Nuclear data

Once the basic core design comprising the number and size of the fuel elements and the type of control rods were decided upon, the final requirements on reactivity and power distribution had to be met by 

Especially in a small core like the FDR, where has to be relatively high, the stuck-rod condition limits the domain of one control rod drive. 

This is also shown by the fact that for a single fuel element of the outer core zone submerged in cold water the value k ff = 0.895 has been calculated. On the other hand, for a given number of control rods this means putting a limitation on the reactivity reserve which can be put into the core. Without the use of burnable poisons operation of the core with a reasonable fuel burnup seems impossible because of the reasons described above. In principle, soluble poison could also be used effectively but this is presently not considered for the stuck-rod condition because of the conservative assumption that it could possibly be washed out of the core in case of an accident. Table III shows values of the effective 

500 fpd xenon peak Cold, clean, fresh fuel all rods in except 1.014 Calc. 

In spite of the relatively low power density of the FDR core (33.8 kW/1) much attention was paid to obtaining a good radial power flattening, since in a self-pressurized reactor like the FDR all channels which have an enthalpy rise above the core average value produce vapor voids. These in turn give rise to reactivity changes when the core is accelerated vertically, which increase with the void content as may be seen from Table V. 

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N. Matsunami and co-workers, Data and Nuclear Data Tables 31, 1—84 (1984). 

Several of the reactor physics parameters are both measurable and calculable from more fundamental properties such as the energy-dependent neutron cross sections and atom number densities. An extensive database. Evaluated Nuclear Data Files (ENDF), has been maintained over several decades. There is an interplay between theory and experiment to guide design of a reactor, as in other engineering systems. 

Nuclear Data Sheets, Academic Press, San Diego, Calif., TvaluatedNuclear Structure Data File (ENSDF), a computer database of nuclear stmcture data evaluated by an international network of evaluators, is maintained at the National Nuclear Data Center, Brookhaven National Laboratory. NUDNTis a computer database of decay data extracted from the ENSDF. 

D. D. Cohen and M. Harrigan. Atomic Data and Nuclear Data Tables. 33,... 

E. Everling, L. A. Koenig, J. H. E. Mattauch, and A. H. Wapstra. I960 Nuclear Data Tables. National Academy of Sciences, Washington, 1961, Part I. Comprehensive listing of Qvalues for reactions involving atoms with A < 66. 

Systems analyses are like formulas, they have little usefulness until the variables are assigned probabilistic numbers from nuclear or chemical data bases. These data concern the probability of failing vessels, pipes, valves, instruments and controls. The primary difference between chemical and nuclear data is that the former may operate in a more chemically active environment, while the later operate in radiation. This chapter addresses both, but most of the data were gathered for nuclear systems. It covers 1) failure rate databases, 2) incident databases, 3) how to prepare failure rates from incidents, and 4) human factors for nuclear and chemical analyses. 

CCPS, 1989b, Process Equipment Reliability Data (Table 4.1-1) is a compilation of chemical and nuclear data. It assesses failure rates for 75 types of chemical process equipment. A taxonomic classification is established and data such as the mean, median, upper and lower (95% and 5%) values, source of information, failure by time and failure by demands are presented. 

The Swedish Thermal Power Reliability Data System (ATV) is maintained and managed by the Swedish State Power Board at Stockholm, Sweden. Engineering and reliability data have been collected from both nuclear and nonnuclear power generating plants. Nuclear data collection began in 1973. Collection of reliability data began in 1976. Over 30,000 events have been recorded in the data base. 

Atomic Energy of Canada Limited. (1999). Nuclear Sector Focus A Summary of Energy, Electricity, and Nuclear Data. Mississauga, Ont. Author. 

Nuclear Data for Elements Analyzed by Neutron Activation . ... 

The nuclear data and reactions for the elements investigated are listed in Table 4 ... 

The magnetic susceptibilities (x) or magnetization (a = x H) for the systems described here were measured by the In-sltu Faraday method described by Mulay [1]. The Mossbauer Spectra were obtained with an Austin Associates spectrometer with a 57co/Rh matrix source (50 mCi) and Nuclear data electronics. In-sltu measurements were made, using a cell similar to that described by Delgass et al. [7]. 

Table 7.1 Nuclear data for Mdssbauer transitions used in transition...

In Table 7.1 at the end of the book), nuclear data are collected for those Mdssbauer transitions of transition metal nuclides that are used in Mossbauer spectroscopy. The symbols used in this table have the following meaning ... 

In the following sections, we discuss the decay schemes for all Mossbauer-active transition metal nuclides other than iron. For the sake of completeness, the decay scheme for Fe (see Fig. 7.1) is inserted here. The relevant nuclear data,... 

The essential nuclear data of Ni may be taken from Table 7.1 (end of the book) or Part IV of the CD-ROM. More about nuclear properties has been summarized in [4]. 

There are two iridium isotopes, ir and Ir, suitable for Mossbauer spectroscopy. Each of them possesses two nuclear transitions with which nuclear resonance absorption has been observed. Figure 7.58 (from [266]) shows the (simplified) nuclear decay schemes for both iridium Mossbauer isotopes the Mossbauer transitions are marked therein with bold arrows. The relevant nuclear data known to date for the four Mossbauer transitions are collected in Table 7.1 at the end of the book. 

There are two y-transitions in Pt amenable to the Mossbauer effect - the 130 keV transition between the 5/2 excited state and the 1/2 ground state and the 99 keV transition between the first excited 3/2 state and the ground state. Figure 7.70 shows the simplified decay scheme of Pt. The relevant nuclear data may be taken from Table 7.1 (at the end of the book). 

Dilute alloys of Au with Fe, Co, Ni Au nuclear data, line width as function of absorber thickness... 

LBL. 2000. The Evaluated Nuclear Structure Data File (ENSDF), The National Nuclear Data Center (NNDC). Isotope Explorer version 3.0 bl. Lawrence Berkeley National Laboratory, http //ie.lbl.gov. December 13, 2000. 

The fc0-NAA method has been developed to overcome the labour-intensive and time-consuming work of preparing multi-element standards when routine multielement or panoramic analyses are required [447]. It is intended to be an absolute technique in which uncertain nuclear data are replaced by a composite nuclear constant, the T 0-factor, which has been determined experimentally for each radionuclide with high accuracy. This k0 is given by ... 

O Kelly GD, Goeking CF Jr., Collins LL Jr (1973) private communication to Nuclear Data Group... 

Nuclear Data Tables (1970). Way, K., Ed. (Academic Press, New York). 

P. Descouvemont, A. Adahchour, C. Angulo, A. Coc and E. Vangioni-Flam, At. Data and Nuclear Data Tables, 88, 203, 2004. 

Non-adiabaticity, 36 Nonlinear Kerr response, 84 Nonlinear propagation, 82 Nuclear data, 160... 

Evaluated Nuclear Data Files (ENDF) database, 17 566... 

A description of nuclear matter as an ideal mixture of protons and neutrons, possibly in (5 equilibrium with electrons and neutrinos, is not sufficient to give a realistic description of dense matter. The account of the interaction between the nucleons can be performed in different ways. For instance we have effective nucleon-nucleon interactions, which reproduce empirical two-nucleon data, e.g. the PARIS and the BONN potential. On the other hand we have effective interactions like the Skyrme interaction, which are able to reproduce nuclear data within the mean-field approximation. The most advanced description is given by the Walecka model, which is based on a relativistic Lagrangian and models the nucleon-nucleon interactions by coupling to effective meson fields. Within the relativistic mean-field approximation, quasi-particles are introduced, which can be parameterized by a self-energy shift and an effective mass. 

To eliminate the need for recalibration during a measurement and to obtain additional information, the Royco instrument was supplemented with a Nuclear Data ND-60 Multichannel Analyser (MCA). The amplified signal of the Royco 225 (which is proportional to the cimount of light scattered from each particle) was connected to the input of the MCA which cem count and classify pulsed input signals into as many as 2048 channels and display the results on a cathode ray tube (CRT). This number of cells is of course much more than required to determine the PSD. The data were therefore grouped into eleven cells whose limits were consistent with those used earlier (5), emd the counts in these cells were then printed on a Texas Instruments 743 KSR Data Terminal interfaced with the MCA. 

In preliminary evaluations a Nuclear Data ND-PSA Particle Sizing Amplifier (PSA) was interfaced between the Royco and the MCA. The PSA, which could serve as either a linear or logarithmic amplifier, was operated in the log mode to develop an output signal which would be more nearly proportional to the log of the particle diameter and spread the small-diameter particle count over a larger number of chemnels. The distribution displayed on... 

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