"The problem of radiation derange to the walls of two types of vacuum chamber for the 6 Bev Cambridge Electron Accelerator was studied. Radiation damage may arise from the synchrotron radiation and from electrons which are not accepted at injection. The synchrotron radiation produces a large amount of secondary x radiation which is isotropic, and therefore complicates the arrangement of internal shielding. The 20 Mev electrons from the lines cannot be attenuated by shielding. It is concluded that dosages of the order of 10/sup 7/ rad/day near the inflector are unavoidable. This would exceed the allowable dosage for a tube made by cementing a stainless steel liner to supporting ribs, and also exceed the test dosages (so far as we know) for alumina ceramics."

Various nuclear characteristics of two-region spherical homogeneous reactors have been computed in order to provide information for the design of HRE-3. Equilibrium isotope concentrations were established using an ORACLE code, and a two-group model was used to obtain critical concentrations and flux distributions. Breeding ratio is plotted as a function of reactor size, blanket thorium concentration, and other design and operating parameters, and the time required for a demonstration breeding is discussed. Tables of results, including neutron balances, are given for selected reactors. a number or relations are presented for estimating the effects of fission products, copper, corrosion products, H2O, and the core tank on breeding ratio.

Design calculations were made for a system consisting of a pump, one hundred feet of pipe, and a heat exchanger to remove 1 Mw of heat from various aqueous thorium oxide slurries. The rheological properties of the slurries were varied over a range of yield stresses from 0 to 1.5 lb/sq ft and of coefficients of rigidity from 1/2 to 2 centipoise. Two different cases were studied: a heat exchanger having fixed axial and radial delta T in which the tube length was allowed to vary and a heat exchanger having fixed tube length in which the axial and radial delta T were allowed to vary. It was shown that the pump power must be increased by a factor of 15 to 30 in order to maintain satisfactory operation of the heat exchanger as the slurry yield stress is increased form 0 to 1.5 lb/sq ft. However the pump power is essentially independent of heat exchanger tube diameter for any given slurry. The rated capacity of a slurry heat exchange is essentially independent of slurry yield stress and coefficient of rigidity, provided that the tube velocity can be suitably increased as the slurry yield stress in increased.

A falling ball viscometer under development at ORNL, employing a flow system and an electromagnetically operated dash-pot pump, was evaluated for possible use with aqueous ThO2 slurry systems under reactor irradiation. Interchangeable check valve inserts were designed and fabricated to investigate several pump designs. Magnetic flux concentrations which originally prevented circulation of the ferritic stainless steel viscometer ball through the electromagnetic pump were eliminated by substitution of iron-magnetic stainless steel inserts. Viscosity was correlated through a logarithmic plot of the dimensionless Reynolds number vs. Froude number with the ratio of ball diameter to tube diameter as a parameter. The relation is linear in the laminar flow region.

Some refined calculations have been made, relative to a proposed delay prior to a dump, to determine the expected D2 concentration in the vent stream from the pressurizer gas bleeds during a dump of the Homogeneous Reactor Test (HRT). These calculations indicate that for vent valves have a Cv of 0.07 (venting time from 2000 psia to D2O saturation pressure of approximately 12 minutes), a delay period is not required since the D2 concentration is well below lower explosive limit. For vent valves having a Cv of 0.3 (venting time approximately 2.4 minutes), the calculation indicate that a delay before venting of approximately two minutes will be required. This is due entirely to the possibility of mass ebullition the D2. Since the pressure drops so quickly, the reactor solution becomes saturated with D2 before appreciable recombination can occur.

A new type of continuous density meter, applicable for use with ThO2 slurry in high temperature-pressure systems, was tested successfully in a low temperature slurry loop.

The so-called Fluoride Volatility Processes refer to several proposed non-aqueous methods of processing irradiated fuel elements. In each of these methods, the uranium is fluorinated to UF6 and then decontaminated by distillation. One of those methods, involving the direct fluorination of the uranium by bromine trifluoride (BTF), has been under investigation at BNL since 1950. In 1952, it was demonstrated at BNL that uranium, as UF6, could be satisfactorily decontaminated by distillation in small-scale pilot plant equipment; end in 1953, BNL undertook the job of determining the technical feasibility of a continuous dissolver on a pilot-plant scale. The reason for the project was that the economic superiority of the process seemed to depend upon its amenability to continuous operation.

The following report studies uranium and vanadium ore deposits found in the Calyx No. 3 mine in the Temple Mountain area of the San Rafael Swell in Utah.

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A Darex flowsheet is presented wherein dissolution of stainiess steel- type fuel elements in dilute aqua regia, stripping of chloride from spent dissolver solution, adjustment of stripper product composition and rectification of HNO/sub 3/ --H/sub 2/O vapors are accomplished in a completely continuous relatively simple loop process. Product from the loop needs only dilution with water to be made suitable as feed for a solvent extraction processing plant. The proposed scheme differs from earlier concepts. A continuous, pot dissolver (well- mixed liquid phase) is utilized rather than a trickle type dissolver. A strip vapor slightly lower in HNO/sub 3/ concentration than the azeotrope is used. A feed adjustment tank serves not only to recover HNO/sbu 3/ --H/sub 2/O vapor, but also to dehydrate any silica present and to adjust the product composition such that upon water addition the material is ready for feed to solvent extraction. In most previous concepts, separate, batchwise feed adjustment was contemplated. (auth)

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Molten salts provide the basis of a new family of liquid fuel power reactors. The range of solubility of uranium and thorium compounds makes the system flexible, and allows the consideration of a variety of reactors. Suitable salt mixtures have meltirg points in the 85O to 95O deg F range and will probably prove to be sufficiently compatible with known alloys and to provide lorg-lived components, if the temperature is kept below 13OO deg F. Thus the salt systems naturally tend to operate in a temperature region suitable for modern steam plants and achieve these temperatures in unpressurized systems. Some economic and other considerations are made. (T.R.H.)

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The most important variable in water quality on the uniform corrosion of Al was the pH. Solutions of distilled water containing phosphate ions and citrate ions were the only media which showed a definite specific ion effect. Phosphate inhibited the corrosion and citrate increased it. Oxalate ions appeared to increase corrosion, but the effect is not definitely demonstrated by the data. Corrosion was dependent only on pH in tap water, reactor process water, distilled water, and distilled water containing up to 100 ppm of chloride, nitrate, sulfate, bicarbonate, hydrogen peroxide, acetate, arsenate, silicate, dichromate, molybdate, and mixtures of these ions. Solutions of up to 10,000 ppm chloride in distilled water showed no specific ion effect upon uniform Al corrosion. The effects of 0 to 10 ppm of dichromate and phosphate ions were investigated over the range pH 4 to pH 7. Phosphate at 10 ppm inhibited corrosion in solutions containing up to 2 ppm of dichromate, but at 10 ppm dichromate the phosphate does not appear to inhibit corrosion. Also at 10 ppm dichromate, the effect of pH is diminished over the range pH 4 to pH 7. Corrosion rates varied with the flow rates of the test solutions at …

Tests using a Westinghouse 400A canned motor circulating pump with various motor to impeller seal configurations are described. A configuration was found which allows very low flow rates and increases pump life. (T.R.H.)

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A series of explosions, estimated at five, occurred over a period of ten seconds within the continuous dissolver pilot plant, of the Fluoride Volatility Project on May 15, 1957. The explosive reactions occurred in the dissolver vessels as a result of violent chemical reactions between uranium and an interhalogen mixture. Just what the conditions were which triggered the explosions, have not been definitely established. Nevertheless, based upon the evidence which has been collected, several possible explanations, listed according to probability, are presented. A number of recommendations are included to be followed before operation of the pilot plant is resumed. These recommendations relate to additional laboratory research, equipment design, facility design, and use of a review committee. Safety rules for handling BrF/ sub 3/, BrF/sub 5/, ClF/sub 3/, and Br/sub 2/ are appended. (C.H.)

The feasftbility of using gamma -ray attenuation techniques was demonstrated in determining the density and homogeneity of slurries circulating at 300 deg C. The method appears to have general utility in the engineering studies of slurry because the equipment is mounted externally and does not interfere with the system under investigation. Two types of detector systems were evaluated for routine service. The decimal counter-recorder system was found more adaptable for rugged operations, whereas the single channel analyzer was fouW to be more accurate and flexible. (auth)

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Inactive UO/sub 2/ oxidizes at 180 deg C by tbe formation of a tetragonal oxide (U/sub 3/O/sub 7/), which is unsthble, on heating above 300 deg C. The U/sub 3/C/sub 7/ in compositions below UO/sub 2.25/ reacts with UO/sub 2/ to form UC/sub 2+x/ and U/sub 4/O/sub 9/. At compositions above UO/sub 2.25/, the tetragomal phase is stable to 600 deg C. In the homogenized condition, both U/ sub 3/O/sub 7/ and U/sub 4/O/sub 9/ are n-type conductors, while UO/sub 2+x/ is p- type. The solubility limit of O in UO/sub 2/, as determimed by x-ray diffraction data and electrical measurements, is UO/sub 2.08/ at 25 and 200 deg C, UO/sub 2.11/ at 400 deg C, UO/sub 2.17/at 600 deg C, and UO/sub 2.20/ above 700 deg C. The active UO/sub 2/ oxidation product retains the cubic symmetry of UO/sub 2/ up to the composition UO/sub 2.40/ and is stable to 600 deg C in vacuum. The structural behavior of the active oxide in this composition range is significantly different from that of the inactive oxide. (auth)

Examination of corrosion specimens from the 948 hour slurry blanket mock- up Run SM-3 lndicated generally low attack rates on type 347 stainless steel, titanium -75A, and Zircaloy-2. The upstream coupon of the array, of type 347 stainless steel, suffered moderate but more severe attack. Coupons of SA-212 grade B carbon steel were severely attacked. No stress corrosion cracking was noted on samples, placed in the pressurizer, of types 347 and AM 350 stainless steels, titanium aluminum--vanadium alloy, or Zircaloy-2. (auth)