ISSN:0550-3043    

DOI:10.13182/NT70-A28708

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

A concept of a facility for carrying out a series of in-pile tests of varying sizes for ensuring LMFBR safety is needed. The chief problems to be overcome are those arising from nuclear feedback from the test zone and the need to contain the test in a loop. The suggested solution involves using a zoned core coupled to the test region by a nickel reflector. This suggestion is based on the observation that, as the test size is changed, the reactivity changes are easily accommodated by control rod movement if the loop wall thickness does not change much.To increase the test size safely without increasing test loop wall thickness requires the successful extrapolation of knowledge of energy yield and absorption gained on earlier, smaller tests. Such a procedure is termed a bootstrap procedure.

ISSN:0550-3043    

DOI:10.13182/NT70-A28709

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

The Turkey Point pressurized water reactor was analyzed as a Civil Defense problem in a nuclear attack. It is postulated that the reactor presents no additional hazard in a target area unless a large fraction of the fission product inventory in the core can be promptly released due to weapon effects. High explosive tests on scale models of the pressure vessel and pertinent shielding were employed to determine the required delivery accuracy of nuclear weapons to rupture the pressure vessel and release the core fission product inventory.We conclude that the presence of a power reactor in a target area will not add significantly to the number of casualties produced by a nuclear weapon unless the reactor receives essentially a direct hit. Further, preferentially targeting a PWR would be prohibitively expensive because, with existing missile accuracies, a large number of weapons would have to be targeted on the reactor to ensure getting a direct hit.

ISSN:0550-3043    

DOI:10.13182/NT70-A28710

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

Two models which are designed to perform fuel inventory calculations without the use of detailed and expensive computer programs have been developed. The accuracies of these models have been evaluated by comparing results obtained with them to measurements of discharged fuel from the Yankee Rowe reactor. In general, the models predict the235U depletion to within±2% of the measured values and the total plutonium production to within±5% for fuel batches consisting of about 70 fuel assemblies. Uncertainties in the computational results have been ascertained to be about±2% for the total235U content and±3% for the total plutonium production.

ISSN:0550-3043    

DOI:10.13182/NT70-A28711

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

The Molten Salt Reactor Experiment has been refueled with an enriching salt concentrate,7LiFUF4(73 to 27 mole%). Sixty-three kilograms of this was prepared in a shielded cell in the Thorium-Uranium Recycle Facility at Oak Ridge National Laboratory. The preparation process involved reducing233UO3to UO2by treatment with hydrogen, converting the233UO2to233UF4by hydrofluorination, and fusing the233UF4with LiF. Its preparation in a shielded cell was required because of the high232U content (222 ppm) of the233U.The product salt, containing 39 kg of uranium (91.4%233U), was low in oxide content (50 ppm) and the concentration of the corrosion products, chromium, iron, and nickel, was minimal at less than (0.05%) total.

ISSN:0550-3043    

DOI:10.13182/NT70-A28712

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

An empirical formula has been developed for determining the individual diameter of essentially unreflected cylinders in a critical planar array.The formula isThe independent variables are N, the number of cylinders in the array; S, the edge-to-edge spacing between adjacent cylinders; H, the solution height in the array; C, the concentration of the solution [U ~93 wt%235U]; G, the geometry factor determined by the shape of the array; and ki(i = 1, 2,…, 8), the constants determined by the type of solution, either uranyl nitrate or uranyl fluoride. These independent variables, the formula ranges, and approximations are discussed. The critical cylinder diameter, calculated by this formula, is within±8% of the experimentally measured diameter for 112 experimental data points. Therefore, the formula can be used as a guideline for nuclear criticality safety.

ISSN:0550-3043    

DOI:10.13182/NT70-A28713

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

Residues from aqueous and organic intermediate- level radioactive waste can be incorporated in asphalt or polyethylene to reduce the mobility of radionuclides after burial or storage of the solidified waste product. Asphalt or polyethylene products containing up to 60 wt% of nonoxidizing inorganic solids have a chemical resistance similar to that of pure asphalt or polyethylene. Leach rates projected over 200 years indicate that ~5% of a soluble element (sodium or cesium) or 0.6% of an insoluble nuclide (106Ru) would be leached from a 55-gal drum of product submerged in water. Polyethylene accommodated up to 40 wt% of organic liquids, such as tributyl phosphate (TBP), while asphalt products containing 25% TBP were not entirely satisfactory. Polyethylene products were also superior to asphalt products in flammability and radiation stability tests. Incorporation in asphalt is not recommended for waste solids containing significant amounts of oxidants.

ISSN:0550-3043    

DOI:10.13182/NT70-A28714

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

The first synthetic actinide element, neptunium, was discovered in 1940. The last element of the actinide series, lawrencium, was created for the first time in 1961. These and the nine other intervening elements have added a new dimension to science, technology, industry, medicine, and politics in an extraordinarily short period of time. Each synthetic actinide element from atomic number 93 to atomic number 98 (with the exception of berkelium, atomic number 97) can now be manufactured in essentially any desired quantity, a truly remarkable achievement.

ISSN:0550-3043    

DOI:10.13182/NT70-A28715

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

A pulsed-neutron activation analysis system capable of handling and analyzing short-lived radioisotopes with half-lives as short as 1 to 2 sec was developed. Since a single reactor pulse will induce more activity for short-lived neutron reaction products than continuous irradiation to saturation at a normal reactor power level, experimental procedures were formulated to analyze quantitatively a few important fast neutron reactions with short-lived products and to establish limits of detection for these reactions using this system. To augment the fast neutron reactions, a cadmium-lined in-core terminus was utilized to reduce (n,γ) interference reactions.The reactions analyzed were16O(n,ρ)l6N,19F(n,α)16N,19F(n,γ)20F,23Na(n,ρ)23Ne,23Na(n,α)20F,34S(n,ρ)34P, and31P(n,α)28Al. The detection limits which were attained for these reactions utilizing this system were: 54.8μg for16O, 0.23 and 0.19μg for19F, 1.8 and 8.0μg for23Na, 150μg for34S, and 2.6μg for31P. Most of these limits are an order of magnitude or more lower than those reported by users of the Cockroft-Walton neutron generators usually employed for these analyses.

ISSN:0550-3043    

DOI:10.13182/NT70-A28716

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor

摘要:

Proton microprobe analysis utilizing the strong, narrow 0.874-MeV resonance in the19F(ρ,αγ)16O reaction was employed to identify fluorine as a contaminant and to measure its concentration profile in the surface of silver-coated copper wiring on the Lunar Module.

ISSN:0550-3043    

DOI:10.13182/NT70-A28717

出版商:Taylor&Francis    

年代:1970

数据来源: Taylor