The intensity and number of transmitted singly scattered photons were calculated for 1.0, 2.0, 4.0, 6.0, 8.0 and 10.0 MeV γ-rays normally incident on slabs of lead, iron, concrete and water varying from 1 to 4 mean free paths in thickness.
Energy build-up factors were obtained by integrating them using Simpson's formula. The calculation for composite shields included 1.0, 3.0 and 6.0 MeV γ-rays normally incident on a lead-water shield. The results obtained show good agreement with the values calculated by the Monte Carlo method and the moments method.

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Reactor transfer function measurements by various methods have been very active in recent years.
Zero power reactor transfer functions are investigated in the present report from the viewpoint of space dependency and two energy group theory. In part [A], the space dependency of reactor transfer function is discussed, and compared with the ordinary space independent transfer function. In part [B], it is pointed out that the transfer function derived from two energy group theory may be utilized to determine subcriticality, as well as fast and thermal neutron lifetimes.

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The exchange rate of uranium isotopes was investigated in a mixed system of natural U(VI) solution and cation exchange resin containing depleted U(IV) and U(VI) ions at various acid concentrations and temperatures. The experiments showed the presence of two isotopic exchange paths: (1) a first exchange process- "U(IV)-U(VI) exchange occurring within the resinous phase", and (2) second exchange process- "U(VI)-U(VI) exchange between the resinous and solution phases".
Based on the experimental results, it was found that
(1) The exchange rate constant for the first process is very sensitive to hydrogen ion concentration in the resinous phase.
(2) The exchange rate constant for the second process is almost independent of hydrogen ion concentration in the system.
(3) The apparent activation energy is 13.9 kcal/mol for the first process, and 5.84 kcal/mol for the second.
(4) The cation exchange resin used is an ideal material as adsorbent of U(IV), because U(IV) is stable in the resinous phase and complete mixing of U(IV) and U(VI) is prevented by using this system.

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As part of research on the vibratory compaction method of fabricating UO2 fuel elements, the effect of vibration character (frequency, acceleration and so on) on the compaction density was studied with sinusoidal wave vibration generated by an electrodynamic-shaker, with the view to optimization of vibration conditions for obtaining high compaction densities. Fused UO2 with a particle size distribution of -6, +12 mesh: 67.5 w/o, -40, +70 mesh: 20.0 w/o, -200 mesh: 12.5 w/o (mesh: US. Unit) was compacted into 40" long, 0.5" outer diameter and 0.035" wall 304 stainless steel tubes. Optimum results (88 % of theoretical density) were obtained with the following stepwise acceleration increase procedure:
(1) Powder blend is poured into the tube while it is vibrating at 8 G's and 300 cps.
(2) After the tube is filled, acceleration is increased to 20 G's at the same frequency of 300 cps and vibration is maintained for 2 min.
(3) Then, acceleration is increased to 40 G's and sweeping of frequencies between 300 and 3, 000 cps is initiated at the rapid speed of 4.4 decades/min, while maintaining a constraining load of 4 kg on the powder.
(4) After 2 min vibration at 40 G's, acceleration is increased to 60 G's and sweeping vibration is kept for 10-15 min.

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The neutron self-shielding factor of 59Co resonance foil as an example of foils whose scattering crosssection predominate over their absorption cross sections was obtained by both Monte Carlo method (analog) and the collision probability method for various thicknesses of the foil. Also, the ansmission and reflection probabilities of neutrons which have various energies near the resonance energy were obtained, and the effects of multiple scattering of neutrons on the neutron self-shielding factor are discussed.
The neutron self-shielding factors obtained by the Monte Carlo method and by the collision probability method agreed well with each other in the cases Σt ?? 4.0, in which the Monte Carlo method requires considerably longer machine time. Although for the cases of large Σt( ?? 4.0) the agreement is not always good because of the flat flux approximation in the collision probability method, the calculation time by Monte Carlo is conveniently short. A combination of both methods is useful in obtaining the neutron self-shielding factor of resonance foils.

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