ISSN:0550-3043    

DOI:10.13182/NT69-A28381

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

Vibration testing of nuclear reactors is discussed as a part of the determination of the response of such systems to earthquakes. The basic theory of vibration testing is presented along with a comparison of impulse, ambient, and steady-state testing. Steady-state tests provide a method of obtaining the complete dynamic characteristics of a system and of selectively studying each of the components of the system; e.g., containment, steam generator, pressure vessel, instrumentation, etc. Generally, both impulse and ambient studies do not provide as much detailed information while being less time consuming and creating less interference with other operations.A series of tests performed on the UCLA research reactor, the Carolinas-Virginia Tube Reactor, and the Experimental Gas-cooled Reactor at Oak Ridge are used to illustrate results obtained with steady-state tests. These illustrate the effect of the vibrations on instrumentation as well as the response of the reactor cores, fuel elements, biological shielding, steam generators, exhaust stacks, and the containment structures. The tests of the UCLA reactor included tests with the reactor at full power. The examples illustrate the complexity of the soil-structure-reactor system while also indicating the nature of the results which may be obtained with vibration tests.

ISSN:0550-3043    

DOI:10.13182/NT69-A28382

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

Production rates (atoms/gram megawatt day) of58Co,54Mn,55Fe,63Ni, and60Co in the Experimental Breeder Reactor-II (EBR-II) irradiated stainless steel are reported. These rates can be used as precise flux and fluence monitors in fast reactors when appropriate spectrum-averaged cross sections are applied. Seven spectrum-averaged cross sections for the core and four spectrum-averaged cross sections at eight radial positions in EBR-II are also reported. The ratio of54Mn/55Fe atoms produced from54Fe represents a sensitive spectral hardness indicator for fast-reactor spectra. This study also indicates that in EBR-II the flux per megawatt measured at high power is the same as that measured at low power by other authors. Results show that a diffusion theory calculation provides a reasonably accurate representation of the flux in the core of EBR-II but overestimates the flux in the blanket region.

ISSN:0550-3043    

DOI:10.13182/NT69-A28383

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

The economics of enriched-uranium production in USAEC facilities have been analyzed and the equations of an optimizing economic model of the enriched-uranium industry developed. The objective junction that is minimized by the model is the present value of the combined controllable costs of the USAEC and of the users of enriched uranium. The economic system considered is thus unusually comprehensive and the optimization problem correspondingly complex. A basic consideration in developing the optimum operating strategy is that the existing AEC investment in diffusion plant and feed stockpiles may be used to preproduce economically some of the future requirements for enriched uranium. The model has been used extensively in USAEC enriched-uranium production planning.

ISSN:0550-3043    

DOI:10.13182/NT69-A28384

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

An infrared scanning system for producing thermal contour maps of radioactive waste storage tanks is capable of detecting a 1-ft2area on the bottom of a 75-ft-diam tank if the temperature of the scanned area exceeds the background temperature by 3°C. Representative thermal maps of storage tank bottoms with artificially-introduced target regions are illustrated. Although the scanning system is primarily intended to measure temperature differences, it can be used to make background temperature measurements in the storage tanks by the use of a calibrated target.

ISSN:0550-3043    

DOI:10.13182/NT69-A28385

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

Neutron emission rates and neutron spectra were determined for two238Pu power sources: SNAP 27-1, a 1482-W plutonium dioxide source for the Apollo Space Program, and HP 15-2, a 15.84-W plutonium metal source for the Artificial Heart Program. The measurements were made with a single stilbene crystal fast-neutron spectrometer and a long counter. The specific neutron yields were (2.2±0.1)×104n/sec per gram of238Pu for SNAP 27-1 and (3.9±0.2)×103n/sec per gram of238Pu for HP 15-2. Neutrons from these sources are due to spontaneous fission of238Pu, neutron-induced fission of plutonium, and (α, n) reactions. The contributions to the two spectra due to neutrons from each of these reactions are shown. Factors for converting from neutron fluence to dose equivalent (whole body) were calculated to be (3.34±0.11)×10−5mrem per n/cm2for SNAP 27-1 and (3.13±0.15)×10−5mrem per n/cm2for HP 15-2.

ISSN:0550-3043    

DOI:10.13182/NT69-A28386

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

Tensile properties of irradiated Type-304 stainless steel have been measured. These results have been correlated with microstructural observations obtained by optical and transmission electron microscopy techniques. The material studied was irradiated in a fast-neutron environment to a peak exposure of 4.8×1022n/cm2at temperatures ranging from 371 to 463°C in the EBR-II reactor.True yield stresses were observed to increase, and true uniform strains to decrease with both increasing neutron exposure and decreasing irradiation temperature for test temperatures<750°C. At 750°C no increases in true yield stresses over control values were noted while sharp decreases in true uniform strains were observed. It is suggested that some annealing of the microstructure occurs at this elevated temperature, allowing helium to be accumulated at grain boundaries.Microstructural examination by transmission electron microscopy revealed homogeneous distributions of polyhedral voids and Frank dislocation loops. Neither deject was observed to form on grain boundaries. It is suggested that the dislocation loop formation is primarily responsible for the increased strength of the irradiated material.Immersion density measurements are included. These results indicate that the peak void formation did not occur at the maximum flux position, thus indicating the importance of temperature to the phenomenon.

ISSN:0550-3043    

DOI:10.13182/NT69-A28387

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

A new calibration has been developed for the electromagnetic flowmeters located on the 14-in. lines of the primary sodium coolant system of the Enrico Fermi Atomic Power Plant. This new calibration has incorporated the experimental hydraulic characteristics of the primary sodium coolant loop, the voltage outputs of the flowmeters on the 14- and 6-in. lines, and the original calibration of the flowmeters on the 6-in. lines. Utilizing this new calibration, the system pressure drop was found to vary as the 1.9'th power of the flow rate of the primary system. This relationship is in good agreement with theory.A comparison of the measured sodium flow using the new calibration with the calculated value from heat balance measurements showed good agreement, with an average deviation of 1.7%. (The“as-read”values from the flowmeters based on the previous calibration, which were developed using pump hydraulic characteristics and the pump affinity laws, were too high by an average of 10%.) This new calibration is now being used in the Fermi plant.

ISSN:0550-3043    

DOI:10.13182/NT69-A28388

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

A derivative neutron activation procedure determines the element magnesium using the chelating agent 5, 7-dibromo-8-hydroxyquinoline. By selective solvent extraction, the magnesium chelate is isolated from interfering elements and separated from excess chelating agent using paper chromatography. The amount of magnesium present is then inferred from the bromine activity after neutron irradiation of the isolated chelate. The method improves the sensitivity for magnesium detection by a factor of 5 and removes the time constraint characteristic of conventional activation determination of magnesium.

ISSN:0550-3043    

DOI:10.13182/NT69-A28389

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

Fluence-to-kerma factors (where fluence is the time-integrated neutron flux and kerma is equal to the totalkineticenergyreleased inmaterials resulting from direct neutron interaction per unit mass of the irradiated medium) were calculated at discrete neutron energies from 0.025 eV to 15 MeV for various compositions of the human body—tissue, muscle, bone, lung, brain, red marrow, and the“standard man”composition. The 11 most common elements in man were considered and the latest cross sections used. An attempt was made to include all significant reactions, namely elastic scattering with an anisotropic correction, inelastic scattering, neutron capture, (n, 2n) reactions, (n, charged particle) reactions, and beta or positron emissions from these reactions. These calculations show improvements in the entire energy range over previously reported neutron kerma factors.

ISSN:0550-3043    

DOI:10.13182/NT69-A28390

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor