The feasibility of operation with an enriched core to ``override`` the xenon transient and thus reduce minimum downtime has been reasonably well established. The principle economic disadvantage of the present technique is associated with the use of boron splines for compensating the reactivity effect of the core during normal operation. The boron-containing spline parasitically absorb the excess neutrons produced in the core thus wasting these surplus neutrons during the operation when the enriched core is compensated by poison; also, because of the relatively slow removal rate of irradiated splines, a significant portion of the potential downtime reduction is used to remove the splines from the core. The purpose of this report is to point out incentives and alternate methods for improved poison control with the xenon override core and to present current plans for resolving these limitations to the xenon override concept.

From abstract: "The preparation of pure molybdenum(IV) bromide was accomplished conveniently by the reaction between molybdenum(III) bromide and liquid bromine at ca. 55°. Molybdenum(IV) bromide was found to be soluble in liquid bromine, and this property was utilized to separate and purify the molybdenum(IV) bromide. The solution of MoBr4 in bromine was a poor electrical conductor. No evidence was found for the formation of MoBr4 from MoBr3 and bromine vapor at 2-4 atm. and temperatures from 180 to 400°. However, MoBr4 was completely decomposed at 110-130°, in vacuo, with formation of MoBr3 and bromine."

Using the group vibratibn method of McMurry, the normal frequencies and coordinates of propane and three of its symmetrical deuterium substituted compounds were obtained. The force constants used were taken from a variety of previous works on hydrocarbons. The results give reasonable agreements with the experimental frequency and mode assignments of others. (auth)

A code (RAPTURE) was programmed for the Philco TRANSAC 2000 computer to perform calculations needed for the evaluation of Doppler Coefficients in fast reactors with degraded neuron spectra. This code computes resonance integrals, averages them over resonance parameter distributions, and computes fission and capture cross sections as a function of fuel temperature and of potential scattering cross section per absorber isotope.

A procedure is described for the sequential separation and determination of Arsenic-76 and Phosphorous-32 in reactor effluent water. The analysis can be performed in less than one hour and the arsenic fraction is scanned immediately after separation on a multi-channel gamma spectrometer. The discrete gamma energy of .56 MEV for Arsenic-76 makes further purification unnecessary. The organic phase containing the Phosphorous-32 is dry mounted on a one-inch stainless steel dish for beta counting.

In order to study resonances in the {Sigma}-{pi} system, we have analyzed reactions in which a {Sigma} hyperon and two or three pions are produced in K{sup -}-p interactions at 1.22 {+-} 0.040 and 1.51 {+-} 0.050 GeV/c incident K{sup -} momentum (i. e., 1895 and 2025 MeV center-of-mass energy), using the Lawrence Radiation Laboratory's 72-in. hydrogen bubble chamber.