A nonnuclear explosion involving an evaporator occurred in a shielded cell in the Radiochemical Processing Pilot plant at Oak Ridge National Laboratory. Plutonium released from the processing cell contaminated areas in the pilot plant building and nearby streets and building surfaces. The explosion is considered the result of rapid reaction of nitrated organic compounds formed by the inadvertent nitration of about 14 liters of a proprietary decontaminating reagent.

The mathematics has been developed for the determination of the radial coupling coefficient for a hollow cylinder of electro-strictive material whose length is small compared to its outside diameter.

Fourier analyses are made on two functions. The first is a step function forward from periodic samples of a sinusoid. If the frequency of the sinusoid is less than one-half of the sampling frequency, it is shown that the step function has no frequency components less than one-half of the sampling frequency other than that of phase, and duration with respect to the interval of the analysis. It is shown that the insertion of a blank space in the period of analysis reduces greatly the uncertainty of the amplitude of the initial sinusoid as estimated from the results of the Fourier analysis. The results of the analyses are useful in the design and evaluation of certain analog data-analyzing systems.

This memorandum is a compilation of general information concerned with the arrangement of elements on a control panel. Arrangement considerations that lead to to improved ease and accuracy of operation are presented to assist the engineer in designing new control panels.

Simon (1960) has given a general steady state theory of plasma accumulation (without energy losses) in an OGRA device. Such a device is fed by injection of energetic molecular ions which dissociate to produce trapped protons. Initial trapping is achieved by dissociation in the background gas. Such a device is usually characterized by a critical input current of critical plasma density (a function of input current) above which plasma density builds up to a value limited by Coulomb-scattering losses. For a regime of operation of current interest at Oak Ridge National Laboratory (600-kev hydrogen molecular ion injection and dissociation, highly efficient ion-pumping action of the trapped plasma), extremely simple approximate formulas have been derived which describe with a fair degree of accuracy the critical current of density for plasma build-up.

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.

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 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.

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.

The theory of mass transfer into a flowing fluid is utilizes to estimate the effect of gas film resistance on overall rates of transfer through a porous septum. The expressions developed for the mass transfer ratio...

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.