

1991-04-01

Nuclear fuels should produce cheaper electricity than coal, considering their high specific energy and low cost. To exploit these properties, the scheme proposed here replaces the expensive reactor/steam-turbine system with an engine in which the expansion of a gas heated by a nuclear explosion raises a mass of liquid, thereby producing stored hydraulic energy. This energy could be converted to electricity by hydroelectric generation with water as the working fluid or by magnetohydrodynamic (MHD) generation with molten metal. A rough cost analysis suggests the hydroelectric system could reduce the present cost of electricity by two-thirds, and the MHD system by even more. Such cheap power would make feasible large-scale electrolysis to produce hydrogen and other fuels and chemical raw materials. 2 refs., 1 fig

An extrapolation scheme for solid-state NMR chemical shift calculations

Science.gov (United States)

Nakajima, Takahito

2017-06-01

Conventional quantum chemical and solid-state physical approaches include several problems to accurately calculate solid-state nuclear magnetic resonance (NMR) properties. We propose a reliable computational scheme for solid-state NMR chemical shifts using an extrapolation scheme that retains the advantages of these approaches but reduces their disadvantages. Our scheme can satisfactorily yield solid-state NMR magnetic shielding constants. The estimated values have only a small dependence on the low-level density functional theory calculation with the extrapolation scheme. Thus, our approach is efficient because the rough calculation can be performed in the extrapolation scheme.

Evaluation of β intensity data in nuclear decay schemes: comments on some pitfalls

International Nuclear Information System (INIS)

Reich, C.W.

1986-01-01

Some of the problems which arise in the evaluation of decay-schemes data to obtain values for the intensities of β transitions are discussed. As examples of these problems, the decay schemes of 87 Br and 233 Pa are examined. No specific solutions to these problems are offered; but by pointing them out to the participants in the International Nuclear Structure and Decay Data Evaluation Network, it is hoped that a general understanding of them can be gained, which may ultimately lead to a consistent means of dealing with them. 14 refs., 2 figs., 1 tab

Evaluation of beta intensity data in nuclear decay schemes: Comments on some pitfalls

International Nuclear Information System (INIS)

Reich, C.W.

1987-02-01

Some of the problems that arise in the evaluation of decay-schemes data to obtain values for the intensities of beta transitions are discussed. As examples of these problems, the decay schemes of 87 Br and 233 Pa are examined. No specific solutions to these problems are offered; but by pointing out to the participants in the International Nuclear Structure and Decay Data Evaluation Network, and to others, it is hoped that a general understanding of them can be gained, which may ultimately lead to a consistent means of dealing with them. 14 refs., 2 figs

Sensor Data Security Level Estimation Scheme for Wireless Sensor Networks

Science.gov (United States)

Ramos, Alex; Filho, Raimir Holanda

2015-01-01

Due to their increasing dissemination, wireless sensor networks (WSNs) have become the target of more and more sophisticated attacks, even capable of circumventing both attack detection and prevention mechanisms. This may cause WSN users, who totally trust these security mechanisms, to think that a sensor reading is secure, even when an adversary has corrupted it. For that reason, a scheme capable of estimating the security level (SL) that these mechanisms provide to sensor data is needed, so that users can be aware of the actual security state of this data and can make better decisions on its use. However, existing security estimation schemes proposed for WSNs fully ignore detection mechanisms and analyze solely the security provided by prevention mechanisms. In this context, this work presents the sensor data security estimator (SDSE), a new comprehensive security estimation scheme for WSNs. SDSE is designed for estimating the sensor data security level based on security metrics that analyze both attack prevention and detection mechanisms. In order to validate our proposed scheme, we have carried out extensive simulations that show the high accuracy of SDSE estimates. PMID:25608215

Sensor Data Security Level Estimation Scheme for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Alex Ramos

2015-01-01

Full Text Available Due to their increasing dissemination, wireless sensor networks (WSNs have become the target of more and more sophisticated attacks, even capable of circumventing both attack detection and prevention mechanisms. This may cause WSN users, who totally trust these security mechanisms, to think that a sensor reading is secure, even when an adversary has corrupted it. For that reason, a scheme capable of estimating the security level (SL that these mechanisms provide to sensor data is needed, so that users can be aware of the actual security state of this data and can make better decisions on its use. However, existing security estimation schemes proposed for WSNs fully ignore detection mechanisms and analyze solely the security provided by prevention mechanisms. In this context, this work presents the sensor data security estimator (SDSE, a new comprehensive security estimation scheme for WSNs. SDSE is designed for estimating the sensor data security level based on security metrics that analyze both attack prevention and detection mechanisms. In order to validate our proposed scheme, we have carried out extensive simulations that show the high accuracy of SDSE estimates.

Analysis of floor technology scheme in open-top construction of nuclear power project

International Nuclear Information System (INIS)

Zhang Shuxia; Lu Qinwu; Han Xiaoping

2014-01-01

Open-top construction is general technology in Ⅲ generation in nuclear power project. Because traditional floor structure and its form board upholding doesn't meet open-top construction, four floor scheme are presented, whose characters, advantages and disadvantages, and its application are summarized. The research results will help to the application of open-top construction. (authors)

Single particle level scheme for alpha decay

International Nuclear Information System (INIS)

Mirea, M.

1998-01-01

The fine structure phenomenon in alpha decay was evidenced by Rosenblum. In this process the kinetic energy of the emitted particle has several determined values related to the structure of the parent and the daughter nucleus. The probability to find the daughter in a low lying state was considered strongly dependent on the spectroscopic factor defined as the square of overlap between the wave function of the parent in the ground state and the wave functions of the specific excited states of the daughter. This treatment provides a qualitative agreement with the experimental results if the variations of the penetrability between different excited states are neglected. Based on single particle structure during fission, a new formalism explained quantitatively the fine structure of the cluster decay. It was suggested that this formalism can be applied also to alpha decay. For this purpose, the first step is to construct the level scheme of this type of decay. Such a scheme, obtained with the super-asymmetric two-center potential, is plotted for the alpha decay of 223 Ra. It is interesting to note that, diabatically, the level with spin 3/2 emerging from 1i 11/2 (ground state of the parent) reaches an excited state of the daughter in agreement with the experiment. (author)

A Robust Control Scheme for Medium-Voltage-Level DVR Implementation

DEFF Research Database (Denmark)

Blaabjerg, Frede; Loh, Poh Chiang; Li, Yun Wei

2007-01-01

of Hinfin controller weighting function selection, inner current loop tuning, and system disturbance rejection capability is presented. Finally, the designed control scheme is extensively tested on a laboratory 10-kV MV-level DVR system with varying voltage sag (balanced and unbalanced) and loading (linear....../nonlinear load and induction motor load) conditions. It is shown that the proposed control scheme is effective in both balanced and unbalanced sag compensation and load disturbance rejection, as its robustness is explicitly specified....

Macro-level integrated renewable energy production schemes for sustainable development

International Nuclear Information System (INIS)

Subhadra, Bobban G.

2011-01-01

The production of renewable clean energy is a prime necessity for the sustainable future existence of our planet. However, because of the resource-intensive nature, and other challenges associated with these new generation renewable energy sources, novel industrial frameworks need to be co-developed. Integrated renewable energy production schemes with foundations on resource sharing, carbon neutrality, energy-efficient design, source reduction, green processing plan, anthropogenic use of waste resources for the production green energy along with the production of raw material for allied food and chemical industries is imperative for the sustainable development of this sector especially in an emission-constrained future industrial scenario. To attain these objectives, the scope of hybrid renewable production systems and integrated renewable energy industrial ecology is briefly described. Further, the principles of Integrated Renewable Energy Park (IREP) approach, an example for macro-level energy production, and its benefits and global applications are also explored. - Research highlights: → Discusses the need for macro-level renewable energy production schemes. → Scope of hybrid and integrated industrial ecology for renewable energy production. → Integrated Renewable Energy Parks (IREPs): A macro-level energy production scheme. → Discusses the principle foundations and global applications of IREPs. → Describes the significance of IREPs in the carbon-neutral future business arena.

Role of proper response schemes, legislation and regional cooperation in combating illicit trafficking of nuclear materials in developing countries

International Nuclear Information System (INIS)

Sterzov, A.

2002-01-01

Full text: The suitable geographical situation on the crossroad between Europe, the former Soviet Union and the Middle East puts Bulgaria into the stream of many illegal traffics - people, arms, drugs etc. The illicit traffic of nuclear and radioactive materials is a serious violation of nonproliferation laws as well as a risk for the health of the population. Criminal diversion of fissile materials could lead to the potential construction of nuclear weapon or applied with conventional explosives the radioactive material could pose a threat to dwelling places, water supplies etc. The traffic of nuclear and radioactive materials in Bulgaria can be divided in two main parts -- internal and transit. I. Internal traffic The internal traffic consisted of stolen radioactive sources mainly imported with the Soviet equipment from companies or plants that were privatized or stopped functioning due to the economic changes in the country. There there were attempts to divert and transport materials from the Uranium mining industry including different amounts of 'yellow cake', depleted Uranium containers or shielding. These devices consisted of level and dense meters, irradiation devices, removing static electricity, smoke detectors etc. mainly containing the isotopes Cs-137, Co-60, Ir-192, Ra-226, Am-241 etc. II. External traffic The external traffic of illicit nuclear materials is connected with the transfer of raw materials and expensive metals from the former Soviet Union towards Western Europe and the Middle East. This traffic included Al, Os, Cs, Sc, Rare earth elements, Red Mercury, Pu, Enriched U. The traffic of the last three items is of greatest concern and should be addressed with highest priority. III. Response to the illicit traffic of nuclear materials The detection of both the internal and external traffic raises serious problems to the Bulgarian controlling organs both for equipment and qualified personnel at the borders and inside the country. The creation of

High level nuclear wastes

International Nuclear Information System (INIS)

Lopez Perez, B.

1987-01-01

The transformations involved in the nuclear fuels during the burn-up at the power nuclear reactors for burn-up levels of 33.000 MWd/th are considered. Graphs and data on the radioactivity variation with the cooling time and heat power of the irradiated fuel are presented. Likewise, the cycle of the fuel in light water reactors is presented and the alternatives for the nuclear waste management are discussed. A brief description of the management of the spent fuel as a high level nuclear waste is shown, explaining the reprocessing and giving data about the fission products and their radioactivities, which must be considered on the vitrification processes. On the final storage of the nuclear waste into depth geological burials, both alternatives are coincident. The countries supporting the reprocessing are indicated and the Spanish programm defined in the Plan Energetico Nacional (PEN) is shortly reviewed. (author) 8 figs., 4 tabs

A resolution adaptive deep hierarchical (RADHicaL) learning scheme applied to nuclear segmentation of digital pathology images.

Science.gov (United States)

Janowczyk, Andrew; Doyle, Scott; Gilmore, Hannah; Madabhushi, Anant

2018-01-01

Deep learning (DL) has recently been successfully applied to a number of image analysis problems. However, DL approaches tend to be inefficient for segmentation on large image data, such as high-resolution digital pathology slide images. For example, typical breast biopsy images scanned at 40× magnification contain billions of pixels, of which usually only a small percentage belong to the class of interest. For a typical naïve deep learning scheme, parsing through and interrogating all the image pixels would represent hundreds if not thousands of hours of compute time using high performance computing environments. In this paper, we present a resolution adaptive deep hierarchical (RADHicaL) learning scheme wherein DL networks at lower resolutions are leveraged to determine if higher levels of magnification, and thus computation, are necessary to provide precise results. We evaluate our approach on a nuclear segmentation task with a cohort of 141 ER+ breast cancer images and show we can reduce computation time on average by about 85%. Expert annotations of 12,000 nuclei across these 141 images were employed for quantitative evaluation of RADHicaL. A head-to-head comparison with a naïve DL approach, operating solely at the highest magnification, yielded the following performance metrics: .9407 vs .9854 Detection Rate, .8218 vs .8489 F -score, .8061 vs .8364 true positive rate and .8822 vs 0.8932 positive predictive value. Our performance indices compare favourably with state of the art nuclear segmentation approaches for digital pathology images.

High-spin level scheme of odd-odd 142Pm

International Nuclear Information System (INIS)

Liu Minliang; Zhang Yuhu; Zhou Xiaohong; He Jianjun; Guo Yingxiang; Lei Xiangguo; Huang Wenxue; Liu Zhong; Luo Yixiao; Feng Xichen; Zhang Shuangquan; Xu Xiao; Zheng Yong; Luo Wanju

2002-01-01

The level structure of doubly odd nucleus 142 Pm has been studied via the 128 Te( 19 F, 5nγ) 142 Pm reaction in the energy region from 75 to 95 MeV. In-beam γ rays were measured including the excited function, γ-ray singles and γ-γ coincidences in experiment. The level scheme of 142 Pm has been extended up to excitation energy of 7030.0 keV including 25 new γ rays and 13 new levels. Based on the measured γ-ray anisotropies, the level spins in 142 Pm have been suggested

Multi-model predictive control method for nuclear steam generator water level

International Nuclear Information System (INIS)

Hu Ke; Yuan Jingqi

2008-01-01

The dynamics of a nuclear steam generator (SG) is very different according to the power levels and changes as time goes on. Therefore, it is an intractable as well as challenging task to improve the water level control system of the SG. In this paper, a robust model predictive control (RMPC) method is developed for the level control problem. Based on a multi-model framework, a combination of a local nominal model with a polytopic uncertain linear parameter varying (LPV) model is built to approximate the system's non-linear behavior. The optimization problem solved here is based on a receding horizon scheme involving the linear matrix inequality (LMI) technique. Closed loop stability and constraints satisfaction in the entire operating range are guaranteed by the feasibility of the optimization problem. Finally, simulation results show the effectiveness and the good performance of the proposed method

The scheme optimization and management innovation for the first containment integrated in-service test of nuclear power plant

International Nuclear Information System (INIS)

Wang Haiwei; Yang Gang

2014-01-01

The containment integrated test is a large-scale, high risk and very difficult test in pressurized water reactor nuclear power plants. By simulating peak pressure inside the containment in DESIGN-BASIS accident conditions, measuring the total leakage rate of the containment with the peak pressure, and implementing the structure inspection test on several pressure levels, the containment's performance can be verified. Containment integrated test is an important witness point supervised by NNSA. The test results crucially decide the reactor to be started or not. The containment integrated test in 301 overhaul is the first in-service test of Unit 3. By the experience of the same 6 former tests in Qinshan Second Nuclear Power Plant and the feedback from other plants, the test scheme get more scientific and the organization management more standardized. This article discusses the containment integrated test in 301 overhaul and summarizes the experience to provide some references for the following containment integrated tests in the future. (authors)

New data on excited level scheme of 73Ge nucleus

International Nuclear Information System (INIS)

Kosyak, Yu.G.; Kaipov, D.K.; Chekushina, L.V.

1990-01-01

New data on the scheme of 73 Ge decay obtained by the method of reactor fast neutron inelastic scattering are presented. γ-Spectra from reaction 73 Ge(n, n'γ) 73 Ge at the angles of 90 and 124 deg of relatively incident neutron beam have been measured. Experimental populations of the levels are studied. 29 new γ-transitions have been identified, two new levels have been introduced

A Study on the Security Levels of Spread-Spectrum Embedding Schemes in the WOA Framework.

Science.gov (United States)

Wang, Yuan-Gen; Zhu, Guopu; Kwong, Sam; Shi, Yun-Qing

2017-08-23

Security analysis is a very important issue for digital watermarking. Several years ago, according to Kerckhoffs' principle, the famous four security levels, namely insecurity, key security, subspace security, and stego-security, were defined for spread-spectrum (SS) embedding schemes in the framework of watermarked-only attack. However, up to now there has been little application of the definition of these security levels to the theoretical analysis of the security of SS embedding schemes, due to the difficulty of the theoretical analysis. In this paper, based on the security definition, we present a theoretical analysis to evaluate the security levels of five typical SS embedding schemes, which are the classical SS, the improved SS (ISS), the circular extension of ISS, the nonrobust and robust natural watermarking, respectively. The theoretical analysis of these typical SS schemes are successfully performed by taking advantage of the convolution of probability distributions to derive the probabilistic models of watermarked signals. Moreover, simulations are conducted to illustrate and validate our theoretical analysis. We believe that the theoretical and practical analysis presented in this paper can bridge the gap between the definition of the four security levels and its application to the theoretical analysis of SS embedding schemes.

Level density from realistic nuclear potentials

International Nuclear Information System (INIS)

Calboreanu, A.

2006-01-01

Nuclear level density of some nuclei is calculated using a realistic set of single particle states (sps). These states are derived from the parameterization of nuclear potentials that describe the observed sps over a large number of nuclei. This approach has the advantage that one can infer level density for nuclei that are inaccessible for a direct study, but are very important in astrophysical processes such as those close to the drip lines. Level densities at high excitation energies are very sensitive to the actual set of sps. The fact that the sps spectrum is finite has extraordinary consequences upon nuclear reaction yields due to the leveling-off of the level density at extremely high excitation energies wrongly attributed so far to other nuclear effects. Single-particle level density parameter a parameter is extracted by fitting the calculated densities to the standard Bethe formula

Study of nuclear level densities for exotic nuclei

International Nuclear Information System (INIS)

Nasrabadi, M. N.; Sepiani, M.

2012-01-01

Nuclear level density is one of the properties of nuclei with widespread applications in astrophysics and nuclear medicine. Since there has been little experimental and theoretical research on the study of nuclei which are far from stability line, studying nuclear level density for these nuclei is of crucial importance. Also, as nuclear level density is an important input for nuclear research codes, hence studying the methods for calculation of this parameter is essential. Besides introducing various methods and models for calculating nuclear level density for practical applications, we used exact spectra distribution (SPDM) for determining nuclear level density of two neutron and proton enriched exotic nuclei with the same mass number.

Principal scheme of preventive maintenance support system for nuclear power plants

International Nuclear Information System (INIS)

Nishiyama, Takuya; Terano, Takao; Yokoo, Takeshi; Shinohara, Yasushi

1985-01-01

It is of great importance to turn lessons learned from abnormal event experiences to advantage as well as taking apriori actions for prevention of abnormal events in nuclear power plants. From this point of view, a consultation system, named as Preventive Maintenance Support System (PMSS), which is to possess accumulated knowledges drawn from the past abnormal events in nuclear power plants infer occurrences, factors and developments of abnormal events and recommend preventive countermeasures on the basis of the knowledges, has been proposed. This report presents the principal scheme of PMSS. To begin with, following to the discussion of the purpose and use of PMSS, the fundamental functions PMSS should perform are specified. They are (1) event factors analyzation, (2) event prediction (event development estimation and analogous event estimation), (3) event significance evaluation and (4) preventive countermeasures presentation. In the next place, it is asserted that such a system should be constructed as a knowledge engineering one. Then, the R and D subjects and related schedule for PMSS are set up. (author)

Scheme of 2-dimensional atom localization for a three-level atom via quantum coherence

OpenAIRE

Zafar, Sajjad; Ahmed, Rizwan; Khan, M. Khalid

2013-01-01

We present a scheme for two-dimensional (2D) atom localization in a three-level atomic system. The scheme is based on quantum coherence via classical standing wave fields between the two excited levels. Our results show that conditional position probability is significantly phase dependent of the applied field and frequency detuning of spontaneously emitted photons. We obtain a single localization peak having probability close to unity by manipulating the control parameters. The effect of ato...

A proposal of new nuclear communication scheme based on qualitative research

International Nuclear Information System (INIS)

Yagi, Ekou; Takahashi, Makoto; Kitamura, Masaharu

2007-01-01

An action research project called dialogue forum has been conducted in this study. The essential constituent of the project is a series of repetitive dialogue sessions carried out by lay citizens, nuclear experts, and a facilitator. One important feature of the project is that the study has been conducted based on the qualitative research methodology. The changes in opinions and attitude of the dialogue participants have been analyzed by an ethno-methodological approach. The observations are summarized as follows. The opinions of the citizen participants showed a significant shift from emotional to practical representations along with the progression of the dialogue sessions. Meanwhile, their attitude showed a marked tendency from problem-statement-oriented to problem-solving-oriented representation. On the other hand, the statements of the expert participants showed a significant shift from expert-based to citizen-based risk recognition and description, and their attitude showed a clear tendency from teaching-oriented to colearning-oriented thinking. These changes of opinions and attitude have been interpreted as a coevolving rather than a single process. It can be stressed that this type of change is most important for the reestablishment of mutual trust between the citizens and the nuclear experts. In this regard The Process Model of Coevolution of Risk Recognition' has been proposed as a guideline for developing a new scheme of public communication concerning nuclear technology. The proposed process model of coevolution of risk recognition is regarded to be essential for appropriate relationship management between nuclear technology and society in the near future. (author)

Malfunction diagnosis and applications of stable adaptive schemes for a nuclear reactor system

International Nuclear Information System (INIS)

Fukuda, Toshio; Shibata, Heki.

1979-01-01

Malfunction diagnosis concerns a method to detect the abnormal phenomena during nuclear reactor operations, while stable adaptive schemes does the application of Model Reference Adaptive System (MRAS) to the nonlinear dynamics of a reactor for parameter identification and control. The new method for the malfunction diagnosis consists of the following ideas; an index defined as the sum of ratios of the square of a factor score to the contribution weight of the factor, which is evaluated by applying the multi-factor analysis technique to the data of the state of nuclear reactor systems like neutron flux, temperature, flow rate and so on. The excess of the index over some given threshold shows the reactor system would be in an abnormal state. Then a theory of optimal filtering by Kalman with the aid of the stochastic approximation is applied to estimate the neutron flux distribution at its abnormal state and subsequently the squared sum of difference between desirable and estimated flux distributions shows the spot at which the abnormal phenomena would have occurred in terms of the peak of its distribution. Parameter identification and adaptive control schemes are presented for a point reactor and a loosely-coupled-core reactor with internal feedbacks which lead to the nonlinearity of the overall system. Both schemes are shown stable with new representations of the systems, which correspond to the nonminimal system representation, in the vein of the MRAS via the Lyapunov's method. For the sake of the parameter identification, model parameters can be adjusted adaptively as soon as measurements start, while plant parameters can also adaptively be compensated through control input to reduce the output error between the model and the plant for the case of the adaptive control. Some experiments of parameter identification for the thermal-hydraulic system are carried out successfully using a simplified channel in which flow rate is varied in a binary form. (J.P.N.)

Nuclear systems of level measurement

International Nuclear Information System (INIS)

Lara, A.J.; Cabrera, M.J.

1992-01-01

In the industry there are processes in which is necessary to maintain the products level controlled which are handled for their transformation. The majority of such processes and by the operation conditions, they do not admit measure systems of level of invasive type then the application of nuclear techniques for level measurement results a big aid in these cases, since all the system installation is situated beyond frontiers of vessels that contain the product for measuring. In the Department of Nuclear Technology Applications of Mexican Petroleum Institute was developed a level measurement system by gamma rays transmission which operates in the Low Density Polyethylene plant of Petrochemical Complex Escolin at Poza Rica, Veracruz, Mexico. (Author)

Enhanced nuclear level decay in hot dense plasmas

International Nuclear Information System (INIS)

Gosselin, G.; Morel, P.

2004-01-01

A model of nuclear level decay in a plasma environment is described. Nuclear excitation and decay by photon processes, nuclear excitation by electron capture, and decay by internal conversion are taken into account. The electrons in the plasma are described by a relativistic average atom model for the bound electrons and by a relativistic Thomas-Fermi-Dirac model for the free electrons. Nuclear decay of isomeric level may be enhanced through an intermediate level lying above the isomer. An enhanced nuclear decay rate may occur for temperatures far below the excitation energy of the transition to the intermediate level. In most cases, the enhancement factor may reach several decades

Nuclear power: levels of safety

International Nuclear Information System (INIS)

Lidsky, L.M.

1988-01-01

The rise and fall of the nuclear power industry in the United States is a well-documented story with enough socio-technological conflict to fill dozens of scholarly, and not so scholarly, books. Whatever the reasons for the situation we are now in, and no matter how we apportion the blame, the ultimate choice of whether to use nuclear power in this country is made by the utilities and by the public. Their choices are, finally, based on some form of risk-benefit analysis. Such analysis is done in well-documented and apparently logical form by the utilities and in a rather more inchoate but not necessarily less accurate form by the public. Nuclear power has failed in the United States because both the real and perceived risks outweigh the potential benefits. The national decision not to rely upon nuclear power in its present form is not an irrational one. A wide ranging public balancing of risk and benefit requires a classification of risk which is clear and believable for the public to be able to assess the risks associated with given technological structures. The qualitative four-level safety ladder provides such a framework. Nuclear reactors have been designed which fit clearly and demonstrably into each of the possible qualitative safety levels. Surprisingly, it appears that safer may also mean cheaper. The intellectual and technical prerequisites are in hand for an important national decision. Deployment of a qualitatively different second generation of nuclear reactors can have important benefits for the United States. Surprisingly, it may well be the nuclear establishment itself, with enormous investments of money and pride in the existing nuclear systems, that rejects second generation reactors. It may be that we will not have a second generation of reactors until the first generation of nuclear engineers and nuclear power advocates has retired

Nuclear Data Sheets for A=213

International Nuclear Information System (INIS)

Basunia, M.S.

2007-01-01

Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for all nuclei with mass number A=213. This evaluation for A=213 supersedes the earlier one by Y. A. Akovali (1992Ak01), published in Nuclear Data Sheets 66, 237 (1992)

Change in the financing scheme for radioactive waste in Germany

International Nuclear Information System (INIS)

Svobodová, Tereza

2018-01-01

Financing radioactive waste management is an issue every country using nuclear power has to deal with. A European directive even makes this binding for Euratom Member States. Germany changed its financing scheme entirely during the past year, thereby moving closer to other states' schemes. Germany replaced the funds put aside by the operators with a public fund to which the companies contribute. Now it is the government that is responsible for radioactive waste. This paper describes the regulation and information collection system on the European level and analyses the former and current German systems, their advantages and potential hazards. (orig.)

Nuclear database management systems

International Nuclear Information System (INIS)

Stone, C.; Sutton, R.

1996-01-01

The authors are developing software tools for accessing and visualizing nuclear data. MacNuclide was the first software application produced by their group. This application incorporates novel database management and visualization tools into an intuitive interface. The nuclide chart is used to access properties and to display results of searches. Selecting a nuclide in the chart displays a level scheme with tables of basic, radioactive decay, and other properties. All level schemes are interactive, allowing the user to modify the display, move between nuclides, and display entire daughter decay chains

Discrete level schemes sublibrary. Progress report by Budapest group

International Nuclear Information System (INIS)

Oestor, J.; Belgya, T.; Molnar, G.L.

1997-01-01

An entirely new discrete levels file has been created by the Budapest group according to the recommended principles, using the Evaluated Nuclear Structure Data File, ENSDF as a source. The resulting library contains 96,834 levels and 105,423 gamma rays for 2,585 nuclei, with their characteristics such as energy, spin, parity, half-life as well gamma-ray energy and branching percentage

Nuclear transmutation of actinides other than fuel as a radioactive waste management scheme

International Nuclear Information System (INIS)

Cecille, L.; Hage, W.; Hettinger, H.; Mannone, F.; Mousty, F.; Schmidt, E.; Sola, A.; Huber, B.; Koch, L.

1977-01-01

The bulk of fission products in the high-level waste (HLW) decays to innocuous hazard levels within about 600 years. Actinide waste and a few fission products however represent a potential risk up to some hundreds of thousand of years. An alternative to the disposal of the whole HLW in geological formations is its fractionation, a nuclear transmutation of long-lived isotopes in fission reactors and a geological disposal of the other components. This solution would decrease the potential long-term risks of the geological waste disposal and would also accomodate to the demand of public opinion. The results of studies related to this management scheme are outlined with special reference to areas, where additional effort is required for realistic cost/benefit evaluations. Reactor physics calculations demonstrated the feasibility of actinide incineration in thermal and fast reactors. Obtained transmutation rates are sufficiently high to garantee acceptably small actinide inventories in the reactor in the case of self-generated actinide recycling. It appears that fast breeders could be used as transmutation devices without major additional reactor devlopment work. The thermal power rating of actinide fuel elements and the contribution of actinides and of minor amounts of lanthanide impurities to the neutron economy of the reactor has been evaluated. Sensitivity studies indicated that the results are dependent on the reactor operation mode and on the accuracy of the nuclear data. These calculations permitted the identification of isotopes for which cross section masurements and improved theoretical methods are required. The chemical separation of actinides from the HLW with the envisaged decontamination factors is being studied by solvent extraction and precipitation techniques using waste simulates and samples of high activity waste from European reprocessing plants. Up to now, the obtained results do not yet allow a definitive judgement on the feasibility of actinides

An Enhanced Three-Level Voltage Switching State Scheme for Direct Torque Controlled Open End Winding Induction Motor

Science.gov (United States)

Kunisetti, V. Praveen Kumar; Thippiripati, Vinay Kumar

2018-01-01

Open End Winding Induction Motors (OEWIM) are popular for electric vehicles, ship propulsion applications due to less DC link voltage. Electric vehicles, ship propulsions require ripple free torque. In this article, an enhanced three-level voltage switching state scheme for direct torque controlled OEWIM drive is implemented to reduce torque and flux ripples. The limitations of conventional Direct Torque Control (DTC) are: possible problems during low speeds and starting, it operates with variable switching frequency due to hysteresis controllers and produces higher torque and flux ripple. The proposed DTC scheme can abate the problems of conventional DTC with an enhanced voltage switching state scheme. The three-level inversion was obtained by operating inverters with equal DC-link voltages and it produces 18 voltage space vectors. These 18 vectors are divided into low and high frequencies of operation based on rotor speed. The hardware results prove the validity of proposed DTC scheme during steady-state and transients. From simulation and experimental results, proposed DTC scheme gives less torque and flux ripples on comparison to two-level DTC. The proposed DTC is implemented using dSPACE DS-1104 control board interface with MATLAB/SIMULINK-RTI model.

'Level-level correlation and absorption in nuclear reactions'

International Nuclear Information System (INIS)

Hussein, M.S.

Level-level correlation (LLC) in nuclear reactions is discussed in general and it is shown that in the presence of LLC, N sub(μ) = Σ/g μa/ 2 > divided by gamma μ T tilde, where T tilde is the average absorption in the eigen channels [pt

Economy analysis on vertical layout of conventional island of nuclear power plant

International Nuclear Information System (INIS)

Wang Xuefeng; Liu Xiaoyun; Liu Jinwei

2011-01-01

This paper briefly introduces the aboveground layout scheme and integral sinking layout scheme of conventional island of nuclear power plants. Technological-economic analysis formula are given, as a result, main factors influencing scheme selection is obtained. Determination of the layout scheme selection and optimization direction through the curve between the accumulative NPV and related factors is brought forward. The paper carries out the technological-economic comparison to the two schemes referred to a 1000 MW level nuclear power project as the example, getting the curve between the accumulative NPV and the plant ground elevation, and offering the method of selecting the vertical layout scheme of conventional island and vertical layout optimization direction. (authors)

A SCHEME FOR TEMPLATE SECURITY AT FEATURE FUSION LEVEL IN MULTIMODAL BIOMETRIC SYSTEM

Directory of Open Access Journals (Sweden)

Arvind Selwal

2016-09-01

Full Text Available Biometric is the science of human recognition based upon using their biological, chemical or behavioural traits. These systems are used in many real life applications simply from biometric based attendance system to providing security at very sophisticated level. A biometric system deals with raw data captured using a sensor and feature template extracted from raw image. One of the challenges being faced by designers of these systems is to secure template data extracted from the biometric modalities of the user and protect the raw images. To minimize spoof attacks on biometric systems by unauthorised users one of the solutions is to use multi-biometric systems. Multi-modal biometric system works by using fusion technique to merge feature templates generated from different modalities of the human. In this work a new scheme is proposed to secure template during feature fusion level. Scheme is based on union operation of fuzzy relations of templates of modalities during fusion process of multimodal biometric systems. This approach serves dual purpose of feature fusion as well as transformation of templates into a single secured non invertible template. The proposed technique is cancelable and experimentally tested on a bimodal biometric system comprising of fingerprint and hand geometry. Developed scheme removes the problem of an attacker learning the original minutia position in fingerprint and various measurements of hand geometry. Given scheme provides improved performance of the system with reduction in false accept rate and improvement in genuine accept rate.

Materials Science of High-Level Nuclear Waste Immobilization

International Nuclear Information System (INIS)

Weber, William J.; Navrotsky, Alexandra; Stefanovsky, S. V.; Vance, E. R.; Vernaz, Etienne Y.

2009-01-01

With the increasing demand for the development of more nuclear power comes the responsibility to address the technical challenges of immobilizing high-level nuclear wastes in stable solid forms for interim storage or disposition in geologic repositories. The immobilization of high-level nuclear wastes has been an active area of research and development for over 50 years. Borosilicate glasses and complex ceramic composites have been developed to meet many technical challenges and current needs, although regulatory issues, which vary widely from country to country, have yet to be resolved. Cooperative international programs to develop advanced proliferation-resistant nuclear technologies to close the nuclear fuel cycle and increase the efficiency of nuclear energy production might create new separation waste streams that could demand new concepts and materials for nuclear waste immobilization. This article reviews the current state-of-the-art understanding regarding the materials science of glasses and ceramics for the immobilization of high-level nuclear waste and excess nuclear materials and discusses approaches to address new waste streams

Synchronised PWM Schemes for Three-level Inverters with Zero Common-mode Voltage

DEFF Research Database (Denmark)

Oleschuk, Valentin; Blaabjerg, Frede

2002-01-01

This paper presents results of analysis and comparison of novel synchronised schemes of pulsewidth modulation (PWM), applied to three-level voltage source inverters with control algorithms providing elimination of the common-mode voltage. The proposed approach is based on a new strategy of digital...

Three-dimensional coupled Monte Carlo-discrete ordinates computational scheme for shielding calculations of large and complex nuclear facilities

International Nuclear Information System (INIS)

Chen, Y.; Fischer, U.

2005-01-01

Shielding calculations of advanced nuclear facilities such as accelerator based neutron sources or fusion devices of the tokamak type are complicated due to their complex geometries and their large dimensions, including bulk shields of several meters thickness. While the complexity of the geometry in the shielding calculation can be hardly handled by the discrete ordinates method, the deep penetration of radiation through bulk shields is a severe challenge for the Monte Carlo particle transport technique. This work proposes a dedicated computational scheme for coupled Monte Carlo-Discrete Ordinates transport calculations to handle this kind of shielding problems. The Monte Carlo technique is used to simulate the particle generation and transport in the target region with both complex geometry and reaction physics, and the discrete ordinates method is used to treat the deep penetration problem in the bulk shield. The coupling scheme has been implemented in a program system by loosely integrating the Monte Carlo transport code MCNP, the three-dimensional discrete ordinates code TORT and a newly developed coupling interface program for mapping process. Test calculations were performed with comparison to MCNP solutions. Satisfactory agreements were obtained between these two approaches. The program system has been chosen to treat the complicated shielding problem of the accelerator-based IFMIF neutron source. The successful application demonstrates that coupling scheme with the program system is a useful computational tool for the shielding analysis of complex and large nuclear facilities. (authors)

Two-level MOC calculation scheme in APOLLO2 for cross-section library generation for LWR hexagonal assemblies

International Nuclear Information System (INIS)

Petrov, Nikolay; Todorova, Galina; Kolev, Nikola; Damian, Frederic

2011-01-01

The accurate and efficient MOC calculation scheme in APOLLO2, developed by CEA for generating multi-parameterized cross-section libraries for PWR assemblies, has been adapted to hexagonal assemblies. The neutronic part of this scheme is based on a two-level calculation methodology. At the first level, a multi-cell method is used in 281 energy groups for cross-section definition and self-shielding. At the second level, precise MOC calculations are performed in a collapsed energy mesh (30-40 groups). In this paper, the application and validation of the two-level scheme for hexagonal assemblies is described. Solutions for a VVER assembly are compared with TRIPOLI4® calculations and direct 281g MOC solutions. The results show that the accuracy is close to that of the 281g MOC calculation while the CPU time is substantially reduced. Compared to the multi-cell method, the accuracy is markedly improved. (author)

A scheme for the audit of scientific and technological standards in clinical nuclear medicine

International Nuclear Information System (INIS)

Perkins, A.C.; Jarritt, P.H.

2002-01-01

Aim: Audit is the process whereby the quality of a service is monitored and optimised. It forms an essential component of the quality assurance process, whether by self-assessment or by external peer review. In the UK the British Nuclear Medicine Society (BNMS) has undertaken external organisational audit of departments providing clinical nuclear medicine services. This work aimed to develop a more thorough and service specific process for the audit of scientific and technological standards in nuclear medicine. Materials and Methods: The audit process has been implemented using written audit documents to facilitate the audit procedure. A questionnaire forms part of the formal documentation for audit of the scientific and technical standards of a clinical service. Scientific and technical standards were derived from a number of sources including legal requirements, regulatory obligations, notes for guidance, peer reviewed publications and accepted good clinical practice (GCP). Results: The audit process graded the standards of an individual department according to legal or safety requirements (Grade A), good practice (Grade B) and desirable aspects of service delivery (Grade C). The standards have been allocated into eight main categories. These are: Instrumentation; Software and data protection; Electrical Safety; Mechanical Safety; Workstation Safety; The Control of Substances Hazardous to Health (COSHH); Radiation Protection; Scientific and Technical staffing levels. During the audit visit a detailed inspection of clinical and laboratory areas and department written documentation is also necessary to validate the data obtained. Conclusion: The printed scheme now provides a means for external audit or self-assessment. There should be evidence of a well-organised and safe environment for both patients and staff. Health and Safety legislation requires written local rules and these records should be available to demonstrate the standard of service provision. Other

Solving the Sea-Level Equation in an Explicit Time Differencing Scheme

Science.gov (United States)

Klemann, V.; Hagedoorn, J. M.; Thomas, M.

2016-12-01

In preparation of coupling the solid-earth to an ice-sheet compartment in an earth-system model, the dependency of initial topography on the ice-sheet history and viscosity structure has to be analysed. In this study, we discuss this dependency and how it influences the reconstruction of former sea level during a glacial cycle. The modelling is based on the VILMA code in which the field equations are solved in the time domain applying an explicit time-differencing scheme. The sea-level equation is solved simultaneously in the same explicit scheme as the viscoleastic field equations (Hagedoorn et al., 2007). With the assumption of only small changes, we neglect the iterative solution at each time step as suggested by e.g. Kendall et al. (2005). Nevertheless, the prediction of the initial paleo topography in case of moving coastlines remains to be iterated by repeated integration of the whole load history. The sensitivity study sketched at the beginning is accordingly motivated by the question if the iteration of the paleo topography can be replaced by a predefined one. This study is part of the German paleoclimate modelling initiative PalMod. Lit:Hagedoorn JM, Wolf D, Martinec Z, 2007. An estimate of global mean sea-level rise inferred from tide-gauge measurements using glacial-isostatic models consistent with the relative sea-level record. Pure appl. Geophys. 164: 791-818, doi:10.1007/s00024-007-0186-7Kendall RA, Mitrovica JX, Milne GA, 2005. On post-glacial sea level - II. Numerical formulation and comparative reesults on spherically symmetric models. Geophys. J. Int., 161: 679-706, doi:10.1111/j.365-246.X.2005.02553.x

Optimal Face-Iris Multimodal Fusion Scheme

Directory of Open Access Journals (Sweden)

Omid Sharifi

2016-06-01

Full Text Available Multimodal biometric systems are considered a way to minimize the limitations raised by single traits. This paper proposes new schemes based on score level, feature level and decision level fusion to efficiently fuse face and iris modalities. Log-Gabor transformation is applied as the feature extraction method on face and iris modalities. At each level of fusion, different schemes are proposed to improve the recognition performance and, finally, a combination of schemes at different fusion levels constructs an optimized and robust scheme. In this study, CASIA Iris Distance database is used to examine the robustness of all unimodal and multimodal schemes. In addition, Backtracking Search Algorithm (BSA, a novel population-based iterative evolutionary algorithm, is applied to improve the recognition accuracy of schemes by reducing the number of features and selecting the optimized weights for feature level and score level fusion, respectively. Experimental results on verification rates demonstrate a significant improvement of proposed fusion schemes over unimodal and multimodal fusion methods.

Status of transactinium nuclear data in the Evaluated Nuclear Structure Data File

International Nuclear Information System (INIS)

Ewbank, W.B.

1979-01-01

The organization and program of the Nuclear Data Project are described. An Evaluated Nuclear Structure Data File (ENSDF) was designed to contain most of the data of nuclear structure physics. ENSDF includes adopted level information for all 1950 known nuclei, and detailed data for approximately 1500 decay schemes. File organization, management, and retrieval are reviewed. An international network of data evaluation centers has been organized to provide for a four-year cycle of ENSDF revisions. Standard retrieval and display programs can prepare various tables of specific data, which can serve as a good first approximation to a complete up-to-date compilation. Appendixes list, for A > 206, nuclear levels with lifetimes > or = 1 s, strong γ rays from radioisotopes (ordered by nuclide and energy), and strong α particle emissions (similarly ordered). 8 figures

Storage of High Level Nuclear Waste in Germany

Directory of Open Access Journals (Sweden)

Dietmar P. F. Möller

2007-01-01

Full Text Available Nuclear energy is very often used to generate electricity. But first the energy must be released from atoms what can be done in two ways: nuclear fusion and nuclear fission. Nuclear power plants use nuclear fission to produce electrical energy. The electrical energy generated in nuclear power plants does not produce polluting combustion gases but a renewable energy, an important fact that could play a key role helping to reduce global greenhouse gas emissions and tackling global warming especially as the electricity energy demand rises in the years ahead. This could be assumed as an ideal win-win situation, but the reverse site of the medal is that the production of high-level nuclear waste outweighs this advantage. Hence the paper attempt to highlight the possible state-of-art concepts for the safe and sustaining storage of high-level nuclear waste in Germany.

Nuclear structure of 194Pt

International Nuclear Information System (INIS)

Cleveland, W.E.; Zganjar, E.F.

1976-01-01

The decay of 194 Ir has been thoroughly studied resulting in the construction of a decay scheme consisting of 26 excited states and 69 transitions. Nine new levels and 29 new transitions were added to the previously known scheme. Of these, levels at 1,893.6 and 2,053.0 keV as well as 9 γ-ray transitions are new to the 194 Pt level scheme. Precise γ-ray energy and intensity measurements as well as quantitative coincidence measurements were performed, and the internal conversion spectrum was investigated with a Si(Li) detector. Directional correlation measurements were performed for selected cascades with the major result being the unique assignment of 0 + to the new level at 1,893.6 keV. The structure was interpreted within the framework of the PPQ model as well as the effective-core picture including nuclear triaxiality. (orig.) [de

Finite-volume scheme for anisotropic diffusion

Energy Technology Data Exchange (ETDEWEB)

Es, Bram van, E-mail: bramiozo@gmail.com [Centrum Wiskunde & Informatica, P.O. Box 94079, 1090GB Amsterdam (Netherlands); FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, The Netherlands" 1 (Netherlands); Koren, Barry [Eindhoven University of Technology (Netherlands); Blank, Hugo J. de [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, The Netherlands" 1 (Netherlands)

2016-02-01

In this paper, we apply a special finite-volume scheme, limited to smooth temperature distributions and Cartesian grids, to test the importance of connectivity of the finite volumes. The area of application is nuclear fusion plasma with field line aligned temperature gradients and extreme anisotropy. We apply the scheme to the anisotropic heat-conduction equation, and compare its results with those of existing finite-volume schemes for anisotropic diffusion. Also, we introduce a general model adaptation of the steady diffusion equation for extremely anisotropic diffusion problems with closed field lines.

Nuclear accidents and safety measures of domestic nuclear power plants

International Nuclear Information System (INIS)

Song Zurong; Che Shuwei; Pan Xiang

2012-01-01

Based on the design standards for the safety of nuclear and radiation in nuclear power plants, the three accidents in the history of nuclear power are analyzed. And the main factors for these accidents are found out, that is, human factors and unpredicted natural calamity. By combining the design and operation parameters of domestic nuclear plants, the same accidents are studied and some necessary preventive schemes are put forward. In the security operation technology of domestic nuclear power plants nowadays, accidents caused by human factors can by prevented completely. But the safety standards have to be reconsidered for the unpredicted neutral disasters. How to reduce the hazard of nuclear radiation and leakage to the level that can be accepted by the government and public when accidents occur under extreme conditions during construction and operation of nuclear power plants must be considered adequately. (authors)

Preliminary Study of 1D Thermal-Hydraulic System Analysis Code Using the Higher-Order Numerical Scheme

Energy Technology Data Exchange (ETDEWEB)

Lee, Won Woong; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

2016-05-15

The existing nuclear system analysis codes such as RELAP5, TRAC, MARS and SPACE use the first-order numerical scheme in both space and time discretization. However, the first-order scheme is highly diffusive and less accurate due to the first order of truncation error. So, the numerical diffusion problem which makes the gradients to be smooth in the regions where the gradients should be steep can occur during the analysis, which often predicts less conservatively than the reality. Therefore, the first-order scheme is not always useful in many applications such as boron solute transport. RELAP7 which is an advanced nuclear reactor system safety analysis code using the second-order numerical scheme in temporal and spatial discretization is being developed by INL (Idaho National Laboratory) since 2011. Therefore, for better predictive performance of the safety of nuclear reactor systems, more accurate nuclear reactor system analysis code is needed for Korea too to follow the global trend of nuclear safety analysis. Thus, this study will evaluate the feasibility of applying the higher-order numerical scheme to the next generation nuclear system analysis code to provide the basis for the better nuclear system analysis code development. The accuracy is enhanced in the spatial second-order scheme and the numerical diffusion problem is alleviated while indicates significantly lower maximum Courant limit and the numerical dispersion issue which produces spurious oscillation and non-physical results in the higher-order scheme. If the spatial scheme is the first order scheme then the temporal second-order scheme provides almost the same result with the temporal firstorder scheme. However, when the temporal second order scheme and the spatial second-order scheme are applied together, the numerical dispersion can occur more severely. For the more in-depth study, the verification and validation of the NTS code built in MATLAB will be conducted further and expanded to handle two

First Krakow-Berlin workshop on nuclear physics. Slide report

International Nuclear Information System (INIS)

Styczen, J.; Maier, K.H.

1992-01-01

In this workshop new experimental and theoretical results in nuclear spectroscopy are presented. For several nuclei new data: energy level schemes, electromagnetic transitions, quadrupole moments, and nuclear deformation parameters are presented. New nuclei excitation methods and the new detector for the OSIRIS spectrometer are also discussed

First Krakow-Berlin workshop on nuclear physics. Slide report

Energy Technology Data Exchange (ETDEWEB)

Styczen, J. [comp.] [Institute of Nuclear Physics, Cracow (Poland); Maier, K.H. [comp.] [Hahn-Meitner-Institut Berlin GmbH (Germany)

1992-12-31

In this workshop new experimental and theoretical results in nuclear spectroscopy are presented. For several nuclei new data: energy level schemes, electromagnetic transitions, quadrupole moments, and nuclear deformation parameters are presented. New nuclei excitation methods and the new detector for the OSIRIS spectrometer are also discussed.

Water level monitoring device in nuclear reactor

International Nuclear Information System (INIS)

Miura, Kiyohide; Otake, Tomohiro.

1988-01-01

Purpose: To monitor the water level in a pressure vessel of BWR type nuclear reactors at high accuracy by improving the compensation functions. Constitution: In the conventional water level monitor in a nuclear reactor, if the pressure vessel is displaced by the change of the pressure in the reactor or the temperature of the reactor water, the relative level of the reference water head in a condensation vessel is changed to cause deviation between the actual water level and the indicated water level to reduce the monitoring accuracy. According to the invention, means for detecting the position of the reference water head and means for detection the position in the condensation vessel are disposed to the pressure vessel. Then, relative positional change between the condensation vessel and the reference water head is calculated based on detection sinals from both of the means. The water level is compensated and calculated by water level calculation means based on the relative positional change, water level signals from the level gage and the pressure signals from the pressure gage. As a result, if the pressure vessel is displaced due to the change of the temperature or pressure, it is possible to measure the reactor water level accurately thereby remakably improve the reliability for the water level control in the nuclear reactor. (Horiuchi, T.)

Progress on Chinese evaluated nuclear parameter library (CENPL) (II)

International Nuclear Information System (INIS)

Su Zhongdi; Ge Zhigang; Zhou Chunmei

1993-01-01

CENPL collected, evaluated and compiled nuclear basic constants and model parameters. CENPL-1 contain six sub-libraries, they are: (1) Atomic masses and characteristic constants for nuclear ground states; (2) discrete level schemes and branch ratios of γ decay; (3) level density parameters; (4) giant dipole resonance parameters for γ-ray strength function (5) fission barrier parameter; (6) optical model parameters. Their progresses are introduced

Liquid level measurement in high level nuclear waste slurries

International Nuclear Information System (INIS)

Weeks, G.E.; Heckendorn, F.M.; Postles, R.L.

1990-01-01

Accurate liquid level measurement has been a difficult problem to solve for the Defense Waste Processing Facility (DWPF). The nuclear waste sludge tends to plug or degrade most commercially available liquid-level measurement sensors. A liquid-level measurement system that meets demanding accuracy requirements for the DWPF has been developed. The system uses a pneumatic 1:1 pressure repeater as a sensor and a computerized error correction system. 2 figs

Discrete level schemes and their gamma radiation branching ratios (CENPL-DLS): Pt.2

Energy Technology Data Exchange (ETDEWEB)

Limin, Zhang; Zongdi, Su; Zhengjun, Sun [Chinese Nuclear Data Center, Beijing, BJ (China)

1996-06-01

The DLS data files contains the data and information of nuclear discrete levels and gamma rays. At present, it has 79461 levels and 93177 gamma rays for 1908 nuclides. The DLS sub-library has been set up at the CNDC, and widely used for nuclear model calculation and other field. the DLS management retrieval code DLS is introduced and an example is given for {sup 56}Fe. (1 tab.).

Study of nuclear level density parameter and its temperature dependence

International Nuclear Information System (INIS)

Nasrabadi, M. N.; Behkami, A. N.

2000-01-01

The nuclear level density ρ is the basic ingredient required for theoretical studies of nuclear reaction and structure. It describes the statistical nuclear properties and is expressed as a function of various constants of motion such as number of particles, excitation energy and angular momentum. In this work the energy and spin dependence of nuclear level density will be presented and discussed. In addition the level density parameter α will be extracted from this level density information, and its temperature and mass dependence will be obtained

Discrete level schemes and their gamma radiation branching ratios (CENPL-DLS). Pt. 1

International Nuclear Information System (INIS)

Su Zongdi; Zhang Limin; Zhou Chunmei; Sun Zhengjun

1994-01-01

The DLS data file, which is a sub-library (version 1) of Chinese Evaluated Nuclear Parameter Library (CENPL), consists of data and information of discrete levels and gamma radiations. The data and information of this data file are translated from the Evaluated Nuclear Structure Data File (ENSDF). The transforming code from ENSDF to DLS was written. In the DLS data file, there are the data on discrete levels with determinate energy and their gamma radiations. At present, this file contains the data of 79456 levels and 100411 gammas for 1908 nuclides

Recruitment schemes in new nuclear projects

International Nuclear Information System (INIS)

Tielas, M.

2012-01-01

Contracting in New Nuclear Projects: A collaborative model between the Owner and the Supplier is described for building nuclear power plants, and is being implemented in the USA as well as in Europe to solve the problem of the risk in the initial investment as experienced in the past: widely exceeded budgets and construction schedules. (Author)

Effect of pairing in nuclear level density at low temperatures

International Nuclear Information System (INIS)

Rhine Kumar, A.K.; Modi, Swati; Arumugam, P.

2013-01-01

The nuclear level density (NLD) has been an interesting topic for researchers, due its importance in many aspects of nuclear physics, nuclear astrophysics, nuclear medicine, and other applied areas. The calculation of NLD helps us to understand the energy distribution of the excited levels of nuclei, entropy, specific heat, reaction cross sections etc. In this work the effect of temperature and pairing on level-density of the nucleus 116 Sn has been studied

Numerical schemes for explosion hazards

International Nuclear Information System (INIS)

Therme, Nicolas

2015-01-01

In nuclear facilities, internal or external explosions can cause confinement breaches and radioactive materials release in the environment. Hence, modeling such phenomena is crucial for safety matters. Blast waves resulting from explosions are modeled by the system of Euler equations for compressible flows, whereas Navier-Stokes equations with reactive source terms and level set techniques are used to simulate the propagation of flame front during the deflagration phase. The purpose of this thesis is to contribute to the creation of efficient numerical schemes to solve these complex models. The work presented here focuses on two major aspects: first, the development of consistent schemes for the Euler equations, then the buildup of reliable schemes for the front propagation. In both cases, explicit in time schemes are used, but we also introduce a pressure correction scheme for the Euler equations. Staggered discretization is used in space. It is based on the internal energy formulation of the Euler system, which insures its positivity and avoids tedious discretization of the total energy over staggered grids. A discrete kinetic energy balance is derived from the scheme and a source term is added in the discrete internal energy balance equation to preserve the exact total energy balance at the limit. High order methods of MUSCL type are used in the discrete convective operators, based solely on material velocity. They lead to positivity of density and internal energy under CFL conditions. This ensures that the total energy cannot grow and we can furthermore derive a discrete entropy inequality. Under stability assumptions of the discrete L8 and BV norms of the scheme's solutions one can prove that a sequence of converging discrete solutions necessarily converges towards the weak solution of the Euler system. Besides it satisfies a weak entropy inequality at the limit. Concerning the front propagation, we transform the flame front evolution equation (the so called

ENSL and CDRL: Evaluated nuclear structure libraries

International Nuclear Information System (INIS)

Howerton, R.J.

1981-01-01

Two files of nuclear structure data derived largely from the seventh edition of the Table of Isotopes are described. The files are computer oriented, and have been constructed to so that every decay can be traced either to an eventual ground state of to a positive flag that indicates nothing is known about further decay. The ENSL file contains level schemes derived from decay data, and the CDRL file contains the level schemes derived from particle-induced reaction data that have been merged into the ENSL file. (author)

Systematics of nuclear mass and level density formulas

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Hisashi [Fuji Electric Co. Ltd., Kawasaki, Kanagawa (Japan)

1998-03-01

The phenomenological models of the nuclear mass and level density are close related to each other, the nuclear ground and excited state properties are described by using the parameter systematics on the mass and level density formulas. The main aim of this work is to provide in an analytical framework the improved energy dependent shell, pairing and deformation corrections generalized to the collective enhancement factors, which offer a systematic prescription over a great number of nuclear reaction cross sections. The new formulas are shown to be in close agreement with not only the empirical nuclear mass data but the measured slow neutron resonance spacings, and experimental systematics observed in the excitation energy dependent properties. (author)

Nuclear moment of inertia and spin distribution of nuclear levels

International Nuclear Information System (INIS)

Alhassid, Y.; Fang, L.; Liu, S.; Bertsch, G.F.

2005-01-01

We introduce a simple model to calculate the nuclear moment of inertia at finite temperature. This moment of inertia describes the spin distribution of nuclear levels in the framework of the spin-cutoff model. Our model is based on a deformed single-particle Hamiltonian with pairing interaction and takes into account fluctuations in the pairing gap. We derive a formula for the moment of inertia at finite temperature that generalizes the Belyaev formula for zero temperature. We show that a number-parity projection explains the strong odd-even effects observed in shell model Monte Carlo studies of the nuclear moment of inertia in the iron region

A classification scheme for LWR fuel assemblies

Energy Technology Data Exchange (ETDEWEB)

Moore, R.S.; Williamson, D.A.; Notz, K.J.

1988-11-01

With over 100 light water nuclear reactors operating nationwide, representing designs by four primary vendors, and with reload fuel manufactured by these vendors and additional suppliers, a wide variety of fuel assembly types are in existence. At Oak Ridge National Laboratory, both the Systems Integration Program and the Characteristics Data Base project required a classification scheme for these fuels. This scheme can be applied to other areas and is expected to be of value to many Office of Civilian Radioactive Waste Management programs. To develop the classification scheme, extensive information on the fuel assemblies that have been and are being manufactured by the various nuclear fuel vendors was compiled, reviewed, and evaluated. It was determined that it is possible to characterize assemblies in a systematic manner, using a combination of physical factors. A two-stage scheme was developed consisting of 79 assembly types, which are grouped into 22 assembly classes. The assembly classes are determined by the general design of the reactor cores in which the assemblies are, or were, used. The general BWR and PWR classes are divided differently but both are based on reactor core configuration. 2 refs., 15 tabs.

A classification scheme for LWR fuel assemblies

International Nuclear Information System (INIS)

Moore, R.S.; Williamson, D.A.; Notz, K.J.

1988-11-01

With over 100 light water nuclear reactors operating nationwide, representing designs by four primary vendors, and with reload fuel manufactured by these vendors and additional suppliers, a wide variety of fuel assembly types are in existence. At Oak Ridge National Laboratory, both the Systems Integration Program and the Characteristics Data Base project required a classification scheme for these fuels. This scheme can be applied to other areas and is expected to be of value to many Office of Civilian Radioactive Waste Management programs. To develop the classification scheme, extensive information on the fuel assemblies that have been and are being manufactured by the various nuclear fuel vendors was compiled, reviewed, and evaluated. It was determined that it is possible to characterize assemblies in a systematic manner, using a combination of physical factors. A two-stage scheme was developed consisting of 79 assembly types, which are grouped into 22 assembly classes. The assembly classes are determined by the general design of the reactor cores in which the assemblies are, or were, used. The general BWR and PWR classes are divided differently but both are based on reactor core configuration. 2 refs., 15 tabs

Nuclear Level densities from drip line to drip line

International Nuclear Information System (INIS)

Hilaire, S.; Goriely, S.

2007-01-01

New energy-, spin-, parity-dependent level densities based on the microscopic combinatorial model are presented and compared with available experimental data as well as with other nuclear level densities usually employed in nuclear reaction codes. These microscopic level densities are made available in a table format for nearly 8500 nuclei

Practical Calculational Scheme Implementing the Wilsonian RG Results for Nuclear Effective Field Theory Including Pions

International Nuclear Information System (INIS)

Kubo, H.; Harada, K.; Sakaeda, T.; Yamamoto, Y.

2013-01-01

On the basis of the Wilsonian renormalization group (WRG) analysis of nuclear effective field theory (NEFT) including pions, we propose a practical calculational scheme in which the short-distance part of one-pion exchange (S-OPE) is removed and represented as contact terms. The long-distance part of one-pion exchange (L-OPE) is treated as perturbation. The use of dimensional regularization (DR) for diagrams consisting only of contact interactions considerably simplifies the calculation of scattering amplitude and the renormalization group equations. NLO results for nucleon-nucleon elastic scattering in the S-waves are obtained and compared with experiments. A brief comment on NNLO calculations is given. (author)

Federal and state regulatory schemes affecting liability for high-level waste transportation incidents: opportunities for clarification and amendment

International Nuclear Information System (INIS)

Friel, L.E.; Livingston-Behan, E.A.

1985-01-01

The Price-Anderson Act of 1957 provides extensive public liability coverage in the event of a serious accident involving the transportation of nuclear materials to or from certain federally-licensed, or federal contractor-operated facilities. While actual liability for a nuclear incident and the extent of damages are usually determined by state law, the Act establishes a comprehensive system for the payment of such damages. Despite the federally-mandated scheme for liability coverage several aspects of the Act's application to transportation to a permanent repository have not yet been settled and are open to various interpretations. Some areas of uncertainty apply not only to future waste transport to a repository, but also to current transportation activities, and include: coverage for emergency response and clean-up costs; coverage for precautionary evacuations; and the federal government's financial liability. The need to address liability issues is also increasingly recognized at the state level. The state laws which are used to determine liability and the extent of damages in the event of a transportation accident vary widely among states and significantly affect the compensation that an injured person will receive under the provisions of the Price-Anderson Act. Areas of state law deserving special attention include: standards for determining liability; statutes of limitations; standards for proof of causation; state sovereign immunity statutes; and recovery of unique emergency response costs

Examination of State-Level Nuclear Security Evaluation Methods

International Nuclear Information System (INIS)

Kim, Chan Kim; Yim, Man-Sung

2015-01-01

An effective global system for nuclear materials security needs to cover all materials, employing international standards and best practices, to reduce risks by reducing weapons-usable nuclear material stocks and the number of locations where they are found. Such a system must also encourage states to accept peer reviews by outside experts in order to demonstrate that effective security is in place. It is thus critically important to perform state-level evaluation of nuclear security based on an integrative framework of risk assessment. Such evaluation provides a basis of measuring the level and progress of international effort to secure and control all nuclear materials. sensitivity test by differentiating weight factors of each of the indicators and categories will be performed in the future as well

Bit-level quantum color image encryption scheme with quantum cross-exchange operation and hyper-chaotic system

Science.gov (United States)

Zhou, Nanrun; Chen, Weiwei; Yan, Xinyu; Wang, Yunqian

2018-06-01

In order to obtain higher encryption efficiency, a bit-level quantum color image encryption scheme by exploiting quantum cross-exchange operation and a 5D hyper-chaotic system is designed. Additionally, to enhance the scrambling effect, the quantum channel swapping operation is employed to swap the gray values of corresponding pixels. The proposed color image encryption algorithm has larger key space and higher security since the 5D hyper-chaotic system has more complex dynamic behavior, better randomness and unpredictability than those based on low-dimensional hyper-chaotic systems. Simulations and theoretical analyses demonstrate that the presented bit-level quantum color image encryption scheme outperforms its classical counterparts in efficiency and security.

Modulation Schemes of Multi-phase Three-Level Z-Source Inverters

DEFF Research Database (Denmark)

Gao, F.; Loh, P.C.; Blaabjerg, Frede

2007-01-01

different modulation requirement and output performance. For clearly illustrating the detailed modulation process, time domain analysis instead of the traditional multi-dimensional space vector demonstration is assumed which reveals the right way to insert shoot-through durations in the switching sequence...... with minimal commutation count. Lastly, the theoretical findings are verified in Matlab/PLECS simulation and experimentally using constructed laboratory prototypes.......This paper investigates the modulation schemes of three-level multiphase Z-source inverters with either two Z-source networks or single Z-source network connected between the dc sources and inverter circuitry. With the proper offset added for achieving both desired four-leg operation and optimized...

Two-level convolution formula for nuclear structure function

Science.gov (United States)

Ma, Boqiang

1990-05-01

A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions.

Two-level convolution formula for nuclear structure function

International Nuclear Information System (INIS)

Ma Boqiang

1990-01-01

A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions

Nuclear level density parameter 's dependence on angular momentum

International Nuclear Information System (INIS)

Aggarwal, Mamta; Kailas, S.

2009-01-01

Nuclear level densities represent a very important ingredient in the statistical Model calculations of nuclear reaction cross sections and help to understand the microscopic features of the excited nuclei. Most of the earlier experimental nuclear level density measurements are confined to low excitation energy and low spin region. A recent experimental investigation of nuclear level densities in high excitation energy and angular momentum domain with some interesting results on inverse level density parameter's dependence on angular momentum in the region around Z=50 has motivated us to study and analyse these experimental results in a microscopic theoretical framework. In the experiment, heavy ion fusion reactions are used to populate the excited and rotating nuclei and measured the α particle evaporation spectra in coincidence with ray multiplicity. Residual nuclei are in the range of Z R 48-55 with excitation energy range 30 to 40 MeV and angular momentum in 10 to 25. The inverse level density parameter K is found to be in the range of 9.0 - 10.5 with some exceptions

Application of stable adaptive schemes to nuclear reactor systems, (1)

International Nuclear Information System (INIS)

Fukuda, Toshio

1978-01-01

Parameter identification and adaptive control schemes are presented for a point reactor with internal feedbacks which lead to the nonlinearity of the overall system. Both are shown stable with new representation of the system, which corresponds to the nonminimal system representation, in the vein of the Model Reference Adaptive System (MRAS) via the Lyapunov's method. For the sake of the parameter identification, model parameters can be adjusted adaptively as soon as measurements start, while plant parameters can also adaptively be compensated through control input to reduce the output error between the model and the plant for the case of the adaptive control. In the case of the adaptive control, control schemes are presented for two cases, the case of the unknown decay constant of the delayed neutron and the case of the known constant. The adaptive control scheme for the latter case is shown extremely simpler than that for the former. Furthermore, when plant parameters vary slowly with time, computer simulations show that the proposed adaptive control scheme works satisfactorily enough to stabilize an unstable reactor and that it does even in the noise with small variance. (auth.)

Different-Level Simultaneous Minimization Scheme for Fault Tolerance of Redundant Manipulator Aided with Discrete-Time Recurrent Neural Network.

Science.gov (United States)

Jin, Long; Liao, Bolin; Liu, Mei; Xiao, Lin; Guo, Dongsheng; Yan, Xiaogang

2017-01-01

By incorporating the physical constraints in joint space, a different-level simultaneous minimization scheme, which takes both the robot kinematics and robot dynamics into account, is presented and investigated for fault-tolerant motion planning of redundant manipulator in this paper. The scheme is reformulated as a quadratic program (QP) with equality and bound constraints, which is then solved by a discrete-time recurrent neural network. Simulative verifications based on a six-link planar redundant robot manipulator substantiate the efficacy and accuracy of the presented acceleration fault-tolerant scheme, the resultant QP and the corresponding discrete-time recurrent neural network.

Brief of the joint research with universities, etc. for 2002. Except the research by the JNC cooperative research scheme on the nuclear fuel cycle

International Nuclear Information System (INIS)

2003-09-01

The Japan Nuclear Cycle Development Institute (JNC) promote the basic and fundamental research in relation to the research and development projects of JNC through collaboration with universities and other research institutes (referred to as 'universities, etc.' below). This report includes a summary of the results of the research carried out in fiscal year 2002 on 15 joint researches with universities, etc. In addition, this report removes the research by the JNC Cooperative Research Scheme on the Nuclear Fuel Cycle. (author)

Recent advances in measurements of the nuclear level density

International Nuclear Information System (INIS)

John, Bency

2007-01-01

A short review of recent advances in measurements of the nuclear level density is given. First results of the inverse level density parameter - angular momentum correlation in a number of nuclei around Z∼50 shell region at an excitation energy around 0.3 MeV/nucleon are presented. Significant variations observed over and above the expected shell corrections are discussed in context of the emerging trends in microscopic calculations of the nuclear level density. (author)

Examination of the Current Approaches to State-Level Nuclear Security Evaluation

International Nuclear Information System (INIS)

Kim, Chan; Yim, Mansung; Kim, So Young

2014-01-01

An effective global nuclear materials security system will cover all materials, employ international standards and best practices, and reduce risks by reducing weapons-usable nuclear material stocks and the number of locations where they are found. Such a system must also encourage states to accept peer reviews by outside experts in order to demonstrate that effective security is in place. It is thus critically important to create an integrative framework of state-level evaluation of nuclear security as a basis for measuring the level and progress of international effort to secure and control all nuclear materials. There have been studies to represent state-level nuclear security with a quantitative metric. A prime example is the Nuclear Materials Security Index (NMSI) by the Nuclear Threat Initiative (NTI). Another comprehensive study is the State Level Risk Metric by Texas A and M University (TAMU). This paper examines the current methods with respect to their strengths and weaknesses and identifies the directions for future research to improve upon the existing approaches

Scheme of fault tectonic and tectonic activity manifestation in the region of the Crimea nuclear power plant construction

International Nuclear Information System (INIS)

Pasynkov, A.L.

1989-01-01

Characteristic of fault tectonics and tectonic activity manifestation in the region of the Crimea nuclear power plant construction is presented. Mosaic-block structure of the area, predetermined by the development of diagonal systems of activated tectonic dislocations with different displacement amplitudes and different stratigraphic ranges of manifestation, was established. Strained-stressed state of the region is determined by the presence of the South-Azov zone of deep fault and Krasnogorsk-Samarlinks fault system. The presented scheme can be used as tectonic basis of seismogenic activity of the region

Progress on Chinese evaluated nuclear parameters library (CENPL). Pt. 3

International Nuclear Information System (INIS)

Su Zongdi; Ge Zhigang; Zhou Chunmei

1994-01-01

The progress on Chinese evaluated nuclear parameters library (CENPL) is introduced. The setting up work of each sub-library of CENPL has got some new progresses at the past period. These sub-libraries are atomic mass and characteristic constant for nuclear ground state sub-library, discrete level scheme and batch ratio of γ decay sub-library, level density parameter sub-library, giant dipole resonance parameter for γ-ray strength function sub-library and optical model parameter sub-library

About efficient quasi-Newtonian schemes for variational calculations in nuclear structure

International Nuclear Information System (INIS)

Puddu, G.

2009-01-01

The Broyden-Fletcher-Goldhaber-Shanno (BFGS) quasi-Newtonian scheme is known as the most efficient scheme for variational calculations of energies. This scheme is actually a member of a one-parameter family of variational methods, known as the Broyden β-family. In some applications to light nuclei using microscopically derived effective Hamiltonians starting from accurate nucleon-nucleon potentials, we actually found other members of the same family which have better performance than the BFGS method. We also extend the Broyden β -family of algorithms to a two-parameter family of rank-three updates which has even better performances. (orig.)

Power components behavior under nuclear radiations

International Nuclear Information System (INIS)

Jaureguy, J.C.; Azais, B.

1989-01-01

Many apparatus, either fixed or on-board of vehicles, use power converters. The most common scheme includes chopper with bipolar transistors. In case of nuclear radiations, these equipments may be severely damaged. Depending on the disturbance level, the need for changes in power transistor technology has to be considered or not [fr

Developing Curriculum of Nuclear Civil Engineering Degree Programme at Graduate Level

International Nuclear Information System (INIS)

Iqbal, J.

2016-01-01

Full text: The paper suggests the introduction of a new degree, namely nuclear civil engineering at graduate level for better utilization of civil engineers in nuclear power plant (NPP) design and construction. At present, both nuclear engineering and civil engineering degrees are offered at undergraduate and graduate levels in numerous renowned universities of the world. However, when a civil engineer, even after completion of nuclear engineering at postgraduate level, undertakes an assignment related to NPP design, he comes across various problems which are not covered in the present curricula. For instance, NPPs’ siting issues, design of pre-stressed concrete containment against loads of loss of coolant accident (LOCA), various impulsive and impactive loads (e.g., detonations, aircraft crash analysis, etc.) and shielding calculations are some of the core issues during nuclear power plant design. The paper highlights the importance of introduction of nuclear civil engineering degree at the graduate level. Besides, the contents of the proposed course work have also been discussed. Keeping in view the fact that, currently, no such degree is offered in any university of the world, the paper explores useful avenues to human resource development for introducing and expanding nuclear power programmes. (author

Linear source approximation scheme for method of characteristics

International Nuclear Information System (INIS)

Tang Chuntao

2011-01-01

Method of characteristics (MOC) for solving neutron transport equation based on unstructured mesh has already become one of the fundamental methods for lattice calculation of nuclear design code system. However, most of MOC codes are developed with flat source approximation called step characteristics (SC) scheme, which is another basic assumption for MOC. A linear source (LS) characteristics scheme and its corresponding modification for negative source distribution were proposed. The OECD/NEA C5G7-MOX 2D benchmark and a self-defined BWR mini-core problem were employed to validate the new LS module of PEACH code. Numerical results indicate that the proposed LS scheme employs less memory and computational time compared with SC scheme at the same accuracy. (authors)

High-level nuclear waste disposal

International Nuclear Information System (INIS)

Burkholder, H.C.

1985-01-01

The meeting was timely because many countries had begun their site selection processes and their engineering designs were becoming well-defined. The technology of nuclear waste disposal was maturing, and the institutional issues arising from the implementation of that technology were being confronted. Accordingly, the program was structured to consider both the technical and institutional aspects of the subject. The meeting started with a review of the status of the disposal programs in eight countries and three international nuclear waste management organizations. These invited presentations allowed listeners to understand the similarities and differences among the various national approaches to solving this very international problem. Then seven invited presentations describing nuclear waste disposal from different perspectives were made. These included: legal and judicial, electric utility, state governor, ethical, and technical perspectives. These invited presentations uncovered several issues that may need to be resolved before high-level nuclear wastes can be emplaced in a geologic repository in the United States. Finally, there were sixty-six contributed technical presentations organized in ten sessions around six general topics: site characterization and selection, repository design and in-situ testing, package design and testing, disposal system performance, disposal and storage system cost, and disposal in the overall waste management system context. These contributed presentations provided listeners with the results of recent applied RandD in each of the subject areas

Radiation levels in nuclear diagnostic examinations

International Nuclear Information System (INIS)

Vermeulen, A.M.T.I.

1987-01-01

To estimate the risks for a pregnant radiological worker, radiation level measurements are executed for common nuclear diagnostic techniques. These measurements are combined with the time which the radiologic worker is present during the performance of the diagnostic techniques. It is concluded that a radiologic worker is receiving less than 5 mSv during pregnancy. This is the case with in vivo determination in a department of nuclear medicine with common diagnostic techniques. Reduction of radiation doses during pregnancy is possible by reduction of heart function examinations, skeletal examinations and brain scans. 1 figure; 13 tabs

Asynchronous Two-Level Checkpointing Scheme for Large-Scale Adjoints in the Spectral-Element Solver Nek5000

Energy Technology Data Exchange (ETDEWEB)

Schanen, Michel; Marin, Oana; Zhang, Hong; Anitescu, Mihai

2016-01-01

Adjoints are an important computational tool for large-scale sensitivity evaluation, uncertainty quantification, and derivative-based optimization. An essential component of their performance is the storage/recomputation balance in which efficient checkpointing methods play a key role. We introduce a novel asynchronous two-level adjoint checkpointing scheme for multistep numerical time discretizations targeted at large-scale numerical simulations. The checkpointing scheme combines bandwidth-limited disk checkpointing and binomial memory checkpointing. Based on assumptions about the target petascale systems, which we later demonstrate to be realistic on the IBM Blue Gene/Q system Mira, we create a model of the expected performance of our checkpointing approach and validate it using the highly scalable Navier-Stokes spectralelement solver Nek5000 on small to moderate subsystems of the Mira supercomputer. In turn, this allows us to predict optimal algorithmic choices when using all of Mira. We also demonstrate that two-level checkpointing is significantly superior to single-level checkpointing when adjoining a large number of time integration steps. To our knowledge, this is the first time two-level checkpointing had been designed, implemented, tuned, and demonstrated on fluid dynamics codes at large scale of 50k+ cores.

Numerical design of RNnν symmetry-based RF pulse schemes for recoupling and decoupling of nuclear spin interactions at high MAS frequencies

International Nuclear Information System (INIS)

Herbst, Christian; Herbst, Jirada; Leppert, Joerg; Ohlenschlaeger, Oliver; Goerlach, Matthias; Ramachandran, Ramadurai

2009-01-01

An approach for the efficient implementation of RN n ν symmetry-based pulse schemes that are often employed for recoupling and decoupling of nuclear spin interactions in biological solid state NMR investigations is demonstrated at high magic-angle spinning frequencies. RF pulse sequences belonging to the RN n ν symmetry involve the repeated application of the pulse sandwich {R φ R -φ }, corresponding to a propagator U RF = exp(-i4φI z ), where φ = πν/N and R is typically a pulse that rotates the nuclear spins through 180 o about the x-axis. In this study, broadband, phase-modulated 180 o pulses of constant amplitude were employed as the initial 'R' element and the phase-modulation profile of this 'R' element was numerically optimised for generating RN n ν symmetry-based pulse schemes with satisfactory magnetisation transfer characteristics. At representative MAS frequencies, RF pulse sequences were implemented for achieving 13 C- 13 C double-quantum dipolar recoupling and through bond scalar coupling mediated chemical shift correlation and evaluated via numerical simulations and experimental measurements. The results from these investigations are presented here

The effect of hearing aid signal-processing schemes on acceptable noise levels: perception and prediction.

Science.gov (United States)

Wu, Yu-Hsiang; Stangl, Elizabeth

2013-01-01

The acceptable noise level (ANL) test determines the maximum noise level that an individual is willing to accept while listening to speech. The first objective of the present study was to systematically investigate the effect of wide dynamic range compression processing (WDRC), and its combined effect with digital noise reduction (DNR) and directional processing (DIR), on ANL. Because ANL represents the lowest signal-to-noise ratio (SNR) that a listener is willing to accept, the second objective was to examine whether the hearing aid output SNR could predict aided ANL across different combinations of hearing aid signal-processing schemes. Twenty-five adults with sensorineural hearing loss participated in the study. ANL was measured monaurally in two unaided and seven aided conditions, in which the status of the hearing aid processing schemes (enabled or disabled) and the location of noise (front or rear) were manipulated. The hearing aid output SNR was measured for each listener in each condition using a phase-inversion technique. The aided ANL was predicted by unaided ANL and hearing aid output SNR, under the assumption that the lowest acceptable SNR at the listener's eardrum is a constant across different ANL test conditions. Study results revealed that, on average, WDRC increased (worsened) ANL by 1.5 dB, while DNR and DIR decreased (improved) ANL by 1.1 and 2.8 dB, respectively. Because the effects of WDRC and DNR on ANL were opposite in direction but similar in magnitude, the ANL of linear/DNR-off was not significantly different from that of WDRC/DNR-on. The results further indicated that the pattern of ANL change across different aided conditions was consistent with the pattern of hearing aid output SNR change created by processing schemes. Compared with linear processing, WDRC creates a noisier sound image and makes listeners less willing to accept noise. However, this negative effect on noise acceptance can be offset by DNR, regardless of microphone mode

Nuclear analytical chemistry 5. Tables, nomograms and schemes

Energy Technology Data Exchange (ETDEWEB)

Tolgyessy, J; Varga, S; Dillinger, P; Kyrs, M

1976-01-01

Tables, graphs and nomograms are given on aspects of nuclear analytical chemistry. The tables contain data on physical and chemical units and their conversion, exponential functions, the characteristics of radioactive nuclides, data on the interaction of nuclear radiation with matter, data useful in measuring nuclear radiation, in scintillation and semiconductor spectrometry, activation analysis, data on masking reactions of ions in chemical separation, on extraction, ion exchange, accuracy in applying the method of isotope dilution, on radiochemical analysis.

Self consitent description of nuclear level densitities

International Nuclear Information System (INIS)

Barranco, M.; Treiner, J.

1980-03-01

We present a self consistent calculation of the nuclear level density based on a generalization to finite temperature of a modified Thomas-Fermi method. A simple expression is derived for the so-called level density parameter a entering the expression of the density of states Xi(E)=Esup(-5/4)e 2 √aE and relating the excitation energy to the temperature E=a T 2 , in terms of nucleons equilibrium densities at T=0 only. One thus avoids the difficulty of adding external constraints to calculate isolated nuclei at finite temperature which are shown to be unstable against particle emission. The role of the nuclear surface is discussed. It is shown that the effective mass of the interaction plays a crucial role in determining the value of a and comparison with experiment confirms the value m*/m > = 1 near the Fermi level obtained through more microscopic analysis

University students' understanding level about words related to nuclear power

International Nuclear Information System (INIS)

Oiso, Shinichi; Watabe, Motoki

2012-01-01

The authors conducted a survey of university students' understanding level about words related to nuclear power before and after Fukushima Daiichi Power Plant accident, and analyzed the difference between before and after the accident. The results show that university students' understanding level improved after the accident, especially in the case of reported words by mass media. Understanding level of some nuclear power security words which were not reported so much by mass media also improved. That may be caused by rising of people's concern about nuclear power generation after the accident, and there is a possibility that the accident motivated people to access such words via internet, journals, etc. (author)

Scheme for generation of fully-coherent, TW power level hard X-ray pulses from baseline undulators at the European X-ray FEL

International Nuclear Information System (INIS)

Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

2010-07-01

The most promising way to increase the output power of an X-ray FEL (XFEL) is by tapering the magnetic field of the undulator. Also, significant increase in power is achievable by starting the FEL process from a monochromatic seed rather than from noise. This report proposes to make use of a cascade self-seeding scheme with wake monochromators in a tunable-gap baseline undulator at the European XFEL to create a source capable of delivering coherent radiation of unprecedented characteristics at hard X-ray wavelengths. Compared with SASE X-ray FEL parameters, the radiation from the new source has three truly unique aspects: complete longitudinal and transverse coherence, and a peak brightness three orders of magnitude higher than what is presently available at LCLS. Additionally, the new source will generate hard X-ray beam at extraordinary peak (TW) and average (kW) power level. The proposed source can thus revolutionize fields like single biomolecule imaging, inelastic scattering and nuclear resonant scattering. The self-seeding scheme with the wake monochromator is extremely compact, and takes almost no cost and time to be implemented. The upgrade proposed in this paper could take place during the commissioning stage of the European XFEL, opening a vast new range of applications from the very beginning of operations.We present feasibility study and examplifications for the SASE2 line of the European XFEL. (orig.)

Computer-based control of nuclear power information systems at international level

International Nuclear Information System (INIS)

Boniface, Ekechukwu; Okonkwo, Obi

2011-01-01

In most highly industrialized countries of the world information plays major role in anti-nuclear campaign. Information and discussions on nuclear power need critical and objective analysis before the structured information presentation to the public to avoid bias anti-nuclear information on one side and neglect of great risk in nuclear power. This research is developing a computer-based information system for the control of nuclear power at international level. The system is to provide easy and fast information highways for the followings: (1) Low Regulatory dose and activity limit as level of high danger for individuals and public. (2) Provision of relevant technical or scientific education among the information carriers in the nuclear power countries. The research is on fact oriented investigation about radioactivity. It also deals with fact oriented education about nuclear accidents and safety. A standard procedure for dissemination of latest findings using technical and scientific experts in nuclear technology is developed. The information highway clearly analyzes the factual information about radiation risk and nuclear energy. Radiation cannot be removed from our environment. The necessity of radiation utilizations defines nuclear energy as two-edge sword. It is therefore, possible to use computer-based information system in projecting and dissemination of expert knowledge about nuclear technology positively and also to use it in directing the public on the safety and control of the nuclear energy. The computer-based information highway for nuclear energy technology is to assist in scientific research and technological development at international level. (author)

New software tools for evaluating and disseminating nuclear data

International Nuclear Information System (INIS)

Langlands, Tracy L.M.; Miyake, Erik E.; Stone, Craig A.

2001-01-01

Three new related technologies that offer real promise for modeling, processing, and disseminating nuclear data are explored. Extensible Markup Language (XML) provides a simple method of describing nuclear data. Extensible Style Language (XSL) supports XML data searching, filtering and processing. It is shown how the technology can be used to transform an XML-formatted ENSDF file into a table of similar form to those found in the Nuclear Data Sheets. Scalable Vector Graphics (SVG) has been used to convert XML formatted ENSDF files into interactive level scheme

Harmonization of nuclear and radiation safety regulations for nuclear power plants with reference levels of Western European Nuclear Regulators Association (WENRA)

International Nuclear Information System (INIS)

Bojchuk, V.S.; Mikolajchuk, O.A.; Gromov, G.V.; Dibach, O.M.; Godovanyuk, G.M.; Nosovs'kij, A.V.

2014-01-01

Self-evaluation of the Ukrainian regulations on nuclear and radiation safety that apply to nuclear power plants for compliance with the reference levels of the Western European Nuclear Regulators Association (WENRA) is presented. Proposals on improvement of the regulations upon self-evaluation are provided

Low-lying nuclear levels and radiative transitions in hadronic atoms

International Nuclear Information System (INIS)

Popov, V.S.; Kudryavtsev, A.E.; Lisin, V.I.; Mur, V.D.

1985-01-01

The analytic theory of nuclear level shifts permit the position of the nuclear level perturbing the Coulomb spectrum to be calculated on the basis of the magnitude of the level shift of a hadron atom. As an example the K -4 He atom is discussed. The experimental data on the 2p-level shift indicate that a weakly bound p-state with a binding energy and width epsilon approximately γ approximately 0.5 MeV may exist in the system. The probabilities for radiative transitions to this level and the cross section for its creation in a nuclear reaction with 6 Li are calculated. The possible existence of weakly coupled K - and anti p states for other light nuclei is discussed. An exact solution of the model Coulomb problem with short range interaction is obtained and this permits the limits of validity of the initial approximations to be determined

Verification of an objective analysis scheme

International Nuclear Information System (INIS)

Cats, G.J.; Haan, B.J. de; Hafkenscheid, L.M.

1987-01-01

An intermittent data assimilation scheme has been used to produce wind and precipitation fields during the 10 days after the explosion at the Chernobyl nuclear power plant on 25 April 1986. The wind fields are analyses, the precipitation fields have been generated by the forecast model part of the scheme. The precipitation fields are of fair quality. The quality of the wind fields has been monitored by the ensuing trajectories. These were found to describe the arrival times of radioactive air in good agreement with most observational data, taken all over Europe. The wind analyses are therefore considered to be reliable. 25 refs.; 13 figs

Comparisons between a new point kernel-based scheme and the infinite plane source assumption method for radiation calculation of deposited airborne radionuclides from nuclear power plants.

Science.gov (United States)

Zhang, Xiaole; Efthimiou, George; Wang, Yan; Huang, Meng

2018-04-01

Radiation from the deposited radionuclides is indispensable information for environmental impact assessment of nuclear power plants and emergency management during nuclear accidents. Ground shine estimation is related to multiple physical processes, including atmospheric dispersion, deposition, soil and air radiation shielding. It still remains unclear that whether the normally adopted "infinite plane" source assumption for the ground shine calculation is accurate enough, especially for the area with highly heterogeneous deposition distribution near the release point. In this study, a new ground shine calculation scheme, which accounts for both the spatial deposition distribution and the properties of air and soil layers, is developed based on point kernel method. Two sets of "detector-centered" grids are proposed and optimized for both the deposition and radiation calculations to better simulate the results measured by the detectors, which will be beneficial for the applications such as source term estimation. The evaluation against the available data of Monte Carlo methods in the literature indicates that the errors of the new scheme are within 5% for the key radionuclides in nuclear accidents. The comparisons between the new scheme and "infinite plane" assumption indicate that the assumption is tenable (relative errors within 20%) for the area located 1 km away from the release source. Within 1 km range, the assumption mainly causes errors for wet deposition and the errors are independent of rain intensities. The results suggest that the new scheme should be adopted if the detectors are within 1 km from the source under the stable atmosphere (classes E and F), or the detectors are within 500 m under slightly unstable (class C) or neutral (class D) atmosphere. Otherwise, the infinite plane assumption is reasonable since the relative errors induced by this assumption are within 20%. The results here are only based on theoretical investigations. They should

Development of scheme for predicting atmospheric dispersion of radionuclides during nuclear emergency by using atmospheric dynamic model

Energy Technology Data Exchange (ETDEWEB)

Nagai, Haruyasu; Chino, Masamichi; Yamazawa, Hiromi (Japan Atomic Energy Research Inst., Tokyo (Japan))

1999-07-01

The meteorological forecast models are critically important for the accuracy of predicting the atmospheric dispersion of radionuclides discharged into atmosphere during nuclear emergencies. Thus, this paper describes a new scheme for predicting environmental impacts due to accidental release of radionuclides by using an atmospheric dynamic model PHYSIC. The advantages of introducing PHYSIC are, (1) three-dimensional local meteorological forecasts can be conducted, (2) synoptic meteorological changes can be considered by inputting grid data of synoptic forecasts from Japan Meteorological Agency to PHYSIC as initial and boundary conditions, (3) forecasts can be improved by nudging method using local meteorological observations, and (4) atmospheric dispersion model can consider the variation of the mixed layer. (author)

Development of scheme for predicting atmospheric dispersion of radionuclides during nuclear emergency by using atmospheric dynamic model

International Nuclear Information System (INIS)

Nagai, Haruyasu; Chino, Masamichi; Yamazawa, Hiromi

1999-01-01

The meteorological forecast models are critically important for the accuracy of predicting the atmospheric dispersion of radionuclides discharged into atmosphere during nuclear emergencies. Thus, this paper describes a new scheme for predicting environmental impacts due to accidental release of radionuclides by using an atmospheric dynamic model PHYSIC. The advantages of introducing PHYSIC are, (1) three-dimensional local meteorological forecasts can be conducted, (2) synoptic meteorological changes can be considered by inputting grid data of synoptic forecasts from Japan Meteorological Agency to PHYSIC as initial and boundary conditions, (3) forecasts can be improved by nudging method using local meteorological observations, and (4) atmospheric dispersion model can consider the variation of the mixed layer. (author)

Realistic microscopic level densities for spherical nuclei

International Nuclear Information System (INIS)

Cerf, N.

1994-01-01

Nuclear level densities play an important role in nuclear reactions such as the formation of the compound nucleus. We develop a microscopic calculation of the level density based on a combinatorial evaluation from a realistic single-particle level scheme. This calculation makes use of a fast Monte Carlo algorithm allowing us to consider large shell model spaces which could not be treated previously in combinatorial approaches. Since our model relies on a microscopic basis, it can be applied to exotic nuclei with more confidence than the commonly used semiphenomenological formuals. An exhaustive comparison of our predicted neutron s-wave resonance spacings with experimental data for a wide range of nuclei is presented

Economic sustainability, water security and multi-level governance of local water schemes in Nepal

Directory of Open Access Journals (Sweden)

Emma Hakala

2017-07-01

Full Text Available This article explores the role of multi-level governance and power structures in local water security through a case study of the Nawalparasi district in Nepal. It focuses on economic sustainability as a measure to address water security, placing this thematic in the context of a complicated power structure consisting of local, district and national administration as well as external development cooperation actors. The study aims to find out whether efforts to improve the economic sustainability of water schemes have contributed to water security at the local level. In addition, it will consider the interactions between water security, power structures and local equality and justice. The research builds upon survey data from the Nepalese districts of Nawalparasi and Palpa, and a case study based on interviews and observation in Nawalparasi. The survey was performed in water schemes built within a Finnish development cooperation programme spanning from 1990 to 2004, allowing a consideration of the long-term sustainability of water management projects. This adds a crucial external influence into the intra-state power structures shaping water management in Nepal. The article thus provides an alternative perspective to cross-regional water security through a discussion combining transnational involvement with national and local points of view.

Selecting a distillation scheme for purifying ditolymethane for a nuclear heat source

International Nuclear Information System (INIS)

Garanin, V.I.; Stychinskii, G.F.; Chukhlov, G.Z.; Smirnova, V.S.

1989-01-01

Ditolymethane can be used as a coolant in nuclear heat plants, although it needs ongoing purification from radiolytic products, including low-boiling and high-boiling components. Periodic distillation to remove radiolytic products represents world practice. The objective of this study was to develop a distillation system less laborious to service, simpler to automate, and costing less to operate. A continuous-flow plant can have those advantages if one could use the heat from the first loop in the plant (200-240C) to evaporate the ditolymethane and the low-boiling components instead of the more expensive electrical power, while the vapor could be condensed by cheaper air cooling to +30C instead of water cooling, while one could reduce the loss of ditolymethane with the wastes and almost eliminate the loss of low-boiling components in the vacuum pump. The laboratory tests were based on outgassed ditholymethane coolant from the first loop in the ARBUS nuclear heat plant, which had the following mass-fraction composition: ditolylmethane 82 ± 1, low-boiling components 2.3 ± 0.2, and high-boiling ones 16 ± 1%. The low-boiling components included benzene, toluene, xylene, and four unidentified compounds. The high-boiling ones included compounds containing three or more benzene rings and having a mean molecular weight 450. Continuous purification from these components and water was examined in two ways. In a one-stage system, the two types of organic component and the water are removed under a common vacuum by sequential partial condensation from the common vapor flow as the temperature is reduced. The two-stage scheme differed in that the low-boiling components and the water were removed at a lower vacuum (first stage) and the high-boiling ones at a higher vacuum (second stage)

Threshold Signature Schemes Application

Directory of Open Access Journals (Sweden)

Anastasiya Victorovna Beresneva

2015-10-01

Full Text Available This work is devoted to an investigation of threshold signature schemes. The systematization of the threshold signature schemes was done, cryptographic constructions based on interpolation Lagrange polynomial, elliptic curves and bilinear pairings were examined. Different methods of generation and verification of threshold signatures were explored, the availability of practical usage of threshold schemes in mobile agents, Internet banking and e-currency was shown. The topics of further investigation were given and it could reduce a level of counterfeit electronic documents signed by a group of users.

Schemes of radioactive decay, its interpretations in the scope of the radiological protection

International Nuclear Information System (INIS)

Mohamad, N.; Caro, R.A.; Bergoc, R.M.

1998-01-01

Full text: In our teaching experience we have verified that the interpretation of the symbols of radioactive decay schemes is one of the most difficult subject in the study of radioisotope methodologies for almost all professionals, and specially for those who have no solid background in mathematics or physics. The correct interpretation of decay schemes has fundamental importance for the proper election of measurement conditions and for performing the dosimetric and shielding calculations. Nuclides employed in Nuclear Medicine and Biomedicine are beta, gamma or beta/gamma emitters. Interpretation of decay schemes of beta emitters, by β + , β - or electronic capture are not difficult. In gamma emitting nuclides it is frequent that a particular level of energy is de-excited through more than one gamma transition of a given percentage and energy. On the other hand, it is also frequent that conversion electrons are emitted together with gamma photons, the proportion of which is usually given as the conversion factor, e/γ. The fraction of emitted photons is calculated as: 1 / [1+ (e/γ)], whereas the fraction of emitted conversion electrons is equal to: (e/γ) / [1+ (e/γ)]. Special attention should be given to the post-accommodation mechanism after disintegration in which orbital vacancies are produced: electron conversion or electron capture, in which the emission of X-rays and Auger electrons occur. All this information should be taken into account for the correct choice of measurement conditions, as well as internal and external dose calculations. In the present work we describe the analysis and interpretation of disintegration schemes in general and that of the most employed nuclides in Nuclear Medicine and Biomedicine. (author) [es

Assessments of conditioned radioactive waste arisings from existing and committed nuclear installations and assuming a moderate growth in nuclear electricity generation - June 1985

International Nuclear Information System (INIS)

Fairclough, M.P.; Goodill, D.R.; Tymons, B.J.

1985-03-01

This report describes an assessment of conditioned radioactive waste arisings from existing and committed nuclear installations, DOE Revised Scheme 1, and from an assumed nuclear power generation scenario, DOE Revised Scheme 3, representing a moderate growth in nuclear generation. Radioactive waste arise from 3 main groups of installations and activities: i. existing and committed commercial reactors; ii. fuel reprocessing plants, iii. research, industrial and medical activities. Stage 2 decommissioning wastes are considered together with WAGR decommissioning and the 1983 Sea Dump Consignment. The study uses the SIMULATION 2 code which models waste material flows through a system of waste treatment and packaging to disposal. With a knowledge of the accumulations and average production rates of untreated wastes and their isotopic compositions (or total activities), the rates at which conditioned wastes become available for transportation and disposal are calculated, with specific activity levels. The data for the inventory calculations have previously been documented. Some recent revisions and assumptions concerning future operation of nuclear facilities are presented in this report. (author)

An Advanced Detecting Scheme against a Signal Distortion with a Smart Transmitter

International Nuclear Information System (INIS)

Son, Jun Young; Kim, Young Mi

2013-01-01

The analog signal distortion could be detected. Also the data integrity for information security could be provided. The assurance of the integrity in digital information as well as analog signals is necessary. The above proposed schemes can be utilized for detecting the modification of the digital information or analog signal distortion without any of authentication. These effects have merits of the defenses for analog signals and cyber security in terms of information integrity. There are many kinds of measuring nuclear I and C system. Thus, the applicable algorithms may be different according to the lightness or the level of the security in each measuring system. In the future, finding and applying the efficient algorithms in each measuring systems in the nuclear power plant should be studied. As the I and C system will be gradually digitalized, the requirements for basic security concepts should be considered and applied. As IT technology has been much developed, measuring nuclear I and C (Instrument and Control) systems also is going to be evolving. At this point, the smart transmitter has been developed and tried to be applied. Recently, constructed nuclear power plants in Korea have adopted the smart meters. In case of Shin-Kori unit 3, about 59 safety grade smart transmitters and about 180 non-safety grade smart transmitters are used for measuring various signals. In the field of measuring nuclear I and C (Instrument and Control) systems, the cyber security problems can happen more. Thus, providing defense methods against possible cyber attacks are essential. In particular, the defense schemes for providing data information integrity will be essential. In addition, it is necessary to detect the analog signal distortion between the host smart transmitters and the client cabinet. In this paper, applicable one of directions and methods against the above two problems are proposed

An Advanced Detecting Scheme against a Signal Distortion with a Smart Transmitter

Energy Technology Data Exchange (ETDEWEB)

Son, Jun Young; Kim, Young Mi [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2013-10-15

The analog signal distortion could be detected. Also the data integrity for information security could be provided. The assurance of the integrity in digital information as well as analog signals is necessary. The above proposed schemes can be utilized for detecting the modification of the digital information or analog signal distortion without any of authentication. These effects have merits of the defenses for analog signals and cyber security in terms of information integrity. There are many kinds of measuring nuclear I and C system. Thus, the applicable algorithms may be different according to the lightness or the level of the security in each measuring system. In the future, finding and applying the efficient algorithms in each measuring systems in the nuclear power plant should be studied. As the I and C system will be gradually digitalized, the requirements for basic security concepts should be considered and applied. As IT technology has been much developed, measuring nuclear I and C (Instrument and Control) systems also is going to be evolving. At this point, the smart transmitter has been developed and tried to be applied. Recently, constructed nuclear power plants in Korea have adopted the smart meters. In case of Shin-Kori unit 3, about 59 safety grade smart transmitters and about 180 non-safety grade smart transmitters are used for measuring various signals. In the field of measuring nuclear I and C (Instrument and Control) systems, the cyber security problems can happen more. Thus, providing defense methods against possible cyber attacks are essential. In particular, the defense schemes for providing data information integrity will be essential. In addition, it is necessary to detect the analog signal distortion between the host smart transmitters and the client cabinet. In this paper, applicable one of directions and methods against the above two problems are proposed.

Answers to your questions on high-level nuclear waste

International Nuclear Information System (INIS)

1987-11-01

This booklet contains answers to frequently asked questions about high-level nuclear wastes. Written for the layperson, the document contains basic information on the hazards of radiation, the Nuclear Waste Management Program, the proposed geologic repository, the proposed monitored retrievable storage facility, risk assessment, and public participation in the program

Nuclear spin-lattice relaxation in nitroxide spin-label EPR

DEFF Research Database (Denmark)

Marsh, Derek

2016-01-01

that the definition of nitrogen nuclear relaxation rate Wn commonly used in the CW-EPR literature for 14N-nitroxyl spin labels is inconsistent with that currently adopted in time-resolved EPR measurements of saturation recovery. Redefinition of the normalised 14N spin-lattice relaxation rate, b = Wn/(2We), preserves...... of spin-lattice relaxation in this three-level system. Expressions for CW-saturation EPR with the revised definitions are summarised. Data on nitrogen nuclear spin-lattice relaxation times are compiled according to the three-level scheme for 14N-relaxation: T1 n = 1/Wn. Results are compared and contrasted...

Managing the high level waste nuclear regulatory commission licensing process

International Nuclear Information System (INIS)

Baskin, K.P.

1992-01-01

This paper reports that the process for obtaining Nuclear Regulatory Commission permits for the high level waste storage facility is basically the same process commercial nuclear power plants followed to obtain construction permits and operating licenses for their facilities. Therefore, the experience from licensing commercial reactors can be applied to the high level waste facility. Proper management of the licensing process will be the key to the successful project. The management of the licensing process was categorized into four areas as follows: responsibility, organization, communication and documentation. Drawing on experience from nuclear power plant licensing and basic management principles, the management requirement for successfully accomplishing the project goals are discussed

Tergiversating the price of nuclear waste storage

International Nuclear Information System (INIS)

Mills, R.L.

1984-01-01

Tergiversation, the evasion of straightforward action of clearcut statement of position, was a characteristic of high-level nuclear waste disposal until the US Congress passed the Nuclear Waste Policy Act of 1982. How the price of waste storage is administered will affect the design requirements of monitored retrievable storage (MRS) facilities as well as repositories. Those decisions, in part, are internal to the Department of Energy. From the utility's viewpoint, the options are few but clearer. Reprocessing, as performed in Europe, is not a perfect substitute for MRS. The European reprocess-repository sequence will not yield the same nuclear resource base as the American MRS-repository scheme. For the future price of the energy resource represented by nuclear waste, the author notes that tergiversation continues. 3 references

Study on HVAC system in nuclear facility

International Nuclear Information System (INIS)

Baeg, S. Y.; Song, W. S.; Oh, Y. O.; Ju, Y. S.; Hong, K. P.

2003-01-01

Heating, Ventilation and Air Conditioning (HVAC) system in nuclear facility should be equipped and constructed more stable and allowable than that in common facility. The purpose of HVAC system is the maintenance of optimum working environment, the protection of worker against a contaminated air and the prevention of atmospheric contamination due to an outward ventilation, etc.. The basic scheme of a safety operation of nuclear facility is to prevent the atmospheric contamination even in low level. The adaptability of HVAC system which is in operation. In this study, the design requirements of HVAC system in nuclear facility and the HVAC systems in foreign countries are reviewed, and the results can be utilized in the design of HVAC system in nuclear facility

Effect of vibrational states on nuclear level density

International Nuclear Information System (INIS)

Plujko, V. A.; Gorbachenko, O. M.

2007-01-01

Simple methods to calculate a vibrational enhancement factor of a nuclear level density with allowance for damping of collective state are considered. The results of the phenomenological approach and the microscopic quasiparticle-phonon model are compared. The practical method of calculation of a vibrational enhancement factor and level density parameters is recommended

Propagation of frequency-chirped laser pulses in a medium of atoms with a Λ-level scheme

International Nuclear Information System (INIS)

Demeter, G.; Dzsotjan, D.; Djotyan, G. P.

2007-01-01

We study the propagation of frequency-chirped laser pulses in optically thick media. We consider a medium of atoms with a Λ level-scheme (Lambda atoms) and also, for comparison, a medium of two-level atoms. Frequency-chirped laser pulses that induce adiabatic population transfer between the atomic levels are considered. They induce transitions between the two lower (metastable) levels of the Λ-atoms and between the ground and excited states of the two-level atoms. We show that associated with this adiabatic population transfer in Λ-atoms, there is a regime of enhanced transparency of the medium--the pulses are distorted much less than in the medium of two-level atoms and retain their ability to transfer the atomic population much longer during propagation

Visual privacy by context: proposal and evaluation of a level-based visualisation scheme.

Science.gov (United States)

Padilla-López, José Ramón; Chaaraoui, Alexandros Andre; Gu, Feng; Flórez-Revuelta, Francisco

2015-06-04

Privacy in image and video data has become an important subject since cameras are being installed in an increasing number of public and private spaces. Specifically, in assisted living, intelligent monitoring based on computer vision can allow one to provide risk detection and support services that increase people's autonomy at home. In the present work, a level-based visualisation scheme is proposed to provide visual privacy when human intervention is necessary, such as at telerehabilitation and safety assessment applications. Visualisation levels are dynamically selected based on the previously modelled context. In this way, different levels of protection can be provided, maintaining the necessary intelligibility required for the applications. Furthermore, a case study of a living room, where a top-view camera is installed, is presented. Finally, the performed survey-based evaluation indicates the degree of protection provided by the different visualisation models, as well as the personal privacy preferences and valuations of the users.

A Prediction Packetizing Scheme for Reducing Channel Traffic in Transaction-Level Hardware/Software Co-Emulation

OpenAIRE

Lee , Jae-Gon; Chung , Moo-Kyoung; Ahn , Ki-Yong; Lee , Sang-Heon; Kyung , Chong-Min

2005-01-01

Submitted on behalf of EDAA (http://www.edaa.com/); International audience; This paper presents a scheme for efficient channel usage between simulator and accelerator where the accelerator models some RTL sub-blocks in the accelerator-based hardware/software co-simulation while the simulator runs transaction-level model of the remaining part of the whole chip being verified. With conventional simulation accelerator, evaluations of simulator and accelerator alternate at every valid simulation ...

Water level control for a nuclear steam generator

International Nuclear Information System (INIS)

Wen Tan

2011-01-01

Research highlights: → A water level control system for a nuclear steam generator (SG) is proposed. → The parameters of the control system are directly related to those of the plant model thus scheduling is easy to implement in practice. → The proposed gain-scheduled controller can achieve good performance at both low and high power levels. - Abstract: A water level control system for a nuclear steam generator (SG) is proposed. The control system consists of a feedback controller and a feedforward controller. The feedback controller is of first order, the feedforward controller is of second order, and parameters of the two controllers are directly related to the parameters of plant model thus scheduling is easy to implement in practice. Robustness and performance of the feedback and the feedforward controllers are analyzed in details and tuning of the two parameters of the controllers are discussed. Comparisons among a single robust controller, a multi-model controller and a gain-scheduled controller are studied. It is shown that the proposed gain-scheduled controller can achieve good performance at both low and high power levels.

An approach for determining the acceptable levels of nuclear risk

International Nuclear Information System (INIS)

1978-03-01

The objective of this study was to develop a methodology for determining the acceptable levels of risk with respect to nuclear energy. It was concluded that the Atomic Energy Control Board should identify the interest groups that affect its choice of an acceptable level of risk, determine their expectations, and balance the expectations of the various groups such that the resulting acceptable level of risk is still acceptable to the Board. This would be done by interviewing experts on the subject of nuclear safety, developing and pretesting a public questionnaire, and surveying the public on acceptable cost-risk combinations

Technology readiness levels for advanced nuclear fuels and materials development

Energy Technology Data Exchange (ETDEWEB)

Carmack, W.J., E-mail: jon.carmack@inl.gov [Idaho National Laboratory, Idaho Falls, ID (United States); Braase, L.A.; Wigeland, R.A. [Idaho National Laboratory, Idaho Falls, ID (United States); Todosow, M. [Brookhaven National Laboratory, Upton, NY (United States)

2017-03-15

Highlights: • Definition of nuclear fuels system technology readiness level. • Identification of evaluation criteria for nuclear fuel system TRLs. • Application of TRLs to fuel systems. - Abstract: The Technology Readiness process quantitatively assesses the maturity of a given technology. The National Aeronautics and Space Administration (NASA) pioneered the process in the 1980s to inform the development and deployment of new systems for space applications. The process was subsequently adopted by the Department of Defense (DoD) to develop and deploy new technology and systems for defense applications. It was also adopted by the Department of Energy (DOE) to evaluate the maturity of new technologies in major construction projects. Advanced nuclear fuels and materials development is needed to improve the performance and safety of current and advanced reactors, and ultimately close the nuclear fuel cycle. Because deployment of new nuclear fuel forms requires a lengthy and expensive research, development, and demonstration program, applying the assessment process to advanced fuel development is useful as a management, communication, and tracking tool. This article provides definition of technology readiness levels (TRLs) for nuclear fuel technology as well as selected examples regarding the methods by which TRLs are currently used to assess the maturity of nuclear fuels and materials under development in the DOE Fuel Cycle Research and Development (FCRD) Program within the Advanced Fuels Campaign (AFC).

Nuclear structure data file. A manual for preparation of data sets

International Nuclear Information System (INIS)

Ewbank, W.B.; Schmorak, M.R.; Bertrand, F.E.; Feliciano, M.; Horen, D.J.

1975-06-01

The Nuclear Data Project at ORNL is building a computer-based file of nuclear structure data, which is intended for use by both basic and applied users. For every nucleus, the Nuclear Structure Data File contains evaluated nuclear structure information. This manual describes a standard input format for nuclear structure data. The format is sufficiently structured that bulk data can be entered efficiently. At the same time, the structure is open-ended and can accommodate most measured or deduced quantities that yield nuclear structure information. Computer programs have been developed at the Data Project to perform consistency checking and routine calculations. Programs are also used for preparing level scheme drawings. (U.S.)

IAEA advisory group meeting on basic and applied problems of nuclear level densities

International Nuclear Information System (INIS)

Bhat, M.R.

1983-06-01

Separate entries were made in the data base for 17 of the 19 papers included. Two papers were previously included in the data base. Workshop reports are included on (1) nuclear level density theories and nuclear model reaction cross-section calculations and (2) extraction of nuclear level density information from experimental data

The gamma two-step cascade method at Dalat Nuclear Research Reactor

International Nuclear Information System (INIS)

Vuong Huu Tan; Pham Dinh Khang; Nguyen Nhi Dien; Nguyen Xuan Hai; Tran Tuan Anh; Ho Huu Thang; Pham Ngoc Son; Mangengo Lumengano

2014-01-01

The event-event coincidence spectroscopy system was successfully established and operated on thermal neutron beam of channel No. 3 at Dalat Nuclear Research Reactor (DNRR) with resolving time value of about 10 ns. The studies on level density, gamma strength function and decay scheme of intermediate-mass and heavy nuclei have been performed on this system. The achieved results are opening a new research of nuclear structure based on (n, 2γ) reaction. (author)

Missing and Spurious Level Corrections for Nuclear Resonances

International Nuclear Information System (INIS)

Mitchell, G E; Agvaanluvsan, U; Pato, M P; Shriner, J F

2005-01-01

Neutron and proton resonances provide detailed level density information. However, due to experimental limitations, some levels are missed and some are assigned incorrect quantum numbers. The standard method to correct for missing levels uses the experimental widths and the Porter-Thomas distribution. Analysis of the spacing distribution provides an independent determination of the fraction of missing levels. We have derived a general expression for such an imperfect spacing distribution using the maximum entropy principle and applied it to a variety of nuclear resonance data. The problem of spurious levels has not been extensively addressed

Additive operator-difference schemes splitting schemes

CERN Document Server

Vabishchevich, Petr N

2013-01-01

Applied mathematical modeling isconcerned with solving unsteady problems. This bookshows how toconstruct additive difference schemes to solve approximately unsteady multi-dimensional problems for PDEs. Two classes of schemes are highlighted: methods of splitting with respect to spatial variables (alternating direction methods) and schemes of splitting into physical processes. Also regionally additive schemes (domain decomposition methods)and unconditionally stable additive schemes of multi-component splitting are considered for evolutionary equations of first and second order as well as for sy

Using Direct Sub-Level Entity Access to Improve Nuclear Stockpile Simulation Modeling

Energy Technology Data Exchange (ETDEWEB)

Parker, Robert Y. [Brigham Young Univ., Provo, UT (United States)

1999-08-01

Direct sub-level entity access is a seldom-used technique in discrete-event simulation modeling that addresses the accessibility of sub-level entity information. The technique has significant advantages over more common, alternative modeling methods--especially where hierarchical entity structures are modeled. As such, direct sub-level entity access is often preferable in modeling nuclear stockpile, life-extension issues, an area to which it has not been previously applied. Current nuclear stockpile, life-extension models were demonstrated to benefit greatly from the advantages of direct sub-level entity access. In specific cases, the application of the technique resulted in models that were up to 10 times faster than functionally equivalent models where alternative techniques were applied. Furthermore, specific implementations of direct sub-level entity access were observed to be more flexible, efficient, functional, and scalable than corresponding implementations using common modeling techniques. Common modeling techniques (''unbatch/batch'' and ''attribute-copying'') proved inefficient and cumbersome in handling many nuclear stockpile modeling complexities, including multiple weapon sites, true defect analysis, and large numbers of weapon and subsystem types. While significant effort was required to enable direct sub-level entity access in the nuclear stockpile simulation models, the enhancements were worth the effort--resulting in more efficient, more capable, and more informative models that effectively addressed the complexities of the nuclear stockpile.

Single-level resonance parameters fit nuclear cross-sections

Science.gov (United States)

Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

1970-01-01

Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

CSR schemes in agribusiness

DEFF Research Database (Denmark)

Pötz, Katharina Anna; Haas, Rainer; Balzarova, Michaela

2013-01-01

of schemes that can be categorized on focus areas, scales, mechanisms, origins, types and commitment levels. Research limitations/implications – The findings contribute to conceptual and empirical research on existing models to compare and analyse CSR standards. Sampling technique and depth of analysis limit......Purpose – The rise of CSR followed a demand for CSR standards and guidelines. In a sector already characterized by a large number of standards, the authors seek to ask what CSR schemes apply to agribusiness, and how they can be systematically compared and analysed. Design....../methodology/approach – Following a deductive-inductive approach the authors develop a model to compare and analyse CSR schemes based on existing studies and on coding qualitative data on 216 CSR schemes. Findings – The authors confirm that CSR standards and guidelines have entered agribusiness and identify a complex landscape...

Pixel detector readout electronics with two-level discriminator scheme

International Nuclear Information System (INIS)

Pengg, F.

1998-01-01

In preparation for a silicon pixel detector with more than 3,000 readout channels per chip for operation at the future large hadron collider (LHC) at CERN the analog front end of the readout electronics has been designed and measured on several test-arrays with 16 by 4 cells. They are implemented in the HP 0.8 microm process but compatible with the design rules of the radiation hard Honeywell 0.8 microm bulk process. Each cell contains bump bonding pad, preamplifier, discriminator and control logic for masking and testing within a layout area of only 50 microm by 140 microm. A new two-level discriminator scheme has been implemented to cope with the problems of time-walk and interpixel cross-coupling. The measured gain of the preamplifier is 900 mV for a minimum ionizing particle (MIP, about 24,000 e - for a 300 microm thick Si-detector) with a return to baseline within 750 ns for a 1 MIP input signal. The full readout chain (without detector) shows an equivalent noise charge to 60e - r.m.s. The time-walk, a function of the separation between the two threshold levels, is measured to be 22 ns at a separation of 1,500 e - , which is adequate for the 40 MHz beam-crossing frequency at the LHC. The interpixel cross-coupling, measured with a 40fF coupling capacitance, is less than 3%. A single cell consumes 35 microW at 3.5 V supply voltage

A review on the long-range strategy of nuclear power development

International Nuclear Information System (INIS)

An, Shigehiro; Kondo, Shunsuke; Ishida, Hiroshi.

1979-01-01

Nuclear power generation in Japan is proceeding steadily, such as the world's second in power generating capacity and the nation's own development of power reactors. Meanwhile, however, there are number of problems for future solution, like the establishment of nuclear fuel cycle, before nuclear energy is fully harnessed. Looking as far ahead as the 21st century, the long-range strategy of nuclear power development is reviewed: politics on uranium supply outlook, a compromise between uranium enrichment and nuclear nonproliferation, LWR technology with safety, FBR development scheme, uranium resources saving and heavy water reactor, HTGR development, a 2nd fuel reprocessing plant, high level wastes management, reactors decommissioning, research in nuclear energy development, and fostering of a nuclear power industry. (J.P.N.)

Role of national centers of research and development in nuclear technology transfer

International Nuclear Information System (INIS)

Graf, J.-J.; Millies, Pierre.

1977-01-01

National Research Centers are shown to play a leading role in nuclear technology transfer, whatever may be the directing scheme of nuclear development in the country envisaged. The first act of the Center consists in training specialists in the various nuclear fields. It must ensure the transfer of technological knowledge towards industry (in metallurgy, mechanics, electronics) and other nuclear auxiliary techniques, together with the transfer towards administration (laws). A simplified scheme of nuclear development strategy based on the French scheme (the French Atomic Energy Commission (CEA) with its subsidiary Companies) is presented that is usable for developing countries [fr

A novel two-level dynamic parallel data scheme for large 3-D SN calculations

International Nuclear Information System (INIS)

Sjoden, G.E.; Shedlock, D.; Haghighat, A.; Yi, C.

2005-01-01

We introduce a new dynamic parallel memory optimization scheme for executing large scale 3-D discrete ordinates (Sn) simulations on distributed memory parallel computers. In order for parallel transport codes to be truly scalable, they must use parallel data storage, where only the variables that are locally computed are locally stored. Even with parallel data storage for the angular variables, cumulative storage requirements for large discrete ordinates calculations can be prohibitive. To address this problem, Memory Tuning has been implemented into the PENTRAN 3-D parallel discrete ordinates code as an optimized, two-level ('large' array, 'small' array) parallel data storage scheme. Memory Tuning can be described as the process of parallel data memory optimization. Memory Tuning dynamically minimizes the amount of required parallel data in allocated memory on each processor using a statistical sampling algorithm. This algorithm is based on the integral average and standard deviation of the number of fine meshes contained in each coarse mesh in the global problem. Because PENTRAN only stores the locally computed problem phase space, optimal two-level memory assignments can be unique on each node, depending upon the parallel decomposition used (hybrid combinations of angular, energy, or spatial). As demonstrated in the two large discrete ordinates models presented (a storage cask and an OECD MOX Benchmark), Memory Tuning can save a substantial amount of memory per parallel processor, allowing one to accomplish very large scale Sn computations. (authors)

The scheme machine: A case study in progress in design derivation at system levels

Science.gov (United States)

Johnson, Steven D.

1995-01-01

The Scheme Machine is one of several design projects of the Digital Design Derivation group at Indiana University. It differs from the other projects in its focus on issues of system design and its connection to surrounding research in programming language semantics, compiler construction, and programming methodology underway at Indiana and elsewhere. The genesis of the project dates to the early 1980's, when digital design derivation research branched from the surrounding research effort in programming languages. Both branches have continued to develop in parallel, with this particular project serving as a bridge. However, by 1990 there remained little real interaction between the branches and recently we have undertaken to reintegrate them. On the software side, researchers have refined a mathematically rigorous (but not mechanized) treatment starting with the fully abstract semantic definition of Scheme and resulting in an efficient implementation consisting of a compiler and virtual machine model, the latter typically realized with a general purpose microprocessor. The derivation includes a number of sophisticated factorizations and representations and is also deep example of the underlying engineering methodology. The hardware research has created a mechanized algebra supporting the tedious and massive transformations often seen at lower levels of design. This work has progressed to the point that large scale devices, such as processors, can be derived from first-order finite state machine specifications. This is roughly where the language oriented research stops; thus, together, the two efforts establish a thread from the highest levels of abstract specification to detailed digital implementation. The Scheme Machine project challenges hardware derivation research in several ways, although the individual components of the system are of a similar scale to those we have worked with before. The machine has a custom dual-ported memory to support garbage collection

Computerized control and management at the Temelin nuclear power plant

International Nuclear Information System (INIS)

Mitosinka, J.; Korec, J.

1992-01-01

The proposed automation of the nuclear power plant control system includes a division of the control system into three hierarchic levels, supplemented with an additional level. These comprise the automated system of control of technological processes, the all-plant control of the power-generating process, the control of backup activities and of technical and economic activities, and top managerial control. The efficiency of the nuclear power plant operation, i.e. attainment of the maximum electricity output with minimum costs while securing the required safety, is the principal criterion in the design of the data model. Listed are tasks that would lend themselves to automation within the automated system of nuclear power plant control, and the basic scheme of their automation as follows from an analysis performed at the Temelin nuclear power plant. (Z.S). 2 figs., 2 refs

High-level nuclear waste disposal: Ethical considerations

International Nuclear Information System (INIS)

Maxey, M.N.

1985-01-01

Popular skepticism about, and moral objections to, recent legislation providing for the management and permanent disposal of high-level radioactive wastes have derived their credibility from two major sources: government procrastination in enacting waste disposal program, reinforcing public perceptions of their unprecedented danger and the inflated rhetoric and pretensions to professional omnicompetence of influential scientists with nuclear expertise. Ethical considerations not only can but must provide a mediating framework for the resolution of such a polarized political controversy. Implicit in moral objections to proposals for permanent nuclear waste disposal are concerns about three ethical principles: fairness to individuals, equitable protection among diverse social groups, and informed consent through due process and participation

Signature scheme for the microscopic description of nuclear collective excitations

International Nuclear Information System (INIS)

Ogawa, K.

1980-04-01

The symmetries between the proton and neutron systems in a nucleus are described in terms of the signatures. Three kinds of signatures (i.e. the pn-, p anti n- and p anti p- (or n anti n-) signatures) are introduced and they are related to the appearance of various collective motions such as rotations or vibrations. It is shown that the pn-signature scheme provides a band-like structure of deformed nuclei, while the features associated with the quadrupole vibration are obtained in the p anti n- and p anti p-signature scheme. From the detail investigation of the p anti n-symmetric wave functions, it is concluded that the reguralities provided by the present shell model are more analogous to those of the γ-unstable surface vibration model (Wilets-Jean model) than to those of harmonic phonon model. (author)

Implication of dual-purpose nuclear desalination plants

International Nuclear Information System (INIS)

Kutbi, I.I.

1983-01-01

Available dual purpose nuclear desalination schemes are reviewed. Three specific issues namely, impact of availability and reliability of the desalination stage of the plant, integration of the desalination and power production stages and new safety concerns of dual system, relating to desalination schemes are discussed. Results of operational and reliability studies of nuclear power stations, reverse osmosis and multistage flash distillation desalination plants are considered. Operational aspects of nuclear-multistage flash distillation, nuclear-reverse osmosis and nuclear-multistage flash distillation-reverse osmosis are compared. Concludes that the combined nuclear-multistage flash distillation-reverse osmosis plant arrangement permits very large production capacity, high availability, improvement of plant reliability and proovision of savings on the cost of water and power produced. 23 Ref

Application of smart transmitter technology in nuclear engineering measurements with level detection algorithm

International Nuclear Information System (INIS)

Kang, Hyun Gook; Seong, Poong Hyun

1994-01-01

In this study a programmable smart transmitter is designed and applied to the nuclear engineering measurements. In order to apply the smart transmitter technology to nuclear engineering measurements, the water level detection function is developed and applied in this work. In the real time system, the application of level detection algorithm can make the operator of the nuclear power plant sense the water level more rapidly. Furthermore this work can simplify the data communication between the level-sensing thermocouples and the main signal processor because the level signal is determined at field. The water level detection function reduces the detection time to about 8.3 seconds by processing the signal which has the time constant 250 seconds and the heavy noise signal

Study of numerical schemes for two-phase flow in porous media for any meshes: application to storage of nuclear waste

International Nuclear Information System (INIS)

Angelini, O.

2010-01-01

The two-phase flow in porous media is a complex phenomenon and which relate to many industrial problems. EDF works on the feasibility and the safety of a storage in deep geologic layer of nuclear waste. In this domain the simulation of the two-phase flow in porous media is particularly important in at least three domains: first of all during the phase of ventilation of the galleries of the storage which could de-saturate the rock and so modify its properties, but also during the phase of re-saturation of the materials and finally during the arrival of the water on the metal parts contained in the storage which will then involve phenomena of corrosion and a hydrogen release. In this context, EDF wishes to obtain robust numerical methods without restrictive condition on the mesh. This work is dedicated at first to the development of the finite volume scheme SUSHI (Scheme Using Stabilization and Hybrid Interfaces) in the code of mechanics of EDF, Code Aster in order to simulate the two-phase flow in porous media. This scheme was developed in 2D and in 3D. At the same time a new formulation which allows to simulate in a uniform way the flows in saturated and unsaturated porous media for miscible and immiscible problems is proposed. Various studies simulating difficulties related to the problems of the storage of nuclear waste in deep geological layers were study. We can quote the study of a bi-material which advances the capillary re-balancing of a material by an other one possessing properties and initial very heterogeneous conditions in saturation. We will also quote the study of the injection of hydrogen in an porous media initially saturated in pure water which is proposed by the benchmark 'two-phase Flow' proposed by the GNR MOMAS. This study had for objective to bring to light the good treatment of the appearance of a phase in a saturated porous media and thus the relevance of our new formulation to study with a way unified a problem of saturated flow and a

Financing of an integrated nuclear desalination system in developing countries

International Nuclear Information System (INIS)

Bouzguenda, N.; Albouy, M.; Nisan, S.

2007-01-01

This paper focuses on a case study of financing a project of an integrated nuclear desalination system at la Skhira site in Tunisia. More specifically, it shows the financial characteristics of this project, known as TUNDESAL, the main financing mechanisms that can be used, and the principal actions required to attract the potential investors and lenders. The paper describes the basic requirements for the deployment of nuclear energy in a developing or an emerging country, with no previous experience of nuclear power; the specific financial considerations corresponding to the particular characteristics of nuclear desalination projects: high capital costs, high level of risks and uncertainties related in particular to long construction lead times and social and environmental concerns; the main risks of these projects; the profitability study of the TUNDESAL project: application of the discounted cash flow analysis; the main financing sources for the project; the financing schemes that can be used for project implementation and comparison between these schemes in terms of benefits generated, after covering project costs and repayment of lenders and investors; the main actions to be done for making the project financially attractive in order to gain the confidence of investors and international financial institutions (optimal allocation of project risks and uncertainties, a suitable and flexible energy and water tariffs policy, etc.). The analysis has shown that in particular conditions of Tunisia, the most attractive financial scheme could be the 'project financing + leasing'. (authors)

Nuclear level density variation with angular momentum induced shape transition

International Nuclear Information System (INIS)

Aggarwal, Mamta

2016-01-01

Variation of Nuclear level density (NLD) with the excitation energy and angular momentum in particular has been a topic of interest in the recent past and there have been continuous efforts in this direction on the theoretical and experimental fronts but a conclusive trend in the variation of nuclear level density parameter with angular momentum has not been achieved so far. A comprehensive investigation of N=68 isotones around the compound nucleus 119 Sb from neutron rich 112 Ru (Z=44) to neutron deficient 127 Pr (Z= 59) nuclei is presented to understand the angular momentum induced variations in inverse level density parameter and the possible influence of deformation and structural transitions on the variations on NLd

Large model-space calculation of the nuclear level density parameter

International Nuclear Information System (INIS)

Agrawal, B.K.; Samaddar, S.K.; De, J.N.; Shlomo, S.

1998-01-01

Recently, several attempts have been made to obtain nuclear level density (ρ) and level density parameter (α) within the microscopic approaches based on path integral representation of the partition function. The results for the inverse level density parameter K es and the level density as a function of excitation energy are presented

Integrated Radiation Transport and Nuclear Fuel Performance for Assembly-Level Simulations

Energy Technology Data Exchange (ETDEWEB)

Clarno, Kevin T [ORNL; Hamilton, Steven P [ORNL; Philip, Bobby [ORNL; Berrill, Mark A [ORNL; Sampath, Rahul S [ORNL; Allu, Srikanth [ORNL; Pugmire, Dave [ORNL; Dilts, Gary [Los Alamos National Laboratory (LANL); Banfield, James E [ORNL

2012-02-01

The Advanced Multi-Physics (AMP) Nuclear Fuel Performance code (AMPFuel) is focused on predicting the temperature and strain within a nuclear fuel assembly to evaluate the performance and safety of existing and advanced nuclear fuel bundles within existing and advanced nuclear reactors. AMPFuel was extended to include an integrated nuclear fuel assembly capability for (one-way) coupled radiation transport and nuclear fuel assembly thermo-mechanics. This capability is the initial step toward incorporating an improved predictive nuclear fuel assembly modeling capability to accurately account for source-terms and boundary conditions of traditional (single-pin) nuclear fuel performance simulation, such as the neutron flux distribution, coolant conditions, and assembly mechanical stresses. A novel scheme is introduced for transferring the power distribution from the Scale/Denovo (Denovo) radiation transport code (structured, Cartesian mesh with smeared materials within each cell) to AMPFuel (unstructured, hexagonal mesh with a single material within each cell), allowing the use of a relatively coarse spatial mesh (10 million elements) for the radiation transport and a fine spatial mesh (3.3 billion elements) for thermo-mechanics with very little loss of accuracy. In addition, a new nuclear fuel-specific preconditioner was developed to account for the high aspect ratio of each fuel pin (12 feet axially, but 1 4 inches in diameter) with many individual fuel regions (pellets). With this novel capability, AMPFuel was used to model an entire 17 17 pressurized water reactor fuel assembly with many of the features resolved in three dimensions (for thermo-mechanics and/or neutronics), including the fuel, gap, and cladding of each of the 264 fuel pins; the 25 guide tubes; the top and bottom structural regions; and the upper and lower (neutron) reflector regions. The final, full assembly calculation was executed on Jaguar using 40,000 cores in under 10 hours to model over 162

On expectation values for nuclear energy levels

International Nuclear Information System (INIS)

De Wet, J.A.

1978-01-01

The nuclear model is built up by constructing measured states, including the ground state, from the vacuum state. All states are, however, not accessible from the ground state so that selection rules may be found which at the same time impose even more stringent conditions on the labelling of energy levels. These are the subject of this paper

Low-level nuclear waste tested for fertilizer value

International Nuclear Information System (INIS)

Anon.

1987-01-01

The nuclear power industry keeps coming up with proposals for getting rid of radioactive waste - burying it deep in the ground, sinking it at sea and even sending it into space reports Common Cause magazine under a headline, The Latest in Recycling. At its Sequoyah Fuels facility in Oklahoma, Kerr-McGee manufactures fuel for nuclear power plants, generating a low-level radioactive liquid waste product called raphinate. After processing to remove radioactive substances, Kerr-McGee has gotten approval from the Nuclear Regulatory Commission to use the nitrogen-rich residue as a fertilizer - but not to market it. As a result, Kerr-McGee is reported to be buying up thousands of acres of land on which to spread raphinate. The acreage is used to grow hay, which the company has gotten an okay to sell. The recycling effort hasn't exactly won neighborhood friends for the company, noted Common Cause. According to Kerr-McGee's corporate communications direct, When you say to somebody, Sequoyah Fuels is putting nuclear waste (on farmland), people jump up a wall

The behaviour of the lande factor and effective exchange parameter in a group of Pr intermetallics observed through reduced level scheme models

International Nuclear Information System (INIS)

Ranke, P.J. von; Caldas, A.; Palermo, L.

1993-01-01

The present work constitutes a portion of a continuing series of studies dealing with models, in which we retain only the two lowest levels of the crystal field splitting scheme of rare-earth ion in rare-earth intermetallics. In these reduced level scheme models, the crystal field and the magnetic Hamiltonians are represented in matrix notation. These two matrices constitute the model Hamiltonian proposed in this paper, from which we derive the magnetic state equations of interest for this work. Putting into these equations a group of adequate experimental data found in the literature for a particular rare-earth intermetallic we obtain the Lande factor and effective exchange parameter related to this rare-earth intermetallic. This study will be applied to a group of Pr intermetallics, in cubic symmetry, in which the ground level may be a non-magnetic singlet level or a non-magnetic doublet level. In both cases, the first excited level is a triplet one. (orig.)

Low-level nuclear waste in Washington State

International Nuclear Information System (INIS)

Williams, H.

1986-01-01

A commercial disposal site for low-level nuclear wastes opened at Hanford in 1965. By 1971 a total of six were in operation: Hanford, Nevada, South Carolina, Kentucky, New York State, and Illinois. The history of the operation of these sites is described. Only the first three listed are still open. The effects of the large volumes of waste expected from Three Mile Island are described. This paper examines the case history of Hanford operations with low-level waste disposal for lessons that might apply in other states being considered for disposal sites

Nuclear Capacity Building through Research Reactors

International Nuclear Information System (INIS)

2017-01-01

Four Instruments: •The IAEA has recently developed a specific scheme of services for Nuclear Capacity Building in support of the Member States cooperating research reactors (RR) willing to use RRs as a primary facility to develop nuclear competences as a supporting step to embark into a national nuclear programme. •The scheme is composed of four complementary instruments, each of them being targeted to specific objective and audience: Distance Training: Internet Reactor Laboratory (IRL); Basic Training: Regional Research Reactor Schools; Intermediate Training: East European Research Reactor Initiative (EERRI); Group Fellowship Course Advanced Training: International Centres based on Research Reactors (ICERR)

Comparison of reactivity estimation performance between two extended Kalman filtering schemes

International Nuclear Information System (INIS)

Peng, Xingjie; Cai, Yun; Li, Qing; Wang, Kan

2016-01-01

Highlights: • The performances of two EKF schemes using different Jacobian matrices are compared. • Numerical simulations are used for the validation and comparison of these two EKF schemes. • The simulation results show that the EKF scheme adopted by this paper performs better than the one adopted by previous literatures. - Abstract: The extended Kalman filtering (EKF) technique has been utilized in the estimation of reactivity which is a significantly important parameter to indicate the status of the nuclear reactor. In this paper, the performances of two EKF schemes using different Jacobian matrices are compared. Numerical simulations are used for the validation and comparison of these two EKF schemes, and the results show that the Jacobian matrix obtained directly from the discrete-time state model performs better than the one which is the discretization form of the Jacobian matrix obtained from the continuous-time state model.

Development of Cyber Security Scheme for Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Hong, S. B.; Choi, Y. S.; Cho, J. W. (and others)

2009-12-15

Nuclear I and C system is considered to be safe on the cyber threat because of the use of exclusive communication network and operating system. But the trend of open architecture and standardization on the equipment of I and C system, it is not safe on the cyber threat such as hacking and cyber terror. It is needed to protect nuclear I and C systems by the cyber attack, Countermeasures of the cyber security is required a lot of time and endeavors because there are many factors on the environment of cyber security and cyber attack. For the nuclear cyber security, we should make structural framework and eliminate cyber vulnerabilities by the analysis of cyber environment. The framework for the cyber security includes planning, embodiment of security technologies, security audit, security management and security maintenance. In this report, we examined IT security technology and the trend of standard in the industrial I and C system, and proposed a method to construct cyber security for the nuclear power plant. We analysed the threat of cyber security, vulnerability and cyber risk, then we present a method for the cyber security structure and the countermeasures.

Development of Cyber Security Scheme for Nuclear Power Plant

International Nuclear Information System (INIS)

Hong, S. B.; Choi, Y. S.; Cho, J. W.

2009-12-01

Nuclear I and C system is considered to be safe on the cyber threat because of the use of exclusive communication network and operating system. But the trend of open architecture and standardization on the equipment of I and C system, it is not safe on the cyber threat such as hacking and cyber terror. It is needed to protect nuclear I and C systems by the cyber attack, Countermeasures of the cyber security is required a lot of time and endeavors because there are many factors on the environment of cyber security and cyber attack. For the nuclear cyber security, we should make structural framework and eliminate cyber vulnerabilities by the analysis of cyber environment. The framework for the cyber security includes planning, embodiment of security technologies, security audit, security management and security maintenance. In this report, we examined IT security technology and the trend of standard in the industrial I and C system, and proposed a method to construct cyber security for the nuclear power plant. We analysed the threat of cyber security, vulnerability and cyber risk, then we present a method for the cyber security structure and the countermeasures

Calculation of nuclear level density parameters of some light deformed medical radionuclides using collective excitation modes of observed nuclear spectra

International Nuclear Information System (INIS)

Okuducu, S.; Sarac, H.; Akti, N. N.; Boeluekdemir, M. H.; Tel, E.

2010-01-01

In this study the nuclear energy level density based on nuclear collective excitation mechanism has been identified in terms of the low-lying collective level bands at near the neutron binding energy. Nuclear level density parameters of some light deformed medical radionuclides used widely in medical applications have been calculated by using different collective excitation modes of observed nuclear spectra. The calculated parameters have been used successfully in estimation of the neutron-capture cross section basic data for the production of new medical radionuclides. The investigated radionuclides have been considered in the region of mass number 40< A< 100. The method used in the present work assumes equidistance spacing of the collective coupled state bands of the interest radionuclides. The present calculated results have been compared with the compiled values from the literatures for s-wave neutron resonance data.

Experimental energy-dependent nuclear spin distributions

International Nuclear Information System (INIS)

Egidy, T. von; Bucurescu, D.

2009-01-01

A new method is proposed to determine the energy-dependent spin distribution in experimental nuclear-level schemes. This method compares various experimental and calculated moments in the energy-spin plane to obtain the spin-cutoff parameter σ as a function of mass A and excitation energy using a total of 7202 levels with spin assignment in 227 nuclei between F and Cf. A simple formula, σ 2 =0.391 A 0.675 (E-0.5Pa ' ) 0.312 , is proposed up to about 10 MeV that is in very good agreement with experimental σ values and is applied to improve the systematics of level-density parameters.

Further assessments of the attractiveness of materials in advanced nuclear fuel cycles from a safeguards perspective

International Nuclear Information System (INIS)

Bathke, Charles G.; Jarvinen, Gordon D.; Wallace, Richard K.; Ireland, John R.; Johnson, M.W.; Sleaford, Brad W.; Ebbinghaus, Bartley B.; Bradley, Keith S.; Collins, Brian A.; Smith, Brian W.; Prichard, Andrew W.

2010-01-01

This paper summarises the results of an extension to an earlier study [1] that examined the attractiveness of materials mixtures containing special nuclear materials (SNM) associated with the Purex, Urex+ and COEX reprocessing schemes. This study focuses on the materials associated with the Urex, COEX, Thorex and PYROX reprocessing schemes. This study also examines what is required to render plutonium as 'unattractive.' Furthermore, combining the results of this study with those from the earlier study permits a comparison of the uranium- and thorium-based fuel cycles on the basis of the attractiveness of the SNM associated with each fuel cycle. Both studies were performed at the request of the United States Department of Energy (DOE), and are based on the calculation of 'attractiveness levels' that has been couched in terms chosen for consistency with those normally used for nuclear materials in DOE nuclear facilities [2]. The methodology and key findings will be presented. Additionally, how these attractiveness levels relate to proliferation resistance (e.g. by increasing impediments to the diversion, theft, undeclared production of SNM for the purpose of acquiring a nuclear weapon), and how they could be used to help inform policy makers, will be discussed. (authors)

Multiple external hazards compound level 3 PSA methods research of nuclear power plant

Science.gov (United States)

Wang, Handing; Liang, Xiaoyu; Zhang, Xiaoming; Yang, Jianfeng; Liu, Weidong; Lei, Dina

2017-01-01

2011 Fukushima nuclear power plant severe accident was caused by both earthquake and tsunami, which results in large amount of radioactive nuclides release. That accident has caused the radioactive contamination on the surrounding environment. Although this accident probability is extremely small, once such an accident happens that is likely to release a lot of radioactive materials into the environment, and cause radiation contamination. Therefore, studying accidents consequences is important and essential to improve nuclear power plant design and management. Level 3 PSA methods of nuclear power plant can be used to analyze radiological consequences, and quantify risk to the public health effects around nuclear power plants. Based on multiple external hazards compound level 3 PSA methods studies of nuclear power plant, and the description of the multiple external hazards compound level 3 PSA technology roadmap and important technical elements, as well as taking a coastal nuclear power plant as the reference site, we analyzed the impact of off-site consequences of nuclear power plant severe accidents caused by multiple external hazards. At last we discussed the impact of off-site consequences probabilistic risk studies and its applications under multiple external hazards compound conditions, and explained feasibility and reasonableness of emergency plans implementation.

76 FR 35137 - Vulnerability and Threat Information for Facilities Storing Spent Nuclear Fuel and High-Level...

Science.gov (United States)

2011-06-16

... High-Level Radioactive Waste AGENCY: U.S. Nuclear Regulatory Commission. ACTION: Public meeting... Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater Than Class C Waste,'' and 73... Spent Nuclear Fuel (SNF) and High-Level Radioactive Waste (HLW) storage facilities. The draft regulatory...

Nuclear safety chains

International Nuclear Information System (INIS)

Robbins, M.C.; Eames, G.F.; Mayell, J.R.

1981-01-01

An original scheme has been developed for expressing the complex interrelationships associated with the engineered safeguards provided for a nuclear power station. This management tool, based upon network diagrams called Nuclear Safety Chains, looks at the function required of a particular item of safety plant, defines all of the vital supplies and support features necessary for successful operation, and expresses them in visual form, to facilitate analysis and optimisation for operations and maintenance staff. The safety chains are confined to manual schemes at present, although they are designed to be compatible with modern computer techniques. Their usefulness with any routine maintenance planning application on high technology plant is already being appreciated. (author)

SMAFS, Steady-state analysis Model for Advanced Fuel cycle Schemes

International Nuclear Information System (INIS)

LEE, Kwang-Seok

2006-01-01

1 - Description of program or function: The model was developed as a part of the study, 'Advanced Fuel Cycles and Waste Management', which was performed during 2003-2005 by an ad-hoc expert group under the Nuclear Development Committee in the OECD/NEA. The model was designed for an efficient conduct of nuclear fuel cycle scheme cost analyses. It is simple, transparent and offers users the capability to track down the cost analysis results. All the fuel cycle schemes considered in the model are represented in a graphic format and all values related to a fuel cycle step are shown in the graphic interface, i.e., there are no hidden values embedded in the calculations. All data on the fuel cycle schemes considered in the study including mass flows, waste generation, cost data, and other data such as activities, decay heat and neutron sources of spent fuel and high-level waste along time are included in the model and can be displayed. The user can modify easily the values of mass flows and/or cost parameters and see the corresponding changes in the results. The model calculates: front-end fuel cycle mass flows such as requirements of enrichment and conversion services and natural uranium; mass of waste based on the waste generation parameters and the mass flow; and all costs. It performs Monte Carlo simulations with changing the values of all unit costs within their respective ranges (from lower to upper bounds). 2 - Methods: In Monte Carlo simulation, it is assumed that all unit costs follow a triangular probability distribution function, i.e., the probability that the unit cost has a value increases linearly from its lower bound to the nominal value and then decreases linearly to its upper bound. 3 - Restrictions on the complexity of the problem: The limit for the Monte Carlo iterations is the one of an Excel worksheet, i.e. 65,536

Level and decay schemes of even-A Se and Ge isotopes from (n,n'γ) reaction studies

Energy Technology Data Exchange (ETDEWEB)

Sigaud, J.; Patin, Y.; McEllistrem, M. T.; Haouat, G.; Lachkar, J.

1975-06-01

The energy levels and the decay schemes of {sup 76}Se, {sup 78}Se, {sup 80}Se, {sup 82}Se and {sup 76}Ge have been studied through the measurements of (n,n'γ) differential cross sections. Gamma-ray excitation functions have been measured between 2.0- and 4.1-MeV incident neutron energy, and angular distribution have been observed for all of these isotopes.

A Velocity-Level Bi-Criteria Optimization Scheme for Coordinated Path Tracking of Dual Robot Manipulators Using Recurrent Neural Network.

Science.gov (United States)

Xiao, Lin; Zhang, Yongsheng; Liao, Bolin; Zhang, Zhijun; Ding, Lei; Jin, Long

2017-01-01

A dual-robot system is a robotic device composed of two robot arms. To eliminate the joint-angle drift and prevent the occurrence of high joint velocity, a velocity-level bi-criteria optimization scheme, which includes two criteria (i.e., the minimum velocity norm and the repetitive motion), is proposed and investigated for coordinated path tracking of dual robot manipulators. Specifically, to realize the coordinated path tracking of dual robot manipulators, two subschemes are first presented for the left and right robot manipulators. After that, such two subschemes are reformulated as two general quadratic programs (QPs), which can be formulated as one unified QP. A recurrent neural network (RNN) is thus presented to solve effectively the unified QP problem. At last, computer simulation results based on a dual three-link planar manipulator further validate the feasibility and the efficacy of the velocity-level optimization scheme for coordinated path tracking using the recurrent neural network.

Determination of leveled costs of electric generation for gas plants, coal and nuclear

International Nuclear Information System (INIS)

Alonso V, G.; Palacios H, J.C.; Ramirez S, J.R.; Gomez, A.

2005-01-01

The present work analyzes the leveled costs of electric generation for different types of nuclear reactors known as Generation III, these costs are compared with the leveled costs of electric generation of plants with the help of natural gas and coal. In the study several discount rates were used to determine their impact in the initial investment. The obtained results are comparable with similar studies and they show that it has more than enough the base of the leveled cost the nuclear option it is quite competitive in Mexico. Also in this study it is also thinks about the economic viability of a new nuclear power station in Mexico. (Author)

Development and validation of calculation schemes dedicated to the interpretation of small reactivity effects for nuclear data improvement

International Nuclear Information System (INIS)

Gruel, A.

2011-01-01

Reactivity measurements by the oscillation technique, as those performed in the Minerve reactor, enable to access various neutronic parameters on materials, fuels or specific isotopes. Usually, expected reactivity effects are small, about ten pcm at maximum. Then, the modeling of these experiments should be very precise, to obtain reliable feedback on the pointed parameters. Especially, calculation biases should be precisely identified, quantified and reduced to get precise information on nuclear data. The goal of this thesis is to develop a reference calculation scheme, with well quantified uncertainties, for in-pile oscillation experiments. In this work are presented several small reactivity calculation methods, based on deterministic and/or stochastic calculation codes. Those method are compared thanks to a numerical benchmark, against a reference calculation. Three applications of these methods are presented here: a purely deterministic calculation with exact perturbation theory formalism is used for the experimental validation of fission product cross sections, in the frame of reactivity loss studies for irradiated fuel; an hybrid method, based on a stochastic calculation and the exact perturbation theory is used for the readjustment of nuclear data, here 241 Am; and a third method, based on a perturbative Monte Carlo calculation, is used in a conception study. (author) [fr

Immobilisation of high level nuclear reactor wastes in SYNROC

Energy Technology Data Exchange (ETDEWEB)

Ringwood, A E; Kesson, S E; Ware, N G; Hibberson, W; Major, A [Australian National Univ., Canberra. Inst. of Advanced Studies

1979-03-15

It is stated that the elements occurring in high-level nuclear reactor wastes can be safely immobilised by incorporating them within the crystal lattices of the constituent minerals of a synthetic rock (SYNROC). The preferred form of SYNROC can accept up to 20% of high level waste calcine to form dilute solid solutions. The constituent minerals, or close structural analogues, have survived in a wide range of geochemical environments for periods of 20 to 2,000 Myr whilst immobilising the same elements present in nuclear wastes. SYNROC is unaffected by leaching for 24 hours in pure water or 10 wt % NaCl solution at high temperatures and pressure whereas borosilicate glasses completely decompose in a few hours in much less severe hydrothermal conditions. The combination of these leaching results with the geological evidence of long-term stability indicates that SYNROC would be vastly superior to glass in its capacity to safely immobilise nuclear wastes, when buried in a suitable geological repository. A dense, compact, mechanically strong form of SYNROC suitable for geological disposal can be produced by a process as economical as that which incorporates radioactive waste in borosilicate glasses.

Management of the high-level nuclear power facilities

International Nuclear Information System (INIS)

Preda, Marin

2003-05-01

This thesis approaches current issues in the management of the high power nuclear facilities and as such it appears to be important particularly for nuclear power plant operation topics. Of special interest are the failure events entailing possible catastrophic situations. The contents is structured onto ten chapters. The first chapter describes the operation regimes of the nuclear high power facilities. Highlighted here are the thesis scope and the original features of the work. The second chapter deals with operational policies developed in order to ensure the preventive maintenance of the nuclear installations. Also managing structures are described devoted to practical warranting the equipment safety function of non-classical power stations. In the third chapter cases of nuclear accidents are analyzed especially stressing the probabilistic risk and the operation regimes having in view the elimination of catastrophic events. In the fourth and fifth chapters the control of nuclear radiation emission is treated focusing the quality issue of nuclear installations required to avoid hazardous effects at level of nuclear reactor operation stage. At the same time set of operational measures is given here for preventing risks, catastrophes and chaotic situations. The chapter five presents both theoretical and practical approaches of the nuclear reactor core management concerning particularly the fuel testing, the water primary system and the quality of the involved equipment. In the sixth and seventh chapters issues of risk-quality correlations are approached as well as the structure of expert systems for monitoring the operational regimes of nuclear facilities. The efficiency of the power systems with nuclear injection is discussed and some original ideas developed in this work are evidenced in the eighth and ninth chapters. Presented are here both the operational principles and models of raising the efficiency of the interconnected nuclear stations and prices' policy

Level repulsion, nuclear chaos, and conserved quantum numbers

International Nuclear Information System (INIS)

Garrett, J.D.

1993-01-01

A statistical analysis of the distribution of level spacings for states with the same spin and parity is described in which the average spacing is calculated for the total ensemble. Though the resulting distribution of level spacings for states of deformed nuclei with Z = 62 - 75 and A = 155 - 185 is the closest to that of a Poisson distribution yet obtained for nuclear levels, significant deviations are observed for small level spacings. Many, but not all, of the very closely-spaced levels have K-values differing by several units. The analysis of level spacings in 157 Ho indicate that considerable caution should be excerised when drawing conclusions from such an analysis for a single deformed nucleus, since the sizable number of spacings that can be obtained from a few rotational bands are not all independent

University-level education in nuclear and radiochemistry in Slovenia

International Nuclear Information System (INIS)

Smodis, B.

2006-01-01

The status of education in nuclear and radiochemistry in Slovenia is reviewed and elucidated at both undergraduate and graduate levels. It is observed that both the quantity and the quality of studies have deteriorated during recent years/decades, thus following similar trends in the developed countries. Presently, no dedicated study of radioactivity is offered within the country. The main reason for this deterioration is a general decline of interest for studying nuclear sciences and the limited need for such specialization in a small country such as Slovenia. (author)

A Secure and Efficient Certificateless Short Signature Scheme

Directory of Open Access Journals (Sweden)

Lin Cheng

2013-07-01

Full Text Available Certificateless public key cryptography combines advantage of traditional public key cryptography and identity-based public key cryptography as it avoids usage of certificates and resolves the key escrow problem. In 2007, Huang et al. classified adversaries against certificateless signatures according to their attack power into normal, strong and super adversaries (ordered by their attack power. In this paper, we propose a new certificateless short signature scheme and prove that it is secure against both of the super type I and the super type II adversaries. Our new scheme not only achieves the strongest security level but also has the shortest signature length (one group element. Compared with the other short certificateless signature schemes which have a similar security level, our new scheme has less operation cost.

Levelized Costs for Nuclear, Gas and Coal for Electricity, under the Mexican Scenario

Energy Technology Data Exchange (ETDEWEB)

Palacios, J.C.; Alonso, G.; Ramirez, R.; Gomez, A.; Ortiz, J.; Longoria, L.C.

2004-10-06

In the case of new nuclear power stations, it is necessary to pay special attention to the financial strategy that will be applied, time of construction, investment cost, and the discount and return rate. The levelized cost quantifies the unitary cost of the electricity (the kWh) generated during the lifetime of the nuclear power plant; and allows the immediate comparison with the cost of other alternative technologies. The present paper shows levelized cost for different nuclear technologies and it provides comparison among them as well as with gas and coal electricity plants. For the calculations we applied our own methodology to evaluate the levelized cost considering investment, fuel and operation and maintenance costs, making assumptions for the Mexican market, and taking into account the gas prices projections. The study also shows comparisons using different discount rates (5% and 10%), and some comparisons between our results and an OECD 1998 study. The results are i n good agreement and shows that nuclear option is cost competitive in Mexico on the basis of levelized costs.

Levelized Costs for Nuclear, Gas and Coal for Electricity, under the Mexican Scenario

International Nuclear Information System (INIS)

Palacios, J.C.; Alonso, G.; Ramirez, R.; Gomez, A.; Ortiz, J.; Longoria, L.C.

2004-01-01

In the case of new nuclear power stations, it is necessary to pay special attention to the financial strategy that will be applied, time of construction, investment cost, and the discount and return rate. The levelized cost quantifies the unitary cost of the electricity (the kWh) generated during the lifetime of the nuclear power plant; and allows the immediate comparison with the cost of other alternative technologies. The present paper shows levelized cost for different nuclear technologies and it provides comparison among them as well as with gas and coal electricity plants. For the calculations we applied our own methodology to evaluate the levelized cost considering investment, fuel and operation and maintenance costs, making assumptions for the Mexican market, and taking into account the gas prices projections. The study also shows comparisons using different discount rates (5% and 10%), and some comparisons between our results and an OECD 1998 study. The results are i n good agreement and shows that nuclear option is cost competitive in Mexico on the basis of levelized costs

Table of Half-Lives for Excited Nuclear Levels

Energy Technology Data Exchange (ETDEWEB)

Malmskog, S G

1970-07-15

The knowledge of the half-lives of excited states is often a valuable information in the investigation of the nuclear level structure. The present paper contains a collection of such half-lives being published in the current literature over the period 1967-1970. The data is arranged in increasing order of mass number.

Nuclear fuel accounting

International Nuclear Information System (INIS)

Aisch, D.E.

1977-01-01

After a nuclear power plant has started commercial operation the actual nuclear fuel costs have to be demonstrated in the rate making procedure. For this purpose an accounting system has to be developed which comprises the following features: 1) All costs associated with nuclear fuel shall be correctly recorded; 2) it shall be sufficiently flexible to cover also deviations from proposed core loading patterns; 3) it shall be applicable to different fuel cycle schemes. (orig./RW) [de

US program for the immobilization of high-level nuclear wastes

International Nuclear Information System (INIS)

Crandall, J.L.

1979-01-01

A program has been developed for long-term management of high-level nuclear waste. The Savannah River Operations Office of the US Department of Energy is acting as the lead office for this program with technical advice from the E.I. du Pont de Nemours and Company. The purpose of the long-term program is to immobilize the DOE high-level waste in forms that act as highly efficient barriers against radionuclide release to the disposal site and to provide technology for similar treatment of commercial high-level waste in case reprocessing of commercial nuclear fuels is ever resumed. Descriptions of existing DOE and commercial wastes, program strategy, program expenditures, development of waste forms, evaluation and selection of waste forms, regulatory aspects of waste form selection, project schedules, and cost estimates for immobilization facilities are discussed

On the evaluation of semiclassical nuclear many-particle many-hole level densities

International Nuclear Information System (INIS)

Blin, A.H.; Hiller, B.; Schuck, P.; Yannouleas, C.

1985-10-01

An exact general scheme is described to calculate the m-particle n-hole fermion level densities for an arbitrary single particle Hamiltonian taking into account the Pauli exclusion principle. This technique is applied to obtain level densities of the three dimensional isotropic harmonic oscillator semiclassically in the Thomas-Fermi approach. In addition, we study the l-particle l-hole level density of the Woods-Saxon potential. For the harmonic oscillator we analyze the temperature dependence of the linear response function and the influence of pairing correlations on the l-particle l-hole level density. Finally, a Taylor expansion method of the m-particle n-hole level densities is discussed

Cost-based droop scheme for DC microgrid

DEFF Research Database (Denmark)

Nutkani, Inam Ullah; Wang, Peng; Loh, Poh Chiang

2014-01-01

voltage level, less on optimized operation and control of generation sources. The latter theme is perused in this paper, where cost-based droop scheme is proposed for distributed generators (DGs) in DC microgrids. Unlike traditional proportional power sharing based droop scheme, the proposed scheme......-connected operation. Most importantly, the proposed scheme can reduce overall total generation cost in DC microgrids without centralized controller and communication links. The performance of the proposed scheme has been verified under different load conditions.......DC microgrids are gaining interest due to higher efficiencies of DC distribution compared with AC. The benefits of DC systems have been widely researched for data centers, IT facilities and residential applications. The research focus, however, has been more on system architecture and optimal...

Low temperature nuclear orientation studies of nuclei far from stability

International Nuclear Information System (INIS)

Brown, D.E.

1990-01-01

One of the major current interests in nuclear physics is to study transitional nuclei which lie between well known regions of spherical and deformed nuclei. The neutron deficient Tellurium and Iodine isotopes are examples of such nuclei. In both cases, the influence of a πg 9/2 intruder orbital is expected to be strong at low excitation energies and at A ∼120. The 120 Te decay scheme has been investigated in detail by LTNO supported by γ-γ coincidences and conversion electron spectroscopy. An interaction of the level scheme using an IBM-2 calculation which allows for mixing between the ground state and a (4p-2h) intruder state is made. The success of this calculation provides strong evidence for the existence of the intruder configuration in 120 Te. In addition, the relative electric quadrupole moments of the ground states in 120-123 I have been measured. The light Platinum isotopes are also transitional nuclei. The ground state magnetic dipole and electric quadrupole moments have been measured for 185,187 Pt which lie inside the region in which the shape transition is known to occur. An interpretation of nuclear moments and level structures in the range 179≤A≤193 using a particle plus triaxial core shows that the shape change takes place gradually via a broad region in which the nuclear shape is triaxial. (author)

Slovak Electric, plc, Mochovce Nuclear Power Plant

International Nuclear Information System (INIS)

1999-01-01

In this popular scientific brochure a brief description of construction scheme of Bohunice Nuclear Power Plant is presented. Electricity generation in a nuclear power plant is described. Instrumentation and control system as well as nuclear safety principles applied on the NPP are presented

A CU-Level Rate and Distortion Estimation Scheme for RDO of Hardware-Friendly HEVC Encoders Using Low-Complexity Integer DCTs.

Science.gov (United States)

Lee, Bumshik; Kim, Munchurl

2016-08-01

In this paper, a low complexity coding unit (CU)-level rate and distortion estimation scheme is proposed for High Efficiency Video Coding (HEVC) hardware-friendly implementation where a Walsh-Hadamard transform (WHT)-based low-complexity integer discrete cosine transform (DCT) is employed for distortion estimation. Since HEVC adopts quadtree structures of coding blocks with hierarchical coding depths, it becomes more difficult to estimate accurate rate and distortion values without actually performing transform, quantization, inverse transform, de-quantization, and entropy coding. Furthermore, DCT for rate-distortion optimization (RDO) is computationally high, because it requires a number of multiplication and addition operations for various transform block sizes of 4-, 8-, 16-, and 32-orders and requires recursive computations to decide the optimal depths of CU or transform unit. Therefore, full RDO-based encoding is highly complex, especially for low-power implementation of HEVC encoders. In this paper, a rate and distortion estimation scheme is proposed in CU levels based on a low-complexity integer DCT that can be computed in terms of WHT whose coefficients are produced in prediction stages. For rate and distortion estimation in CU levels, two orthogonal matrices of 4×4 and 8×8 , which are applied to WHT that are newly designed in a butterfly structure only with addition and shift operations. By applying the integer DCT based on the WHT and newly designed transforms in each CU block, the texture rate can precisely be estimated after quantization using the number of non-zero quantized coefficients and the distortion can also be precisely estimated in transform domain without de-quantization and inverse transform required. In addition, a non-texture rate estimation is proposed by using a pseudoentropy code to obtain accurate total rate estimates. The proposed rate and the distortion estimation scheme can effectively be used for HW-friendly implementation of

Financial study of an integrated nuclear desalination system in Tunisia: the Tundesal Project

International Nuclear Information System (INIS)

Bouzguenda Benzarti, Neila; Albouy, Michel; Nisan, Simon

2006-01-01

This paper focuses on a case study of financing an integrated nuclear desalination system at la Skhira site in Tunisia. More specifically, it shows the financial characteristics of the study, known as the TUNDESAL project, the main financing mechanisms that can be used, and the principal actions required to attract the potential investors and lenders. The paper describes: - The specific financial considerations corresponding to the particular characteristics of nuclear desalination projects: high capital costs, high level of risks and uncertainties, relatively long construction lead times and social and environmental concerns; - The main risks involved in nuclear energy projects; - The profitability study of the TUNDESAL project with the application of the Discounted Cash Flow Analysis; - The main financing sources for the project; - The financing schemes that can be used for project implementation and comparison between these schemes in terms of benefits generated, after covering project costs and repayment of lenders and investors; - The main actions to be done for making the project financially attractive in order to gain the confidence of investors and international financial institutions (optimal allocation of project risks and uncertainties, a suitable and flexible energy and water tariffs policy). Analysis has shown that in particular conditions of Tunisia, the most attractive financial scheme could be the 'project financing + leasing'. (authors)

Transport synthetic acceleration scheme for multi-dimensional neutron transport problems

Energy Technology Data Exchange (ETDEWEB)

Modak, R S; Kumar, Vinod; Menon, S V.G. [Theoretical Physics Div., Bhabha Atomic Research Centre, Mumbai (India); Gupta, Anurag [Reactor Physics Design Div., Bhabha Atomic Research Centre, Mumbai (India)

2005-09-15

The numerical solution of linear multi-energy-group neutron transport equation is required in several analyses in nuclear reactor physics and allied areas. Computer codes based on the discrete ordinates (Sn) method are commonly used for this purpose. These codes solve external source problem and K-eigenvalue problem. The overall solution technique involves solution of source problem in each energy group as intermediate procedures. Such a single-group source problem is solved by the so-called Source Iteration (SI) method. As is well-known, the SI-method converges very slowly for optically thick and highly scattering regions, leading to large CPU times. Over last three decades, many schemes have been tried to accelerate the SI; the most prominent being the Diffusion Synthetic Acceleration (DSA) scheme. The DSA scheme, however, often fails and is also rather difficult to implement. In view of this, in 1997, Ramone and others have developed a new acceleration scheme called Transport Synthetic Acceleration (TSA) which is much more robust and easy to implement. This scheme has been recently incorporated in 2-D and 3-D in-house codes at BARC. This report presents studies on the utility of TSA scheme for fairly general test problems involving many energy groups and anisotropic scattering. The scheme is found to be useful for problems in Cartesian as well as Cylindrical geometry. (author)

Transport synthetic acceleration scheme for multi-dimensional neutron transport problems

International Nuclear Information System (INIS)

Modak, R.S.; Vinod Kumar; Menon, S.V.G.; Gupta, Anurag

2005-09-01

The numerical solution of linear multi-energy-group neutron transport equation is required in several analyses in nuclear reactor physics and allied areas. Computer codes based on the discrete ordinates (Sn) method are commonly used for this purpose. These codes solve external source problem and K-eigenvalue problem. The overall solution technique involves solution of source problem in each energy group as intermediate procedures. Such a single-group source problem is solved by the so-called Source Iteration (SI) method. As is well-known, the SI-method converges very slowly for optically thick and highly scattering regions, leading to large CPU times. Over last three decades, many schemes have been tried to accelerate the SI; the most prominent being the Diffusion Synthetic Acceleration (DSA) scheme. The DSA scheme, however, often fails and is also rather difficult to implement. In view of this, in 1997, Ramone and others have developed a new acceleration scheme called Transport Synthetic Acceleration (TSA) which is much more robust and easy to implement. This scheme has been recently incorporated in 2-D and 3-D in-house codes at BARC. This report presents studies on the utility of TSA scheme for fairly general test problems involving many energy groups and anisotropic scattering. The scheme is found to be useful for problems in Cartesian as well as Cylindrical geometry. (author)

Final disposal of high levels waste and spent nuclear fuel

International Nuclear Information System (INIS)

Gelin, R.

1984-05-01

Foreign and international activities on the final disposal of high-level waste and spent nuclear fuel have been reviewed. A considerable research effort is devoted to development of acceptable disposal options. The different technical concepts presently under study are described in the report. Numerous studies have been made in many countries of the potential risks to future generations from radioactive wastes in underground disposal repositories. In the report the safety assessment studies and existing performance criteria for geological disposal are briefly discussed. The studies that are being made in Canada, the United States, France and Switzerland are the most interesting for Sweden as these countries also are considering disposal into crystalline rocks. The overall time-tables in different countries for realisation of the final disposal are rather similar. Normally actual large-scale disposal operations for high-level wastes are not foreseen until after year 2000. In the United States the Congress recently passed the important Nuclear Waste Policy Act. It gives a rather firm timetable for site-selection and construction of nuclear waste disposal facilities. According to this act the first repository for disposal of commercial high-level waste must be in operation not later than in January 1998. (Author)

Is nuclear economical in comparison to renewables?

International Nuclear Information System (INIS)

Suna, Demet; Resch, Gustav

2016-01-01

The European Union is divided on the issue of electricity production. While there is consensus that generation technologies need to be low on greenhouse gas emissions, the question of whether to use renewables or nuclear to meet this power demand is highly controversial. Both options still require financial support and this is not going to change in the near future. This raises the question of where public money should be invested in order to achieve greater economic efficiency: into support for renewable energies (RE) or support for nuclear power plants? This paper sets out to answer this question. The detailed model-based prospective scenario assessment performed in this study provides the basis for estimating future cost developments. After discussing the existing support schemes for renewables, the paper compares these with a nuclear model. The comparison is conducted exemplarily for the United Kingdom (UK) at a country level and for the EU 28 overall. The recent state aid case for the construction of the Hinkley Point nuclear power plant (NPP) in the UK serves as the model for the nuclear option. - Highlights: • State aids for new nuclear power is compared with incentives for renewables. • Hinkley Point C in the UK is considered as example for new nuclear power. • Comparison is conducted for the UK at a country level and for the EU 28 overall. • Analysis shows that renewable energies are more economical than nuclear power.

New level schemes with high-spin states of 105,107,109Tc

International Nuclear Information System (INIS)

Luo, Y.X.; Rasmussen, J.O.; Lee, I.Y.; Fallon, P.; Hamilton, J.H.; Ramayya, A.V.; Hwang, J.K.; Gore, P.M.; Zhu, S.J.; Wu, S.C.; Ginter, T.N.; Ter-Akopian, G.M.; Daniel, A.V.; Stoyer, M.A.; Donangelo, R.; Gelberg, A.

2004-01-01

New level schemes of odd-Z 105,107,109 Tc are proposed based on the 252 Cf spontaneous-fission-gamma data taken with Gammasphere in 2000. Bands of levels are considerably extended and expanded to show rich spectroscopic information. Spin/parity and configuration assignments are made based on determinations of multipolarities of low-lying transitions and the level analogies to the previously reported levels, and to those of the neighboring Rh isotopes. A non-yrast negative-parity band built on the 3/2 - [301] orbital is observed for the first time in 105 Tc. A positive-parity band built on the 1/2 + [431] intruder orbital originating from the π(g 7/2 /d 5/2 ) subshells and having a strong deformation-driving effect is observed for the first time in 105 Tc, and assigned in 107 Tc. A positive-parity band built on the excited 11/2 + level, which has rather low excitation energy and predominantly decays into the 9/2 + level of the ground state band, provides evidence of triaxiality in 107,109 Tc, and probably also in 105 Tc. Rotational constants are calculated and discussed for the K=1/2 intruder bands using the Bohr-Mottelson formula. Level systematics are discussed in terms of the locations of proton Fermi levels and deformations. The band crossings of yrast positive-parity bands are observed, most likely related to h 11/2 neutron alignment. Triaxial-rotor-plus-particle model calculations performed with ε=0.32 and γ=-22.5 deg. on the prolate side of maximum triaxiality yielded the best reproduction of the excitation energies, signature splittings, and branching ratios of the positive-parity bands (except for the intruder bands) of these Tc isotopes. The significant discrepancies between the triaxial-rotor-plus-particle model calculations and experiment for the K=1/2 intruder bands in 105,107 Tc need further theoretical studies

ATTILA (All Type Target Independent Lund Algorithm) for nuclear collisions at ≅ 200 AGeV

International Nuclear Information System (INIS)

Gyulassy, M.; Lawrence Berkeley Lab., CA

1987-08-01

The Lund string model, Fritiof, is applied in the form of a Monte-Carlo event generator, ATTILA, to nuclear collisions in the 200 AGeV range. We study how uncertainties at the pp level amplify at the AB level and compare preliminary CERN data on multiplicity, transverse energy, and veto energy distributions to this linear extrapolation scheme from pp to AB dynamics. (orig.)

Romanian knowledge transfer network in nuclear physics and engineering - REFIN

International Nuclear Information System (INIS)

Ghitescu, Petre; Prisecaru, Ilie

2007-01-01

According to the requirements of the Romanian Nuclear Programme regarding the education and training of the skilled personnel for the nuclear facilities, a knowledge transfer network named REFIN (in Romanian: Retea Educationala in Fizica si Ingineria Nucleara) was developed since 2005. The knowledge target field is nuclear physics and engineering. The main objective of this network is to develop an effective, flexible and modern educational system in the nuclear physics and engineering area which could meet the requirements of all known types of nuclear facilities and therewith be redundant with the perspectives of the European Research Area (FP7, EURATOM). A global strategy was proposed in order to harmonize the curricula between the network facilities to implement pilot modern teaching programs (courses/modules), to introduce advanced learning methods (as Systematic Approach to Training, e-learning and distance-learning), to strengthen and better use the existing research infrastructures of the research institutes in network. The education and training strategy is divided into several topics: university engineering , master, post-graduate, Ph.D. degree, post-doctoral activity, training for industry, improvement. For the first time in our country, a modular scheme is used allowing staff with different technical background to participate at different levels. In this respect, the European system with transferable credits (ECTS) is used. Based on this strategy, courses in 'Radioactive Waste Management' and 'Numerical and Experimental Methods in Reactor Physics' for both MS students and for industry. This way the training activity which a student attends will allow him or her to be involved, depending on specific professional needs, into a flexible educational scheme. This scheme will ensure competence and enhancement and also the possibility of qualification development and a better mobility on labour market. This kind of activity is already in progress in the

Cyclic features of the consequences from a postulated nuclear accident: a case study of the third level probabilistic safety assessment

International Nuclear Information System (INIS)

Xinhe, LIU; Homma, Toshimitsu

2002-01-01

In the third level probabilistic safety assessment, one of the three popular meteorological sequence sampling methods is cyclic sampling. The rationale of cyclic sampling is obviously that cyclic variation is the significant characteristics of the meteorological sequences and the health consequences resulting from a postulated nuclear accident are also remarkably of cyclic features. In this work, a set of time series was established for different health consequences using S3 source term and a whole year meteorological data. OSCAAR software system was utilized in the calculation of the health consequences. It is shown by the analysis that diurnal variation is remarked for all the kinds of health consequences, implying that cyclic sampling would be more effective than random sampling. The results also showed that there are not any dominating frequencies in the spectra of the consequences so that cyclic sampling might be incompetent to reduce the third level PSA to a satisfied level. Therefore, new schemes of meteorological sampling should be developed in the light of consideration of complex coupling of meteorological condition and population distribution rather than the consideration of meteorological condition alone

PSA Level 2:Scope And Method Of PSA Level 2 For Nuclear Power Plant

International Nuclear Information System (INIS)

Widodo, Surip; Antariksawan, Anhar R.

2001-01-01

A study of scope and method of PSA Level 2 had been conducted. The background of the study is the need to gain the capability to well perform PSA Level 2 for nuclear facilities. This study is a literature survey. The scope of PSA Level 2 consists of generating plant damage states, accident progression analysis, and grouping source terms. Concerning accident progression analysis, several methods are used, among others event tree method, named accident progression event tree (APET) or containment event tree (CET), and fault tree method. The end result of PSA Level 2 is release end states which is grouped into release bins. The results will be used for PSA Level 3

International nuclear model and code comparison on pre-equilibrium effects

International Nuclear Information System (INIS)

Gruppelaar, H.; van der Kamp, H.A.J.; Nagel, P.

1983-01-01

This paper gives the specification of an intercomparison of statistical nuclear models and codes with emphasis on pre-equilibrium effects. It is partly based upon the conclusions of a meeting of an ad-hoc working group on this subject. The parameters studied are: masses, Q values, level scheme data, optical model parameters, X-ray competition parameters, total level-density specifications, for 86 Rb, 89 Sr, 90 Y, 92 Y, 92 Zr, 93 Zr, 89 Y, 91 Nb, 92 Nb and 93 Nb

Survey of ambient electromagnetic and radio-frequency interference levels in nuclear power plants

International Nuclear Information System (INIS)

Kercel, S.W.; Moore, M.R.; Blakeman, E.D.; Ewing, P.D.; Wood, R.T.

1996-11-01

This document reports the results of a survey of ambient electromagnetic conditions in representative nuclear power plants. The U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research engaged the Oak Ridge National Laboratory (ORNL) to perform these measurements to characterize the electromagnetic interference (EMI) and radio-frequency interference (RFI) levels that can be expected in nuclear power plant environments. This survey is the first of its kind, being based on long-term unattended observations. The data presented in this report were measured at eight different nuclear units and required 14 months to collect. A representative sampling of power plant conditions (reactor type, operating mode, site location) monitored over extended observation periods (up to 5 weeks) were selected to more completely determine the characteristic electromagnetic environment for nuclear power plants. Radiated electric fields were measured over the frequency range of 5 MHz to 8 GHz. Radiated magnetic fields and conducted EMI events were measured over the frequency range of 305 Hz to 5 MHz. Highest strength observations of the electromagnetic ambient environment across all measurement conditions at each site provide frequency-dependent profiles for EMI/RFI levels in nuclear power plants

Interband cascade laser-based ppbv-level mid-infrared methane detection using two digital lock-in amplifier schemes

Science.gov (United States)

Song, Fang; Zheng, Chuantao; Yu, Di; Zhou, Yanwen; Yan, Wanhong; Ye, Weilin; Zhang, Yu; Wang, Yiding; Tittel, Frank K.

2018-03-01

A parts-per-billion in volume (ppbv) level mid-infrared methane (CH4) sensor system was demonstrated using second-harmonic wavelength modulation spectroscopy (2 f-WMS). A 3291 nm interband cascade laser (ICL) and a multi-pass gas cell (MPGC) with a 16 m optical path length were adopted in the reported sensor system. Two digital lock-in amplifier (DLIA) schemes, a digital signal processor (DSP)-based DLIA and a LabVIEW-based DLIA, were used for harmonic signal extraction. A limit of detection (LoD) of 13.07 ppbv with an averaging time of 2 s was achieved using the DSP-based DLIA and a LoD of 5.84 ppbv was obtained using the LabVIEW-based DLIA with the same averaging time. A rise time of 0→2 parts-per-million in volume (ppmv) and fall time of 2→0 ppmv were observed. Outdoor atmospheric CH4 concentration measurements were carried out to evaluate the sensor performance using the two DLIA schemes.

Emissions trading and competitiveness: pros and cons of relative and absolute schemes

International Nuclear Information System (INIS)

Kuik, Onno; Mulder, Machiel

2004-01-01

Emissions trading is a hot issue. At national as well as supranational levels, proposals for introduction of emissions trading schemes have been made. This paper assesses alternative emissions trading schemes at domestic level: (1) schemes where the total level of emissions is fixed (absolute cap-and-trade), (2) schemes where the allowable level of emissions per firm is related to some firm-specific indicator (relative cap-and-trade), and (3) mixed schemes which combine elements of the above alternatives. We present a quantitative assessment of these alternatives for climate change policy in the Netherlands. It is concluded that while relative cap-and-trade would avoid negative effects on competitiveness, it would not reduce emissions at the lowest costs. Besides, the addition of a trade system to existing relative standards does not result in additional emission reduction; it should be combined with other policy measures, such as energy taxes, in order to realise further reduction. Absolute cap-and-trade leads to efficient emissions reduction, but, implemented at the national level, its overall macroeconomic costs may be significant. The mixed scheme has as drawback that it treats firms unequal, which leads to high administrative costs. We conclude that none of the trading schemes is an advisable instrument for domestic climate policy

On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme

Directory of Open Access Journals (Sweden)

Wang Daoshun

2010-01-01

Full Text Available Abstract Traditional Secret Sharing (SS schemes reconstruct secret exactly the same as the original one but involve complex computation. Visual Secret Sharing (VSS schemes decode the secret without computation, but each share is m times as big as the original and the quality of the reconstructed secret image is reduced. Probabilistic visual secret sharing (Prob.VSS schemes for a binary image use only one subpixel to share the secret image; however the probability of white pixels in a white area is higher than that in a black area in the reconstructed secret image. SS schemes, VSS schemes, and Prob. VSS schemes have various construction methods and advantages. This paper first presents an approach to convert (transform a -SS scheme to a -VSS scheme for greyscale images. The generation of the shadow images (shares is based on Boolean XOR operation. The secret image can be reconstructed directly by performing Boolean OR operation, as in most conventional VSS schemes. Its pixel expansion is significantly smaller than that of VSS schemes. The quality of the reconstructed images, measured by average contrast, is the same as VSS schemes. Then a novel matrix-concatenation approach is used to extend the greyscale -SS scheme to a more general case of greyscale -VSS scheme.

Reduction and resource recycling of high-level radioactive wastes through nuclear transmutation with PHITS code

International Nuclear Information System (INIS)

Fujita, Reiko

2017-01-01

In the ImPACT program of the Cabinet Office, programs are underway to reduce long-lived fission products (LLFP) contained in high-level radioactive waste through nuclear transmutation, or to recycle/utilize useful nuclear species. This paper outlines this program and describes recent achievements. This program consists of five projects: (1) separation/recovery technology, (2) acquisition of nuclear transmutation data, (3) nuclear reaction theory model and simulation, (4) novel nuclear reaction control and development of elemental technology, and (5) discussions on process concept. The project (1) develops a technology for dissolving vitrified solid, a technology for recovering LLFP from high-level waste liquid, and a technology for separating odd and even lasers. Project (2) acquires the new nuclear reaction data of Pd-107, Zr-93, Se-79, and Cs-135 using RIKEN's RIBF or JAEA's J-PARC. Project (3) improves new nuclear reaction theory and structural model using the nuclear reaction data measured in (2), improves/upgrades nuclear reaction simulation code PHITS, and proposes a promising nuclear transmutation pathway. Project (4) develops an accelerator that realizes the proposed transmutation route and its elemental technology. Project (5) performs the conceptual design of the process to realize (1) to (4), and constructs the scenario of reducing/utilizing high-level radioactive waste to realize this design. (A.O.)

Awareness and Coverage of the National Health Insurance Scheme ...

African Journals Online (AJOL)

Sub- national levels possess a high degree of autonomy in a number of sectors including health. It is important to assess the level of coverage of the scheme among the formal sector workers in Nigeria as a proxy to gauge the extent of coverage of the scheme and derive suitable lessons that could be used in its expansion.

Low-level waste management at the Nuclear Research Center

International Nuclear Information System (INIS)

Montanez, O.; Blanco, D.; Vallarino, V.; Calisto, W.

1986-01-01

A general overview of low-level radioactive waste management at the Nuclear Investigation Centre (CIN) of Uruguay is presented. The CIN is a pilot centre of research and development of techniques for implementing measurements for radioactive waste storage and control. (M.C.K.) [pt

Use of reconnaissance level information for environmental assessment

International Nuclear Information System (INIS)

Foster, R.F.; Rickard, W.H.; Strand, J.A.; Warner, M.L.

1979-11-01

Reconnaissance level information (RLI) sufficient for comparing the environmental and socio-economic features of candidate sites for nuclear power stations and for guiding plant design, baseline surveys, and operational practices is usually available from published reports, public records, and knowledgeable individuals. Environmental concerns of special importance for site evaluation include: aquatic ecology, terrestrial ecology, land and water use, socio-economics, and institutional constraints. A scheme is suggested for using RLI to assign classifications to candidate sites based on the potential level of concern associated with the different environmental features

Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

International Nuclear Information System (INIS)

Boatner, L.A.; Sales, B.C.

1989-01-01

This patent describes lead-iron phosphate glasses containing a high level of Fe 2 O 3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90 0 C, with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10 2 to 10 3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe 2 O 3 in forming the lead-iron phosphate glass is critical. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms

Radioactive waste assessment using 'moderate growth in nuclear electricity generation' scenario

International Nuclear Information System (INIS)

Richardson, J.A.; Goodill, D.R.; Tymons, B.J.

1985-05-01

This report describes an assessment of radioactive waste management arisings from a defined nuclear power generation scenario -Scheme 3. Scheme 3 assumes a moderate growth in nuclear generation scenario with raw waste arisings from 3 main groups: (i) existing and committed commercial reactors; (ii) fuel reprocessing plants; (iii) research, industry and medicine. No decommissioning wastes are considered except for arisings from the final fuel cores from decommissioned reactors. The study uses the SIMULATION2 code which models waste material flows through the system. With a knowledge of the accumulations and average production rates of the raw wastes and their isotopic compositions (or total activities), the rates at which conditioned wastes become available for transportation and disposal are calculated, with specific activity levels. The data bases for the inventory calculations and the assumptions concerning future operation of nuclear facilities were those current in 1983. Both the inventory data and plans for the future of existing nuclear installations have been updated since these calculations were completed. Therefore the results from this assessment do not represent the most up-to-date information available. The report does, however, illustrate the methodology of assessment, and indicates the type of information that can be generated. (author)

Seismic fragility levels of nuclear power plant equipment

International Nuclear Information System (INIS)

Bandyopadhyay, K.K.; Hofmayer, C.H.

1987-01-01

Seismic fragility levels of safety-related electrical and mechanical equipment used in nuclear power plants are discussed. The fragility level is defined as the vibration level corresponding to initiation of equipment malfunctions. The test response spectrum is used as a measure of this vibration level. The fragility phenomenon of an equipment is represented by a number of response spectra corresponding to various failure modes. Analysis methods are described for determination of the fragility level by use of existing test data. Useful conversion factors are tabulated to transform test response spectra from one damping value to another. Results are presented for switch-gears and motor control centers. The capacity levels of these equipment assemblies are observed to be limited by malfunctioning of contactors, motor starters, relays and/or switches. The applicability of the fragility levels, determined in terms of test response spectra, to Seismic Margin Studies and Probabilistic Risk Assessments is discussed and specific recommendations are provided

Development and test of a classification scheme for human factors in incident reports

International Nuclear Information System (INIS)

Miller, R.; Freitag, M.; Wilpert, B.

1997-01-01

The Research Center System Safety of the Berlin University of Technology conducted a research project on the analysis of Human Factors (HF) aspects in incident reported by German Nuclear Power Plants. Based on psychological theories and empirical studies a classification scheme was developed which permits the identification of human involvement in incidents. The classification scheme was applied in an epidemiological study to a selection of more than 600 HF - relevant incidents. The results allow insights into HF related problem areas. An additional study proved that the application of the classification scheme produces results which are reliable and independent from raters. (author). 13 refs, 1 fig

Estimation of the common cause failure probabilities on the component group with mixed testing scheme

International Nuclear Information System (INIS)

Hwang, Meejeong; Kang, Dae Il

2011-01-01

Highlights: ► This paper presents a method to estimate the common cause failure probabilities on the common cause component group with mixed testing schemes. ► The CCF probabilities are dependent on the testing schemes such as staggered testing or non-staggered testing. ► There are many CCCGs with specific mixed testing schemes in real plant operation. ► Therefore, a general formula which is applicable to both alternate periodic testing scheme and train level mixed testing scheme was derived. - Abstract: This paper presents a method to estimate the common cause failure (CCF) probabilities on the common cause component group (CCCG) with mixed testing schemes such as the train level mixed testing scheme or the alternate periodic testing scheme. In the train level mixed testing scheme, the components are tested in a non-staggered way within the same train, but the components are tested in a staggered way between the trains. The alternate periodic testing scheme indicates that all components in the same CCCG are tested in a non-staggered way during the planned maintenance period, but they are tested in a staggered way during normal plant operation. Since the CCF probabilities are dependent on the testing schemes such as staggered testing or non-staggered testing, CCF estimators have two kinds of formulas in accordance with the testing schemes. Thus, there are general formulas to estimate the CCF probability on the staggered testing scheme and non-staggered testing scheme. However, in real plant operation, there are many CCCGs with specific mixed testing schemes. Recently, Barros () and Kang () proposed a CCF factor estimation method to reflect the alternate periodic testing scheme and the train level mixed testing scheme. In this paper, a general formula which is applicable to both the alternate periodic testing scheme and the train level mixed testing scheme was derived.

Nuclear level repulsion, order vs. chaos and conserved quantum numbers

International Nuclear Information System (INIS)

Garrett, J.D.

1995-01-01

A statistical analysis of the distribution of level spacings for states with the same angular momentum and parity is described in which the average spacing is calculated for the total ensemble. Though the resulting distribution of level spacings for states of deformed nuclei with Z = 62-75 and A = 155-185 is the closest to that of a Poisson distribution yet obtained for nuclear levels, significant deviations are observed for small level spacings. Many, but not all, of the very closely-spaced levels have K-values differing by several units. (orig.)

Status of the high-level nuclear waste disposal program in Japan

International Nuclear Information System (INIS)

Uematsu, K.

1985-01-01

The Japan Atomic Energy Commission (JAEC) initiated a high-level radioactive waste disposal program in 1976. Since then, the Advisory Committee on Radioactive Waste Management of JAEC has revised the program twice. The latest revision was issued in 1984. The committee recommended a four-phase program and the last phase calls for the beginning of emplacement of the high-level nuclear waste into a selected repository in the Year 2000. The first phase is already completed, and the second phase of this decade calls for the selection of a candidate disposal site and the conducting of the RandD of waste disposal in an underground research laboratory and in a hot test facility. This paper covers the current status of the high-level nuclear waste disposal program in Japan

Evaluated nuclear data file libraries use in nuclear-physical calculations

International Nuclear Information System (INIS)

Gritsaj, O.O.; Kalach, N.Yi.; Kal'chenko, O.Yi.; Kolotij, V.V.; Vlasov, M.F.

1994-01-01

The necessity of nuclear updated usage is founded for neutron experiment modeling calculations, for preparation of suitable data for reactor calculations and for other applications that account of detail energetic structure of cross section is required. The scheme of system to coordinate the work to collect and to prepare evaluated nuclear data on an international scale is presented. Main updated and recommended nuclear data libraries and associated computer programs are reviewed. Total neutron cross sections for 28 energetic groups calculated on the base of natural mixture iron isotopes evaluated nuclear data file (BROND-2, 1991) have been compared with BNAB-78 data. (author). 7 refs., 1 tab., 4 figs

Some legal aspects on high level radioactive waste disposal in Japan

International Nuclear Information System (INIS)

Tanabe, Tomoyuki

1997-01-01

In Japan, it is considered to be an urgent problem to prepare the system for the research and execution of high level radioactive waste disposal. Under what regulation scheme the disposal should be done has not been sufficiently examined. In this research, the examination was carried out on the legal aspects of high level radioactive waste disposal as follows. First, the current legislation on the disposal in Japan was analyzed, and it was made clear that high level radioactive waste disposal has not been stipulated clearly. Next, on the legal choices which are conceivable on the way the legislation for high level radioactive waste disposal should be, from the aspects of applying the law on regulating nuclear reactors and others, applying the law on nuclear power damage reparation, and industrialization by changing the government ordinances, those were arranged in six choices, and the examination was carried out for each choice from the viewpoints of the relation with the base stipulation for waste-burying business, the speciality of high level radioactive waste disposal as compared with other actions of nuclear power business, the coordination with existing nuclear power of nuclear power business, the coordination with existing nuclear power law system and the formation of national consensus. In this research, it was shown that the execution of high level radioactive waste disposal as the business based on the separate legislation is the realistic choice. (K.I.)

Conservative numerical schemes for Euler-Lagrange equations

Energy Technology Data Exchange (ETDEWEB)

Vazquez, L. [Universidad Complutense, Madrid (Spain). Dept. de Matematica Aplicada; Jimenez, S. [Universidad Alfonso X El Sabio, Madrid (Spain). Dept. de Matematica Aplicada

1999-05-01

As a preliminary step to study magnetic field lines, the authors seek numerical schemes that reproduce at discrete level the significant feature of the continuous model, based on an underling Lagrangian structure. The resulting scheme give discrete counterparts of the variation law for the energy as well of as the Euler-Lagrange equations and their symmetries.

A Regev-Type Fully Homomorphic Encryption Scheme Using Modulus Switching

Science.gov (United States)

Chen, Zhigang; Wang, Jian; Song, Xinxia

2014-01-01

A critical challenge in a fully homomorphic encryption (FHE) scheme is to manage noise. Modulus switching technique is currently the most efficient noise management technique. When using the modulus switching technique to design and implement a FHE scheme, how to choose concrete parameters is an important step, but to our best knowledge, this step has drawn very little attention to the existing FHE researches in the literature. The contributions of this paper are twofold. On one hand, we propose a function of the lower bound of dimension value in the switching techniques depending on the LWE specific security levels. On the other hand, as a case study, we modify the Brakerski FHE scheme (in Crypto 2012) by using the modulus switching technique. We recommend concrete parameter values of our proposed scheme and provide security analysis. Our result shows that the modified FHE scheme is more efficient than the original Brakerski scheme in the same security level. PMID:25093212

Temperature and level measurements realized for Nuclear Safety Level Improvement of Slovak NPPs

International Nuclear Information System (INIS)

Badiar, S.; Slanina, M.; Stanc, S.; Golan, P.; Krupa, J.

2001-01-01

Process of continual safety improvement in the individual Slovak nuclear power plants has been in progress since the beginning of nineties with the objective to upgrade the safety level of units in operation up to the European standards. In the framework of these activities, safety instrumentation systems with 1E qualification for the control of WWER reactor coolant systems were built and added. Methods for implementation of safety instrumentation systems for monitoring temperature and level in reactor coolant systems in the particular plants in Slovakia are presented showing the objectives and methods of their implementation. (Authors)

Analysis of opinion about nuclear energy and sustainability in a graduate level population

International Nuclear Information System (INIS)

Meza L, C.D.; Arredondo S, C.

2007-01-01

The Mexican society has a modest knowledge of the nuclear energy, even at the participant students of superior education level in this survey is finds a scarce compression with regard to their obtaining, use and manage. As a result of the lack of interest of the same society and at the problems that know each other like they are: the pollutants that it produces those nuclear waste and the possible use or warlike end, a fear is believed about this energy type. In the Superior School of Physics and Mathematics there is the possibility to make studies so much at master degree level in the one fear of the nuclear energy and the applications of the same one in peaceful uses. However, particularly the studies at master level seem to be immersed in a crisis that requires of different supports to be resolved. For all it previous was thought in carrying out a survey inside a student population with superior level to know the opinion and the knowledge on the nuclear energy in Mexico. In this work the results of the survey are analyzed with the purpose of to determine which is the knowledge of the community mentioned regarding the other energy types, the impact that they have these in the environment, the sustenance of the same ones and in particular on knowledge about the nuclear energy considering the aspects before mentioned. With base had said analysis settles down that the interviewed community knows very little about the nuclear energy but they show interest to study and to obtain bigger information about the same one, for what is very important to diffuse but and better information on the nuclear energy to the population's strata, because it is of supposing that the rest of the population has erroneous information on the nuclear energy. In particular for the community of the Superior School of Physics and Mathematics the diffusion of all the benefits of the peaceful applications of the nuclear energy, including the capacity to generate enormous quantities and energy

Application of stable adaptive schemes to nuclear reactor systems, (2)

International Nuclear Information System (INIS)

Kukuda, Toshio

1979-01-01

The parameter identification and adaptive control schemes applied in a previous study to a nonlinear point reactor are extended to the case of a loosely-coupled-core reactor with internal feedbacks, constituting a nonlinear overall system. Both schemes are shown to be stable, with the system newly represented on the pattern of the Model Reference Adaptive System (MRAS) with use made of the Lyapunov's method. For either parameter identification or adaptive control of a loosely-coupled-core reactor, there exists no canonical form of multiple input-multiple output system which can be directly applied for deriving the MRAS with the matrix version of the Kalman-Yakubovich lemma as it was in the case of the point reactor. This difficulty is circumvented by the practical assumption that the neutron density can be directly measured on each core as reactivity change is applied as input into the coupled core as a whole. For parameter identification, the model parameters are adaptively adjusted to those of each core, while for the adaptive control, plant parameters of each core can be adaptively compensated, again through control inputs, to asymptotically reduce the output error between the model and the plant. The point reactor is shown to correspond to a special case. (author)

Auxiliary System Load Schemes in Large Thermal and Nuclear Power Plants

International Nuclear Information System (INIS)

Kuzle, I.; Bosnjak, D.; Pandzic, H.

2010-01-01

Uninterrupted auxiliary system power supply in large power plants is a key factor for normal operation, transient states, start-ups and shutdowns and particularly during fault conditions. Therefore, there are many challenges in designing the main electrical system as well as the auxiliary systems power supply. Depending upon the type of fuel used and the environmental control system required, a thermal power plant may consume as much as 10% of its total generation for auxiliary power, while a nuclear power plant may require only 4 - 6% auxiliaries. In general, the larger the power generating plant, the higher the voltage selected for the AC auxiliary electric system. Most stations in the 75 to 500 MW range utilize 4,2 kV as the base auxiliary system voltage. Large generating stations 500 - 1000 MW and more use voltage levels of 6,9 kV and more. Some single dedicated loads such as electric driven boiler feed pumps are supplied ba a 13,8 kV bus. While designing the auxiliary electric system, the following areas must be considered: motor starting requirements, voltage regulation requirements, short-circuit duty requirements, economic considerations, reliability and alternate sources. Auxiliary power supply can't be completely generalized and each situation should be studied on its own merits to determine the optimal solution. Naturally, nuclear power plants have more reliability requirements and safety design criteria. Main coolant-pump power supply and continuity of service to other vital loads deserve special attention. This paper presents an overview of some up-to-date power plant auxiliary load system concepts. The main types of auxiliary loads are described and the electric diagrams of the modern auxiliary system supply concepts are given. Various alternative sources of auxiliary electrical supply are considered, the advantages and disadvantages of these are compared and proposals are made for high voltage distribution systems around the thermal and nuclear plant

Nuclear Knowledge Management in Vietnam: Challenges and Approaches

International Nuclear Information System (INIS)

Nguyen, T. T.

2016-01-01

Full text: In Vietnam, nuclear knowledge in general, and in particular in relation to nuclear power remains weak, since training and human resource development in this area have not received adequate attention. In August 18, 2010 the Prime Minister issued the decision 1558 approving the scheme for “Training and development of human resources in the field of atomic energy”. Then, on 10/15/2015 The Prime Minister issued the decision 1756 approving a Plan for the training and retraining of state management personnel, research and development, and technical support to serve nuclear power development till 2020. To implement the training and development of human resources, the organization in the field of atomic energy has planned to conduct recruitment, training and development of human resources. Thus Vietnam has a policy and plan for the development of nuclear knowledge. However, knowledge management has yet to be thoroughly implemented. At Government level there are no specific policy decisions on knowledge management. Level implementation units have not implemented the scientific step, the switch serving the knowledge management. This is one of the main reasons why the development of human resources in the field of atomic energy has been slow. (author

Progress on Plant-Level Components for Nuclear Fuel Recycling: Commonality

International Nuclear Information System (INIS)

De Almeida, Valmor F.

2011-01-01

Progress made in developing a common mathematical modeling framework for plant-level components of a simulation toolkit for nuclear fuel recycling is summarized. This ongoing work is performed under the DOE Nuclear Energy Advanced Modeling and Simulation (NEAMS) program, which has an element focusing on safeguards and separations (SafeSeps). One goal of this element is to develop a modeling and simulation toolkit for used nuclear fuel recycling. The primary function of the SafeSeps simulation toolkit is to enable the time-dependent coupling of separation modules and safeguards tools (either native or third-party supplied) that simulate and/or monitor the individual separation processes in a separations plant. The toolkit integration environment will offer an interface for the modules to register in the toolkit domain based on the commonality of diverse unit operations. This report discusses the source of this commonality from a combined mathematical modeling and software design perspectives, and it defines the initial basic concepts needed for development of application modules and their integrated form, that is, an application software. A unifying mathematical theory of chemical thermomechanical network transport for physicochemical systems is proposed and outlined as the basis for developing advanced modules. A program for developing this theory from the underlying first-principles continuum thermomechanics will be needed in future developments; accomplishment of this task will enable the development of a modern modeling approach for plant-level models. Rigorous, advanced modeling approaches at the plant-level can only proceed from the development of reduced (or low-order) models based on a solid continuum field theory foundation. Such development will pave the way for future programmatic activities on software verification, simulation validation, and model uncertainty quantification on a scientific basis; currently, no satisfactory foundation exists for

Progress on Plant-Level Components for Nuclear Fuel Recycling: Commonality

Energy Technology Data Exchange (ETDEWEB)

de Almeida, Valmor F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2011-08-15

Progress made in developing a common mathematical modeling framework for plant-level components of a simulation toolkit for nuclear fuel recycling is summarized. This ongoing work is performed under the DOE Nuclear Energy Advanced Modeling and Simulation (NEAMS) program, which has an element focusing on safeguards and separations (SafeSeps). One goal of this element is to develop a modeling and simulation toolkit for used nuclear fuel recycling. The primary function of the SafeSeps simulation toolkit is to enable the time-dependent coupling of separation modules and safeguards tools (either native or third-party supplied) that simulate and/or monitor the individual separation processes in a separations plant. The toolkit integration environment will offer an interface for the modules to register in the toolkit domain based on the commonality of diverse unit operations. This report discusses the source of this commonality from a combined mathematical modeling and software design perspectives, and it defines the initial basic concepts needed for development of application modules and their integrated form, that is, an application software. A unifying mathematical theory of chemical thermomechanical network transport for physicochemical systems is proposed and outlined as the basis for developing advanced modules. A program for developing this theory from the underlying first-principles continuum thermomechanics will be needed in future developments; accomplishment of this task will enable the development of a modern modeling approach for plant-level models. Rigorous, advanced modeling approaches at the plant-level can only proceed from the development of reduced (or low-order) models based on a solid continuum field theory foundation. Such development will pave the way for future programmatic activities on software verification, simulation validation, and model uncertainty quantification on a scientific basis; currently, no satisfactory foundation exists for

External radiation levels in installations of nuclear technology center

International Nuclear Information System (INIS)

Maletta, Paulo Guilherme M.; Filipetto, Joao; Wakabayashi, Tetsuaki; Silva, Teogenes A. da

2005-01-01

The radiological protection is a basic activity of nuclear technology center so that can carry through its activities with security, having to be planned and executed with total effectiveness. One of the basic tools of the radiological protection is the adoption of monitoring programs, that have as objective generality to evaluate the radiological conditions of the workstation and to assure that these conditions are acceptable safe for the displayed individuals, either workers or members of the public, as established in the basic norms of radiological protection. The Centro de Desenvolvimento da Tecnologia Nuclear - CDTN, first institution in Brazil, created in 1952 to entirely dedicate the related works to the nuclear area, to own 39 building, of which they are kept the Triga Reactor, Irradiation Gamma Laboratory, Reject Laboratory, Calibration Dosemeters Laboratory and others. In such installations, radioactive materials are produced, handled, processed and stored, being necessary the levels of external radiation ambient monitoring. As part of the radioprotection plan, monitoring 63 points on strategically located in the external areas to the building of CDTN, using characterized and calibrated thermoluminescence dosemeters. This work describes the dose distribution of the points, the doses evaluation procedure and the 4 results carried through between 2001 and 2004. The data demonstrate the attendance to the level of security established in the basic norm, what it contributed for the operation licensing of to the IBAMA. (author)

What are Spent Nuclear Fuel and High-Level Radioactive Waste?

International Nuclear Information System (INIS)

2002-01-01

Spent nuclear fuel and high-level radioactive waste are materials from nuclear power plants and government defense programs. These materials contain highly radioactive elements, such as cesium, strontium, technetium, and neptunium. Some of these elements will remain radioactive for a few years, while others will be radioactive for millions of years. Exposure to such radioactive materials can cause human health problems. Scientists worldwide agree that the safest way to manage these materials is to dispose of them deep underground in what is called a geologic repository

The Korean nuclear power program

International Nuclear Information System (INIS)

Choi, Chang Tong

1996-01-01

Although the world nuclear power industry may appear to be in decline, continued nuclear power demand in Korea indicates future opportunities for growth and prosperity in this country. Korea has one of the world's most vigorous nuclear power programs. Korea has been an active promoter of nuclear power generation since 1978, when the country introduced nuclear power as a source of electricity. Korea now takes pride in the outstanding performance of its nuclear power plants, and has established a grand nuclear power scheme. This paper is aimed at introducing the nuclear power program of Korea, including technological development, international cooperation, and CANDU status in Korea. (author). 2 tabs

Investigation on the MOC with a linear source approximation scheme in three-dimensional assembly

International Nuclear Information System (INIS)

Zhu, Chenglin; Cao, Xinrong

2014-01-01

Method of characteristics (MOC) for solving neutron transport equation has already become one of the fundamental methods for lattice calculation of nuclear design code system. At present, MOC has three schemes to deal with the neutron source of the transport equation: the flat source approximation of the step characteristics (SC) scheme, the diamond difference (DD) scheme and the linear source (LS) characteristics scheme. The MOC for SC scheme and DD scheme need large storage space and long computing time when they are used to calculate large-scale three-dimensional neutron transport problems. In this paper, a LS scheme and its correction for negative source distribution were developed and added to DRAGON code. This new scheme was compared with the SC scheme and DD scheme which had been applied in this code. As an open source code, DRAGON could solve three-dimensional assembly with MOC method. Detailed calculation is conducted on two-dimensional VVER-1000 assembly under three schemes of MOC. The numerical results indicate that coarse mesh could be used in the LS scheme with the same accuracy. And the LS scheme applied in DRAGON is effective and expected results are achieved. Then three-dimensional cell problem and VVER-1000 assembly are calculated with LS scheme and SC scheme. The results show that less memory and shorter computational time are employed in LS scheme compared with SC scheme. It is concluded that by using LS scheme, DRAGON is able to calculate large-scale three-dimensional problems with less storage space and shorter computing time

A positive and entropy-satisfying finite volume scheme for the Baer-Nunziato model

Science.gov (United States)

Coquel, Frédéric; Hérard, Jean-Marc; Saleh, Khaled

2017-02-01

We present a relaxation scheme for approximating the entropy dissipating weak solutions of the Baer-Nunziato two-phase flow model. This relaxation scheme is straightforwardly obtained as an extension of the relaxation scheme designed in [16] for the isentropic Baer-Nunziato model and consequently inherits its main properties. To our knowledge, this is the only existing scheme for which the approximated phase fractions, phase densities and phase internal energies are proven to remain positive without any restrictive condition other than a classical fully computable CFL condition. For ideal gas and stiffened gas equations of state, real values of the phasic speeds of sound are also proven to be maintained by the numerical scheme. It is also the only scheme for which a discrete entropy inequality is proven, under a CFL condition derived from the natural sub-characteristic condition associated with the relaxation approximation. This last property, which ensures the non-linear stability of the numerical method, is satisfied for any admissible equation of state. We provide a numerical study for the convergence of the approximate solutions towards some exact Riemann solutions. The numerical simulations show that the relaxation scheme compares well with two of the most popular existing schemes available for the Baer-Nunziato model, namely Schwendeman-Wahle-Kapila's Godunov-type scheme [39] and Tokareva-Toro's HLLC scheme [44]. The relaxation scheme also shows a higher precision and a lower computational cost (for comparable accuracy) than a standard numerical scheme used in the nuclear industry, namely Rusanov's scheme. Finally, we assess the good behavior of the scheme when approximating vanishing phase solutions.

Transport of Spent Nuclear Fuels, High and Intermediate Level Wastes: A Continuous Challenge

International Nuclear Information System (INIS)

Otton, C.; Blachet, L.

2009-01-01

For more than 45 years TN International has been involved in the radioactive materials transportation field. Since the beginning the used nuclear fuel transportation has been its core business. During all these years TN International, now part of AREVA, has been able to anticipate and fulfil the needs for new transport or storage casks design to fit the nuclear industry evolutions. A whole fleet of casks able to transport all the materials of the nuclear fuel cycle has been developed. In this presentation we will focus on the casks for the spent fuel, high level waste and intermediate level waste transportation. Answering to the constant evolution of the nuclear industry transport needs is a challenge that TN International faces routinely. Concerning the spent nuclear fuel transportation, TN International has developed in the early 80's a fleet of TN12 type casks fitted with several types of baskets able to safely transport all the spent fuel from the nuclear power plant or the research laboratories to AREVA La Hague plant. The current challenge is the design of a new transport cask generation taking into account the needs of the industry for the next 30 years. The replacement of the TN12 cask generation is to be scheduled as the regulations have changed and the fuel characteristics have evolved. The new generation of casks will take into account all the technical evolutions made during the TN12 thirty years of use. MOX spent fuel has now its dedicated cask: the TN112 which certificate of approval has been obtained in July 2008. This cask is able to transport 12 MOX spent fuel elements with a short cooling time. The first loading of the cask has been performed in 2008 in the EDF nuclear power plant of Saint-Laurent-des-Eaux. Concerning the high level waste such as the La Hague vitrified residues a whole fleet of casks has been developed such as the TN 28 VT dedicated to transport, the TN81 and TN85 dedicated to transport and storage. These casks have permitted the

An Optimization Scheme for ProdMod

International Nuclear Information System (INIS)

Gregory, M.V.

1999-01-01

A general purpose dynamic optimization scheme has been devised in conjunction with the ProdMod simulator. The optimization scheme is suitable for the Savannah River Site (SRS) High Level Waste (HLW) complex operations, and able to handle different types of optimizations such as linear, nonlinear, etc. The optimization is performed in the stand-alone FORTRAN based optimization deliver, while the optimizer is interfaced with the ProdMod simulator for flow of information between the two

Future directions in nuclear data publication

International Nuclear Information System (INIS)

Firestone, R.B.; Chu, S.Y.F.; Ekstroem, L.P.; Nordberg, H.

1997-01-01

Rapid advances in computer based technologies provide enormous opportunities and great challenges to the way nuclear data is disseminated. Simple text databases and linear, command driven software are giving way to more complex, indexed databases and object-oriented, menu-driven applications. The Internet will clearly dominate dissemination of nuclear data in for foreseeable future, and CD-ROM technology (or similar high-density media) will replace hard-copy publication. The Isotopes Project has released Version 1.0 of VuENSDF, a versatile, 32-bit, C ++ , Internet enabled application for disseminating nuclear data. VuENSDF can automatically retrieve data over Internet; display decay scheme drawings, level tables, and references; and perform limited database searching of nuclear bands, transition coincidences, and reference authors. Version 2.0 of VuENSDF is being developed and will offer more complete database searches, plotting, and data entry utilities. The Isotopes Project has established a series of home pages on the WWW to provide data for various topics of nuclear physics. The group has also published a CD-ROM version of the Table of Isotopes using Adobe Acrobat software. Updated, Internet versions of the Table of Isotopes are planned. (author)

Lead-iron phosphate glass as a containment medium for the disposal of high-level nuclear wastes

Science.gov (United States)

Boatner, L.A.; Sales, B.C.

1984-04-11

Disclosed are lead-iron phosphate glasses containing a high level of Fe/sub 2/O/sub 3/ for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste

Fate of nuclear waste site remains unclear

International Nuclear Information System (INIS)

Anderson, E.V.

1980-01-01

The only commercial nuclear fuel reprocessing plant in the U.S., located in West Valley, N.Y., has been shut down since 1972, and no efforts have yet been made to clean up the site. The site contains a spent-fuel pool, high level liquid waste storage tanks, and two radioactive waste burial grounds. Nuclear Fuel Services, Inc., has been leasing the site from the New York State Energy RandD Authority. Federal litigation may ensue, prompted by NRC and DOE, if the company refuses to decontaminate the area when its lease expires at the end of 1980. DOE has developed a plan to solidify the liquid wastes at the facility but needs additional legislation and funding to implement the scheme

Recursive polarization of nuclear spins in diamond at arbitrary magnetic fields

International Nuclear Information System (INIS)

Pagliero, Daniela; Laraoui, Abdelghani; Henshaw, Jacob D.; Meriles, Carlos A.

2014-01-01

We introduce an alternate route to dynamically polarize the nuclear spin host of nitrogen-vacancy (NV) centers in diamond. Our approach articulates optical, microwave, and radio-frequency pulses to recursively transfer spin polarization from the NV electronic spin. Using two complementary variants of the same underlying principle, we demonstrate nitrogen nuclear spin initialization approaching 80% at room temperature both in ensemble and single NV centers. Unlike existing schemes, our approach does not rely on level anti-crossings and is thus applicable at arbitrary magnetic fields. This versatility should prove useful in applications ranging from nanoscale metrology to sensitivity-enhanced NMR

Sound classification of dwellings - Comparison of schemes in Europe

DEFF Research Database (Denmark)

Rasmussen, Birgit

2009-01-01

National sound classification schemes for dwellings exist in nine countries in Europe, and proposals are under preparation in more countries. The schemes specify class criteria concerning several acoustic aspects, the main criteria being about airborne and impact sound insulation between dwellings......, facade sound insulation and installation noise. The quality classes reflect dierent levels of acoustical comfort. The paper presents and compares the sound classification schemes in Europe. The schemes have been implemented and revised gradually since the 1990es. However, due to lack of coordination...

Presentation of the information report on the greenhouse gas emission trading scheme

International Nuclear Information System (INIS)

2010-01-01

This document reports the hearing during which the results of an investigation on European Union Emission Trading Scheme (ETS) have been commented. The author of this investigation briefly describes the scheme, how it has been implemented. He outlines some of its weaknesses and discusses how it could be improved, notably by extending it to different sectors, for example the air transport sector. He also outlines how this European Union scheme could be an example for the rest of the world. The author and the Commission members then discuss several aspects: the origins of CO 2 emissions and how to take them into account, the international negotiations and the positions of China or India, the taxing possibilities, and the fact that the nuclear energy does not award credits

Modeling by GASP-IV simulation of high-level nuclear waste disposal

International Nuclear Information System (INIS)

Kurstedt, H.A. Jr.; DePorter, E.L.; Turek, J.L.; Funk, S.K.; Rasbach, C.E.

1981-01-01

High-level nuclear waste generated by defense-oriented and commercial nuclear energy activities are to be stored ultimately in underground repositories. Research continues on the waste-form and waste-form processing. DOE managers must coordinate the results of this research, the capacities and availability times of the permanent geologic storage repositories, and the capacities and availability times of interim storage facilities (pending availability of permanent repositories). Comprehensive and active DOE program-management information systems contain predicted generation of nuclear wastes from defense and commercial activities; milestones on research on waste-forms; and milestones on research and development, design, acquisition, and construction of facilities and repositories. A GASP IV simulation model is presented which interfaces all of these data. The model accepts alternate management decisions; relates all critical milestones, all research and development data, and the generation of waste nuclear materials; simulates the passage of time; then, predicts the impact of those alternate decisions on the availability of storage capacity for waste nuclear materials. 3 references, 3 figures

Unified model of nuclear mass and level density formulas

International Nuclear Information System (INIS)

Nakamura, Hisashi

2001-01-01

The objective of present work is to obtain a unified description of nuclear shell, pairing and deformation effects for both ground state masses and level densities, and to find a new set of parameter systematics for both the mass and the level density formulas on the basis of a model for new single-particle state densities. In this model, an analytical expression is adopted for the anisotropic harmonic oscillator spectra, but the shell-pairing correlation are introduced in a new way. (author)

Nuclear spin-lattice relaxation in nitroxide spin-label EPR.

Science.gov (United States)

Marsh, Derek

2016-11-01

Nuclear relaxation is a sensitive monitor of rotational dynamics in spin-label EPR. It also contributes competing saturation transfer pathways in T 1 -exchange spectroscopy, and the determination of paramagnetic relaxation enhancement in site-directed spin labelling. A survey shows that the definition of nitrogen nuclear relaxation rate W n commonly used in the CW-EPR literature for 14 N-nitroxyl spin labels is inconsistent with that currently adopted in time-resolved EPR measurements of saturation recovery. Redefinition of the normalised 14 N spin-lattice relaxation rate, b=W n /(2W e ), preserves the expressions used for CW-EPR, whilst rendering them consistent with expressions for saturation recovery rates in pulsed EPR. Furthermore, values routinely quoted for nuclear relaxation times that are deduced from EPR spectral diffusion rates in 14 N-nitroxyl spin labels do not accord with conventional analysis of spin-lattice relaxation in this three-level system. Expressions for CW-saturation EPR with the revised definitions are summarised. Data on nitrogen nuclear spin-lattice relaxation times are compiled according to the three-level scheme for 14 N-relaxation: T 1 n =1/W n . Results are compared and contrasted with those for the two-level 15 N-nitroxide system. Copyright © 2016 Elsevier Inc. All rights reserved.

Future health physics prospects in high-level nuclear waste management

International Nuclear Information System (INIS)

Waite, D.A.; Mayberry, J.J.

1986-01-01

The objective of this presentation is to provide an overview of health physics activities anticipated to be required at a high-level nuclear waste repository and to project the numbers of health physics personnel expected to be required to carry out these activities. Health physics personnel receiving consideration in the projections include the health physics manager, shift supervisors, area supervisors, health physicists, and technologists. Phases of the repository addressed are construction, operation, retrieval, and decommissioning. Specific topics discussed in the process of developing the projections are: (a) the basic features of a geologic repository, (b) the staffing requirements of such a repository, (c) health physics involvement in repository operations, and (d) the anticipated schedule for operation of repositories in the United States. A quantitative assessment of future health physics prospects in high-level nuclear waste management is included

Siting high-level nuclear waste repositories: A progress report for Rhode Island

International Nuclear Information System (INIS)

Frohlich, R.K.; Vild, B.F.

1986-03-01

In this booklet, we will not try to argue the pros and cons of nuclear power or weapons production. We will focus instead on the issue of nuclear waste disposal. With the passage of the Nuclear Waste Policy Act (NWPA) of 1982, the US Congress and the President charged federal and state regulators with the responsibility of settling that issue by the end of this century - with extensive public involvement. This booklet, now in its second printing, is designed to explain the nature of ''high-level'' nuclear waste, the essential criteria for its safe and permanent disposal, and Rhode Island's participation in the federal repository program. It has been funded from a USDOE grant derived from a utility-financed Nuclear Waste Fund established under the NWPA. 17 refs., 10 figs., 2 tabs

The case for international nuclear co-operation. An IAEA perspective

International Nuclear Information System (INIS)

Klerk, P. de

2001-01-01

In the light of the diminished commitment to the promotion and development of nuclear technologies by governments, and in view of the globalization of major parts of the nuclear sector, international cooperation is becoming increasingly more important. Continued strong cooperation is expected in the areas of nuclear safety and the advanced, development of nuclear power plant projects, the decommissioning of nuclear installations, and in waste management. The broad range of activities this entails for the future also add to the duties and the scope of activities of the International Atomic Energy Agency (IAEA) as one of the main coordinating international institutions. In addition to the Agency's basic duty, i.e. overseeing more than nine hundred nuclear facilities in the non-nuclear weapon states under the non-proliferation scheme, it is mainly coordinating activities which are becoming more and more important in the changing environment. In the research sector alone, 159 projects are currently handled internationally under the 'Coordinated Research Projects' heading. In the interest of making national safety standards compatible, a multi-level international safety system is being developed which is to lay the foundations for decisions about the engineered safeguards design of nuclear plants on the national level which continues to bear responsibility for deciding in matters of safety. This broad range of duties in technology, safety, and oversight will make IAEA an important organization for multilateral cooperation. (orig.) [de

Neutron-capture gamma-ray study of levels in 135Ba and description of nuclear levels in the interacting-boson-fermion model

International Nuclear Information System (INIS)

Chrien, R.E.; Koene, B.K.S.; Stelts, M.L.; Meyer, R.A.; Brant, S.; Paar, V.; Lopac, V.

1993-01-01

We have performed neutron-capture gamma-ray studies on natural and enriched targets of 134 Ba in order to investigate the nuclear levels of 135 Ba. The low-energy level spectra were compared with the calculations using the interacting-boson-fermion model (IBFM) and the cluster-vibration model. The level densities up to 5 MeV that are calculated within the IBFM are in accordance with the constant temperature Fermi gas model. From the spin distribution we have determined the corresponding spin cutoff parameter σ and compared it to the prediction from nuclear systematics

In search of new relationship in NpNn scheme

International Nuclear Information System (INIS)

Kumar, Pradeep; Singh, M.; Gupta, K.K.; Singh, Y.; Bihari, Chhail; Varshney, A.K.; Gupta, D.K.

2013-01-01

It is well understood now that the use of quantity N p N n as a variable to gauge the structure of a given nucleus, and to track the evolution of structure, is called the N p N n scheme. In recent years, effort have been made for minimizing the uncertainties in Grodzins Rule introducing asymmetry in the even symmetric nuclei of medium mass range and to provide new relationship on moment of inertia in N p N n . This new relationship need to be tested in broader way also. Presented here are Ru, Xe, Ba, and Hf isotopic chain covering medium and heavy mass of nuclear chart in N p N n scheme, where the above view point is clearly verified in wider sense

Differentiated influences of benefit and risk perceptions on nuclear power acceptance according to acceptance levels. Evidence from Korea

International Nuclear Information System (INIS)

Roh, Seungkook; Lee Jinwon

2017-01-01

The perceived benefit and risk of nuclear power generation have received considerable attention as determinants of the public's nuclear power acceptance. However, the contingency of the relative importance of these benefit and risk has been less explored. Using Korea as an example, this study explores the possibility that the relative importance of perceived benefit and risk on nuclear power acceptance depends on acceptance levels. Our results from latent class analysis and multinomial probit show that, in determining whether an individual shows a moderate level of nuclear power acceptance rather than a low level, perceived risk plays a dominant role compared to perceived benefit; however, regarding whether he/she shows a high level of nuclear power acceptance rather than a moderate level, this relative importance is reversed. These results carry practical implications for risk governance of nuclear power, particularly with regard to communication with the public. (author)

Dipole rescattering and the nuclear structure function

Energy Technology Data Exchange (ETDEWEB)

Carvalho, F. [Depto de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo, SP (Brazil); Goncalves, V. P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil); Navarra, F. S.; Oliveira, E. G. [Instituto de Fisica, Universidade de Sao Paulo Rua do Matao, Travessa R, 187, 05508-090 Sao Paulo, SP (Brazil)

2013-03-25

In the framework of the dipole model, we study the effects of the dipole multiple scatterings in a nuclear target and compute the nuclear structure function. We compare different unitarization schemes and confront our results with the E665 data.

A positive and entropy-satisfying finite volume scheme for the Baer–Nunziato model

Energy Technology Data Exchange (ETDEWEB)

Coquel, Frédéric, E-mail: frederic.coquel@cmap.polytechnique.fr [CMAP, École Polytechnique CNRS, UMR 7641, Route de Saclay, F-91128 Palaiseau cedex (France); Hérard, Jean-Marc, E-mail: jean-marc.herard@edf.fr [EDF-R& D, Département MFEE, 6 Quai Watier, F-78401 Chatou Cedex (France); Saleh, Khaled, E-mail: saleh@math.univ-lyon1.fr [Université de Lyon, CNRS UMR 5208, Université Lyon 1, Institut Camille Jordan, 43 bd 11 novembre 1918, F-69622 Villeurbanne cedex (France)

2017-02-01

We present a relaxation scheme for approximating the entropy dissipating weak solutions of the Baer–Nunziato two-phase flow model. This relaxation scheme is straightforwardly obtained as an extension of the relaxation scheme designed in for the isentropic Baer–Nunziato model and consequently inherits its main properties. To our knowledge, this is the only existing scheme for which the approximated phase fractions, phase densities and phase internal energies are proven to remain positive without any restrictive condition other than a classical fully computable CFL condition. For ideal gas and stiffened gas equations of state, real values of the phasic speeds of sound are also proven to be maintained by the numerical scheme. It is also the only scheme for which a discrete entropy inequality is proven, under a CFL condition derived from the natural sub-characteristic condition associated with the relaxation approximation. This last property, which ensures the non-linear stability of the numerical method, is satisfied for any admissible equation of state. We provide a numerical study for the convergence of the approximate solutions towards some exact Riemann solutions. The numerical simulations show that the relaxation scheme compares well with two of the most popular existing schemes available for the Baer–Nunziato model, namely Schwendeman–Wahle–Kapila's Godunov-type scheme and Tokareva–Toro's HLLC scheme . The relaxation scheme also shows a higher precision and a lower computational cost (for comparable accuracy) than a standard numerical scheme used in the nuclear industry, namely Rusanov's scheme. Finally, we assess the good behavior of the scheme when approximating vanishing phase solutions.

Nuclear size is sensitive to NTF2 protein levels in a manner dependent on Ran binding

Science.gov (United States)

Vuković, Lidija D.; Jevtić, Predrag; Zhang, Zhaojie; Stohr, Bradley A.; Levy, Daniel L.

2016-01-01

ABSTRACT Altered nuclear size is associated with many cancers, and determining whether cancer-associated changes in nuclear size contribute to carcinogenesis necessitates an understanding of mechanisms of nuclear size regulation. Although nuclear import rates generally positively correlate with nuclear size, NTF2 levels negatively affect nuclear size, despite the role of NTF2 (also known as NUTF2) in nuclear recycling of the import factor Ran. We show that binding of Ran to NTF2 is required for NTF2 to inhibit nuclear expansion and import of large cargo molecules in Xenopus laevis egg and embryo extracts, consistent with our observation that NTF2 reduces the diameter of the nuclear pore complex (NPC) in a Ran-binding-dependent manner. Furthermore, we demonstrate that ectopic NTF2 expression in Xenopus embryos and mammalian tissue culture cells alters nuclear size. Finally, we show that increases in nuclear size during melanoma progression correlate with reduced NTF2 expression, and increasing NTF2 levels in melanoma cells is sufficient to reduce nuclear size. These results show a conserved capacity for NTF2 to impact on nuclear size, and we propose that NTF2 might be a new cancer biomarker. PMID:26823604

Angular momentum dependence of the nuclear level density parameter

International Nuclear Information System (INIS)

Aggarwal, Mamta; Kailas, S.

2010-01-01

Dependence of nuclear level density parameter on the angular momentum and temperature is investigated in a theoretical framework using the statistical theory of hot rotating nuclei. The structural effects are incorporated by including shell correction, shape, and deformation. The nuclei around Z≅50 with an excitation energy range of 30 to 40 MeV are considered. The calculations are in good agreement with the experimentally deduced inverse level density parameter values especially for 109 In, 113 Sb, 122 Te, 123 I, and 127 Cs nuclei.

Advanced display concepts in nuclear control rooms

International Nuclear Information System (INIS)

Clark, M.T.; Banks, W.W.; Blackman, H.S.; Gertman, D.I.

1982-01-01

Precursors necessary for the development of a full-scale predictor display/control system have been under development since the mid 1940's. The predictor display itself has been available for use in manual control systems since 1958. However, the nuclear industry has not yet explored the uses and benefits of predictor systems. The purpose of this paper is to provide information on the application of this technology to the nuclear industry. The possibility of employing a simulation-based control system for nuclear plant systems that currently use conventional auto/manual schemes is discussed. By employing simulation-based systems, a predictor display could be made available to the operator during manual operations, thus facilitating control without outwardly affecting the overall control scheme

Studies of nuclear processes at the Triangle Universities Nuclear Laboratory. Progress report, 1 September 1994--31 August 1995

International Nuclear Information System (INIS)

Ludwig, E.J.

1995-01-01

The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers the second year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas of nuclear physics: parity violation in neutron and charged-particle resonances--the mass and energy dependence of the weak interaction spreading width; chaotic behavior in 30 P from studies of eigenvalue fluctuations in nuclear level schemes; studies of few-body systems; nuclear astrophysics; nuclear data evaluation for A = 3--20, for which TUNL is now the international center; high-spin spectroscopy and superdeformation in nuclei, involving collaborations at Argonne National Laboratory. Developments in technology and instrumentation have been vital to the research and training program. In this progress report the author describes: a proposed polarized γ-beam facility at the Duke Free Electron Laser Laboratory; cryogenic systems and microcalorimeter development; continuing development of the Low Energy Beam Facility. The research summaries presented in this progress report are preliminary

Studies of nuclear processes at the Triangle Universities Nuclear Laboratory. Progress report, 1 September 1994--31 August 1995

Energy Technology Data Exchange (ETDEWEB)

Ludwig, E.J.

1995-09-01

The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers the second year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas of nuclear physics: parity violation in neutron and charged-particle resonances--the mass and energy dependence of the weak interaction spreading width; chaotic behavior in {sup 30}P from studies of eigenvalue fluctuations in nuclear level schemes; studies of few-body systems; nuclear astrophysics; nuclear data evaluation for A = 3--20, for which TUNL is now the international center; high-spin spectroscopy and superdeformation in nuclei, involving collaborations at Argonne National Laboratory. Developments in technology and instrumentation have been vital to the research and training program. In this progress report the author describes: a proposed polarized {gamma}-beam facility at the Duke Free Electron Laser Laboratory; cryogenic systems and microcalorimeter development; continuing development of the Low Energy Beam Facility. The research summaries presented in this progress report are preliminary.

Programs OPTMAN and SHEMMAN Version 6 (1999) - Coupled-Channels optical model and collective nuclear structure calculation -

Energy Technology Data Exchange (ETDEWEB)

Chang, Jong Hwa; Lee, Jeong Yeon; Lee, Young Ouk; Sukhovitski, Efrem Sh [Korea Atomic Energy Research Institute, Taejeon (Korea)

2000-01-01

Programs SHEMMAN and OPTMAN (Version 6) have been developed for determinations of nuclear Hamiltonian parameters and for optical model calculations, respectively. The optical model calculations by OPTMAN with coupling schemes built on wave functions functions of non-axial soft-rotator are self-consistent, since the parameters of the nuclear Hamiltonian are determined by adjusting the energies of collective levels to experimental values with SHEMMAN prior to the optical model calculation. The programs have been installed at Nuclear Data Evaluation Laboratory of KAERI. This report is intended as a brief manual of these codes. 43 refs., 9 figs., 1 tabs. (Author)

Optically induced dynamic nuclear spin polarisation in diamond

International Nuclear Information System (INIS)

Scheuer, Jochen; Naydenov, Boris; Jelezko, Fedor; Schwartz, Ilai; Chen, Qiong; Plenio, Martin B; Schulze-Sünninghausen, David; Luy, Burkhard; Carl, Patrick; Höfer, Peter; Retzker, Alexander; Sumiya, Hitoshi; Isoya, Junichi

2016-01-01

The sensitivity of magnetic resonance imaging (MRI) depends strongly on nuclear spin polarisation and, motivated by this observation, dynamical nuclear spin polarisation has recently been applied to enhance MRI protocols (Kurhanewicz et al 2011 Neoplasia 13 81). Nuclear spins associated with the 13 C carbon isotope (nuclear spin I = 1/2) in diamond possess uniquely long spin lattice relaxation times (Reynhardt and High 2011 Prog. Nucl. Magn. Reson. Spectrosc. 38 37). If they are present in diamond nanocrystals, especially when strongly polarised, they form a promising contrast agent for MRI. Current schemes for achieving nuclear polarisation, however, require cryogenic temperatures. Here we demonstrate an efficient scheme that realises optically induced 13 C nuclear spin hyperpolarisation in diamond at room temperature and low ambient magnetic field. Optical pumping of a nitrogen-vacancy centre creates a continuously renewable electron spin polarisation which can be transferred to surrounding 13 C nuclear spins. Importantly for future applications we also realise polarisation protocols that are robust against an unknown misalignment between magnetic field and crystal axis. (paper)

Towards a framework of nuclear competencies

International Nuclear Information System (INIS)

Ghitescu, P.

2012-01-01

For the countries considering the introduction of a nuclear energy program, the management of human resources should be a part of the wider integrated management system in order to ensure long term safe and reliable operation. Nuclear energy strategy and approaches to human resources development should take into consideration such fundamental aspects as: development and implementation of a workforce plan, required competencies and qualifications, prerequisites for staffing a nuclear energy program, needed training programs and training facilities, qualification and training requirements. Development of common instruments that respond to the above needs and vision has lead to a new concept of European Credit System for Vocational Education and Training. The European Credit System for Vocational Education and Training (ECVET) is based on definition of 'learning outcomes ' in terms of knowledge, skills and competence, and on identification of portfolios of learning outcomes that allow an individual to prove competencies in a coherent manner. ECVET proposes a common understanding of basic definitions of education and training as well as of the new proposed concepts and it should be recognized by all employers in the EU. In this context, a number of 'Euratom Fission Training Schemes' (EFTS) have been launched in specific areas where a shortage of skilled professionals has been identified. In these schemes the competence building is the result of traditional education plus life-long learning, non-traditional learning, and other forms of educational experiences, relying, in particular, on border-less mobility to get acquainted with various sectors. Each particular Training Scheme should follow a similar path for the achievement of the designed learning outcomes (knowledge, skills, and attitudes). This path to the Training Scheme consists of different activities regarding: definition of training scheme learning outcomes and modules, assessment of prerequisites and student

Towards a framework of nuclear competencies

Energy Technology Data Exchange (ETDEWEB)

Ghitescu, P. [Univ. Politehnica Bucharest, Spl. Independentei 313, 060042 (Romania)

2012-07-01

For the countries considering the introduction of a nuclear energy program, the management of human resources should be a part of the wider integrated management system in order to ensure long term safe and reliable operation. Nuclear energy strategy and approaches to human resources development should take into consideration such fundamental aspects as: development and implementation of a workforce plan, required competencies and qualifications, prerequisites for staffing a nuclear energy program, needed training programs and training facilities, qualification and training requirements. Development of common instruments that respond to the above needs and vision has lead to a new concept of European Credit System for Vocational Education and Training. The European Credit System for Vocational Education and Training (ECVET) is based on definition of 'learning outcomes ' in terms of knowledge, skills and competence, and on identification of portfolios of learning outcomes that allow an individual to prove competencies in a coherent manner. ECVET proposes a common understanding of basic definitions of education and training as well as of the new proposed concepts and it should be recognized by all employers in the EU. In this context, a number of 'Euratom Fission Training Schemes' (EFTS) have been launched in specific areas where a shortage of skilled professionals has been identified. In these schemes the competence building is the result of traditional education plus life-long learning, non-traditional learning, and other forms of educational experiences, relying, in particular, on border-less mobility to get acquainted with various sectors. Each particular Training Scheme should follow a similar path for the achievement of the designed learning outcomes (knowledge, skills, and attitudes). This path to the Training Scheme consists of different activities regarding: definition of training scheme learning outcomes and modules, assessment of

Lead-iron phosphate glass: a stable storage medium for high-level nuclear waste

International Nuclear Information System (INIS)

Sales, B.C.; Boatner, L.A.

1984-01-01

Results are presented which show that lead-iron phosphate glasses are a promising new waste form for the safe immobilization of both high-level defense and high-level commercial radioactive waste. Relative to the borosilicate nuclear waste glasses that are currently the ''reference'' waste form for the long-term disposal of nuclear waste, lead-iron phosphate glasses have several distinct advantages: (1) an aqueous corrosion rate that is about 1000 times lower, (2) a processing temperature that is 100 0 to 250 0 C lower and, (3) a much lower melt viscosity in the temperature range from 800 0 to 1000 0 C. Most significantly, the lead-iron phosphate waste form can be processed using a technology similar to that developed for borosilicate nuclear waste glasses

Environmental radioactivity levels, Browns Ferry Nuclear Plant: Annual report, 1986

International Nuclear Information System (INIS)

1986-04-01

The report presents data gathered during radiological monitoring program conducted in the environs of the Browns Ferry Nuclear Plant. Dose estimates were made from concentrations of radioactivity found in samples of media including air, milk, food products, drinking water, and fish. Inhalation and ingestion doses estimated for persons at the indicator locations were essentially identical to those determined for persons at control locations. Greater than 95% of those doses were contributed by the naturally occurring K-40 and by Sr-90 and Cs-137 which are long-lived radioisotopes found in fallout from nuclear weapons testing. Increased levels of I-131 were reported in air, milk, and rainwater following the accident at the Chernobyl nuclear power station. In addition, Ru-103, Cs-137, and Cs-134 were identified in air particulates, and traces of Ru-103 were found in rainwater

Conceptual scheme of a hybrid mesocatalytic fusion reactor

International Nuclear Information System (INIS)

Petrov, Yu.V.

1988-01-01

To test the practical realization of the mesocatalytic method for energy production a preliminary engineering analysis and calculation of the separate units of the conceptual scheme of the hybrid mesocatalytic reactor was made. The construction and efficiency of the most characteristic separate blocks of the conceptual scheme for muon-catalyzed fusion are examined. The muon catalysis cycle in a dt mixture was assessed. The kinetics and energetics of muon production through a pion-forming target and a converter were evaluated. Concomitant questions, particularly the removal of helium from hydrogen, are discussed. Fusion chamber requirements were calculated and problems of heat removal were assessed. Blanket construction and efficiency were examined. The efficiency of different methods for power generation were comparatively reviewed including hybrid thermonuclear, electronuclear nuclear, and hybrid mesocatalytic methods. Energy balances and economic restrictions were examined

Energy mesh optimization for multi-level calculation schemes

International Nuclear Information System (INIS)

Mosca, P.; Taofiki, A.; Bellier, P.; Prevost, A.

2011-01-01

The industrial calculations of third generation nuclear reactors are based on sophisticated strategies of homogenization and collapsing at different spatial and energetic levels. An important issue to ensure the quality of these calculation models is the choice of the collapsing energy mesh. In this work, we show a new approach to generate optimized energy meshes starting from the SHEM 281-group library. The optimization model is applied on 1D cylindrical cells and consists of finding an energy mesh which minimizes the errors between two successive collision probability calculations. The former is realized over the fine SHEM mesh with Livolant-Jeanpierre self-shielded cross sections and the latter is performed with collapsed cross sections over the energy mesh being optimized. The optimization is done by the particle swarm algorithm implemented in the code AEMC and multigroup flux solutions are obtained from standard APOLLO2 solvers. By this new approach, a set of new optimized meshes which encompass from 10 to 50 groups has been defined for PWR and BWR calculations. This set will allow users to adapt the energy detail of the solution to the complexity of the calculation (assembly, multi-assembly, two-dimensional whole core). Some preliminary verifications, in which the accuracy of the new meshes is measured compared to a direct 281-group calculation, show that the 30-group optimized mesh offers a good compromise between simulation time and accuracy for a standard 17 x 17 UO 2 assembly with and without control rods. (author)

Renewable Energy versus Nuclear Power (Summary)

International Nuclear Information System (INIS)

Mraz, G.; Wallner, A.

2014-01-01

each subsequent unit receiving € 104 per MWh), plus an index adjustment. Calculated over 35 years, the duration of the Contract for Difference, this adds up to a Strike Price in 2058 of approximately € 329 per MWh (in nominal terms). On top of this, NNBG will be granted a state loan guarantee for all loans the company takes out on the financial markets to construct the nuclear power plant. After revising the state aid scheme, this contract was declared compatible with EU regulations and approved in October 2014. This decision is highly controversial within the EU. It led Austria to announce that nuclear power should be excluded from state subsidies. EU support for renewable energies While building nuclear power plants is increasingly facing problems with public acceptance, construction cost overruns and the non-existence of final repositories, over the past years renewable energies have been gaining ground. National policies for supporting renewables have been established in accordance with relevant regulations at EU level, such as the directive 2009/28/EC. Analogous to the planned support for nuclear power in UK, renewable energies usually receive support through feed-in tariffs1. Quota systems with tradable green certificates are also common. 1Conclusions: Generating electricity from a variety of renewable sources is more economical than using nuclear power; this is clearly shown by the model-based assessment of future developments up to 2050. Across the EU end consumers can save up to 37% on their electricity costs – in some Member States even up to 74% – when plans to build nuclear power plants are shelved in favour of renewables. In order to achieve these goals it is vital that we act quickly, but with care, to create the infrastructure and regulatory framework this requires, or to adapt that which already exists.(author)

Cost benefit justification of nuclear plant reliability improvement

International Nuclear Information System (INIS)

El-Sayed, M.A.H.; Abdelmonem, N.M.

1986-01-01

Nuclear power costs are evaluated on the bases of general ground rules (a) vary from time to time (b) vary from country to another (c) even vary from one reactor type to another. The main objective of an electric utility is to provide the electric energy to the different consummers at the lowest possible cost with reasonable reliability level. Rapid increase of the construction costs and fuel prices in recent years have stimulated a great deal of interest in improving the reliability and productivity of new and existing power plants. One of the most important areas is the improvement of the secondary steam loop and the reactor cooling system. The method for evaluating the reliability of steam loop and cooling system utilizes the cut-set technique. The developed method can be easily used to show to what extent the overall reliability of the nuclear plant is affected by the possible failures in the steam and cooling subsystem. The cost reliability trade-off analysis is used to evaluate alternative schemes in the design with a view towards meeting a high reliability goal. Based on historical or estimated failure and repair rate, the reliability of the alternate scheme can be calculated

Verifying atom entanglement schemes by testing Bell's inequality

International Nuclear Information System (INIS)

Angelakis, D.G.; Knight, P.L.; Tregenna, B.; Munro, W.J.

2001-01-01

Recent experiments to test Bell's inequality using entangled photons and ions aimed at tests of basic quantum mechanical principles. Interesting results have been obtained and many loopholes could be closed. In this paper we want to point out that tests of Bell's inequality also play an important role in verifying atom entanglement schemes. We describe as an example a scheme to prepare arbitrary entangled states of N two-level atoms using a leaky optical cavity and a scheme to entangle atoms inside a photonic crystal. During the state preparation no photons are emitted, and observing a violation of Bell's inequality is the only way to test whether a scheme works with a high precision or not. (orig.)

A New Graph Drawing Scheme for Social Network

Directory of Open Access Journals (Sweden)

Eric Ke Wang

2014-01-01

visualization is employed to extract the potential information from the large scale of social network data and present the information briefly as visualized graphs. In the process of information visualization, graph drawing is a crucial part. In this paper, we study the graph layout algorithms and propose a new graph drawing scheme combining multilevel and single-level drawing approaches, including the graph division method based on communities and refining approach based on partitioning strategy. Besides, we compare the effectiveness of our scheme and FM3 in experiments. The experiment results show that our scheme can achieve a clearer diagram and effectively extract the community structure of the social network to be applied to drawing schemes.

Application of gaseous core reactors for transmutation of nuclear waste

Science.gov (United States)

Schnitzler, B. G.; Paternoster, R. R.; Schneider, R. T.

1976-01-01

An acceptable management scheme for high-level radioactive waste is vital to the nuclear industry. The hazard potential of the trans-uranic actinides and of key fission products is high due to their nuclear activity and/or chemical toxicity. Of particular concern are the very long-lived nuclides whose hazard potential remains high for hundreds of thousands of years. Neutron induced transmutation offers a promising technique for the treatment of problem wastes. Transmutation is unique as a waste management scheme in that it offers the potential for "destruction" of the hazardous nuclides by conversion to non-hazardous or more manageable nuclides. The transmutation potential of a thermal spectrum uranium hexafluoride fueled cavity reactor was examined. Initial studies focused on a heavy water moderated cavity reactor fueled with 5% enriched U-235-F6 and operating with an average thermal flux of 6 times 10 to the 14th power neutrons/sq cm-sec. The isotopes considered for transmutation were I-129, Am-241, Am-242m, Am-243, Cm-243, Cm-244, Cm-245, and Cm-246.

German Spent Nuclear Fuel Legacy: Characteristics and High-Level Waste Management Issues

Directory of Open Access Journals (Sweden)

A. Schwenk-Ferrero

2013-01-01

Full Text Available Germany is phasing-out the utilization of nuclear energy until 2022. Currently, nine light water reactors of originally nineteen are still connected to the grid. All power plants generate high-level nuclear waste like spent uranium or mixed uranium-plutonium dioxide fuel which has to be properly managed. Moreover, vitrified high-level waste containing minor actinides, fission products, and traces of plutonium reprocessing loses produced by reprocessing facilities has to be disposed of. In the paper, the assessments of German spent fuel legacy (heavy metal content and the nuclide composition of this inventory have been done. The methodology used applies advanced nuclear fuel cycle simulation techniques in order to reproduce the operation of the German nuclear power plants from 1969 till 2022. NFCSim code developed by LANL was adopted for this purpose. It was estimated that ~10,300 tonnes of unreprocessed nuclear spent fuel will be generated until the shut-down of the ultimate German reactor. This inventory will contain ~131 tonnes of plutonium, ~21 tonnes of minor actinides, and 440 tonnes of fission products. Apart from this, ca.215 tonnes of vitrified HLW will be present. As fission products and transuranium elements remain radioactive from 104 to 106 years, the characteristics of spent fuel legacy over this period are estimated, and their impacts on decay storage and final repository are discussed.

Nuclear shell theory

CERN Document Server

de-Shalit, Amos; Massey, H S W

1963-01-01

Nuclear Shell Theory is a comprehensive textbook dealing with modern methods of the nuclear shell model. This book deals with the mathematical theory of a system of Fermions in a central field. It is divided into three parts. Part I discusses the single particle shell model. The second part focuses on the tensor algebra, two-particle systems. The last part covers three or more particle systems. Chapters on wave functions in a central field, tensor fields, and the m-Scheme are also presented. Physicists, graduate students, and teachers of nuclear physics will find the book invaluable.

Emergency response and nuclear risk governance. Nuclear safety at nuclear power plant accidents

International Nuclear Information System (INIS)

Kuhlen, Johannes

2014-01-01

;'best practice''(stakeholder projects, international harmonization projects) as well as existing deficiencies or challenges that came to light during-the emergency response after Fukushima. Subsequently, the nuclear power plant accident in Fukushima (March 2011) and its consequences are considered. The results of the analyses of the accidents, the accident sequence and their consequences show the need to improve national and international emergency response planning. The author then comes forward with several proposals on how to set up a pan-European emergency response scheme within the framework of a Nuclear Safety Regime, the obstacles (problems) which may interfere with the implementation of these suggestions are addressed and an interim solution for enhanced cross-border cooperation regarding emergency response is proposed. The empirical part of the thesis consists of two topics. Firstly, the national intervention levels for measures to protect the population in case of a nuclear power plant accident are examined by using comparative studies which show a considerable need for action in connection with a crossborder harmonization. One of the results is that the technical basis, e.g. regarding the different dose concepts and parameters for the intervention levels, is lacking. This information is listed in the appendix to this study. Secondly, the empirical part focuses on the collection and analysis of data that result from the answers to a couple of questions which cover all subject areas of emergency preparedness and which are related to intervention levels: With the help of an extensive questionnaire (''Questionnaire Regarding International Harmonization of Emergency Management''), the two politically or technically-oriented professional target groups in the field of Nuclear Emergency were interviewed worldwide during the time period from 23 November 2010 to 15 February 2011, that is, before the Fukushima reactor accident on 11 March 2011. They

Symposium on the development of nuclear waste policy: Siting the high-level nuclear waste repository

International Nuclear Information System (INIS)

Pijawka, K.D.; Mushkatel, A.H.

1991-01-01

The Nuclear Waste Policy Act of 1982 (NWPA) attempted to formulate a viable national policy for managing the disposal of high-level nuclear wastes. The NWPA authorized the selection of two repository sites: the first to be constructed in the West and a second site developed in the eastern United States. A detailed process for site selection was outlined in the NWPA. In addition, the NWPA authorized open-quotes the development of a waste transportation system; required the Department of Energy (DOE) to submit a proposal to construct a facility for monitored retrievable storage (MRS) after conducting a study of the need for, and feasibility of such a facility; and required the President to evaluate the use of the repositories ... for the disposal of high-level waste resulting from defense activitiesclose quotes (DOE, 1988, p. 1). A series of provisions granting oversight participation to states and Indian tribes, as well as a compensation package for the ultimate host state were also included. Responsibility for implementing the NWPA was assigned to DOE

Carbon price instead of support schemes: wind power investments by the electricity market

International Nuclear Information System (INIS)

Petitet, Marie; Finon, Dominique; Janssen, Tanguy

2014-10-01

In this paper we study the development of wind power by the electricity market without any usual support scheme which is aimed at subsidizing non mature renewables, with the sole incentive of a significant carbon price. Long term electricity market and investment decisions simulation by system dynamics modelling is used to trace the electricity generation mix evolution over a 20-year period in a pure thermal system. A range of stable carbon price, as a tax could be, is tested in order to determine the value above which wind power development by market forces becomes economically possible. Not only economic competitiveness in terms of cost price, but also profitability against traditional fossil fuel technologies are necessary for a market-driven development of wind power. Results stress that wind power is really profitable for investors only if the carbon price is very significantly higher than the price required for making wind power MWh's cost price competitive with CCGT and coal-fired plants on the simplistic basis of levelized costs. In this context, the market-driven development of wind power seems only possible if there is a strong commitment to climate policy, reflected by the preference for a stable and high carbon price rather than a fuzzy price of an emission trading scheme. Besides, results show that market-driven development of wind power would require a sky-rocketing carbon price if the initial technology mix includes a share of nuclear plants even with a moratorium on new nuclear development. (authors)

Nuclear structure investigations of neutron deficient nuclei in the region Z=103 to 105

International Nuclear Information System (INIS)

Hessberger, F. P.; Hofmann, S.; Armbruster, P.; Muenzenberg, G.; Stodel, Ch.; Ackermann, D.; Lavrentev, A. Yu.; Popeko, A. G.; Yeremin, A. V.; Saro, S.; Leino, M.

1999-01-01

The isotopes 257,255 Rf, 257,256 Db, 253,252 Lr have been produced in bombardments of 207,208 Pb and 209 Bi target nuclei with 50 Ti and identified by their α-decay. New or improved decay data could be obtained. Analysis of the fine structure of the α-decay pattern of 257 Rf allowed the construction of a first tentative level scheme for the daughter nucleus 253 No and also the identification of a low lying high spin isomeric state, while from α-γ- coincidence measurements for 255 Rf a first tentative level scheme of the daughter nucleus 251 No was derived. For 257 Db we found that two nuclear levels decay by α-emission and populate also different levels in the daughter nucleus 253 Lr. The levels are produced by the reaction process. In bombardments of 209 Bi with 50 Ti at E CN *=26.4 MeV and 30.8 MeV the previously unknown isotopes 256 Db and 252 Lr were identified

Robotics and remote handling concepts for disposal of high-level nuclear waste

International Nuclear Information System (INIS)

McAffee, Douglas; Raczka, Norman; Schwartztrauber, Keith

1997-01-01

This paper summarizes preliminary remote handling and robotic concepts being developed as part of the US Department of Energy's (DOE) Yucca Mountain Project. The DOE is currently evaluating the Yucca Mountain Nevada site for suitability as a possible underground geologic repository for the disposal of high level nuclear waste. The current advanced conceptual design calls for the disposal of more than 12,000 high level nuclear waste packages within a 225 km underground network of tunnels and emplacement drifts. Many of the waste packages may weigh as much as 66 tonnes and measure 1.8 m in diameter and 5.6 m long. The waste packages will emit significant levels of radiation and heat. Therefore, remote handling is a cornerstone of the repository design and operating concepts. This paper discusses potential applications areas for robotics and remote handling technologies within the subsurface repository. It also summarizes the findings of a preliminary technology survey which reviewed available robotic and remote handling technologies developed within the nuclear, mining, rail and industrial robotics and automation industries, and at national laboratories, universities, and related research institutions and government agencies

A progressive diagonalization scheme for the Rabi Hamiltonian

International Nuclear Information System (INIS)

Pan, Feng; Guan, Xin; Wang, Yin; Draayer, J P

2010-01-01

A diagonalization scheme for the Rabi Hamiltonian, which describes a qubit interacting with a single-mode radiation field via a dipole interaction, is proposed. It is shown that the Rabi Hamiltonian can be solved almost exactly using a progressive scheme that involves a finite set of one variable polynomial equations. The scheme is especially efficient for the lower part of the spectrum. Some low-lying energy levels of the model with several sets of parameters are calculated and compared to those provided by the recently proposed generalized rotating-wave approximation and a full matrix diagonalization.

Studies of nuclear processes at the Triangle Universities Nuclear Laboratory. Progress report, 1 September 1995--31 August 1996

International Nuclear Information System (INIS)

Ludwig, E.J.

1996-01-01

The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers parts of the second and third year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas: precision test of parity-invariance violation in resonance neutron scattering at LANSCE/LANL; parity violation measurements using charged-particle resonances in A = 20--40 targets and the A = 4 system at TUNL; chaotic behavior in the nuclei 30 P and 34 Cl from studies of eigenvalue fluctuations in nuclear level schemes; search for anomalies in the level density (pairing phase transition) in 1f-2p shell nuclei using GEANIE at LANSCE/LANL; parity-conserving time-reversal noninvariance tests using 166 Ho resonances at Geel, ORELA, or LANSCE/LANL; nuclear astrophysics; few-body nuclear systems; Nuclear Data evaluation for A = 3--20 for which TUNL is now the international center. Developments in technology and instrumentation are vital to the research and training program. Innovative work was continued in: polarized beam development; polarized target development; designing new cryogenic systems; designing new detectors; improving high-resolution beams for the KN and FN accelerators; development of an unpolarized Low-Energy Beam Facility for radiative capture studies of astrophysical interest. Preliminary research summaries are presented

Studies of nuclear processes at the Triangle Universities Nuclear Laboratory. Progress report, 1 September 1995--31 August 1996

Energy Technology Data Exchange (ETDEWEB)

Ludwig, E.J.

1996-09-01

The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers parts of the second and third year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas: precision test of parity-invariance violation in resonance neutron scattering at LANSCE/LANL; parity violation measurements using charged-particle resonances in A = 20--40 targets and the A = 4 system at TUNL; chaotic behavior in the nuclei {sup 30}P and {sup 34}Cl from studies of eigenvalue fluctuations in nuclear level schemes; search for anomalies in the level density (pairing phase transition) in 1f-2p shell nuclei using GEANIE at LANSCE/LANL; parity-conserving time-reversal noninvariance tests using {sup 166}Ho resonances at Geel, ORELA, or LANSCE/LANL; nuclear astrophysics; few-body nuclear systems; Nuclear Data evaluation for A = 3--20 for which TUNL is now the international center. Developments in technology and instrumentation are vital to the research and training program. Innovative work was continued in: polarized beam development; polarized target development; designing new cryogenic systems; designing new detectors; improving high-resolution beams for the KN and FN accelerators; development of an unpolarized Low-Energy Beam Facility for radiative capture studies of astrophysical interest. Preliminary research summaries are presented.

An instrumentation and control philosophy for high-level nuclear waste processing facilities

International Nuclear Information System (INIS)

Weigle, D.H.

1990-01-01

The purpose of this paper is to present an instrumentation and control philosophy which may be applied to high-level nuclear waste processing facilities. This philosophy describes the recommended criteria for automatic/manual control, remote/local control, remote/local display, diagnostic instrumentation, interlocks, alarm levels, and redundancy. Due to the hazardous nature of the process constituents of a high-level nuclear waste processing facility, it is imperative that safety and control features required for accident-free operation and maintenance be incorporated. A well-instrumented and controlled process, while initially more expensive in capital and design costs, is generally safer and less expensive to operate. When the long term cost savings of a well designed process is coupled with the high savings enjoyed by accident avoidance, the benefits far outweigh the initial capital and design costs

Small-scale classification schemes

DEFF Research Database (Denmark)

Hertzum, Morten

2004-01-01

Small-scale classification schemes are used extensively in the coordination of cooperative work. This study investigates the creation and use of a classification scheme for handling the system requirements during the redevelopment of a nation-wide information system. This requirements...... classification inherited a lot of its structure from the existing system and rendered requirements that transcended the framework laid out by the existing system almost invisible. As a result, the requirements classification became a defining element of the requirements-engineering process, though its main...... effects remained largely implicit. The requirements classification contributed to constraining the requirements-engineering process by supporting the software engineers in maintaining some level of control over the process. This way, the requirements classification provided the software engineers...

Nuclear spectroscopy using the neutron capture reaction

International Nuclear Information System (INIS)

Egidy, T.

1982-01-01

Experimental methods using neutron spectroscopy as a means to study the nucleus structure are described. Since reactions of neutron capture (n, γ) are non-selective, they permit to study the nature of excitation (monoparticle and collective) of nuclear levels, the nature of vibrational excitations, to check the connection between shell model and liquid drop model etc. In many cases (n, γ) reactions are the only way to check the forecast of nuclear models. Advantages of (n, γ) spectroscopy, possessing a high precision of measurement and high sensitivity, are underlined. Using neutron spectroscopy on facilities with a high density of neutron flux the structures of energy levels of a large group of nuclei are studied. In different laboratories complete schemes of energy levels of nuclei are obtained, a great number of new levels are found, the evergy level densities are determined, multipolarities of γ-transitions, spins, level parities are considered. StrUctures of rotational bands of heavy deformed nuclei are studied. The study of the structure of high-spin states is possible only using the methods of (n, γ) spectroscopy Investigation results of the nuclei 24 Na, 114 Cd, 154 Eu, 155 Cd, 155 Sm, 233 Th are considered as examples. The most interesting aspects of the investigations using neutron spectroscopy are discUssed

International cooperation and guarantee of nuclear safety in the implementation of national nuclear law

International Nuclear Information System (INIS)

Schneider, Horst

2011-01-01

The provisions against damage to be made in accordance with the state of the art as a precondition for licensing under Sec.7, Para.2, No.3 of the German Atomic Energy Act more than ever relate to international findings and practice in science as well as technology. In view of the peaceful use of nuclear power worldwide, together with the manifold institutionalized international and European schemes for cooperation within IAEA (International Atomic Energy Agency), OECD/NEA (Organisation for Economic Cooperation and Development Nuclear Energy Agency), and within the framework of EURATOM, these can be gleaned only from the global state of the art. In addition, there are informal associations and bilateral cooperation schemes of countries within which knowledge is exchanged and, in part, even specific measures ensuring nuclear safety are agreed upon. Also existing international rules and regulations are important. It is for the national enforcement authorities in the nuclear field to determine and assess the bandwidths of scientific opinions and theoretical as well as practical technical availabilities with regard to all tenable scientific findings and technical developments known on the international horizon. (orig.)

Nuclear - a chance for the Czech Republic

International Nuclear Information System (INIS)

Pazdera, F.

2007-01-01

The contribution is structured as follows: Physical principles of gaining nuclear energy; Specifics of power generation by nuclear and fossil fuel fired power plants; The nuclear fuel cycle; The potential of nuclear power; Global conflicts of nuclear power plant suppliers; Can power consumption be reduced by energy savings? What is better for the Czech Republic: the carbon tax or the emission trading scheme? In conclusion, the future benefits and requirements are summarized with respect to the Czech Republic. (P.A.)

Training at the masters degree level in physics and technology of nuclear reactors in the uk

International Nuclear Information System (INIS)

Weaver, D.R.

2000-01-01

This paper discusses the current situation of university-based training for the nuclear power industry in the UK, drawing on information gathered as part of the survey for a review currently being undertaken by the Committee for Technical and Economic Studies on Nuclear Energy Development and Fuel Cycle (NDC) of the Nuclear Energy Agency (NEA) of the OECD. A particular focus will be the Physics and Technology of Nuclear Reactors MSc course at the University of Birmingham. In the past there were other similar MSc courses in the UK, but through the evolution of time the Birmingham course is now unique in its role of providing masters level training so specifically aimed at the commercial nuclear programme. Mention will, however, be made of other training at the postgraduate level elsewhere in the UK. A description is given of the need to consider a new form of relationship between industry and university in order to provide optimise the provision of masters level training. (author)

Nuclear Data Sheets for A = 196

International Nuclear Information System (INIS)

Huang Xiaolong

2007-01-01

The 1998 version of nuclear data sheets for A = 196 has been revised and updated on the basis of the experimental results from various decay and reaction studies before January 2006. The experimental data for all known nuclei of A = 196 (Os,Ir,Pt,Au,Hg, Tl,Pb,Bi,Po,At,Rn) have been reevaluated. The experimental methods, references,Jπ arguments,and necessary comments are given in the text. Summary band structure drawings and level schemes from both radioactive decay and reaction studies are presented. Also of special interest are the new identification of superdeformed bands in 196 Pb and 196 Bi

ETGAR - Information system for abnormal occurrences in nuclear power plants

International Nuclear Information System (INIS)

Baram, J.; Nagar, M.; Pultorak, G.

1975-01-01

The need for extensive information on systems and components arises early in the planning stage of a nuclear power plant. This information is equally necessary during the building of the plant and during the licensing process. Another type of information helps preventive maintenance during the operating life of the plant. In the case of abnormal occurrences additional information on their possible consequences and on possible ways of handling them, is essential. To cover these four needs, the ETGAR system, which at present covers mostly PWR and BWR type nuclear power plants, collects and evaluates information on abnormal occurrences in nuclear power plants. The information is coded, using a three-level coding scheme for systems and components, and put on magnetic tape. A search program enables the retrieval of any pertinent information from the data base. The sources for the ETGAR data base are reports on abnormal occurrences in nuclear power plants. Most of them are USAEC dockets, originated at U.S.A. power plants. The relevant documents are accessible through a standard query run for ETGAR in the INIS data base which is maintained by the INIS centre in Israel. This query retrieves every two weeks all the documents which come under the ETGAR scope and these are handed as microfiches to the ETGAR evaluators after each INIS run. The evaluation and coding of the documents, the ETGAR coding scheme and the computer programs are described. (B.G.)

Teaching nuclear science: A cosmological approach

International Nuclear Information System (INIS)

Viola, V.E.

1994-01-01

Theories of the origin of the chemical elements can be used effectively to provide a unifying theme in teaching nuclear phenomena to chemistry students. By tracing the element-producing steps that are thought to characterize the chemical evolution of the universe, one can introduce the basic principles of nuclear nomenclature, structure, reactions, energetics, and decay kinetics in a self-consistent context. This approach has the additional advantage of giving the student a feeling for the origin of the elements and their relative abundances in the solar system. Further, one can logically introduce all of the basic forces and particles of nature, as well as the many analogies between nuclear and atomic systems. The subjects of heavy-element synthesis, dating, and the practical applications of nuclear phenomena fit naturally in this scheme. Within the nucleosynthesis framework it is possible to modify the presentation of nuclear behavior to suit the audience--ranging from an emphasis on description for the beginning student to a quantitative theoretical approach for graduate students. The subject matter is flexible in that the basic principles can be condensed into a few lecture as part of a more general course of expanded into an entire course. The following sections describe this approach, with primary emphasis on teaching at the elementary level

Explicit TE/TM scheme for particle beam simulations

International Nuclear Information System (INIS)

Dohlus, M.; Zagorodnov, I.

2008-10-01

In this paper we propose an explicit two-level conservative scheme based on a TE/TM like splitting of the field components in time. Its dispersion properties are adjusted to accelerator problems. It is simpler and faster than the implicit version. It does not have dispersion in the longitudinal direction and the dispersion properties in the transversal plane are improved. The explicit character of the new scheme allows a uniformly stable conformal method without iterations and the scheme can be parallelized easily. It assures energy and charge conservation. A version of this explicit scheme for rotationally symmetric structures is free from the progressive time step reducing for higher order azimuthal modes as it takes place for Yee's explicit method used in the most popular electrodynamics codes. (orig.)

A naval nuclear port: the costs to Rosyth

International Nuclear Information System (INIS)

Hines, C.

1988-07-01

This report is part of Greenpeace's Nuclear Free Seas Campaign. Previous publications have detailed the global inventory of the growing naval nuclear arsenals, the increasingly dangerous maritime strategies, and the UK's role in the naval nuclear arms race. The purpose of this research is to bring to the public's attention the environmental dangers that threaten Rosyth as a result of its role in the infrastructure that supports the UK's nuclear navy. The dockyard is used for replacing the fuel (refuelling) and maintenance (refitting) of nuclear powered submarines. It is also home port to four Type 42 Destroyers which are capable of carrying nuclear depth bombs for their helicopters. The presence in Rosyth of HMS Dreadnought, the first of Britain's nuclear powered submarines to be decommissioned, raises the additional question of the final destination of this and the nine other nuclear submarines scheduled to have their nuclear fuel removed in the next 12 years. The report considers the likelihood of a serious accident involving a nuclear reactor or nuclear weapon in Rosyth 'Public Safety Scheme' which is supposedly designed to cope with a nuclear reactor accident. The study looks at the dangers inherent in the 'normal' activities of nuclear powered submarines in Rosyth. It considers the adequacy of the present monitoring of the radiation that comes with their presence, looks at the health implications for workers and examines the high level of leukaemia in the under 25 age group that have been recorded in the area. (author)

Investigation of optimal photoionization schemes for Sm by multi-step resonance ionization

International Nuclear Information System (INIS)

Cha, H.; Song, K.; Lee, J.

1997-01-01

Excited states of Sm atoms are investigated by using multi-color resonance enhanced multiphoton ionization spectroscopy. Among the ionization signals one observed at 577.86 nm is regarded as the most efficient excited state if an 1-color 3-photon scheme is applied. Meanwhile an observed level located at 587.42 nm is regarded as the most efficient state if one uses a 2-color scheme. For 2-color scheme a level located at 573.50 nm from this first excited state is one of the best second excited state for the optimal photoionization scheme. Based on this ionization scheme various concentrations of standard solutions for samarium are determined. The minimum amount of sample which can be detected by a 2-color scheme is determined as 200 fg. The detection sensitivity is limited mainly due to the pollution of the graphite atomizer. copyright 1997 American Institute of Physics

General scheme for elucidating the structure of organic compounds using spectroscopic and spectrometric methods

International Nuclear Information System (INIS)

Ribeiro, Carlos Magno R.; Souza, Nelson Angelo de

2007-01-01

This work describes a systematic method to be applied in undergraduate courses of organic chemistry, correlating infrared spectra, hydrogen and carbon-13 nuclear magnetic resonance, and mass spectra. To this end, a scheme and a table were developed to conduct the elucidation of the structure of organic compounds initially using infrared spectra. Interpretation of hydrogen and carbon-13 nuclear magnetic resonance spectra and of mass spectra is used to confirm the proposed structure. (author)

An evaluation scheme for nanotechnology policies

International Nuclear Information System (INIS)

Soltani, Ali M.; Tabatabaeian, Seyed H.; Hanafizadeh, Payam; Bamdad Soofi, Jahanyar

2011-01-01

Dozens of countries are executing national nanotechnology plans. No rigorous evaluation scheme for these plans exists, although stakeholders—especially policy makers, top-level agencies and councils, as well as the society at large—are eager to learn the outcome of these policies. In this article, we recommend an evaluation scheme for national nanotechnology policies that would be used to review the whole or any component part of a national nanotechnology plan. In this scheme, a component at any level of aggregation is evaluated. The component may be part of the plan’s overarching policy goal, which for most countries is to create wealth and improve the quality of life of their nation with nanotechnology. Alternatively, the component may be a programme or an activity related to a programme. The evaluation could be executed at different times in the policy’s life cycle, i.e., before the policy is formulated, during its execution or after its completion. The three criteria for policy evaluation are appropriateness, efficiency and effectiveness. The evaluator should select the appropriate qualitative or quantitative methods to evaluate the various components of national nanotechnology plans.

The amendment of the law on compensation for nuclear damage in Japan

International Nuclear Information System (INIS)

Tanikawa, H.

2000-01-01

The legal regime relating to the compensation for nuclear damage in Japan is governed by 'the Law on Compensation for Nuclear Damage' and the 'Law on indemnity Agreement for Compensation of Nuclear Damage'. The basic liability scheme on compensation for nuclear damage in the Compensation law is constituted on the basis of strict and unlimited liability, and such liability is channeled to a nuclear undertaker who is engaged on the operation of the reactor, etc.Furthermore, in order to operate a reactor a nuclear undertaker has to have provided financial security for compensation of nuclear damage by means of contracts, for liability insurance in respect of potential nuclear damage and an indemnity agreement for compensation of nuclear damage or the deposit. In addition to this financial security, in the event that nuclear damage occurs, and if necessary, the Government shall give to a nuclear undertaker such aid as required for him to compensate the nuclear damage. The financial security amount specified in the compensation Law has been increased to JPY (Japan yen) 60 billion. The necessity for special requirements in relation to financial security and/or the level of its amount in case of decommissioning of reactors, storage of nuclear spent fuel outside the power plant, radioisotopes other than nuclear fuel materials, or high level waste of nuclear fuel material, or the operation of experimental reactors for nuclear fusion, etc. shall be examined in the near future according to developments made in this field and the corresponding necessity for financial security for each case. (N.C.)

A Stereo Music Preprocessing Scheme for Cochlear Implant Users.

Science.gov (United States)

Buyens, Wim; van Dijk, Bas; Wouters, Jan; Moonen, Marc

2015-10-01

Listening to music is still one of the more challenging aspects of using a cochlear implant (CI) for most users. Simple musical structures, a clear rhythm/beat, and lyrics that are easy to follow are among the top factors contributing to music appreciation for CI users. Modifying the audio mix of complex music potentially improves music enjoyment in CI users. A stereo music preprocessing scheme is described in which vocals, drums, and bass are emphasized based on the representation of the harmonic and the percussive components in the input spectrogram, combined with the spatial allocation of instruments in typical stereo recordings. The scheme is assessed with postlingually deafened CI subjects (N = 7) using pop/rock music excerpts with different complexity levels. The scheme is capable of modifying relative instrument level settings, with the aim of improving music appreciation in CI users, and allows individual preference adjustments. The assessment with CI subjects confirms the preference for more emphasis on vocals, drums, and bass as offered by the preprocessing scheme, especially for songs with higher complexity. The stereo music preprocessing scheme has the potential to improve music enjoyment in CI users by modifying the audio mix in widespread (stereo) music recordings. Since music enjoyment in CI users is generally poor, this scheme can assist the music listening experience of CI users as a training or rehabilitation tool.

European insurance scheme to cover geological risk related to geothermal operations

Energy Technology Data Exchange (ETDEWEB)

Tiberi, U [European Community, General Directorate XVII, ALTERNER Program, Bruxelles (Belgium); Demange, J [BRGM, Orleans (France)

1997-12-01

The development of geothermal energy can contribute significantly to the growth of NRE (new and renewable energies that are non-nuclear and non-combustible) within the European Community and within Europe as a whole. However, the `mining risk` related to this type of operation still constitutes a major obstacle to its development. Operators find it difficult to raise the necessary financing without a guarantee against the risk of failure during the drilling stage. Standard insurance companies will not cover this type of risk, due to its very nature. We must thus therefore find a specific solution. As a result of the oil crises during the 1970s, the French Government decided promote the use of renewable energies in France. The support provided to these energies, or at least to geothermal energy, was to set up a scheme whereby the resource is guaranteed. Thus the operator, by subscribing to the scheme, benefits from a guarantee of the resource. The insurance works at two level: - in the first place, it covers the mining risk during the drilling stage, i.e. should the resource prove to be insufficient, whether in discharge or temperature, for an economically viable operation, then the totality of the costs are reimbursed, apart form the premium and any government subsidy that might have been received. - A second level of guarantee covers the risk of change in the resource`s parameters over a period of 15 years (a study is in progress to consider the possibility of extending this period to 25 years). (orig.)

Matching soil salinization and cropping systems in communally managed irrigation schemes

Science.gov (United States)

Malota, Mphatso; Mchenga, Joshua

2018-03-01

Occurrence of soil salinization in irrigation schemes can be a good indicator to introduce high salt tolerant crops in irrigation schemes. This study assessed the level of soil salinization in a communally managed 233 ha Nkhate irrigation scheme in the Lower Shire Valley region of Malawi. Soil samples were collected within the 0-0.4 m soil depth from eight randomly selected irrigation blocks. Irrigation water samples were also collected from five randomly selected locations along the Nkhate River which supplies irrigation water to the scheme. Salinity of both the soil and the irrigation water samples was determined using an electrical conductivity (EC) meter. Analysis of the results indicated that even for very low salinity tolerant crops (ECi water was suitable for irrigation purposes. However, root-zone soil salinity profiles depicted that leaching of salts was not adequate and that the leaching requirement for the scheme needs to be relooked and always be adhered to during irrigation operation. The study concluded that the crop system at the scheme needs to be adjusted to match with prevailing soil and irrigation water salinity levels.

Dynamic nuclear polarization at high Landau levels in a quantum point contact

Science.gov (United States)

Fauzi, M. H.; Noorhidayati, A.; Sahdan, M. F.; Sato, K.; Nagase, K.; Hirayama, Y.

2018-05-01

We demonstrate a way to polarize and detect nuclear spin in a gate-defined quantum point contact operating at high Landau levels. Resistively detected nuclear magnetic resonance (RDNMR) can be achieved up to the fifth Landau level and at a magnetic field lower than 1 T. We are able to retain the RDNMR signals in a condition where the spin degeneracy of the first one-dimensional (1D) subband is still preserved. Furthermore, the effects of orbital motion on the first 1D subband can be made smaller than those due to electrostatic confinement. This developed RDNMR technique is a promising means to study electronic states in a quantum point contact near zero magnetic field.

Radiochemistry and nuclear methods of analysis

International Nuclear Information System (INIS)

Ehmann, W.D.; Vance, D.E.

1993-01-01

In comparison with other aspects of physical science, nuclear and radiochemistry are small contributors to the overall scheme of things. Nuclear science is, however, an important player in various aspects of medicine, life sciences, industrial technology, physical sciences, archeometry and art, and theoretical/computational sciences. This new book fills the need for a contemporary text with a good mix of simple introductory theory, experimental methodology, and instrumentation for beginning students of nuclear science

The Hagedorn spectrum, nuclear level densities and first order phase transitions

International Nuclear Information System (INIS)

Moretto, Luciano G.; Larsen, A. C.; Guttormsen, M.; Siem, S.

2015-01-01

An exponential mass spectrum, like the Hagedorn spectrum, with slope 1/T H was interpreted as fixing an upper limiting temperature T H that the system can achieve. However, thermodynamically, such spectrum indicates a 1 st order phase transition at a fixed temperature T H . A much lower energy example is the log linear level nuclear density below the neutron binding energy that prevails throughout the nuclear chart. We show that, for non-magic nuclei, such linearity implies a 1 st order phase transition from the pairing superfluid to an ideal gas of quasi particles

Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

Science.gov (United States)

Boatner, Lynn A.; Sales, Brian C.

1989-01-01

Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

Carrier-based modulation schemes for various three-level matrix converters

DEFF Research Database (Denmark)

Blaabjerg, Frede; Loh, P.C.; Rong, R.C.

2008-01-01

different performance merits. To avoid confusion and hence fasten the converter applications in the industry, it would surely be better for modulation schemes to be developed from a common set of modulation principles that unfortunately has not yet been thoroughly defined. Contributing to that area...... a limited set of switching vectors because of its lower semiconductor count. Through simulation and experimental testing, all the evaluated matrix converters are shown to produce satisfactory sinusoidal input and output quantities using the same set of generic modulation principles, which can conveniently...

A Modified Computational Scheme for the Stochastic Perturbation Finite Element Method

Directory of Open Access Journals (Sweden)

Feng Wu

Full Text Available Abstract A modified computational scheme of the stochastic perturbation finite element method (SPFEM is developed for structures with low-level uncertainties. The proposed scheme can provide second-order estimates of the mean and variance without differentiating the system matrices with respect to the random variables. When the proposed scheme is used, it involves finite analyses of deterministic systems. In the case of one random variable with a symmetric probability density function, the proposed computational scheme can even provide a result with fifth-order accuracy. Compared with the traditional computational scheme of SPFEM, the proposed scheme is more convenient for numerical implementation. Four numerical examples demonstrate that the proposed scheme can be used in linear or nonlinear structures with correlated or uncorrelated random variables.

Ceramic process and plant design for high-level nuclear waste immobilization

International Nuclear Information System (INIS)

Grantham, L.F.; McKisson, R.L.; De Wames, R.E.; Guon, J.; Flintoff, J.F.; McKenzie, D.E.

1983-01-01

In the last 3 years, significant advances in ceramic technology for high-level nuclear waste solidification have been made. Product quality in terms of leach-resistance, compositional uniformity, structural integrity, and thermal stability promises to be superior to borosilicate glass. This paper addresses the process effectiveness and preliminary designs for glass and ceramic immobilization plants. The reference two-step ceramic process utilizes fluid-bed calcination (FBC) and hot isostatic press (HIP) consolidation. Full-scale demonstration of these well-developed processing steps has been established at DOE and/or commercial facilities for processing radioactive materials. Based on Savannah River-type waste, our model predicts that the capital and operating cost for the solidification of high-level nuclear waste is about the same for the ceramic and glass options. However, when repository costs are included, the ceramic option potentially offers significantly better economics due to its high waste loading and volume reduction. Volume reduction impacts several figures of merit in addition to cost such as system logistics, storage, transportation, and risk. The study concludes that the ceramic product/process has many potential advantages, and rapid deployment of the technology could be realized due to full-scale demonstrations of FBC and HIP technology in radioactive environments. Based on our finding and those of others, the ceramic innovation not only offers a viable backup to the glass reference process but promises to be a viable future option for new high-level nuclear waste management opportunities

Nuclear material attractiveness: an assessment of used-fuel assemblies

International Nuclear Information System (INIS)

Bathke, Charles Gary; Edelman, Paul G.; Hase, Kevin R.; Ebbinghaus, Bartley B.; Sleaford, Brad W.; Robel, Martin; Collins, B.A.; Prichard, Andrew W.; Smith, B Brian W.

2011-01-01

This paper examines the material attractiveness of used-fuel assemblies in a hypothetical scenario in which terrorists steal one or more assemblies in order to use the special nuclear materials (SNM) within an assembly in a nuclear explosive device. For assessing material attractiveness, this paper uses the Figure of Merit (FOM) that was used in earlier studies to examine the attractiveness of the SNM associated with the reprocessing of used light water reactor (LWR) fuel by various reprocessing schemes. However, for a theft scenario the mass used in the Acquisition Factor of the FOM is the mass of the stolen object conta ining SNM ; whereas the mass used for analyzing the material attractiveness of the products of various reprocessing schemes in the earlier studies was a fraction of the bare critical mass in recognition that a successful proliferator must avoid a criticality accident. This paper will indicate how long after discharge the radiation emanating from a cooling assembly is no longer self-protecting. Additionally, this paper will give the time scale for the SNM within the assembly to become more attractive. These studies were performed at the request of the United States Department of Energy (DOE), and are based on the calculation of ''attractiveness levels'' that has been couched in terms chosen for consistency with those normally used for nuclear materials in DOE nuclear facilities. The methodology and key findings will be presented. Additionally, this paper discusses how the results presented herein impact the application of safeguards and the securitization of SNM, and how they could be used to help inform policy makers.

Two-loop corrections for nuclear matter in the Walecka model

International Nuclear Information System (INIS)

Furnstahl, R.J.; Perry, R.J.; Serot, B.D.; Department of Physics, The Ohio State University, Columbus, Ohio 43210; Physics Department and Nuclear Theory Center, Indiana University, Bloomington, Indiana 47405)

1989-01-01

Two-loop corrections for nuclear matter, including vacuum polarization, are calculated in the Walecka model to study the loop expansion as an approximation scheme for quantum hadrodynamics. Criteria for useful approximation schemes are discussed, and the concepts of strong and weak convergence are introduced. The two-loop corrections are evaluated first with one-loop parameters and mean fields and then by minimizing the total energy density with respect to the scalar field and refitting parameters to empirical nuclear matter saturation properties. The size and nature of the corrections indicate that the loop expansion is not convergent at two-loop order in either the strong or weak sense. Prospects for alternative approximation schemes are discussed

Oscillating molecular dipoles require strongly correlated electronic and nuclear motion

International Nuclear Information System (INIS)

Chang, Bo Y; Shin, Seokmin; Palacios, Alicia; Martín, Fernando; Sola, Ignacio R

2015-01-01

To create an oscillating electric dipole in an homonuclear diatomic cation without an oscillating driver one needs (i) to break the symmetry of the system and (ii) to sustain highly correlated electronic and nuclear motion. Based on numerical simulations in H 2 + we present results for two schemes. In the first one (i) is achieved by creating a superposition of symmetric and antisymmetric electronic states freely evolving, while (ii) fails. In a second scheme, by preparing the system in a dressed state of a strong static field, both conditions hold. We then analyze the robustness of this scheme with respect to features of the nuclear wave function and its intrinsic sources of decoherence. (tutorial)

Patterns of agri-environmental scheme participation in Europe

DEFF Research Database (Denmark)

Pavlis, Evangelos S.; Terkenli, Theano S.; Kristensen, Søren Bech Pilgaard

2016-01-01

This paper investigates the personal and property characteristics of landowners who use EU Rural Development agri-environmental schemes (AES), as well as their motives for participation or non-participation in such schemes. The study is based on a questionnaire survey with landowners, in selected...... areas with marginal potential for agriculture. Motives for non-participation were also found to be dependent on the level of farming engagement and on case-area landscape types.......This paper investigates the personal and property characteristics of landowners who use EU Rural Development agri-environmental schemes (AES), as well as their motives for participation or non-participation in such schemes. The study is based on a questionnaire survey with landowners, in selected...... geographical particularities and on subjective factors, farmers' individualities, different rural cultures, landscape types, EU and national policies and special needs of the study areas—all areas where agricultural production is increasingly marginalized, for different reasons. Subsidy scheme participation...

Simplified scheme or radioactive plume calculations

International Nuclear Information System (INIS)

Gibson, T.A.; Montan, D.N.

1976-01-01

A simplified mathematical scheme to estimate external whole-body γ radiation exposure rates from gaseous radioactive plumes was developed for the Rio Blanco Gas Field Nuclear Stimulation Experiment. The method enables one to calculate swiftly, in the field, downwind exposure rates knowing the meteorological conditions and γ radiation exposure rates measured by detectors positioned near the plume source. The method is straightforward and easy to use under field conditions without the help of mini-computers. It is applicable to a wide range of radioactive plume situations. It should be noted that the Rio Blanco experiment was detonated on May 17, 1973, and no seep or release of radioactive material occurred

Chemical Plant Accidents in a Nuclear Hydrogen Generation Scheme

International Nuclear Information System (INIS)

Brown, Nicholas R.; Revankar, Shripad T.

2011-01-01

A high temperature nuclear reactor (HTR) could be used to drive a steam reformation plant, a coal gasification facility, an electrolysis plant, or a thermochemical hydrogen production cycle. Most thermochemical cycles are purely thermodynamic, and thus achieve high thermodynamic efficiency. HTRs produce large amounts of heat at high temperature (1100 K). Helium-cooled HTRs have many passive, or inherent, safety characteristics. This inherent safety is due to the high design basis limit of the maximum fuel temperature. Due to the severity of a potential release, containment of fission products is the single most important safety issue in any nuclear reactor facility. A HTR coupled to a chemical plant presents a complex system, due primarily to the interactive nature of both plants. Since the chemical plant acts as the heat sink for the nuclear reactor, it important to understand the interaction and feedback between the two systems. Process heat plants and HTRs are generally very different. Some of the major differences include: time constants of plants, safety standards, failure probability, and transient response. While both the chemical plant and the HTR are at advanced stages of testing individually, no serious effort has been made to understand the operation of the integrated system, especially during accident events that are initiated in the chemical plant. There is a significant lack of knowledge base regarding scaling and system integration for large scale process heat plants coupled to HTRs. Consideration of feedback between the two plants during time-dependent scenarios is absent from literature. Additionally, no conceptual studies of the accidents that could occur in either plant and impact the entire coupled system are present in literature

Progress with multigrid schemes for hypersonic flow problems

International Nuclear Information System (INIS)

Radespiel, R.; Swanson, R.C.

1995-01-01

Several multigrid schemes are considered for the numerical computation of viscous hypersonic flows. For each scheme, the basic solution algorithm employs upwind spatial discretization with explicit multistage time stepping. Two-level versions of the various multigrid algorithms are applied to the two-dimensional advection equation, and Fourier analysis is used to determine their damping properties. The capabilities of the multigrid methods are assessed by solving three different hypersonic flow problems. Some new multigrid schemes based on semicoarsening strategies are shown to be quite effective in relieving the stiffness caused by the high-aspect-ratio cells required to resolve high Reynolds number flows. These schemes exhibit good convergence rates for Reynolds numbers up to 200 X 10 6 and Mach numbers up to 25. 32 refs., 31 figs., 1 tab

The Attractiveness of Materials in Advanced Nuclear Fuel Cycles for Various Proliferation and Theft Scenarios

International Nuclear Information System (INIS)

Bathke, C.G.; Wallace, R.K.; Ireland, J.R.; Johnson, M.W.; Hase, Kevin R.; Jarvinen, G.D.; Ebbinghaus, B.B.; Sleaford, Brad W.; Bradley, Keith S.; Collins, Brian A.; Smith, Brian W.; Prichard, Andrew W.

2010-01-01

This paper is an extension to earlier studies that examined the attractiveness of materials mixtures containing special nuclear materials (SNM) and alternate nuclear materials (ANM) associated with the PUREX, UREX, COEX, THOREX, and PYROX reprocessing schemes. This study extends the figure of merit (FOM) for evaluating attractiveness to cover a broad range of proliferant state and sub-national group capabilities. The primary conclusion of this study is that all fissile material needs to be rigorously safeguarded to detect diversion by a state and provided the highest levels of physical protection to prevent theft by sub-national groups; no 'silver bullet' has been found that will permit the relaxation of current international safeguards or national physical security protection levels. This series of studies has been performed at the request of the United States Department of Energy (DOE) and is based on the calculation of 'attractiveness levels' that are expressed in terms consistent with, but normally reserved for nuclear materials in DOE nuclear facilities. The expanded methodology and updated findings are presented. Additionally, how these attractiveness levels relate to proliferation resistance and physical security are discussed.

The attractiveness of materials in advanced nuclear fuel cycles for various proliferation and theft scenarios

International Nuclear Information System (INIS)

Bathke, Charles G.; Wallace, Richard K.; Ireland, John R.; Johnson, M.W.; Hase, Kevin R.; Jarvinen, Gordon D.; Ebbinghaus, Bartley B.; Sleaford, Brad A.; Bradley, Keith S.; Collins, Brian W.; Smith, Brian W.; Prichard, Andrew W.

2009-01-01

This paper is an extension to earlier studies that examined the attractiveness of materials mixtures containing special nuclear materials (SNM) and alternate nuclear materials (ANM) associated with the PUREX, UREX, COEX, THOREX, and PYROX reprocessing schemes. This study extends the figure of merit (FOM) for evaluating attractiveness to cover a broad range of proliferant state and sub-national group capabilities. The primary conclusion of this study is that all fissile material needs to be rigorously safeguarded to detect diversion by a state and provided the highest levels of physical protection to prevent theft by sub-national groups; no 'silver bullet' has been found that will permit the relaxation of current international safeguards or national physical security protection levels. This series of studies has been performed at the request of the United States Department of Energy (DOE) and is based on the calculation of 'attractiveness levels' that are expressed in terms consistent with, but normally reserved for nuclear materials in DOE nuclear facilities. The expanded methodology and updated findings are presented. Additionally, how these attractiveness levels relate to proliferation resistance and physical security are discussed.

A study on the development and application of expert system for nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Woo, Hee Gon; Kim, Seong Bok [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

1995-12-31

It is a final report of the research that is a study on the development and application of expert system for nuclear power plants and development of the schemes computing environments and user interfaces for the expert system, which is a systematic and efficient development of expert system for nuclear power plants in the future. This report is consisted of -Development trends of expert system for nuclear power plants. -Classification of expert system applications for nuclear power plants. -Systematic and efficient developments schemes of expert system for nuclear power plants, and -Suitable computing environments and user interfaces for the expert systems. (author). 113 refs., 85 figs.

A study on the development and application of expert system for nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Woo, Hee Gon; Kim, Seong Bok [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

1996-12-31

It is a final report of the research that is a study on the development and application of expert system for nuclear power plants and development of the schemes computing environments and user interfaces for the expert system, which is a systematic and efficient development of expert system for nuclear power plants in the future. This report is consisted of -Development trends of expert system for nuclear power plants. -Classification of expert system applications for nuclear power plants. -Systematic and efficient developments schemes of expert system for nuclear power plants, and -Suitable computing environments and user interfaces for the expert systems. (author). 113 refs., 85 figs.

Performance of a 229Thorium solid-state nuclear clock

International Nuclear Information System (INIS)

Kazakov, G A; Schreitl, M; Winkler, G; Schumm, T; Litvinov, A N; Romanenko, V I; Yatsenko, L P; Romanenko, A V

2012-01-01

The 7.8 eV nuclear isomer transition in 229 thorium has been suggested as a clock transition in a new type of optical frequency standard. Here we discuss the construction of a ‘solid-state nuclear clock’ from thorium nuclei implanted into single crystals transparent in the vacuum ultraviolet range. We investigate crystal-induced line shifts and broadening effects for the specific system of calcium fluoride. At liquid nitrogen temperatures, the clock performance will be limited by decoherence due to magnetic coupling of the thorium nuclei to neighboring nuclear moments, ruling out the commonly used Rabi or Ramsey interrogation schemes. We propose clock stabilization based on a fluorescence spectroscopy method and present optimized operation parameters. Taking advantage of the large number of quantum oscillators under continuous interrogation, a fractional instability level of 10 −19 might be reached within the solid-state approach. (paper)

Traffic calming schemes : opportunities and implementation strategies.

NARCIS (Netherlands)

Schagen, I.N.L.G. van (ed.)

2003-01-01

Commissioned by the Swedish National Road Authority, this report aims to provide a concise overview of knowledge of and experiences with traffic calming schemes in urban areas, both on a technical level and on a policy level. Traffic calming refers to a combination of network planning and

Alternative health insurance schemes

DEFF Research Database (Denmark)

Keiding, Hans; Hansen, Bodil O.

2002-01-01

In this paper, we present a simple model of health insurance with asymmetric information, where we compare two alternative ways of organizing the insurance market. Either as a competitive insurance market, where some risks remain uninsured, or as a compulsory scheme, where however, the level...... competitive insurance; this situation turns out to be at least as good as either of the alternatives...

Report of the State Office for Nuclear Safety on state supervision of nuclear safety of nuclear facilities and radiation protection in 1998

International Nuclear Information System (INIS)

1999-05-01

The legislative basis of the authority of the State Office for Nuclear Safety as the Czech national regulatory body is outlined, its organizational scheme is presented, and the responsibilities of the various departments are highlighted. The operation of major Czech nuclear facilities, including the Dukovany NPP which is in operation and the Temelin NPP which is under construction, is described with respect to nuclear safety. Since the Office's responsibilities also cover radiation protection in the Czech Republic, a survey of ionizing radiation sources and their supervision is given. Other topics include, among other things, nuclear material transport, the state system for nuclear materials accountancy and control, central registries for radiation protection, nuclear waste management, the National Radiation Monitoring Network, personnel qualification and training, emergency planning, legislative activities, international cooperation, and public information. (P.A.)

The management-retrieval code of nuclear level density sub-library (CENPL-NLD)

International Nuclear Information System (INIS)

Ge Zhigang; Su Zongdi; Huang Zhongfu; Dong Liaoyuan

1995-01-01

The management-retrieval code of the Nuclear Level Density (NLD) is presented. It contains two retrieval ways: single nucleus (SN) and neutron reaction (NR). The latter contains four kinds of retrieval types. This code not only can retrieve level density parameter and the data related to the level density, but also can calculate the relevant data by using different level density parameters and do comparison of the calculated results with related data in order to help user to select level density parameters

Development of national level preparedness for response to nuclear and radiological emergencies

International Nuclear Information System (INIS)

Pradeepkumar, K.S.

2014-01-01

In India, DAE being the nodal agency for technical support for response to any radiation emergency nuclear disaster and various nuclear and radiological emergency scenarios and their impacts are identified. To reduce their consequences development of methodologies for detection and quick impact assessment, trained First Responders and Quick Response Teams (QRTs), twenty two DAE Emergency Response Centers, mobile and aerial radiation monitoring systems, aerial and ground based validation trials etc. are carried out. Study related to radiological threats and simulated RDD experiments conducted using stable isotopes indicates that radiation levels for distances more than 50 m will not be very high as hotspots may be restricted to nearby area. The biggest challenge from an RDD explosion will be handling of the radioactive contamination and 'fear factor' compared to radiation exposure to public or First Responders. Level and pattern of radioactive contamination on ground following releases during nuclear accidents and minimum strength of orphan radioactive sources to be detected are taken into account for optimizing systems and monitoring methodology required for emergency preparedness

Exact analysis of Packet Reversed Packet Combining Scheme and Modified Packet Combining Scheme; and a combined scheme

International Nuclear Information System (INIS)

Bhunia, C.T.

2007-07-01

Packet combining scheme is a well defined simple error correction scheme for the detection and correction of errors at the receiver. Although it permits a higher throughput when compared to other basic ARQ protocols, packet combining (PC) scheme fails to correct errors when errors occur in the same bit locations of copies. In a previous work, a scheme known as Packet Reversed Packet Combining (PRPC) Scheme that will correct errors which occur at the same bit location of erroneous copies, was studied however PRPC does not handle a situation where a packet has more than 1 error bit. The Modified Packet Combining (MPC) Scheme that can correct double or higher bit errors was studied elsewhere. Both PRPC and MPC schemes are believed to offer higher throughput in previous studies, however neither adequate investigation nor exact analysis was done to substantiate this claim of higher throughput. In this work, an exact analysis of both PRPC and MPC is carried out and the results reported. A combined protocol (PRPC and MPC) is proposed and the analysis shows that it is capable of offering even higher throughput and better error correction capability at high bit error rate (BER) and larger packet size. (author)

Nuclear Accidents Intervention Levels for Protection of the Public

International Nuclear Information System (INIS)

1989-01-01

The impact of the 1986 Chernobyl accident called attention to the need to improve international harmonization of the principles and criteria for the protection of the public in the event of a nuclear accident. This report provides observations and guidance related to the harmonization of radiological protection criteria, and is intended to be of use to national authorities and international organizations examining the issue of emergency response planning and intervention levels

197Au(d,3He)196Pt reaction and the supersymmetry scheme

International Nuclear Information System (INIS)

Vergnes, M.; Berrier-Ronsin, G.; Rotbard, G.; Vernotte, J.; Langevin- Joliot, H.; Gerlic, E.; Wiele, J. van de; Guillot, J.

1981-01-01

The 197 Au(d, 3 He) 196 Pt reaction has been studied at Esub(d) = 108 MeV. An important breakdown of the selection rules of the supersymmetry scheme is observed for the 2 2 + level. The generally strong excitation of the 2 2 + level by transfer reactions in the Pt region leads to question the validity of the supersymmetry scheme at least for this level

Radiological environment within an NPP after a severe nuclear accident

Science.gov (United States)

Andgren, Karin; Fritioff, Karin; Buhr, Anna Maria Blixt; Huutoniemi, Tommi

2017-09-01

The radiological environment following a severe nuclear accident can be visualised on building layouts. The direct radiation in an area (or room) can be visualized on the layout by a colouring scheme depending on the dose rate level (for example orange for high gamma dose rate level and purple for an intermediate gamma dose rate level). Following the Fukushima accident, a need for update of these layouts has been identified at the Swedish nuclear power plant of Forsmark. Shielding calculations for areas where access is desired for severe accident management have been performed. Many different sources of radiation together with different types of shielding material contribute to the dose that would be received by a person entering the area. External radiation from radioactivity within e.g. pipes and components is considered and also external radiation from radioactivity in the air (originating from diffuse leakage of the containment atmosphere). Results are presented as dose rates for relevant dose points together with a method for estimating the dose rate levels for each of the rooms of the reactor building.

Radiological environment within an NPP after a severe nuclear accident

Directory of Open Access Journals (Sweden)

Andgren Karin

2017-01-01

Full Text Available The radiological environment following a severe nuclear accident can be visualised on building layouts. The direct radiation in an area (or room can be visualized on the layout by a colouring scheme depending on the dose rate level (for example orange for high gamma dose rate level and purple for an intermediate gamma dose rate level. Following the Fukushima accident, a need for update of these layouts has been identified at the Swedish nuclear power plant of Forsmark. Shielding calculations for areas where access is desired for severe accident management have been performed. Many different sources of radiation together with different types of shielding material contribute to the dose that would be received by a person entering the area. External radiation from radioactivity within e.g. pipes and components is considered and also external radiation from radioactivity in the air (originating from diffuse leakage of the containment atmosphere. Results are presented as dose rates for relevant dose points together with a method for estimating the dose rate levels for each of the rooms of the reactor building.

Constraints on the high-density nuclear equation of state from the phenomenology of compact stars and heavy-ion collisions

International Nuclear Information System (INIS)

Klaehn, T.; Blaschke, D.; Typel, S.; Dalen, E. N. E. van; Faessler, A.; Fuchs, C.; Gaitanos, T.; Wolter, H. H.; Grigorian, H.; Ho, A.; Weber, F.; Kolomeitsev, E. E.; Miller, M. C.; Roepke, G.; Truemper, J.; Voskresensky, D. N.

2006-01-01

A new scheme for testing nuclear matter equations of state (EoSs) at high densities using constraints from neutron star (NS) phenomenology and a flow data analysis of heavy-ion collisions is suggested. An acceptable EoS shall not allow the direct Urca process to occur in NSs with masses below 1.5M · , and also shall not contradict flow and kaon production data of heavy-ion collisions. Compact star constraints include the mass measurements of 2.1±0.2M · (1σ level) for PSR J0751+1807 and of 2.0±0.1M · from the innermost stable circular orbit for 4U 1636-536, the baryon mass--gravitational mass relationships from Pulsar B in J0737-3039 and the mass-radius relationships from quasiperiodic brightness oscillations in 4U 0614+09 and from the thermal emission of RX J1856-3754. This scheme is applied to a set of relativistic EoSs which are constrained otherwise from nuclear matter saturation properties. We demonstrate on the given examples that the test scheme due to the quality of the newly emerging astrophysical data leads to useful selection criteria for the high-density behavior of nuclear EoSs

Nuclear performance and reliability

International Nuclear Information System (INIS)

Rothwell, G.

1993-01-01

If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive. There has been a significant improvement in nuclear power plant performance, due largely to a decline in the forced outage rate and a dramatic drop in the average number of forced outages per fuel cycle. If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive over time. To encourage further increases in performance, regulatory incentive schemes should reward reactor operators for improved reliability and safety, as well as for improved performance

Level-one modules library for DSNP: Dynamic Simulator for Nuclear Power-plants

International Nuclear Information System (INIS)

Saphier, D.

1978-09-01

The Dynamic Simulator for Nuclear Power-plants (DSNP) is a system of programs and data sets by which a nuclear power plant or part thereof can be simulated at different levels of sophistication. The acronym DSNP is used interchangeably for the DSNP language, for the DSNP precompiler, for the DSNP libraries, and for the DSNP document generator. The DSNP language is a set of simple block oriented statements, which together with the appropriate data, comprise a simulation of a nuclear power plant. The majority of the DSNP statements will result in the inclusion of a simulated physical module into the program. FORTRAN statements can be inserted with no restrictions among DSNP statements

Virtual experiment instrument of nuclear pulse measuring

International Nuclear Information System (INIS)

Shan Jian; Zhao Xiuliang; Yu Hong; Zhang Meiqin

2009-01-01

Study on the scheme of application of virtual instrument(VI) technique in measuring of nuclear pulse. The system of Counter based on technology of LabVIEW and NI company's products USB-6009-DAQ is developed. Virtual nuclear instrument-Virtual Counter is realized. This system extends the application of technology of virtual instrument. The experimental results indicate that the system of Counter had the good counting measuring function of Nuclear Pulse. (authors)

Higher serum levels of rheumatoid factor and anti-nuclear antibodies in helicobacter pylori-infected peptic ulcer patients.

Science.gov (United States)

Jafarzadeh, Abdollah; Nemati, Maryam; Rezayati, Mohammad Taghi; Nabizadeh, Mansooreh; Ebrahimi, Medhi

2013-07-01

H. pylori infection has been associated with some autoimmune disorders. The aim of this study was to evaluate the serum concentrations of rheumatoid factor and anti-nuclear antibodies in H. pylori-infected peptic ulcer patients, H. pylori-infected asymptomatic carriers and a healthy control group. A Total of 100 H. pylori-infected peptic ulcer patients, 65 asymptomatic carriers and 30 healthy H. pylori-negative subjects (as a control group) were enrolled into study. Serum samples of participants tested for the levels of rheumatoid factor and anti-nuclear antibodies by use of ELISA. The mean serum levels of rheumatoid factor and anti-nuclear antibodies in peptic ulcer group was significantly higher in comparison to the control group (ppeptic ulcer patients and asymptomatic carriers groups regarding the mean serum levels of rheumatoid factor and anti-nuclear antibodies. The mean serum levels of rheumatoid factor in men with peptic ulcer was significantly higher compared to the group of healthy men (ppeptic ulcer patients or asymptomatic carriers groups, the mean serum levels of rheumatoid factor was higher than that in healthy women, but the differences were not statistically significant. Also, no significant differences were observed between men and women with peptic ulcer, asymptomatic carriers control groups based on the serum levels of anti-nuclear antibodies. The results showed higher serum levels of rheumatoid factor and anti-nuclear antibodies in H. pylori-infected patients with peptic ulcer disease which represent the H. pylori-related immune disturbance in these patients. Additional follow-up studies are necessary to clarify the clinical significance of these autoantibodies in patients with H. pylori infection.

Multiobjective hyper heuristic scheme for system design and optimization

Science.gov (United States)

Rafique, Amer Farhan

2012-11-01

As system design is becoming more and more multifaceted, integrated, and complex, the traditional single objective optimization trends of optimal design are becoming less and less efficient and effective. Single objective optimization methods present a unique optimal solution whereas multiobjective methods present pareto front. The foremost intent is to predict a reasonable distributed pareto-optimal solution set independent of the problem instance through multiobjective scheme. Other objective of application of intended approach is to improve the worthiness of outputs of the complex engineering system design process at the conceptual design phase. The process is automated in order to provide the system designer with the leverage of the possibility of studying and analyzing a large multiple of possible solutions in a short time. This article presents Multiobjective Hyper Heuristic Optimization Scheme based on low level meta-heuristics developed for the application in engineering system design. Herein, we present a stochastic function to manage meta-heuristics (low-level) to augment surety of global optimum solution. Generic Algorithm, Simulated Annealing and Swarm Intelligence are used as low-level meta-heuristics in this study. Performance of the proposed scheme is investigated through a comprehensive empirical analysis yielding acceptable results. One of the primary motives for performing multiobjective optimization is that the current engineering systems require simultaneous optimization of conflicting and multiple. Random decision making makes the implementation of this scheme attractive and easy. Injecting feasible solutions significantly alters the search direction and also adds diversity of population resulting in accomplishment of pre-defined goals set in the proposed scheme.

Float level switch for a nuclear power plant containment vessel

International Nuclear Information System (INIS)

Powell, J.G.

1993-01-01

This invention is a float level switch used to sense rise or drop in water level in a containment vessel of a nuclear power plant during a loss of coolant accident. The essential components of the device are a guide tube, a reed switch inside the guide tube, a float containing a magnetic portion that activates a reed switch, and metal-sheathed, ceramic-insulated conductors connecting the reed switch to a monitoring system outside the containment vessel. Special materials and special sealing techniques prevent failure of components and allow the float level switch to be connected to a monitoring system outside the containment vessel. 1 figures

Float level switch for a nuclear power plant containment vessel

Science.gov (United States)

Powell, James G.

1993-01-01

This invention is a float level switch used to sense rise or drop in water level in a containment vessel of a nuclear power plant during a loss of coolant accident. The essential components of the device are a guide tube, a reed switch inside the guide tube, a float containing a magnetic portion that activates a reed switch, and metal-sheathed, ceramic-insulated conductors connecting the reed switch to a monitoring system outside the containment vessel. Special materials and special sealing techniques prevent failure of components and allow the float level switch to be connected to a monitoring system outside the containment vessel.

The Hagedorn spectrum, nuclear level densities and first order phase transitions

Energy Technology Data Exchange (ETDEWEB)

Moretto, Luciano G., E-mail: lgmoretto@lbl.gov [Department of Chemistry, University of California, Berkeley, Lawrence Berkeley National Laboratory 1 Cyclotron Road, Berkeley, CA 94720 (United States); Larsen, A. C.; Guttormsen, M.; Siem, S. [Department of Physics, University of Oslo, N-0316 Oslo (Norway)

2015-10-15

An exponential mass spectrum, like the Hagedorn spectrum, with slope 1/T{sub H} was interpreted as fixing an upper limiting temperature T{sub H} that the system can achieve. However, thermodynamically, such spectrum indicates a 1{sup st} order phase transition at a fixed temperature T{sub H}. A much lower energy example is the log linear level nuclear density below the neutron binding energy that prevails throughout the nuclear chart. We show that, for non-magic nuclei, such linearity implies a 1{sup st} order phase transition from the pairing superfluid to an ideal gas of quasi particles.

Decay schemes of the radioactive nuclei A = 225 to 229. Skhemy raspada radioaktivnykh yader A = 225 - 229

Energy Technology Data Exchange (ETDEWEB)

Dzhelepov, B S; Ivanov, R B; Mikhailova, M A

1976-01-01

This monograph is devoted to properties of atomic nuclei with mass numbers A = 225 to 229. The book collects and systematizes all of the experimental data characterizing properties of radioactive isotopes: information concerning masses of nuclei, magnetic and electric moments, lifetimes of nuclear states, the most reliable information on characteristics of radiations, quantum characteristics of levels and other properties of the studied nuclei. On basis of a critical analysis of the totality of information, decay schemes of radioactive nuclei with mass numbers A = 225 to 229 were constructed, as well as the series of excited states of the isotopes which lie in this region of nuclei.

Attempted development and cross-validation of predictive models of individual-level and organizational-level turnover of nuclear power operators

International Nuclear Information System (INIS)

Vasa-Sideris, S.J.

1989-01-01

Nuclear power accounts for 209% of the electric power generated in the U.S. by 107 nuclear plants which employ over 8,700 operators. Operator turnover is significant to utilities from the economic point of view since it costs almost three hundred thousand dollars to train and qualify one operator, and because turnover affects plant operability and therefore plant safety. The study purpose was to develop and cross-validate individual-level and organizational-level models of turnover of nuclear power plant operators. Data were obtained by questionnaires and from published data for 1983 and 1984 on a number of individual, organizational, and environmental predictors. Plants had been in operation for two or more years. Questionnaires were returned by 29 out of 50 plants on over 1600 operators. The objectives were to examine the reliability of the turnover criterion, to determine the classification accuracy of the multivariate predictive models and of categories of predictors (individual, organizational, and environmental) and to determine if a homology existed between the individual-level and organizational-level models. The method was to examine the shrinkage that occurred between foldback design (in which the predictive models were reapplied to the data used to develop them) and cross-validation. Results did not support the hypothesis objectives. Turnover data were accurate but not stable between the two years. No significant differences were detected between the low and high turnover groups at the organization or individual level in cross-validation. Lack of stability in the criterion, restriction of range, and small sample size at the organizational level were serious limitations of this study. The results did support the methods. Considerable shrinkage occurred between foldback and cross-validation of the models

Multi-level iteration optimization for diffusive critical calculation

International Nuclear Information System (INIS)

Li Yunzhao; Wu Hongchun; Cao Liangzhi; Zheng Youqi

2013-01-01

In nuclear reactor core neutron diffusion calculation, there are usually at least three levels of iterations, namely the fission source iteration, the multi-group scattering source iteration and the within-group iteration. Unnecessary calculations occur if the inner iterations are converged extremely tight. But the convergence of the outer iteration may be affected if the inner ones are converged insufficiently tight. Thus, a common scheme suit for most of the problems was proposed in this work to automatically find the optimized settings. The basic idea is to optimize the relative error tolerance of the inner iteration based on the corresponding convergence rate of the outer iteration. Numerical results of a typical thermal neutron reactor core problem and a fast neutron reactor core problem demonstrate the effectiveness of this algorithm in the variational nodal method code NODAL with the Gauss-Seidel left preconditioned multi-group GMRES algorithm. The multi-level iteration optimization scheme reduces the number of multi-group and within-group iterations respectively by a factor of about 1-2 and 5-21. (authors)

A breed and burn reshuffling scheme for an Astrid-like reactor concept design

Energy Technology Data Exchange (ETDEWEB)

Garcia C, E. Y.; Francois L, J. L., E-mail: eliasgarcerv@hotmail.com [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac 8532, 62550 Jiutepec, Morelos (Mexico)

2016-09-15

The greenhouse emissions has a serious impact on environmental terms, reason why energy supply needs to be provided by low carbon emission technologies. Nuclear power is and environmentally friendly energy with future concepts and designs that ensure safety, and in this paper is taken as a solution to be considered in the energy supply mix. This study presents an extension on the operation of the Advanced Sodium Technological Reactor for Industrial demonstration (Astrid) nuclear reactor through a breed and burn operation to extend the operation of the reactor. The Astrid nuclear reactor is a fourth generation sodium-cooled fast reactor of 1500 MWt h, and it considers an innovative design: the low void effect core (Cfv: Coeur a Faible effet de Vidange sodium) due to the reactor configuration and the radial and axial position of the fuel subassemblies. Previous research in the Astrid-like cores aimed the model validation of a conventional oxide-fueled core and its comparison with a proposed metallic-fueled core. Taking into account the amount of fissile material (mainly 239-Pu) after the first cycle, a reshuffling scheme was suggested, which consists in changing strategically the position of the nuclear fuel assemblies when the reactivity drops near to the critical state of the reactor. Two different reshuffling schemes were simulated in every developed model, having operation extensions of 805 days and 1775 days for the oxide and metallic designs respectively. The implementation of the reshuffling schemes in the developed models enhanced the fuel utilization and could save up to 2.20 and 5.96 tons of plutonium for oxide and metallic designs respectively, which has an economic impact. The breeding of 239-Pu achieved in the fertile zone of the metallic design reached half of the initial concentration of the 239-Pu in the fissile zone and for the oxide design, the breeding reached one third of the initial concentration of the 239-Pu in the fissile zone. (Author)

A breed and burn reshuffling scheme for an Astrid-like reactor concept design

International Nuclear Information System (INIS)

Garcia C, E. Y.; Francois L, J. L.

2016-09-01

The greenhouse emissions has a serious impact on environmental terms, reason why energy supply needs to be provided by low carbon emission technologies. Nuclear power is and environmentally friendly energy with future concepts and designs that ensure safety, and in this paper is taken as a solution to be considered in the energy supply mix. This study presents an extension on the operation of the Advanced Sodium Technological Reactor for Industrial demonstration (Astrid) nuclear reactor through a breed and burn operation to extend the operation of the reactor. The Astrid nuclear reactor is a fourth generation sodium-cooled fast reactor of 1500 MWt h, and it considers an innovative design: the low void effect core (Cfv: Coeur a Faible effet de Vidange sodium) due to the reactor configuration and the radial and axial position of the fuel subassemblies. Previous research in the Astrid-like cores aimed the model validation of a conventional oxide-fueled core and its comparison with a proposed metallic-fueled core. Taking into account the amount of fissile material (mainly 239-Pu) after the first cycle, a reshuffling scheme was suggested, which consists in changing strategically the position of the nuclear fuel assemblies when the reactivity drops near to the critical state of the reactor. Two different reshuffling schemes were simulated in every developed model, having operation extensions of 805 days and 1775 days for the oxide and metallic designs respectively. The implementation of the reshuffling schemes in the developed models enhanced the fuel utilization and could save up to 2.20 and 5.96 tons of plutonium for oxide and metallic designs respectively, which has an economic impact. The breeding of 239-Pu achieved in the fertile zone of the metallic design reached half of the initial concentration of the 239-Pu in the fissile zone and for the oxide design, the breeding reached one third of the initial concentration of the 239-Pu in the fissile zone. (Author)

TE/TM scheme for computation of electromagnetic fields in accelerators

International Nuclear Information System (INIS)

Zagorodnov, Igor; Weiland, Thomas

2005-01-01

We propose a new two-level economical conservative scheme for short-range wake field calculation in three dimensions. The scheme does not have dispersion in the longitudinal direction and is staircase free (second order convergent). Unlike the finite-difference time domain method (FDTD), it is based on a TE/TM like splitting of the field components in time. Additionally, it uses an enhanced alternating direction splitting of the transverse space operator that makes the scheme computationally as effective as the conventional FDTD method. Unlike the FDTD ADI and low-order Strang methods, the splitting error in our scheme is only of fourth order. As numerical examples show, the new scheme is much more accurate on the long-time scale than the conventional FDTD approach

Sources of funding for community schemes

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-11-01

There is an increasing level of interest amongst community groups in the UK to become involved in the development of renewable energy schemes. Often however these community groups have only limited funds of their own, so any additional funds that can be identified to help fund their renewable energy scheme can be very useful. There are a range of funding sources available that provide grants or loans for which community groups are eligible to apply. Few of these funding sources are targeted towards renewable energy specifically, nevertheless the funds may be applicable to renewable energy schemes under appropriate circumstances. To date, however, few of these funds have been accessed by community groups for renewable energy initiatives. One of the reasons for this low take-up of funds on offer could be that the funding sources may be difficult and time-consuming to identify, especially where the energy component of the fund is not readily apparent. This directory draws together details about many of the principal funding sources available in the UK that may consider providing funds to community groups wanting to develop a renewable energy scheme. (author)

The scope and nature of the problem of high level nuclear waste disposal

International Nuclear Information System (INIS)

Jennekens, J.

1981-09-01

The disposal of high level nuclear waste poses a challenge to the Canadian technical and scientific communities, but a much greater challenge to government and industry leaders who must convince the public that the so-called 'problem' can be resolved by a pragmatic approach utilizing existing skills and knowledge. This paper outlines the objectives of radioactive waste management, the quantities of high level waste expected to be produced by the Canadian nuclear power program, the regulatory process which will apply and the government initiatives which have been and will be taken to ensure that the health, safety, security, and environmental interests of the public will be protected. (author)

Atmospheric Dispersion Simulation for Level 3 PSA at Ulchin Nuclear Site using a PUFF model

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Jun; Han, Seok-Jung; Jeong, Hyojoon; Jang, Seung-Cheol [KAERI, Daejeon (Korea, Republic of)

2015-05-15

Air dispersion prediction is a key in the level 3 PSA to predict radiation releases into the environment for preparing an effective strategy for an evacuation as a basis of the emergency preparedness. To predict the atmospheric dispersion accurately, the specific conditions of the radiation release location should be considered. There are various level 3 PSA tools and MACSS2 is one of the widely used level 3 PSA tools in many countries including Korea. Due to the characteristics of environmental conditions in Korea, it should be demonstrated that environmental conditions of Korea nuclear sites can be appropriately illustrated by the tool. In Korea, because all nuclear power plants are located on coasts, sea and land breezes might be a significant factor. The objectives of this work is to simulate the atmospheric dispersion for Ulchin nuclear site in Korea using a PUFF model and to generate the data which can be used for the comparison with that of PLUME model. A nuclear site has own atmospheric dispersion characteristics. Especially in Korea, nuclear sites are located at coasts and it is expected that see and land breeze effects are relatively high. In this work, the atmospheric dispersion at Ulchin nuclear site was simulated to evaluate the effect of see and land breezes in four seasons. In the simulation results, it was observed that the wind direction change with time has a large effect on atmospheric dispersion. If the result of a PLUME model is more conservative than most severe case of a PUFF model, then the PLUME model could be used for Korea nuclear sites in terms of safety assessment.

Advanced I and C system of security level for nuclear power station

International Nuclear Information System (INIS)

Liu Yanyang

2001-01-01

Advanced I and C system of security level using for PWR developed by Framatome and Schneider collective, SPINLINE3, are introduced. The technology is used to outside reactor nuclear measurement system in Qinshan II period. It's succeed benefits by Framatome and Schneider's more years development experience in nuclear power station digitallization security level I and C system field, which improve security and reliability of PWR, and, easy operation and maintains. SPINLINE3 based on digitallization and modularization technical proposal, and covered entireness reactor protect system and correlative control system. The paper also introduce CLARISSE (computer aided design aid) and SCADE (embedded software aid) for developing SPINLINE3. SPINLINE3 fills correlative IS and rule, based on software and hardware unit which certificate and launch into operation. After brief review of Framatome and Schneider's experience, the paper are introducing design guideline, application technology and how to fill demand of security level I and C system

Status of commercial nuclear high-level waste disposal. Special report

International Nuclear Information System (INIS)

Dau, G.J.; Williams, R.F.

1976-09-01

The results of this review, presented in the form of a functional description of high level waste management system, shows that technology is available to dispose of nuclear waste safely by several different processes. The most attractive alternative in terms of available technology and shortness of time to demonstrate it at commercial scale is a system that converts the waste to a solid by immobilizing the radioactive elements in a glass matrix. Brief comments are also given on international efforts in high level waste management and advanced disposal concepts

Analytical theory for the nuclear level shift of hadronic atoms

International Nuclear Information System (INIS)

Kudryavtsev, A.E.; Lisin, V.I.; Popov, V.S.

1982-01-01

The spectrum problem in the Coulomb potential distorted at small distances is considered. Nuclear shifts of 3-levels in p anti p and Σ - p atoms are calculated. The probabilities of radiative transitions from p-states to the shifted s-states in hadronic atom are also given. It is shown that the reconstruction of atomic levels switches to oscillation regime when absorption increases. The limits of applicability of the perturbation theory in terms of the scattering length for different values of absorption is discussed. An exactly solvable model, Coulomb plus Yamaguchi potential, is considered

Study of the decay scheme of 159Tm

International Nuclear Information System (INIS)

Aguer, Pierre; Bastin, Genevieve; Chin Fan Liang; Libert, Jean; Paris, Pierre; Peghaire, Alain

1975-01-01

The energy levels of 159 Er have been investigated from the decay of 159 Tm (T(1/2)=9mn). Samples were obtained by (p,xn) reaction and on-line separation through Isocele facility. A level scheme is proposed with 24 levels between 0 and 1.3MeV [fr

Geology of high-level nuclear waste disposal

International Nuclear Information System (INIS)

Roxburgh, I.S.

1988-01-01

The concept of geological disposal is set out by describing the major rock types in terms of their ability to isolate high-level nuclear waste. The advantages and problems posed by particular rock formations are explored and the design and construction of geological repositories is considered, along with the methods used to estimate their safety. It gives special consideration to the use of sea-covered rock and sediment as well as the on-land situation. Throughout the book the various principles and problems inherent in geological disposal are explained and illustrated by reference to a multitude of European and North American case studies, backed up by a large number of tables, figures and an extensive bibliography

Oxygen- and nitrogen-chemisorbed carbon nanostructures for Z-scheme photocatalysis applications

International Nuclear Information System (INIS)

Qian Zhao; Pathak, Biswarup; Nisar, Jawad; Ahuja, Rajeev

2012-01-01

Here focusing on the very new experimental finding on carbon nanomaterials for solid-state electron mediator applications in Z-scheme photocatalysis, we have investigated different graphene-based nanostructures chemisorbed by various types and amounts of species such as oxygen (O), nitrogen (N) and hydroxyl (OH) and their electronic structures using density functional theory. The work functions of different nanostructures have also been investigated by us to evaluate their potential applications in Z-scheme photocatalysis for water splitting. The N-, O–N-, and N–N-chemisorbed graphene-based nanostructures (32 carbon atoms supercell, corresponding to lattice parameter of about 1 nm) are found promising to be utilized as electron mediators between reduction level and oxidation level of water splitting. The O- or OH-chemisorbed nanostructures have potential to be used as electron conductors between H 2 -evolving photocatalysts and the reduction level (H + /H 2 ). This systematic study is proposed to understand the properties of graphene-based carbon nanostructures in Z-scheme photocatalysis and guide experimentalists to develop better carbon-based nanomaterials for more efficient Z-scheme photocatalysis applications in the future.

Finite Boltzmann schemes

NARCIS (Netherlands)

Sman, van der R.G.M.

2006-01-01

In the special case of relaxation parameter = 1 lattice Boltzmann schemes for (convection) diffusion and fluid flow are equivalent to finite difference/volume (FD) schemes, and are thus coined finite Boltzmann (FB) schemes. We show that the equivalence is inherent to the homology of the

Comparison of actinides and fission products recycling scheme with the normal plutonium recycling scheme in fast reactors

Directory of Open Access Journals (Sweden)

Salahuddin Asif

2013-01-01

Full Text Available Multiple recycling of actinides and non-volatile fission products in fast reactors through the dry re-fabrication/reprocessing atomics international reduction oxidation process has been studied as a possible way to reduce the long-term potential hazard of nuclear waste compared to that resulting from reprocessing in a wet PUREX process. Calculations have been made to compare the actinides and fission products recycling scheme with the normal plutonium recycling scheme in a fast reactor. For this purpose, the Karlsruhe version of isotope generation and depletion code, KORIGEN, has been modified accordingly. An entirely novel fission product yields library for fast reactors has been created which has replaced the old KORIGEN fission products library. For the purposes of this study, the standard 26 groups data set, KFKINR, developed at Forschungszentrum Karlsruhe, Germany, has been extended by the addition of the cross-sections of 13 important actinides and 68 most important fission products. It has been confirmed that these 68 fission products constitute about 95% of the total fission products yield and about 99.5% of the total absorption due to fission products in fast reactors. The amount of fissile material required to guarantee the criticality of the reactor during recycling schemes has also been investigated. Cumulative high active waste per ton of initial heavy metal is also calculated. Results show that the recycling of actinides and fission products in fast reactors through the atomics international reduction oxidation process results in a reduction of the potential hazard of radioactive waste.

Evaluation of the Norwegian R&D Tax Credit Scheme

Directory of Open Access Journals (Sweden)

Ådne Cappelen

2010-11-01

Full Text Available We find that the Norwegian R&D tax credit scheme introduced in 2002 mainly works as intended. The scheme is cost-effective and it is used by a large number of firms. It stimulates these firms to invest more in R&D, and, in particular, the effect is positive for small firms with little R&D experience. The returns on the R&D investments supported by the scheme are positive and generally not different from the returns to other R&D investments. We have found examples of what can be interpreted as tax motivated adjustments to the scheme, but to some extent this must be accepted as a cost to subsidy and support schemes intended for use by a large number of economic agents. This is particularly so when attempts are made to keep administrative expenditures and control routines at a low level.

The ICRM non-neutron nuclear data request list

International Nuclear Information System (INIS)

Bambynek, W.

1980-01-01

This survey of the requirement of users of non-neutron nuclear data was carried out in an attempt to support the activity of the International Committee for Radionuclide Metrology (ICRM) Working Group Non-Neutron Nuclear Data. It includes mainly information on radionuclide decay scheme parameters and some atomic data

Digitization and simulation realization of full range control system for steam generator water level

International Nuclear Information System (INIS)

Qian Hong; Ye Jianhua; Qian Fei; Li Chao

2010-01-01

In this paper, a full range digital control system for the steam generator water level is designed by a control scheme of single element control and three-element cascade feed-forward control, and the method to use the software module configuration is proposed to realize the water level control strategy. This control strategy is then applied in the operation of the nuclear power simulation machine. The simulation result curves indicate that the steam generator water level maintains constant at the stable operation condition, and when the load changes, the water level changes but finally maintains the constant. (authors)

Atmospheric methods for nuclear test monitoring

International Nuclear Information System (INIS)

Simons, D.J.

1995-01-01

The U.S. DOE sponsored research investigating atmospheric infrasound as a means of detecting both atmospheric and underground nuclear tests. Various detection schemes were examined and were found to be effective for different situations. It has been discovered that an enhanced sensitivity is realizable for the very lowest frequency disturbances by detecting the infrasound at the top of the atmosphere using ratio sound techniques. These techniques are compared to more traditional measurement schemes

Slovenske elektrarne, a.s., Mochovce Nuclear Power Plant

International Nuclear Information System (INIS)

1998-01-01

In this booklet the uranium atom nucleus fission as well as electricity generation in a nuclear power plant (primary circuit, reactor, reactor pressure vessel, fuel assembly, control rod and reactor power control) are explained. Scheme of electricity generation in nuclear power plant and Cross-section of Mochovce Nuclear Power Plant unit are included. In next part a reactor scram, refuelling of fuel, instrumentation and control system as well as principles of nuclear safety and safety improvements are are described

Evaluation of PBL schemes in WRF for high Arctic conditions

DEFF Research Database (Denmark)

Kirova-Galabova, Hristina; Batchvarova, Ekaterina; Gryning, Sven-Erik

2015-01-01

was examined through two configurations (25 vertical levels and 4km grid step, 42 vertical levels and 1.33 km grid step). WRF was run with two planetary boundary layer schemes: Mellor –Yamada – Janjic with local vertical closure and non – local Yonsei University scheme. Temporal evolution of planetary boundary...... for temperature, above 150 m for relative humidity and for all levels for wind speed. Direct comparison of model and measured data showed that vertical profiles of studied parameters were reconstructed by the model relatively better in cloudy sky conditions, compared to clear skies....

Application of PSA to Assess the Safety Level of Nuclear Power Plants

International Nuclear Information System (INIS)

Berg, H. P.; Goertz, R.

2000-01-01

This paper reviews the application of PSA in German nuclear power plant regulation. From a fundamental point of view, it has to be mentioned that as stipulated in the corresponding requirements, regulatory decision making in Germany is primarily based on deterministic analyses and evaluations. Therefore, PSA is not used as a stand alone but as a supplementary basis. In this context PSA has developed a valuable tool with continuously growing importance. Level 1+ PSAs are now elaborated for all German nuclear power plants in operation, most of them are already reviewed by the competent supervisory authority and its experts. Current research activities on the federal level primarily concentrate on the further development of the methodology in the areas human factor, common cause failures, accident management measures and reduction of uncertainties in methods and data. (author)

Status of the United States' high-level nuclear waste disposal program

International Nuclear Information System (INIS)

Rusche, B.

1985-01-01

The Nuclear Waste Policy Act of 1982 is a remarkable piece of legislation in that there is general agreement on its key provisions. Nevertheless, this is a program intended to span more than a century, with some choices by Congress, states, Indian tribes and the nuclear power industry yet to be made. The crafters of the Act clearly recognized this. And further, the crafters recognized ''. . .that. . .state, Indian tribe and public participation in the planning and development of repositories is essential in order to promote public confidence in the safety of disposal of such waste and spent fuel . . . High-level radioactive waste and spent nuclear fuel have become major subjects of public concern, and appropriate precautions must be taken to ensure that such waste and spent fuel do not adversely affect the public health and safety and the environment for this or future generations

Catalog of gamma-rays unplaced in radioactive decay schemes

International Nuclear Information System (INIS)

Narita, Tsutomu; Kitao, Kensuke.

1991-03-01

A catalog is made for gamma-rays emitted in decay of radioactive nuclides but not placed in their decay schemes. It consists of two tables. In Table 1, the number of these unplaced gamma-ray components by a nuclide is given together with the fraction of total intensity of these gamma-rays to that of all observed gamma-rays. In Table 2, the unplaced gamma-rays are arranged in order of increasing energy. Each line of this table contains the gamma-ray energy, intensity, nuclide identification, and energies and intensities of the most prominent gamma-rays from the decay of the radionuclides. This catalog is a compilation from Evaluated Nuclear Structure Data File (ENSDF) maintained by National Nuclear Data Center at Brookhaven National Laboratory, of at February 1990. (author)

Global and local level density models

International Nuclear Information System (INIS)

Koning, A.J.; Hilaire, S.; Goriely, S.

2008-01-01

Four different level density models, three phenomenological and one microscopic, are consistently parameterized using the same set of experimental observables. For each of the phenomenological models, the Constant Temperature Model, the Back-shifted Fermi gas Model and the Generalized Superfluid Model, a version without and with explicit collective enhancement is considered. Moreover, a recently published microscopic combinatorial model is compared with the phenomenological approaches and with the same set of experimental data. For each nuclide for which sufficient experimental data exists, a local level density parameterization is constructed for each model. Next, these local models have helped to construct global level density prescriptions, to be used for cases for which no experimental data exists. Altogether, this yields a collection of level density formulae and parameters that can be used with confidence in nuclear model calculations. To demonstrate this, a large-scale validation with experimental discrete level schemes and experimental cross sections and neutron emission spectra for various different reaction channels has been performed

Fuel operation of EDF nuclear fleet presentation of the centralized organization for operational engineering at the nuclear generation division

International Nuclear Information System (INIS)

Paulin, Ph.

2006-01-01

The main feature of EDF Nuclear Fleet is the standardization, with 'series' of homogeneous plants (same equipment, fuel and operation technical documents). For fuel operation, this standardization is related to the concept of 'fuel management scheme' (typical fuel reloads with fixed number and enrichment of fresh assemblies) for a whole series of plants. The context of the Nuclear Fleet lead to the choice of a centralized organization for fuel engineering at the Nuclear Generation Division (DPN), located at UNIPE (National Department for Fleet Operation Engineering) in Lyon. The main features of this organization are the following: - Centralization of the engineering activities for fuel operation support in the Fuel Branch of UNIPE, - Strong real-time link with the nuclear sites, - Relations with various EDF Departments in charge of design, nuclear fuel supply and electricity production optimization. The purposes of the organization are: - Standardization of operational engineering services and products, - Autonomy with independent methods and computing tools, - Reactivity with a technical assistance for sites (24 hours 'hot line'), - Identification of different levels (on site and off site) to solve core operation problems, - Collection, analysis and valorization of operation feedback, - Contribution to fuel competence global management inside EDF. This paper briefly describes the organization. The main figures of annual engineering production are provided. A selection of examples illustrates the contribution to the Nuclear Fleet performance. (authors)

Segmentation Scheme for Safety Enhancement of Engineered Safety Features Component Control System

International Nuclear Information System (INIS)

Lee, Sangseok; Sohn, Kwangyoung; Lee, Junku; Park, Geunok

2013-01-01

Common Caused Failure (CCF) or undetectable failure would adversely impact safety functions of ESF-CCS in the existing nuclear power plants. We propose the segmentation scheme to solve these problems. Main function assignment to segments in the proposed segmentation scheme is based on functional dependency and critical function success path by using the dependency depth matrix. The segment has functional independence and physical isolation. The segmentation structure is that prohibit failure propagation to others from undetectable failures. Therefore, the segmentation system structure has robustness to undetectable failures. The segmentation system structure has functional diversity. The specific function in the segment defected by CCF, the specific function could be maintained by diverse control function that assigned to other segments. Device level control signals and system level control signals are separated and also control signal and status signals are separated due to signal transmission paths are allocated independently based on signal type. In this kind of design, single device failure or failures on signal path in the channel couldn't result in the loss of all segmented functions simultaneously. Thus the proposed segmentation function is the design scheme that improves availability of safety functions. In conventional ESF-CCS, the single controller generates the signal to control the multiple safety functions, and the reliability is achieved by multiplication within the channel. This design has a drawback causing the loss of multiple functions due to the CCF (Common Cause Failure) and single failure Heterogeneous controller guarantees the diversity ensuring the execution of safety functions against the CCF and single failure, but requiring a lot of resources like manpower and cost. The segmentation technology based on the compartmentalization and functional diversification decreases the CCF and single failure nonetheless the identical types of controllers

Segmentation Scheme for Safety Enhancement of Engineered Safety Features Component Control System

Energy Technology Data Exchange (ETDEWEB)

Lee, Sangseok; Sohn, Kwangyoung [Korea Reliability Technology and System, Daejeon (Korea, Republic of); Lee, Junku; Park, Geunok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

Common Caused Failure (CCF) or undetectable failure would adversely impact safety functions of ESF-CCS in the existing nuclear power plants. We propose the segmentation scheme to solve these problems. Main function assignment to segments in the proposed segmentation scheme is based on functional dependency and critical function success path by using the dependency depth matrix. The segment has functional independence and physical isolation. The segmentation structure is that prohibit failure propagation to others from undetectable failures. Therefore, the segmentation system structure has robustness to undetectable failures. The segmentation system structure has functional diversity. The specific function in the segment defected by CCF, the specific function could be maintained by diverse control function that assigned to other segments. Device level control signals and system level control signals are separated and also control signal and status signals are separated due to signal transmission paths are allocated independently based on signal type. In this kind of design, single device failure or failures on signal path in the channel couldn't result in the loss of all segmented functions simultaneously. Thus the proposed segmentation function is the design scheme that improves availability of safety functions. In conventional ESF-CCS, the single controller generates the signal to control the multiple safety functions, and the reliability is achieved by multiplication within the channel. This design has a drawback causing the loss of multiple functions due to the CCF (Common Cause Failure) and single failure Heterogeneous controller guarantees the diversity ensuring the execution of safety functions against the CCF and single failure, but requiring a lot of resources like manpower and cost. The segmentation technology based on the compartmentalization and functional diversification decreases the CCF and single failure nonetheless the identical types of

Mineral-modeled ceramics for long-term storage of high-level nuclear wastes

International Nuclear Information System (INIS)

Vance, E.R.

1980-01-01

Over the past ten years, Penn State's Materials Research Laboratory has done extensive work on mineral-modeled ceramics for high-level nuclear waste storage. These ceramics are composed of several mineral analogues that form a monolithic polycrystalline aggregate. Mineral-modeling can be made in a similar fashion to nuclear waste glasses, and their naturally occurring analogues are known to last millions, and even billions, of years in hot, wet conditions. It is believed that such ceramics could reduce dispersal of radionuclides by leaching to a minimum

Recent Advances in Low-Level Nuclear Measurements at the CEA

International Nuclear Information System (INIS)

Mahe, C.; Lamadie, F.; Le Goaller, C.

2009-01-01

For several years the CEA has been performing nuclear measurements at different stages of decommissioning projects. The characterization tools initially developed for high-level radioactive waste analysis must be adapted to a new area of application: low-level measurements. Recent technical improvements in gamma imaging, gamma spectrometry detectors, and data analysis make it possible to provide relevant radiological data for waste management, as well as to develop robust and optimized decommissioning scenarios from the initial dose rate mapping to the final declared activity. These techniques have been implemented at various nuclear sites for both trial measurement campaigns and expert investigations to localize residual contamination, to identify the radioelements and to provide an accurate estimate of the declarable activity. Different types of measurements and devices have been used: gamma cameras, coded aperture techniques, alpha imaging prototypes, gamma spectrometry detectors (CdZnTe, HPGe, NaI, and LaBr 3 ), dose rate cartography, and calculation codes (Mercure, MCNP, etc.), all of which provide complementary data for radioactive waste categorization. This paper describes the latest developments and methods deployed on decommissioning projects focusing on low-level in situ applications. Waste drum characterization and in situ glove box measurements are discussed and the technologies and performance of gamma imaging systems, gamma spectrometry detectors, calculation codes and software are described. The paper concludes with a review of future developments and tests necessary for these applications. (authors)

Spin assignments of nuclear levels above the neutron binding energy in $^{88}$Sr

CERN Multimedia

Neutron resonances reveal nuclear levels in the highly excited region of the nucleus around the neutron binding energy. Nuclear level density models are therefore usually calibrated to the number of observed levels in neutron-induced reactions. The gamma-ray cascade from the decay of the highly excited compound nucleus state to the ground state show dierences dependent on the initial spin. This results in a dierence in the multiplicity distribution which can be exploited. We propose to use the 4${\\pi}$ total absorption calorimeter (TAC) at the n TOF facility to determine the spins of resonances formed by neutrons incident on a metallic $^{87}$Sr sample by measuring the gamma multiplicity distributions for the resolved resonances. In addition we would like to use the available enriched $^{87}$Sr target for cross section measurements with the C$\\scriptscriptstyle{6}$D$\\scriptscriptstyle{6}$ detector setup.

Dose estimation for nuclear power plant 4 accident in Taiwan at Fukushima nuclear meltdown emission level

International Nuclear Information System (INIS)

Tang, Mei-Ling; Tsuang, Ben-Jei; Kuo, Pei-Hsuan

2016-01-01

An advanced Gaussian trajectory dispersion model is used to evaluate the evacuation zone due to a nuclear meltdown at the Nuclear Power Plant 4 (NPP4) in Taiwan, with the same emission level as that occurred at Fukushima nuclear meltdown (FNM) in 2011. Our study demonstrates that a FNM emission level would pollute 9% of the island's land area with annual effective dose ≥50 mSv using the meteorological data on 11 March 2011 in Taiwan. This high dose area is also called permanent evacuation zone (denoted as PEZ). The PEZ as well as the emergency-planning zone (EPZ) are found to be sensitive to meteorological conditions on the event. In a sunny day under the dominated NE wind conditions, the EPZ can be as far as 100 km with the first 7-day dose ≥20 mSv. Three hundred sixty-five daily events using the meteorological data from 11 March 2011 to 9 March 2012 are evaluated. It is found that the mean land area of Taiwan in becoming the PEZ is 11%. Especially, the probabilities of the northern counties/cities (Keelung, New Taipei, Taipei, Taoyuan, Hsinchu City, Hsinchu County and Ilan County) to be PEZs are high, ranging from 15% in Ilan County to 51% in Keelung City. Note that the total population of the above cities/counties is as high as 10 million people. Moreover, the western valleys of the Central Mountain Range are also found to be probable being PEZs, where all of the reservoirs in western Taiwan are located. For example, the probability can be as high as 3% in the far southern-most tip of Taiwan Island in Pingtung County. This shows that the entire populations in western Taiwan can be at risk due to the shortage of clean water sources under an event at FNM emission level, especially during the NE monsoon period. - Highlights: • An advanced Gaussian-type trajectory model to evaluate the evacuation zone at Nuclear Power Plant 4 in Taiwan. • Mean land area of Taiwan in becoming the permanent evacuation zone is 11%. • The probabilities of the northern

Four themes that underlie the high-level nuclear waste management program

International Nuclear Information System (INIS)

Sprecher, W.M.

1989-01-01

In 1982, after years of deliberation and in response to mounting pressures from environmental, industrial, and other groups, the US Congress enacted the Nuclear Waste Policy Act (NWPA) of 1982, which was signed into law by the President in January 1983. That legislation signified a major milestone in the nation's management of high-level nuclear waste, since it represented a consensus among the nation's lawmakers to tackle a problem that had evaded solution for decades. Implementation of the NWPA has proven to be exceedingly difficult, as attested by the discord generated by the US Department of Energy's (DOE's) geologic repository and monitored retrievable storage (MRS) facility siting activities. The vision that motivated the crafters of the 1982 act became blurred as opposition to the law increased. After many hearings that underscored the public's concern with the waste management program, the Congress enacted the Nuclear Waste Policy Amendments Act of 1987 (Amendments Act), which steamlined and focused the program, while establishing three independent bodies: the MRS Review Commission, the Nuclear Waste Technical Review Board, and the Office of the Nuclear Waste Negotiator. Yet, even as the program evolves, several themes characterizing the nation's effort to solve the waste management problem continue to prevail. The first of these themes has to do with social consciousness, and the others that follow deal with technical leadership, public involvement and risk perceptions, and program conservatism

Hendry collides with nuclear power

International Nuclear Information System (INIS)

Wade, S.

1979-01-01

It is argued that nuclear power is not the answer to future energy needs in the UK. Problems associated with nuclear power programmes are summarized (cost; lead time; ecological; safety; reliability; waste disposal). It is suggested, instead, that conservation is the first key to economic stability over the next decade, and steps are proposed. Particular emphasis is laid on combined heat and power schemes, linked to a district heating network. (U.K.)

An integrated approach for multi-level sample size determination

International Nuclear Information System (INIS)

Lu, M.S.; Teichmann, T.; Sanborn, J.B.

1997-01-01

Inspection procedures involving the sampling of items in a population often require steps of increasingly sensitive measurements, with correspondingly smaller sample sizes; these are referred to as multilevel sampling schemes. In the case of nuclear safeguards inspections verifying that there has been no diversion of Special Nuclear Material (SNM), these procedures have been examined often and increasingly complex algorithms have been developed to implement them. The aim in this paper is to provide an integrated approach, and, in so doing, to describe a systematic, consistent method that proceeds logically from level to level with increasing accuracy. The authors emphasize that the methods discussed are generally consistent with those presented in the references mentioned, and yield comparable results when the error models are the same. However, because of its systematic, integrated approach the proposed method elucidates the conceptual understanding of what goes on, and, in many cases, simplifies the calculations. In nuclear safeguards inspections, an important aspect of verifying nuclear items to detect any possible diversion of nuclear fissile materials is the sampling of such items at various levels of sensitivity. The first step usually is sampling by ''attributes'' involving measurements of relatively low accuracy, followed by further levels of sampling involving greater accuracy. This process is discussed in some detail in the references given; also, the nomenclature is described. Here, the authors outline a coordinated step-by-step procedure for achieving such multilevel sampling, and they develop the relationships between the accuracy of measurement and the sample size required at each stage, i.e., at the various levels. The logic of the underlying procedures is carefully elucidated; the calculations involved and their implications, are clearly described, and the process is put in a form that allows systematic generalization

Developing a contributing factor classification scheme for Rasmussen's AcciMap: Reliability and validity evaluation.

Science.gov (United States)

Goode, N; Salmon, P M; Taylor, N Z; Lenné, M G; Finch, C F

2017-10-01

One factor potentially limiting the uptake of Rasmussen's (1997) Accimap method by practitioners is the lack of a contributing factor classification scheme to guide accident analyses. This article evaluates the intra- and inter-rater reliability and criterion-referenced validity of a classification scheme developed to support the use of Accimap by led outdoor activity (LOA) practitioners. The classification scheme has two levels: the system level describes the actors, artefacts and activity context in terms of 14 codes; the descriptor level breaks the system level codes down into 107 specific contributing factors. The study involved 11 LOA practitioners using the scheme on two separate occasions to code a pre-determined list of contributing factors identified from four incident reports. Criterion-referenced validity was assessed by comparing the codes selected by LOA practitioners to those selected by the method creators. Mean intra-rater reliability scores at the system (M = 83.6%) and descriptor (M = 74%) levels were acceptable. Mean inter-rater reliability scores were not consistently acceptable for both coding attempts at the system level (M T1  = 68.8%; M T2  = 73.9%), and were poor at the descriptor level (M T1  = 58.5%; M T2  = 64.1%). Mean criterion referenced validity scores at the system level were acceptable (M T1  = 73.9%; M T2  = 75.3%). However, they were not consistently acceptable at the descriptor level (M T1  = 67.6%; M T2  = 70.8%). Overall, the results indicate that the classification scheme does not currently satisfy reliability and validity requirements, and that further work is required. The implications for the design and development of contributing factors classification schemes are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Domestic nuclear power plants tested in the Earth's orbits

International Nuclear Information System (INIS)

Gryaznov, G.M.; Pupko, V.Ya.

1995-01-01

The authors review the history of developing the TOPAZ nuclear power units, their design, the fall of the Kosmos-954 satellite with a nuclear unit of thermoelectric type on the territory of Canada. The details of the structural scheme of the TOPAZ nuclear power unit, the main directions of its modification, some aspects of ensuring nuclear and radiation safety are considered as well as the importance of thermoemission units for telecommunication satellites

A method for assay of special nuclear material in high level liquid waste streams

International Nuclear Information System (INIS)

Venkata Subramani, C.R.; Swaminathan, K.; Asuvathraman, R.; Kutty, K.V.G.

2003-01-01

The assay of special nuclear material in the high level liquid waste streams assumes importance as this is the first stage in the extraction cycle and considerable losses of plutonium could occur here. This stream contains all the fission products as also the minor actinides and hence normal nuclear techniques cannot be used without prior separation of the special nuclear material. This paper presents the preliminary results carried out using wavelength dispersive x-ray fluorescence as part of the developmental efforts to assay SNM in these streams by instrumental techniques. (author)

Nuclear damage compensation and energy reform

International Nuclear Information System (INIS)

Yokemoto, Masafumi

2013-01-01

Nuclear damage compensation and energy reform were closely related. Nuclear damage compensation cost should be part of generation cost of nuclear power. Extend of nuclear damage compensation was limited by compensation standard of Tokyo Electric Power Co. (TEPCO) following guidelines of Dispute Reconciliation Committee for Nuclear Damage Compensation. TEPCO had already paid compensation of about two trillion yen until now, which was only a part of total damage compensation cost. TEPCO had been provided more than 3.4 trillion yen by Nuclear Damage Liability Facilitation Cooperation, which would be put back by nuclear operators including TEPCO. TEPCO could obtain present raising funds and try to reconstruct business with restart of nuclear power, which might disturb energy reform. Present nuclear damage compensation scheme had better be reformed with learning more from Minamata disease case in Japan. (T. Tanaka)

Mutual influences of rated currents, short circuit levels, fault durations and integrated protective schemes for industrial distribution MV switchgears

Energy Technology Data Exchange (ETDEWEB)

Gaidano, G. (FIAT Engineering, Torino, Italy); Lionetto, P.F.; Pelizza, C.; Tommazzolli, F.

1979-01-01

This paper deals with the problem of integrated and coordinated design of distribution systems, as regards the definition of system structure and parameters together with protection criteria and schemes. Advantages in system operation, dynamic response, heavier loads with reduced machinery rating margins and overall cost reduction, can be achieved. It must be noted that MV switchgears installed in industrial main distribution substations are the vital nodes of the distribution system. Very large amounts of power (up to 100 MW and more) are conveyed through MV busbars, coming from Utility and from in-plant generators and outgoing to subdistribution substations, to step-down transformers and to main concentrated loads (big drivers, furnaces etc.). Criteria and methods already studied and applied to public distribution are examined to assess service continuity and economics by means of the reduction of thermal stresses, minimization of disturbances and improvement of system stability. The life of network components depends on sizing, on fault energy levels and on probability of fault occurrence. Constructional measures and protection schemes, which reduce probability and duration of faults, are the most important tools to improve overall reliability. The introduction of advanced techniques, mainly based on computer application, not only allows drastic reduction of fault duration, but also permits the system to operate, under any possible contingency, in the optimal conditions, as the computer provides adaptive control. This mode of system management makes it possible to size network components with reference to the true magnitude of system quantities, avoiding expensive oversizing connected to the unflexibility of conventional protection and control schemes.

Two-Factor User Authentication with Key Agreement Scheme Based on Elliptic Curve Cryptosystem

Directory of Open Access Journals (Sweden)

Juan Qu

2014-01-01

Full Text Available A password authentication scheme using smart card is called two-factor authentication scheme. Two-factor authentication scheme is the most accepted and commonly used mechanism that provides the authorized users a secure and efficient method for accessing resources over insecure communication channel. Up to now, various two-factor user authentication schemes have been proposed. However, most of them are vulnerable to smart card loss attack, offline password guessing attack, impersonation attack, and so on. In this paper, we design a password remote user authentication with key agreement scheme using elliptic curve cryptosystem. Security analysis shows that the proposed scheme has high level of security. Moreover, the proposed scheme is more practical and secure in contrast to some related schemes.

The development of the nuclear physics in Latvia

International Nuclear Information System (INIS)

Ulmanis, U.

2003-01-01

The history of the nuclear physics (NP) in Latvia begun in the 50-ies of the past century and is associated with the Institute of Physics (IP) Latvian Academy of Science. The plan of 1952 has contained theoretical works about interaction of elementary particles (P.Kunin and I.Taksar), the use of radioactive isotopes as 'labelled atoms' in industry (the marketing of steel tapes) and other topics. During 1952-1955 in the IP as the leader of NP works has been Arshavir Karamyan, scientific worker of D.Mendeleev All-Union Research Institute of Metrology in St.Petersburg (then Leningrad). He has been also scientific supervisors of the IP scientist Peteris Prokofjevs post-graduate studies in St.Petersburg on 1952-1956. The theme of this thesis was related with the construction of magnetic gamma-spectrometer. During the period 195-1957 the practical use of radioisotopes as labelled atoms and sources of ionising radiation has been developed in laboratory of radioactive methods in automation (leader V.Janushkovskii). At that time different apparatus with radioisotopes for counting of things, regulation of temperature, current, voltage, measure of different liquid levels etc. have been well known in the world (exhibitions, international conferences). The other, isotope laboratory (leader J.Chudars) was connected with research in nuclear spectroscopy and interaction of radiation with matter problems: construction of gamma- and beta spectrometers, gamma-gamma and gamma-beta coincidence schemes, measure of decay schemes of different radioisotopes (L. Pelekis, J.Chudars, I.Taure, L.Bambe) measure of periods of half-decay (V.Breslav) and the gamma-ray scattering in materials (U.Ulmanis and N.Dubinska). The next stage of the development of nuclear physics in Latvia is connected with the research nuclear reactor in Salaspils. (author)

Unequal Error Protected JPEG 2000 Broadcast Scheme with Progressive Fountain Codes

OpenAIRE

Chen, Zhao; Xu, Mai; Yin, Luiguo; Lu, Jianhua

2012-01-01

This paper proposes a novel scheme, based on progressive fountain codes, for broadcasting JPEG 2000 multimedia. In such a broadcast scheme, progressive resolution levels of images/video have been unequally protected when transmitted using the proposed progressive fountain codes. With progressive fountain codes applied in the broadcast scheme, the resolutions of images (JPEG 2000) or videos (MJPEG 2000) received by different users can be automatically adaptive to their channel qualities, i.e. ...

Dose estimation for nuclear power plant 4 accident in Taiwan at Fukushima nuclear meltdown emission level.

Science.gov (United States)

Tang, Mei-Ling; Tsuang, Ben-Jei; Kuo, Pei-Hsuan

2016-05-01

An advanced Gaussian trajectory dispersion model is used to evaluate the evacuation zone due to a nuclear meltdown at the Nuclear Power Plant 4 (NPP4) in Taiwan, with the same emission level as that occurred at Fukushima nuclear meltdown (FNM) in 2011. Our study demonstrates that a FNM emission level would pollute 9% of the island's land area with annual effective dose ≥50 mSv using the meteorological data on 11 March 2011 in Taiwan. This high dose area is also called permanent evacuation zone (denoted as PEZ). The PEZ as well as the emergency-planning zone (EPZ) are found to be sensitive to meteorological conditions on the event. In a sunny day under the dominated NE wind conditions, the EPZ can be as far as 100 km with the first 7-day dose ≥20 mSv. Three hundred sixty-five daily events using the meteorological data from 11 March 2011 to 9 March 2012 are evaluated. It is found that the mean land area of Taiwan in becoming the PEZ is 11%. Especially, the probabilities of the northern counties/cities (Keelung, New Taipei, Taipei, Taoyuan, Hsinchu City, Hsinchu County and Ilan County) to be PEZs are high, ranging from 15% in Ilan County to 51% in Keelung City. Note that the total population of the above cities/counties is as high as 10 million people. Moreover, the western valleys of the Central Mountain Range are also found to be probable being PEZs, where all of the reservoirs in western Taiwan are located. For example, the probability can be as high as 3% in the far southern-most tip of Taiwan Island in Pingtung County. This shows that the entire populations in western Taiwan can be at risk due to the shortage of clean water sources under an event at FNM emission level, especially during the NE monsoon period. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Determination of leveled costs of electric generation for gas plants, coal and nuclear; Determinacion de costos nivelados de generacion electrica para plantas de gas, carbon y nucleares

Energy Technology Data Exchange (ETDEWEB)

Alonso V, G.; Palacios H, J.C.; Ramirez S, J.R.; Gomez, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: galonso@nuclear.inin.mx

2005-07-01

The present work analyzes the leveled costs of electric generation for different types of nuclear reactors known as Generation III, these costs are compared with the leveled costs of electric generation of plants with the help of natural gas and coal. In the study several discount rates were used to determine their impact in the initial investment. The obtained results are comparable with similar studies and they show that it has more than enough the base of the leveled cost the nuclear option it is quite competitive in Mexico. Also in this study it is also thinks about the economic viability of a new nuclear power station in Mexico. (Author)

Using electrochemical separation to reduce the volume of high-level nuclear waste

International Nuclear Information System (INIS)

Slater, S.A.; Gay, E.C.

1998-01-01

Argonne National Laboratory (ANL) has developed an electrochemical separation technique called electrorefining that will treat a variety of metallic spent nuclear fuel and reduce the volume of high-level nuclear waste that requires disposal. As part of that effort, ANL has developed a high throughput electrorefiner (HTER) that has a transport rate approximately three times faster than electrorefiners previously developed at ANL. This higher rate is due to the higher electrode surface area, a shorter transport path, and more efficient mixing, which leads to smaller boundary layers about the electrodes. This higher throughput makes electrorefining an attractive option in treating Department of Energy spent nuclear fuels. Experiments have been done to characterize the HTER, and a simulant metallic fuel has been successfully treated. The HTER design and experimental results is discussed

Nuclear material attractiveness: an assessment of material associated with a closed fuel cycle

International Nuclear Information System (INIS)

Bathke, C.G.; Wallace, R.K.; Hase, K.R.; Jarvinen, G.D.; Ireland, J.R.; Johnson, M.W.; Ebbinghaus, B.B.; Sleaford, B.W.; Robel, M.; Bradley, K.S.; Collins, B.A.; Prichard, A.W.; Smith, B.W.

2010-01-01

This paper examines the attractiveness of materials mixtures containing special nuclear materials (SNM) associated with the various processing steps required for a closed fuel cycle. This paper combines the results from earlier studies that examined the attractiveness of SNM associated with the processing of spent light water reactor (LWR) fuel by various reprocessing schemes and the recycle of plutonium as a mixed oxide (MOX) fuel in LWR with new results for the final, repeated burning of SNM in fast-spectrum reactors: fast reactors and accelerator driven systems (ADS). The results of this paper suggest that all reprocessing products evaluated so far need to be rigorously safeguarded and provided moderate to high levels of physical protection. These studies were performed at the request of the United States Department of Energy (DOE), and are based on the calculation of 'attractiveness levels' that has been couched in terms chosen for consistency with those normally used for nuclear materials in DOE nuclear facilities. The methodology and key findings will be presented. Additionally, how these attractiveness levels relate to proliferation resistance (e.g. by increasing impediments to the diversion, theft, or undeclared production of SNM for the purpose of acquiring a nuclear weapon), and how they could be used to help inform policy makers, will be discussed. (authors)

Nuclear Material Attractiveness: An Assessment Of Material Associated With A Closed Fuel Cycle

International Nuclear Information System (INIS)

Bathke, C.G.; Ebbinghaus, B.; Sleaford, Brad W.; Wallace, R.K.; Collins, Brian A.; Hase, Kevin R.; Robel, Martin; Jarvinen, G.D.; Bradley, Keith S.; Ireland, J.R.; Johnson, M.W.; Prichard, Andrew W.; Smith, Brian W.

2010-01-01

This paper examines the attractiveness of materials mixtures containing special nuclear materials (SNM) associated with the various processing steps required for a closed fuel cycle. This paper combines the results from earlier studies that examined the attractiveness of SNM associated with the processing of spent light water reactor (LWR) fuel by various reprocessing schemes and the recycle of plutonium as a mixed oxide (MOX) fuel in LWR with new results for the final, repeated burning of SNM in fast-spectrum reactors: fast reactors and accelerator driven systems (ADS). The results of this paper suggest that all reprocessing products evaluated so far need to be rigorously safeguarded and provided moderate to high levels of physical protection. These studies were performed at the request of the United States Department of Energy (DOE), and are based on the calculation of 'attractiveness levels' that has been couched in terms chosen for consistency with those normally used for nuclear materials in DOE nuclear facilities. The methodology and key findings will be presented. Additionally, how these attractiveness levels relate to proliferation resistance (e.g. by increasing impediments to the diversion, theft, or undeclared production of SNM for the purpose of acquiring a nuclear weapon), and how they could be used to help inform policy makers, will be discussed.

Nuclear hydrogen production: re-examining the fusion option

International Nuclear Information System (INIS)

Baindur, S.

2007-01-01

This paper describes a scheme for nuclear hydrogen production by fusion. The basic idea is to use nuclear energy of the fuel (hydrogen plasma) to produce molecular hydrogen fro carbon-free hydrogen compounds. The hydrogen is then stored and utilized electrochemically in fuel cells or chemically as molecular hydrogen in internal combustion engines

QoS Support Polling Scheme for Multimedia Traffic in Wireless LAN MAC Protocol

Institute of Scientific and Technical Information of China (English)

YANG Zhijun; ZHAO Dongfeng

2008-01-01

Quality of service (QoS) support is a key attribute for multimedia traffic including video, voice, and data in wireless local area networks (LANs) but is limited in 802.11-based wireless LANs. A polling-based scheme called the point coordination function (PCF) was developed for 802.11 LANs to support the trans-mission of multimedia traffic. However, the PCF is not able to meet the desired practical traffic differentiation requirements for real-time data. This paper describes a QoS support polling scheme based on the IEEE 802.11 medium access control (MAC) protocol. The scheme uses a two-level polling mechanism with the QoS classes differentiated by two different access policies. Stations with higher priority traffic such as key or real-time data form the first level and can access the common channel through an exhaustive access policy. Other stations with lower priority traffic form the second level and can access the channel through a gated access policy. A system model based on imbedded Markov chain theory and a generation function were setup to explicitly analyze the mean information packet waiting time of the two-level polling scheme. Theo-retical and simulation results show that the new scheme efficiently differentiates services to guarantee better QoS and system stability.

A classification scheme for risk assessment methods.

Energy Technology Data Exchange (ETDEWEB)

Stamp, Jason Edwin; Campbell, Philip LaRoche

2004-08-01

This report presents a classification scheme for risk assessment methods. This scheme, like all classification schemes, provides meaning by imposing a structure that identifies relationships. Our scheme is based on two orthogonal aspects--level of detail, and approach. The resulting structure is shown in Table 1 and is explained in the body of the report. Each cell in the Table represent a different arrangement of strengths and weaknesses. Those arrangements shift gradually as one moves through the table, each cell optimal for a particular situation. The intention of this report is to enable informed use of the methods so that a method chosen is optimal for a situation given. This report imposes structure on the set of risk assessment methods in order to reveal their relationships and thus optimize their usage.We present a two-dimensional structure in the form of a matrix, using three abstraction levels for the rows and three approaches for the columns. For each of the nine cells in the matrix we identify the method type by name and example. The matrix helps the user understand: (1) what to expect from a given method, (2) how it relates to other methods, and (3) how best to use it. Each cell in the matrix represent a different arrangement of strengths and weaknesses. Those arrangements shift gradually as one moves through the table, each cell optimal for a particular situation. The intention of this report is to enable informed use of the methods so that a method chosen is optimal for a situation given. The matrix, with type names in the cells, is introduced in Table 2 on page 13 below. Unless otherwise stated we use the word 'method' in this report to refer to a 'risk assessment method', though often times we use the full phrase. The use of the terms 'risk assessment' and 'risk management' are close enough that we do not attempt to distinguish them in this report. The remainder of this report is organized as follows. In

Nuclear Level Mixing: From a Curiosity to Applications in Nuclear Physics, Solid State Physics and Gamma Optics

International Nuclear Information System (INIS)

Neyens, Gerda

2001-01-01

The history of 'Nuclear Level Mixing' is closely related to the research that Prof. Coussement performed during the last 25 years. In particular, the impact of this quantum mechanical concept on different research fields will be discussed. Without going in detail, we aim to give the reader an idea of how one single concept may lead to different discoveries

Chemical digestion of low level nuclear solid waste material

International Nuclear Information System (INIS)

Cooley, C.R.; Lerch, R.E.

1976-01-01

A chemical digestion for treatment of low level combustible nuclear solid waste material is provided and comprises reacting the solid waste material with concentrated sulfuric acid at a temperature within the range of 230 0 --300 0 C and simultaneously and/or thereafter contacting the reacting mixture with concentrated nitric acid or nitrogen dioxide. In a special embodiment spent ion exchange resins are converted by this chemical digestion to noncombustible gases and a low volume noncombustible residue. 6 claims, no drawings

Power Peaking Effect of OTTO Fuel Scheme Pebble Bed Reactor

Science.gov (United States)

Setiadipura, T.; Suwoto; Zuhair; Bakhri, S.; Sunaryo, G. R.

2018-02-01

Pebble Bed Reactor (PBR) type of Hight Temperature Gas-cooled Reactor (HTGR) is a very interesting nuclear reactor design to fulfill the growing electricity and heat demand with a superior passive safety features. Effort to introduce the PBR design to the market can be strengthen by simplifying its system with the Once-through-then-out (OTTO) cycle PBR in which the pebble fuel only pass the core once. Important challenge in the OTTO fuel scheme is the power peaking effect which limit the maximum nominal power or burnup of the design. Parametric survey is perform in this study to investigate the contribution of different design parameters to power peaking effect of OTTO cycle PBR. PEBBED code is utilized in this study to perform the equilibrium PBR core analysis for different design parameter and fuel scheme. The parameters include its core diameter, height-per-diameter (H/D), power density, and core nominal power. Results of this study show that diameter and H/D effectsare stronger compare to the power density and nominal core power. Results of this study might become an importance guidance for design optimization of OTTO fuel scheme PBR.

Financing Nuclear Power Plant Projects. A New Paradigm?

International Nuclear Information System (INIS)

Pehuet Lucet, Fabienne

2015-05-01

There are currently 435 operable nuclear power reactors around the world, with a further 71 under construction. Two main proven financing models were applied to nuclear plants in the past: the national model, and the corporate model. The historical model of financing is the national model. It allowed for the most efficient risk allocation model in then-regulated national electricity markets: government or state-owned utilities with government guarantee assumed the risks of building nuclear power plants locally. The national model has proven to be efficient in France, Russia and the USA where it was modified to support private business initiatives. It was then replicated in Japan, Korea and China where significant nuclear programs were developed. In the corporate business model, the owner of the plant assumes most of the risk, but various schemes are used to mitigate the owner's risk by transmitting large areas of risks to others: vendors for construction risk as in Finland, government through loans guarantees etc. As projects became international, a set of common principles were approved by OECD countries concerning financing and the role of Export Credit Agencies. The objective was to provide competition rules whereby exporters compete on the basis of the price and quality of their products rather than the financial terms provided. Various combinations of these models were and still are implemented. Pure Project Finance was not implemented for nuclear power plants, but the model nurtures reflections about new financing models. The context in which nuclear power projects are now decided and financed changed drastically: it is a new paradigm. Risk allocation and financial conditions are at the forefront of competition to win new nuclear projects' tenders insofar as reducing uncertainties is a decisive competition edge. In a context of electricity market deregulation and high construction risks, investors and lenders require more and more securities to

Nuclear Exodus: Herpesviruses Lead the Way