Abstract: A multigroup P1 approximation for hydrogen scattered neutrons has been developed and applied to the study of neutron flux distributions in titanium hydride and steel shield systems.

Abstract: Various methods and techniques of measuring void fractions in boiling heat transfer media are discussed.

Operation and maintenance procedures for 30 megawatt heat exchanger and steam generator for sodium cooled reactor system.

From introduction: "This is the thirteenth in a series of quarterly reports which will cover the progress and results from the conceptual design, economic evaluations and research and development work performed by the General Electric Company as part of the Nuclear Superheat Project."

Report issued by the Argonne National Laboratory discussing progress made by the Reactor Development Program during April 1963. Reactor physics, experiments, and safety studies are presented. This report includes tables, and illustrations.

Abstract: The acid hydrolysis of [Pt(NH3)3Cl] has been shown to occur to a measurable extent. for this reaction: [APt(NH3)cCl]+ + H2O [chemical equilibrium symbol with rate constant k-1 above and k1 below] [Pt(NH3)c(H2O)]++ + Cl-, the equilibrium quotient was measured at 25 degree C and 35 degree C. At 25 degree C this quotient was 8.4 x 10-5 at [Mu] (ionic strength) = 0 and 25 x 10-5 at [mu] = .318 M. This variation is consistent with the expected changes in activity coefficients. [Delta]H for the reaction was found to be approximately 0. The rate constant, k1 was 2.3 x 10-5 sec.-1 at 25 degree C and it was nearly independent of ionic strength. The acid hydrolysis provides a mechanism for the exchange of the chloride ligand and Cl-. Exchange experiments with Cl36 showed that in addition to the acid hydrolysis, a process, first order in both, [Pt(NH3)3Cl] and Cl- with a rate constant of 6. 10-5 sec.-1M.-1 contributes to the exchange. The behavior of the entire series of chloro-ammines of platinum(II) toward acid hydrolysis and chloride exchange has been summarized, and a likely mechanism for the process has been discussed.