摘要:

Some recent experiments on an open-cycle gaseous-fueled nuclear rocket engine concept have been performed. In such an engine, the gaseous fuel and the propellant are in direct contact. This feature removes the requirement of using solid fuel elements. These experiments have shown there is a relatively large central volume into which the simulated fuel expands. The fuel-to-cavity volume fraction depends on the propellant to fuel-flow-rate ratio. Fuel volume fractions varied from 0.5 to 0.3 as the mass-flow ratio varied from 25 to 1 up to 100 to 1, respectively.

ISSN:0550-3043    

DOI:10.13182/NT70-A28628

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

The removal of methyl iodide from containment atmospheres by reactive sprays proceeds by a simultaneous process of absorption and chemical reaction. A theoretical development is presented to show how the relative values of reaction time and other time constants of the system determine the rate-controlling process. Theoretical predictions are compared with the results of 12 experiment So For the fast-reaction case (when the reaction time is equal to or less than the fall time of the drops), the calculated removal half-times averaged 2.25 times the observed. The reasons for the difference are identified and appear to be due to erroneous equilibrium data, neglect of internal circulation in the calculation, and neglect of wall effects. A reduction factor of at least 2.0 in the 2-h dose due to methyl iodide appears readily attainable.

ISSN:0550-3043    

DOI:10.13182/NT70-A28629

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

Porous UO2microspheres, or kernels, can be produced by reduction of fired U3O8kernels to the lower oxidation state. The temperature at which the U3O8kernel is fired is a major parameter in establishing the degree of porosity, and subsequent reduction from the U3O8state must be carefully controlled to prevent formation of internal cracks. Restricting the furnace temperature to<1000°C and providing small incremental increases in the quantity of reducing gas added to the furnace inert atmosphere produced well-distributed porosity in the ceramic body without creating cracks in the internal structure of the kernel.

ISSN:0550-3043    

DOI:10.13182/NT70-A28630

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

Refluxing capsule tests were conducted to evaluate the corrosion properties of alloys Nb, Nb-1% Zr, Nb-10% W-1% Zr, Ta-8% W-2% Hf, Mo-0.5% Ti-0.1% Zr, Nb-10% W-10% Hf-0.5% Y, and W-26% Re in boiling potassium at 1100 to 1400°C. Nb-1% Zr was also evaluated in refluxing sodium, rubidium, and cesium at 1200°C.Alloys of niobium or tantalum that contained strong oxide formers, such as zirconium or hafnium, showed negligible corrosion effects up to 1300°C for times as long as 5000 h. Nb-1% Zr exposed to the other alkali metals was similar. Weight changes in insert specimens from condenser sections were small and in most tests were traced to the migration of oxygen in the system. Unalloyed niobium, on the other hand, was very heavily attacked under similar conditions. Mass transfer of tungsten was observed in a W-26% Re capsule.Capsule geometry can be an important variable in comparing the results between various corrosion investigations.

ISSN:0550-3043    

DOI:10.13182/NT70-A28631

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

Estimates were made in the Republic of Singapore of the cost of desalting water and generating electricity there. These estimates were for both nuclear and fossil-fired plants and were obtained with the help of a generalized International Atomic Energy Agency technical report and nine economic studies performed by US firms for specific locations throughout the world.The results indicated that sea water could not be desalted for less than perhaps 5O¢/1000 gal from dual-purpose plants of the largest size satisfactory for Singapore, i.e.,∼200 MW(e) and 20 to 100 million gallons per day. This cost appeared approximately the same whether from nuclear or fossil-fired plants. The results also indicated that electricity could probably be generated at a somewhat lower cost in a single-purpose fossil-fired plant than in a single-purpose nuclear unit.It was concluded that the use of nuclear energy did not appear to offer highly significant benefits to Singapore for desalting water or generating electricity during the next ten years.

ISSN:0550-3043    

DOI:10.13182/NT70-A28632

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

The previously reported enhanced volatility of tellurium dioxide due to water vapor has been confirmed over the temperature range 825 to 970°K through vapor pressure measurements with a mass transport apparatus. Investigations of the temperature dependence of the characteristic equilibrium constant yield a value of 30.4 kcal/ mole for the heat of the (assumed) reaction TeO2(s) + H2O(g) = TeO(OH)2(g). Attempts to identify the gaseous hydroxide species through mass spectrometry were unsuccessful. Mass spectrometer studies of TeO2vapor, however, indicate ~20% dimer formation within the temperature range 920 to 1050°K.

ISSN:0550-3043    

DOI:10.13182/NT70-A28633

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

The dissolution of the corrosion products of metals in deionized water at 38°C (100°F) is discussed. Copper, tungsten, cadmium, and Mallory-1000 give soluble corrosion products. Mention is made of 304 stainless steel, 1100 aluminum, titanium, tantalum, silver, and boron steel, all of which showed no soluble corrosion products. The significance of soluble corrosion products in reactor cooling water is discussed. Data were. obtained by chemical analyses of the water rather than from physical measurement of the test specimen.

ISSN:0550-3043    

DOI:10.13182/NT70-A28634

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

The purification of cesium by ion exchange with a synthetic aluminosilicate zeolite was demonstrated on a laboratory scale for use in preparing exceptionally pure137Cs irradiation sources. Cesium ions are preferentially loaded on a column of granular Zeolon from a solution that contains Na+, K+, and Rb+impurities. The impurities are eluted from the column with a dilute ammonium carbonate scrub solution which also elutes a small amount of the cesium during the latter part of the scrub cycle. To minimize the cesium waste loss, the latter portion of the scrub is recycled to the column ahead of the next batch of feed. The cesium remaining on the Zeolon column is eluted with a concentrated ammonium carbonate solution. The ammonium carbonate eluant is evaporated to yield a cesium carbonate which contains<1% total metal ion impurities. Cesium waste losses were also<1%.

ISSN:0550-3043    

DOI:10.13182/NT70-A28635

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

Alpha contamination on the hands and shoes of personnel can be quickly detected with large-area air proportional counters modified to overcome sensitivity to microphonics and humidity. The monitor requires practically no servicing and is easily decontaminated.

ISSN:0550-3043    

DOI:10.13182/NT70-A28636

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

The results of an experimental investigation of a gunpowder residue test based on the addition of 0.1 wt% of rare earth oxide to gunpowder is reported. A total of 512 test samples have been subjected to statistical analysis. The findings of this investigation demonstrate that the use of europium-labeled gunpowder can provide the basis for a rapid and simple instrumental gunpowder-residue test which can detect the firing of a weapon with a high degree of probability. The results of the tests with europium-labeled gunpowder are compared with the analysis of barium and antimony in primer residues.A cost analysis indicates that europium labeling of gunpowder will increase the cost of ammunition by<2%.

ISSN:0550-3043    

DOI:10.13182/NT70-A28637

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor