The importance of the experimental method to thermalstress-fatigue test results is clarified. It is shown that a significant increase in apparent fatigue life can be obtained by measuring maximum strain per cycle instead of an average strain. Extrapoiation curves are given to convert the litter into the formed. A varying-cross-section specimen of zero'' gage length is shown to allow measurement of true, maximum strain. (auth)

Completion of zero-power critical experiments with the ORNL Health Physics Research Reactor is reported. A description is given concerning these experiments which were used to determine the critical size, fission-rate distributions, reactivity calibrations of its movable parts, the temperature coefficient of reactivity, and the reactivity effects of the presence of neutron- reflecting materials adjacent to the reactor. (J.R.D.)

The time-dependent behavior was investigated of the neutron population in an unreflected unmoderated cylindrical assembly of 90 wt.% U (93.2 wt.% U/sup 235/), 10 wt.% Mo alloy following rapid establishment of a super-prompt critical c ondition with negligible initial neutron population. Reactivity increases up to 11 cents above prompt critical resulted in bursts yielding as many as 1.8 x 10/ sup 17/ fissions with reactor periods as short as 16 mu sec and temperature increases as large as 400 deg C. Pressure waves generated in a portion of the core held in position by an electromagnet for bursts greater than ~6 x 10/sup 16/ fissions initiated the removal of this section about 225 mu sec after the peak burst. (auth)

Data and information are presented concerning analyses of PL-2 transient performance, normal startup and shutdown procedures, and shield design. (J.R.D.)

On December 12, 196l, the Engineering Test Reactor experienced fuel fission breaks which resulted from obstructions to the flow of cooling water through several fuel elements. A total of six fuel elements had breaks in from one to eight fuel plates. A discussion and description of damage to the fuel is presented. The reactor operating conditions preceding the break are described, including events immediately before the manual scram. Results of investigations conducted after the scram, including effects upon the reactor as well as fuel element damage, are reported. (auth)

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Abstract: Distribution coefficients have been measured for the partition of metal ions between cation exchange resin and acetone-water-hydrochloric acid solutions. the differences in distribution coefficients of metal ions are greater in acetone-water media than in aqueous media of the same hydrochloric acid concentration. Using distribution coefficient data, conditions for column separations of mixtures can be selected. Column separations of metal ion mixtures can be effected by eluting with acetone-water-hydrochloric acid solutions of different compositions. Successful separations of a number of mixtures are reported.